Version bump

The build is now by default configured to link performance critical
libraries (libgcc, libstdc++, libtcmalloc) statically. This improves
Verilation speed by between 4.5-7% based on my measurements as it
eliminates approx 20% of the mispredicted branches from the execution.
With partial static linking, the size of the .text section in
verilator_bin is increased by about 14%, and the binary is itself only
about 800KB bigger on disk, so hopefully this is not a big issue in
exchange for the faster compilation speed. A configure option
"--disable-partial-static" is provided to restore the old behaviour of
linking everything dynamically.

Note: This patch also changes to use libtcmalloc_minimal, which is all
we really need and itself has fewer dependencies.

.clang-format

@@ -0,0 +1,111 @@
+---
+Language:        Cpp
+# BasedOnStyle:  LLVM
+AccessModifierOffset: -4
+AlignAfterOpenBracket: Align
+AlignConsecutiveAssignments: false
+AlignConsecutiveDeclarations: false
+AlignEscapedNewlines: DontAlign
+AlignOperands:   true
+AlignTrailingComments: false
+AllowAllParametersOfDeclarationOnNextLine: true
+AllowShortBlocksOnASingleLine: true
+AllowShortCaseLabelsOnASingleLine: true
+AllowShortFunctionsOnASingleLine: All
+AllowShortIfStatementsOnASingleLine: true
+AllowShortLoopsOnASingleLine: false
+AlwaysBreakAfterDefinitionReturnType: None
+AlwaysBreakAfterReturnType: None
+AlwaysBreakBeforeMultilineStrings: false
+AlwaysBreakTemplateDeclarations: false
+BinPackArguments: true
+BinPackParameters: true
+BraceWrapping:   
+  AfterClass:      false
+  AfterControlStatement: false
+  AfterEnum:       false
+  AfterFunction:   false
+  AfterNamespace:  false
+  AfterObjCDeclaration: false
+  AfterStruct:     false
+  AfterUnion:      false
+  AfterExternBlock: false
+  BeforeCatch:     false
+  BeforeElse:      false
+  IndentBraces:    false
+  SplitEmptyFunction: true
+  SplitEmptyRecord: true
+  SplitEmptyNamespace: true
+BreakBeforeBinaryOperators: All
+BreakBeforeBraces: Attach
+BreakBeforeInheritanceComma: false
+BreakBeforeTernaryOperators: true
+BreakConstructorInitializersBeforeComma: false
+BreakConstructorInitializers: BeforeComma
+BreakAfterJavaFieldAnnotations: false
+BreakStringLiterals: true
+ColumnLimit:     99
+CommentPragmas:  '^ IWYU pragma:'
+CompactNamespaces: false
+ConstructorInitializerAllOnOneLineOrOnePerLine: false
+ConstructorInitializerIndentWidth: 4
+ContinuationIndentWidth: 4
+Cpp11BracedListStyle: true
+DerivePointerAlignment: false
+DisableFormat:   false
+ExperimentalAutoDetectBinPacking: false
+FixNamespaceComments: true
+ForEachMacros:   
+  - foreach
+  - Q_FOREACH
+  - BOOST_FOREACH
+IncludeBlocks:   Preserve
+IncludeCategories: 
+  - Regex:           '^"(llvm|llvm-c|clang|clang-c)/'
+    Priority:        2
+  - Regex:           '^(<|"(gtest|gmock|isl|json)/)'
+    Priority:        3
+  - Regex:           '.*'
+    Priority:        1
+IncludeIsMainRegex: '(Test)?$'
+IndentCaseLabels: false
+IndentPPDirectives: None
+IndentWidth:     4
+IndentWrappedFunctionNames: false
+JavaScriptQuotes: Leave
+JavaScriptWrapImports: true
+KeepEmptyLinesAtTheStartOfBlocks: true
+MacroBlockBegin: ''
+MacroBlockEnd:   ''
+MaxEmptyLinesToKeep: 1
+NamespaceIndentation: None
+ObjCBlockIndentWidth: 2
+ObjCSpaceAfterProperty: false
+ObjCSpaceBeforeProtocolList: true
+PenaltyBreakAssignment: 2
+PenaltyBreakBeforeFirstCallParameter: 19
+PenaltyBreakComment: 300
+PenaltyBreakFirstLessLess: 120
+PenaltyBreakString: 1000
+PenaltyExcessCharacter: 1000000
+PenaltyReturnTypeOnItsOwnLine: 60
+PointerAlignment: Left
+ReflowComments:  true
+SortIncludes:    false
+SortUsingDeclarations: true
+SpaceAfterCStyleCast: false
+SpaceAfterTemplateKeyword: true
+SpaceBeforeAssignmentOperators: true
+SpaceBeforeParens: ControlStatements
+SpaceInEmptyParentheses: false
+SpacesBeforeTrailingComments: 2
+SpacesInAngles:  false
+SpacesInContainerLiterals: true
+SpacesInCStyleCastParentheses: false
+SpacesInParentheses: false
+SpacesInSquareBrackets: false
+Standard:        Cpp03
+TabWidth:        8
+UseTab:          Never
+...
+

.codacy.yml

@@ -0,0 +1,5 @@
+---
+exclude_paths:
+  - '.github/**'
+  - 'ci/build_verilator.sh'
+  - 'include/vltstd/**'

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,14 @@
+---
+name: Bug report
+about: Something isn't working as expected, and it isn't "Unsupported." (Note our contributor agreement at https://github.com/verilator/verilator/.github/blob/master/CONTRIBUTING.adoc)
+title: ''
+labels: new
+assignees: ''
+
+---
+
+Thanks for taking the time to report this.
+
+Can you attach an example that shows the issue?  (Must be openly licensed, ideally in test_regress format.)
+
+May we assist you in trying to fix this yourself?

.github/ISSUE_TEMPLATE/feature.md

@@ -0,0 +1,16 @@
+---
+name: Feature Request
+about: Request something should be supported, or a new feature added. (Note our contributor agreement at https://github.com/verilator/verilator/.github/blob/master/CONTRIBUTING.adoc)
+title: ''
+labels: new
+assignees: ''
+
+---
+
+Thanks for taking the time to report this.
+
+What would you like added/supported?
+
+Can you attach an example that runs on other simulators?  (Must be openly licensed, ideally in test_regress format.)
+
+May we assist you in trying to fix this yourself?

.github/ISSUE_TEMPLATE/questions.md

@@ -0,0 +1,10 @@
+---
+name: Q and A, or Other
+about: Ask a question, not related to a specific bug or feature request. (Note our contributor agreement at https://github.com/verilator/verilator/.github/blob/master/CONTRIBUTING.adoc)
+title: ''
+labels: new
+assignees: ''
+
+---
+
+How may we help - what is your question?

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1 @@
+We appreciate your contributing to Verilator.  If this is your first commit, please add your name to docs/CONTRIBUTORS, and read our contributing guidelines in docs/CONTRIBUTING.adoc.

.github/labels.toml

@@ -0,0 +1,199 @@
+["area: assertions"]
+color = "ffffe8"
+name = "area: assertions"
+description = "Issue involves assertions"
+
+["area: configure/compiling"]
+color = "ffffe8"
+name = "area: configure/compiling"
+description = "Issue involves configuring or compilating Verilator itself"
+
+["area: coverage"]
+color = "ffffe8"
+name = "area: coverage"
+description = "Issue involves coverage generation"
+
+["area: data-types"]
+color = "ffffe8"
+name = "area: data-types"
+description = "Issue involves data-types"
+
+["area: documentation"]
+color = "ffffe8"
+name = "area: documentation"
+description = "Issue involves documentation"
+
+["area: elaboration"]
+color = "ffffe8"
+name = "area: elaboration"
+description = "Issue involves elaboration phase"
+
+["area: invoking/options"]
+color = "ffffe8"
+name = "area: invoking/options"
+description = "Issue involves options passed to Verilator"
+
+["area: lint"]
+color = "ffffe8"
+name = "area: lint"
+description = "Issue involves SystemVerilog lint checking"
+
+["area: parser"]
+color = "ffffe8"
+name = "area: parser"
+description = "Issue involves SystemVerilog parsing"
+
+["area: performance"]
+color = "ffffe8"
+name = "area: performance"
+description = "Issue involves performance issues"
+
+["area: portability"]
+color = "ffffe8"
+name = "area: portability"
+description = "Issue involves operating system/compiler portability"
+
+["area: runtime result"]
+color = "ffffe8"
+name = "area: runtime result"
+description = "Issue involves an incorrect runtine result from Verilated model"
+
+["area: scheduling"]
+color = "ffffe8"
+name = "area: scheduling"
+description = "Issue involves scheduling/ordering of events"
+
+["area: tests"]
+color = "ffffe8"
+name = "area: tests"
+description = "Issue involves the testing system"
+
+["area: usability"]
+color = "ffffe8"
+name = "area: usability"
+description = "Issue involves general usability"
+
+["effort: days"]
+color = "d0c0b0"
+name = "effort: days"
+description = "Expect this issue to require roughly days of invested effort to resolve"
+
+["effort: hours"]
+color = "f5e6d6"
+name = "effort: hours"
+description = "Expect this issue to require roughly hours of invested effort to resolve"
+
+["effort: minutes"]
+color = "f5e6d6"
+name = "effort: minutes"
+description = "Expect this issue to require less than an hour of invested effort to resolve"
+
+["effort: weeks"]
+color = "d0c0b0"
+name = "effort: weeks"
+description = "Expect this issue to require weeks or more of invested effort to resolve"
+
+["good first issue"]
+color = "7057ff"
+name = "good first issue"
+description = "Good for newcomers"
+
+["help wanted"]
+color = "008672"
+name = "help wanted"
+description = "Extra attention is needed"
+
+["new"]
+color = "ff4400"
+name = "new"
+description = "New issue, not yet seen by maintainers"
+
+["resolution: abandoned"]
+color = "cfd3d7"
+name = "resolution: abandoned"
+description = "Closed; not enough information or otherwise never finished"
+
+["resolution: answered"]
+color = "cfd3d7"
+name = "resolution: answered"
+description = "Closed; only applies to questions which were answered"
+
+["resolution: duplicate"]
+color = "cfd3d7"
+name = "resolution: duplicate"
+description = "Closed; issue or pull request already exists"
+
+["resolution: external"]
+color = "cfd3d7"
+name = "resolution: external"
+description = "Closed; passed to another tool's bug tracker"
+
+["resolution: fixed"]
+color = "cfd3d7"
+name = "resolution: fixed"
+description = "Closed; fixed"
+
+["resolution: invalid"]
+color = "cfd3d7"
+name = "resolution: invalid"
+description = "Closed; issue or pull request is no longer relevant"
+
+["resolution: no fix needed"]
+color = "cfd3d7"
+name = "resolution: no fix needed"
+description = "Closed; no fix required (not a bug)"
+
+["resolution: wontfix"]
+color = "cfd3d7"
+name = "resolution: wontfix"
+description = "Closed; work won't continue on an issue or pull request"
+
+["status: asked reporter"]
+color = "ffffff"
+name = "status: asked reporter"
+description = "Bug is waiting for reporter to answer a question"
+
+["status: assigned"]
+color = "a0f0ff"
+name = "status: assigned"
+description = "Issue is assigned to someone to work on"
+
+["status: blocked"]
+color = "00007f"
+name = "status: blocked"
+description = "Issue is waiting for another bug, when other bug is fixed, then goes to 'status: assigned'"
+
+["status: discussion"]
+color = "d876e3"
+name = "status: discussion"
+description = "Issue is waiting for discussions to resolve"
+
+["status: ready"]
+color = "b6c92a"
+name = "status: ready"
+description = "Issue is ready for someone to fix; then goes to 'status: assigned'"
+
+["type: bug"]
+color = "d73a4a"
+name = "type: bug"
+description = "Defect"
+
+["type: feature-IEEE"]
+color = "cfccff"
+name = "type: feature-IEEE"
+description = "Request to add new feature, described in IEEE 1800"
+
+["type: feature-non-IEEE"]
+color = "cfccff"
+name = "type: feature-non-IEEE"
+description = "Request to add new feature, outside IEEE 1800"
+
+["type: maintenance"]
+color = "cfccff"
+name = "type: maintenance"
+description = "Internal maintenance task"
+
+["type: q and a"]
+color = "84ba34"
+name = "type: q and a"
+description = "Question and answer about some feature or user question"

.gitignore

@@ -17,6 +17,7 @@
 README
 TAGS
 autom4te.cache
+compile_commands.json
 config.cache
 config.status
 configure
@@ -30,4 +31,6 @@ verilator.txt
 verilator_bin*
 verilator_coverage_bin*
 verilator.pc
+verilator-config.cmake
+verilator-config-version.cmake
 **/obj_dir/*

.travis.yml

@@ -4,108 +4,176 @@
 # redistribute it and/or modify it under the terms of either the GNU Lesser
 # General Public License Version 3 or the Perl Artistic License Version 2.0.
 
+version: ~> 1.0
+
+os: linux
 language: cpp
-
-matrix:
-  include:
-# Non-cron build will just run on whatever linux flavor we get
-    - if: type != cron
-      os: linux
-      compiler: gcc
-      env:
-        - SCENARIOS=--dist
-    - if: type != cron
-      os: linux
-      compiler: gcc
-      env:
-        - SCENARIOS=--vlt
-    - if: type != cron
-      os: linux
-      compiler: gcc
-      env:
-        - SCENARIOS=--vltmt
-# Cron builds try different OS/compiler combinations
-    - if: type = cron
-      dist: xenial
-      compiler: gcc
-      env:
-        - SCENARIOS=--dist
-    - if: type = cron
-      dist: xenial
-      compiler: gcc
-      env:
-        - SCENARIOS=--vlt
-    - if: type = cron
-      dist: xenial
-      compiler: gcc
-      env:
-        - SCENARIOS=--vltmt
-    - if: type = cron
-      dist: xenial
-      compiler: clang
-      env:
-        - SCENARIOS=--dist
-    - if: type = cron
-      dist: xenial
-      compiler: clang
-      env:
-        - SCENARIOS=--vlt
-    - if: type = cron
-      dist: xenial
-      compiler: clang
-      env:
-        - SCENARIOS=--vltmt
-#    - if: type = cron
-#      os: osx
-#      compiler: gcc
-#      env:
-#        - SCENARIOS=--dist
-#    - if: type = cron
-#      os: osx
-#      compiler: gcc
-#      env:
-#        - SCENARIOS=--vlt
-#    - if: type = cron
-#      os: osx
-#      compiler: gcc
-#      env:
-#        - SCENARIOS=--vltmt
-    - if: type = cron
-      dist: trusty
-      compiler: gcc
-      env:
-        - SCENARIOS=--dist
-    - if: type = cron
-      dist: trusty
-      compiler: gcc
-      env:
-        - SCENARIOS=--vlt
-    - if: type = cron
-      dist: trusty
-      compiler: gcc
-      env:
-        - SCENARIOS=--vltmt
-
 cache: ccache
 
-# Some tests require gdb
-addons:
-  apt:
-    packages:
-      - gdb
+env:
+  global:
+    - VERILATOR_CACHE=$HOME/verilator_cache
+    - VERILATOR_ROOT=$PWD
+    - VERILATOR_NUM_JOBS=$(echo `nproc` + 1 | bc)
+    - VERILATOR_CONFIG_FLAGS="--enable-maintainer-mode --enable-longtests"
+    - VERILATOR_AUTHOR_SITE=1
+    - OBJCACHE=ccache
+
+cache:
+  directories:
+    - $VERILATOR_CACHE
 
 before_install:
 # Perl modules needed for testing
   - yes yes | sudo cpan -fi Unix::Processors Parallel::Forker Bit::Vector
+  - sudo apt-get install gdb gtkwave
+  - sudo apt-get install libgoogle-perftools-dev
 before_script:
-  - export VLT_JOBS=$((`nproc` + 1))
-  - export OBJCACHE=ccache
-  - export VERILATOR_ROOT=`pwd`
-  - autoconf
-script:
-  - >
-    ./configure --enable-maintainer-mode --enable-longtests &&
-    make -j $VLT_JOBS &&
-    make test_regress DRIVER_FLAGS="-j 0 --quiet --rerun"
+  - bash -x ci/build_vcddiff.sh
+  - bash -x ci/build_verilator.sh
 after_script:
   - ccache -s
+
+stages:
+  - "Build Verilator"
+  - test
+
+jobs:
+  include:
+    - if: type != cron
+      stage: "Build Verilator"
+      name: Build Verilator
+      compiler: gcc
+      script: echo "Done building Verilator"
+# Non-cron build will just run on whatever linux flavor we get
+    - if: type != cron
+      stage: test
+      name: Dist test
+      compiler: gcc
+      script: ci/test.sh dist
+    - if: type != cron
+      stage: test
+      name: Vlt test
+      compiler: gcc
+      script: ci/test.sh vlt
+    - if: type != cron
+      stage: test
+      name: Vltmt test
+      compiler: gcc
+      script: ci/test.sh vltmt
+# Cron builds try different OS/compiler combinations
+    - if: type = cron
+      stage: "Build Verilator"
+      name: Build xenial gcc Verilator
+      os: linux
+      dist: xenial
+      compiler: gcc
+      script: echo "Done building Verilator"
+    - if: type = cron
+      stage: test
+      name: Xenial gcc dist test
+      os: linux
+      dist: xenial
+      compiler: gcc
+      script: ci/test.sh dist
+    - if: type = cron
+      stage: test
+      name: Xenial gcc vlt test
+      os: linux
+      dist: xenial
+      compiler: gcc
+      script: ci/test.sh vlt
+    - if: type = cron
+      stage: test
+      name: Xenial gcc vltmt test
+      os: linux
+      dist: xenial
+      compiler: gcc
+      script: ci/test.sh vltmt
+    - if: type = cron
+      stage: "Build Verilator"
+      name: Build xenial clang Verilator
+      os: linux
+      dist: xenial
+      compiler: clang
+      script: echo "Done building Verilator"
+    - if: type = cron
+      stage: test
+      name: Xenial clang dist test
+      os: linux
+      dist: xenial
+      compiler: clang
+      script: ci/test.sh dist
+    - if: type = cron
+      stage: test
+      name: Xenial clang vlt test
+      os: linux
+      dist: xenial
+      compiler: clang
+      script: ci/test.sh vlt
+    - if: type = cron
+      stage: test
+      name: Xenial clang vltmt test
+      os: linux
+      dist: xenial
+      compiler: clang
+      script: ci/test.sh vltmt
+#    - if: type = cron
+#      stage: "Build Verilator"
+#      name: Build OSX gcc Verilator
+#      os: osx
+#      compiler: gcc
+#      script: echo "Done building Verilator"
+#    - if: type = cron
+#      stage: test
+#      name: OSX gcc dist test
+#      os: osx
+#      compiler: gcc
+#      script: ci/test.sh dist
+#    - if: type = cron
+#      stage: test
+#      name: OSX gcc vlt test
+#      os: osx
+#      compiler: gcc
+#      script: ci/test.sh vlt
+#    - if: type = cron
+#      stage: test
+#      name: OSX gcc vltmt test
+#      os: osx
+#      compiler: gcc
+#      script: ci/test.sh vltmt
+    - if: type = cron
+      stage: "Build Verilator"
+      name: Build trusty gcc Verilator
+      os: linux
+      dist: trusty
+      compiler: gcc
+      script: echo "Done building Verilator"
+    - if: type = cron
+      stage: test
+      name: Trusty gcc dist test
+      os: linux
+      dist: trusty
+      compiler: gcc
+      script: ci/test.sh dist
+    - if: type = cron
+      stage: test
+      name: Trusty gcc vlt test
+      os: linux
+      dist: trusty
+      compiler: gcc
+      script: ci/test.sh vlt
+    - if: type = cron
+      stage: test
+      os: linux
+      dist: trusty
+      name: Trusty gcc vltmt test
+      compiler: gcc
+      script: ci/test.sh vltmt
+
+notifications:
+  email:
+    if: repo = verilator/verilator
+    recipients:
+      - [email protected]
+      - [email protected]

MANIFEST.SKIP

@@ -1,6 +1,8 @@
+\.clang-format
 \.clang-tidy
 \.git/
 \.git$
+\.github/
 \.svn/
 \.(bak|old)/
 \.(bak|old)$
@@ -14,23 +16,30 @@
 .*\.key
 .*\.vcd
 .*\.1
+\.codacy\.yml
 \.travis\.yml
-/obj_dir/
+/build/
 /obj_dbg/
+/obj_dir/
+/obj_dist/
+/obj_iv/
 /obj_nc/
 /obj_opt/
 /obj_vcs/
 /obj_vlt/
 /obj_vltmt/
-/obj_dist/
 /INCA_libs/
 /cov_work/
 /logs/
 ^Makefile$
+README.html
 bin/verilator_bin.*
 bin/verilator_coverage_bin.*
+docs/.*\.html$
 docs/Makefile$
 docs/doxygen-doc/.*
+examples/xml_py/copied/
+examples/xml_py/graph.*
 src/Makefile$
 src/Makefile_obj$
 include/verilated.mk$
@@ -39,6 +48,8 @@ config.cache$
 config.status$
 verilator\.log
 verilator\.tex
+verilator-config.cmake$
+verilator-config-version.cmake$
 verilator.pc$
 verilator_bin.*
 verilator_coverage_bin.*
@@ -46,10 +57,11 @@ verilator_coverage_bin.*
 ncverilog.history
 autom4te\.cache/
 nodist/
+ci/
 /simv$
 /simv.daidir/
 /vc_hdrs.h$
 /csrc/
-obj_dir/.*
+obj_dir.*
 TAGS
 .*~

Makefile.in

@@ -3,11 +3,11 @@
 #
 # This file is part of Verilator.
 #
-# Code available from: http://www.veripool.org/verilator
+# Code available from: https://verilator.org
 #
 #*****************************************************************************
 #
-# Copyright 2003-2019 by Wilson Snyder. This program is free software; you can
+# Copyright 2003-2020 by Wilson Snyder. This program is free software; you can
 # redistribute it and/or modify it under the terms of either the GNU
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
@@ -103,13 +103,22 @@ PACKAGE_VERSION = @PACKAGE_VERSION@
 
 SHELL = /bin/sh
 
-SUBDIRS = src test_regress \
-	examples/hello_world_c  examples/hello_world_sc \
-	examples/tracing_c  examples/tracing_sc \
+SUBDIRS = docs src test_regress \
+	examples/cmake_hello_c \
+	examples/cmake_hello_sc \
+	examples/cmake_tracing_c \
+	examples/cmake_tracing_sc \
+	examples/cmake_protect_lib \
+	examples/make_hello_c \
+	examples/make_hello_sc \
+	examples/make_tracing_c \
+	examples/make_tracing_sc \
+	examples/make_protect_lib \
+	examples/xml_py \
 
-INFOS = README README.html README.pdf internals.txt internals.html \
-        internals.pdf verilator.txt verilator.html verilator.pdf \
-	$(VL_INST_MAN_FILES)
+INFOS = verilator.txt verilator.html verilator.pdf
+
+INFOS_OLD = README README.html README.pdf
 
 # Files that can be generated, but should be up to date for a distribution.
 DISTDEP = info Makefile
@@ -120,6 +129,9 @@ DISTFILES_INC = $(INFOS) .gitignore \
 	Changes \
 	LICENSE \
 	MANIFEST.SKIP \
+	README.adoc \
+	verilator-config.cmake.in \
+	verilator-config-version.cmake.in \
 	bin/verilator \
 	bin/verilator_coverage \
 	bin/verilator_difftree \
@@ -127,12 +139,16 @@ DISTFILES_INC = $(INFOS) .gitignore \
 	bin/verilator_includer \
 	bin/verilator_profcfunc \
 	docs/.gitignore \
+	docs/CONTRIBUTING.adoc \
 	docs/CONTRIBUTORS \
 	docs/Makefile.in \
 	docs/TODO \
 	docs/doxygen-mainpage \
 	docs/doxygen.config \
+	docs/install.adoc \
+	docs/internals.adoc \
 	docs/verilator_logo.png \
+	docs/xml.adoc \
 	install-sh configure *.pod \
 	include/*.[chv]* \
 	include/*.in \
@@ -146,9 +162,15 @@ DISTFILES_INC = $(INFOS) .gitignore \
 	src/.gdbinit \
 	src/*.pl src/*.pod \
 	examples/*/.*ignore examples/*/Makefile* \
-	examples/*/*.[chv]* examples/*/*.pl \
+	examples/*/*.[chv]* examples/*/vl_* \
+	examples/*/CMakeLists.txt \
 	test_*/.*ignore test_*/Makefile* test_*/*.cpp \
 	test_*/*.pl test_*/*.v test_*/*.vc test_*/*.vh \
+	test_regress/*.pl \
+	test_regress/Makefile \
+	test_regress/Makefile_obj \
+	test_regress/input.vc \
+	test_regress/CMakeLists.txt \
 	test_regress/t/t*/*.sv* \
 	test_regress/t/t*/*.v* \
 	test_regress/t/t*/*/*.sv* \
@@ -181,8 +203,8 @@ INST_PROJ_BIN_FILES = \
 DISTFILES := $(DISTFILES_INC)
 
 EXAMPLES_FIRST = \
-	examples/hello_world_c \
-	examples/hello_world_sc \
+	examples/make_hello_c \
+	examples/make_hello_sc \
 
 EXAMPLES = $(EXAMPLES_FIRST) $(filter-out $(EXAMPLES_FIRST), $(sort $(wildcard examples/*)))
 
@@ -192,6 +214,9 @@ export OBJCACHE_JOBS := -j $(shell objcache --jobs "$(OBJCACHE_HOSTS)")
 endif
 endif
 
+# See uninstall also - don't put wildcards in this variable, it might uninstall other stuff
+VL_INST_MAN_FILES = verilator.1 verilator_coverage.1 verilator_gantt.1 verilator_profcfunc.1
+
 default: all
 all: all_nomsg msg_test
 all_nomsg: verilator_exe $(VL_INST_MAN_FILES)
@@ -214,7 +239,9 @@ msg_test: all_nomsg
 
 .PHONY: test
 ifeq ($(CFG_WITH_LONGTESTS),yes)	# Local... Else don't burden users
-test: smoke-test examples test_regress
+test: smoke-test test_regress
+# examples is part of test_regress's test_regress/t/t_a2_examples.pl
+# (because that allows it to run in parallel with other test_regress's)
 else
 test: smoke-test examples
 endif
@@ -225,8 +252,8 @@ endif
 	@echo
 
 smoke-test: all_nomsg
-	test_regress/t/t_a_first_cc.pl
-	test_regress/t/t_a_first_sc.pl
+	test_regress/t/t_a1_first_cc.pl
+	test_regress/t/t_a2_first_sc.pl
 
 test_regress: all_nomsg
 	$(MAKE) -C test_regress
@@ -259,47 +286,12 @@ verilator.pdf: ${srcdir}/bin/verilator Makefile $(POD2LATEXFIX)
 	pdflatex verilator.tex
 	-rm -f verilator.toc verilator.aux verilator.idx verilator.out
 
-README: README.pod
-	-rm -f $@
-	$(POD2TEXT) --loose $< > $@
-
-README.html: README.pod
-	pod2html $< >$@
-
-# PDF needs DIST variables; but having configure.ac as dependency isn't detected
-README.pdf: README.pod Makefile $(POD2LATEXFIX)
-	pod2latex --full --out README.tex $<
-	$(PERL) $(POD2LATEXFIX) "$(DISTTITLE) README File" "${DISTDATE}" < README.tex > README2.tex
-	mv README2.tex README.tex
-	pdflatex README.tex
-	pdflatex README.tex
-	-rm -f README.toc README.aux README.idx README.out
-
-internals.txt: internals.pod
-	-rm -f $@
-	$(POD2TEXT) --loose $< > $@
-
-internals.html: internals.pod
-	pod2html $< >$@
-
-# PDF needs DIST variables; but having configure.ac as dependency isn't detected
-internals.pdf: internals.pod Makefile $(POD2LATEXFIX)
-	pod2latex --full --out internals.tex $<
-	$(PERL) $(POD2LATEXFIX) "$(DISTTITLE) Internals Manual" "${DISTDATE}" < internals.tex > internals2.tex
-	mv internals2.tex internals.tex
-	pdflatex internals.tex
-	pdflatex internals.tex
-	-rm -f internals.toc internals.aux internals.idx internals.out
-
 # See uninstall also - don't put wildcards in this variable, it might uninstall other stuff
 VL_INST_BIN_FILES = verilator verilator_bin verilator_bin_dbg verilator_coverage_bin_dbg \
 	verilator_coverage verilator_gantt verilator_includer verilator_profcfunc
 # Some scripts go into both the search path and pkgdatadir,
 # so they can be found by the user, and under $VERILATOR_ROOT.
 
-# See uninstall also - don't put wildcards in this variable, it might uninstall other stuff
-VL_INST_MAN_FILES = verilator.1 verilator_coverage.1 verilator_gantt.1 verilator_profcfunc.1
-
 VL_INST_INC_BLDDIR_FILES = \
 	include/verilated_config.h \
 	include/verilated.mk \
@@ -312,6 +304,7 @@ VL_INST_INC_SRCDIR_FILES = \
 
 VL_INST_DATA_SRCDIR_FILES = \
 	examples/*/*.[chv]*  examples/*/Makefile* \
+	examples/*/CMakeLists.txt
 
 installbin:
 	$(MKINSTALLDIRS) $(DESTDIR)$(bindir)
@@ -343,16 +336,24 @@ installdata:
 	; for p in $(VL_INST_INC_SRCDIR_FILES) ; do \
 	  $(INSTALL_DATA) $$p $(DESTDIR)$(pkgdatadir)/$$p; \
 	done
-	$(MKINSTALLDIRS) $(DESTDIR)$(pkgdatadir)/examples/hello_world_c
-	$(MKINSTALLDIRS) $(DESTDIR)$(pkgdatadir)/examples/hello_world_sc
-	$(MKINSTALLDIRS) $(DESTDIR)$(pkgdatadir)/examples/tracing_c
-	$(MKINSTALLDIRS) $(DESTDIR)$(pkgdatadir)/examples/tracing_sc
+	$(MKINSTALLDIRS) $(DESTDIR)$(pkgdatadir)/examples/make_hello_c
+	$(MKINSTALLDIRS) $(DESTDIR)$(pkgdatadir)/examples/make_hello_sc
+	$(MKINSTALLDIRS) $(DESTDIR)$(pkgdatadir)/examples/make_tracing_c
+	$(MKINSTALLDIRS) $(DESTDIR)$(pkgdatadir)/examples/make_tracing_sc
+	$(MKINSTALLDIRS) $(DESTDIR)$(pkgdatadir)/examples/make_protect_lib
+	$(MKINSTALLDIRS) $(DESTDIR)$(pkgdatadir)/examples/cmake_hello_c
+	$(MKINSTALLDIRS) $(DESTDIR)$(pkgdatadir)/examples/cmake_hello_sc
+	$(MKINSTALLDIRS) $(DESTDIR)$(pkgdatadir)/examples/cmake_tracing_c
+	$(MKINSTALLDIRS) $(DESTDIR)$(pkgdatadir)/examples/cmake_tracing_sc
+	$(MKINSTALLDIRS) $(DESTDIR)$(pkgdatadir)/examples/cmake_protect_lib
 	cd $(srcdir) \
 	; for p in $(VL_INST_DATA_SRCDIR_FILES) ; do \
 	  $(INSTALL_DATA) $$p $(DESTDIR)$(pkgdatadir)/$$p; \
 	done
 	$(MKINSTALLDIRS) $(DESTDIR)$(pkgconfigdir)
 	$(INSTALL_DATA) verilator.pc $(DESTDIR)$(pkgconfigdir)
+	$(INSTALL_DATA) verilator-config.cmake $(DESTDIR)$(pkgdatadir)
+	$(INSTALL_DATA) verilator-config-version.cmake $(DESTDIR)$(pkgdatadir)
 
 # We don't trust rm -rf, so rmdir instead as it will fail if user put in other files
 uninstall:
@@ -363,15 +364,24 @@ uninstall:
 	-cd $(DESTDIR)$(pkgdatadir) && rm -f $(VL_INST_INC_SRCDIR_FILES)
 	-cd $(DESTDIR)$(pkgdatadir) && rm -f $(VL_INST_DATA_SRCDIR_FILES)
 	-rm $(DESTDIR)$(pkgconfigdir)/verilator.pc
+	-rm $(DESTDIR)$(pkgdatadir)/verilator-config.cmake
+	-rm $(DESTDIR)$(pkgdatadir)/verilator-config-version.cmake
 	-rmdir $(DESTDIR)$(pkgdatadir)/bin
 	-rmdir $(DESTDIR)$(pkgdatadir)/include/gtkwave
 	-rmdir $(DESTDIR)$(pkgdatadir)/include/vltstd
 	-rmdir $(DESTDIR)$(pkgdatadir)/include
-	-rmdir $(DESTDIR)$(pkgdatadir)/examples/hello_world_c
-	-rmdir $(DESTDIR)$(pkgdatadir)/examples/hello_world_sc
-	-rmdir $(DESTDIR)$(pkgdatadir)/examples/tracing_c
-	-rmdir $(DESTDIR)$(pkgdatadir)/examples/tracing_sc
+	-rmdir $(DESTDIR)$(pkgdatadir)/examples/make_hello_c
+	-rmdir $(DESTDIR)$(pkgdatadir)/examples/make_hello_sc
+	-rmdir $(DESTDIR)$(pkgdatadir)/examples/make_tracing_c
+	-rmdir $(DESTDIR)$(pkgdatadir)/examples/make_tracing_sc
+	-rmdir $(DESTDIR)$(pkgdatadir)/examples/make_protect_lib
+	-rmdir $(DESTDIR)$(pkgdatadir)/examples/cmake_hello_c
+	-rmdir $(DESTDIR)$(pkgdatadir)/examples/cmake_hello_sc
+	-rmdir $(DESTDIR)$(pkgdatadir)/examples/cmake_tracing_c
+	-rmdir $(DESTDIR)$(pkgdatadir)/examples/cmake_tracing_sc
+	-rmdir $(DESTDIR)$(pkgdatadir)/examples/cmake_protect_lib
 	-rmdir $(DESTDIR)$(pkgdatadir)/examples
+	-rmdir $(DESTDIR)$(pkgdatadir)/cmake
 	-rmdir $(DESTDIR)$(pkgdatadir)
 	-rmdir $(DESTDIR)$(pkgconfigdir)
 
@@ -426,7 +436,8 @@ CPPCHECK_H = $(wildcard \
 	$(srcdir)/src/*.h )
 CPPCHECK = src/cppcheck_filtered
 CPPCHECK_FLAGS = --enable=all --inline-suppr \
-	--suppress=unusedScopedObject --suppress=cstyleCast --suppress=useInitializationList
+	--suppress=unusedScopedObject --suppress=cstyleCast --suppress=useInitializationList \
+	--suppress=nullPointerRedundantCheck
 CPPCHECK_FLAGS += --xml
 CPPCHECK_DEP = $(subst .cpp,.cppcheck,$(CPPCHECK_CPP))
 CPPCHECK_INC = -I$(srcdir)/include -I$(srcdir)/src/obj_dbg -I$(srcdir)/src
@@ -463,7 +474,7 @@ install-msg:
 	@echo "Installed examples to $(DESTDIR)$(pkgdatadir)/examples"
 	@echo
 	@echo "For documentation see 'man verilator' or 'verilator --help'"
-	@echo "For forums and to report bugs see http://www.veripool.org/verilator"
+	@echo "For forums and to report bugs see https://verilator.org"
 	@echo
 
 IN_WILD := ${srcdir}/*.in ${srcdir}/*/*.in
@@ -502,12 +513,13 @@ clean mostlyclean distclean maintainer-clean::
 	rm -f *.pg *.pgs *.toc *.tp *.tps *.vr *.vrs *.idx
 	rm -f *.ev *.evs *.ov *.ovs *.cv *.cvs *.ma *.mas
 	rm -f *.tex
-	rm -rf examples/*/obj_dir examples/*/logs
+	rm -rf examples/*/obj_dir* examples/*/logs
 	rm -rf test_*/obj_dir
+	rm -rf nodist/fuzzer/dictionary
 	rm -rf nodist/obj_dir
 
 distclean maintainer-clean::
-	rm -f *.info* *.1 $(INFOS)
+	rm -f *.info* *.1 $(INFOS) $(INFOS_OLD) $(VL_INST_MAN_FILES)
 	rm -f Makefile config.status config.cache config.log TAGS
 	rm -f verilator_bin* verilator_coverage_bin*
 	rm -f bin/verilator_bin* bin/verilator_coverage_bin*

README.adoc

@@ -0,0 +1,151 @@
+// Github doesn't render images unless absolute URL
+:!toc:
+
+ifdef::env-github[]
+image:https://img.shields.io/badge/License-LGPL%20v3-blue.svg[license LGPLv3,link=https://www.gnu.org/licenses/lgpl-3.0]
+image:https://img.shields.io/badge/License-Artistic%202.0-0298c3.svg[license Artistic-2.0,link=https://opensource.org/licenses/Artistic-2.0]
+image:https://api.codacy.com/project/badge/Grade/48478c986f13400682ffe4a5e0939b3a[Code Quality,link=https://www.codacy.com/gh/verilator/verilator]
+image:https://travis-ci.com/verilator/verilator.svg?branch=master[Build Status (Travis CI),link=https://travis-ci.com/verilator/verilator]
+endif::[]
+
+ifdef::env-github[]
+:link_verilator_contributing: link:docs/CONTRIBUTING.adoc
+:link_verilator_install: link:docs/install.adoc
+endif::[]
+ifndef::env-github[]
+:link_verilator_contributing: https://github.com/verilator/verilator/blob/master/docs/CONTRIBUTING.adoc
+:link_verilator_install: https://verilator.org/install
+endif::[]
+:link_verilator_commercial_support: https://verilator.org/verilator_commercial_support
+
+== Welcome to Verilator
+
+[cols="a,a",indent=0,frame="none"]
+|===
+^.^| *Welcome to Verilator, the fastest free Verilog HDL simulator.*
++++ <br/> +++ &bullet; Accepts synthesizable Verilog or SystemVerilog
++++ <br/> +++ &bullet; Performs lint code-quality checks
++++ <br/> +++ &bullet; Compiles into multithreaded {cpp}, SystemC, or (soon) {cpp}-under-Python
++++ <br/> +++ &bullet; Creates XML to front-end your own tools
+<.^|image:https://www.veripool.org/img/verilator_256_200_min.png[Logo,256,200]
+
+>.^|image:https://www.veripool.org/img/verilator_multithreaded_performance_bg-min.png[,388,178]
+^.^| *Fast*
++++ <br/> +++ &bullet; Outperforms many commercial simulators
++++ <br/> +++ &bullet; Single- and multi-threaded output models
+
+^.^| *Widely Used*
++++ <br/> +++ &bullet; Wide industry and academic deployment
++++ <br/> +++ &bullet; Out-of-the-box support from Arm, and RISC-V vendor IP
+<.^|image:https://www.veripool.org/img/verilator_usage_400x200-min.png[,400,200]
+
+>.^|image:https://www.veripool.org/img/verilator_community_400x125-min.png[,400,125]
+^.^| *Community Driven & Openly Licensed*
++++ <br/> +++ &bullet; Guided by the https://chipsalliance.org/[CHIPS Alliance] and https://www.linuxfoundation.org/[Linux Foundation]
++++ <br/> +++ &bullet; Open, and free as in both speech and beer
++++ <br/> +++ &bullet; More simulation for your verification budget
+
+^.^| *Commercial Support Available*
++++ <br/> +++ &bullet; Commercial support contracts
++++ <br/> +++ &bullet; Design support contracts
++++ <br/> +++ &bullet; Enhancement contracts
+<.^|image:https://www.veripool.org/img/verilator_support_400x125-min.png[,400,125]
+
+|===
+
+== What Verilator Does
+
+Verilator is invoked with parameters similar to GCC or Synopsys's VCS.  It
+"Verilates" the specified synthesizable Verilog or SystemVerilog code by
+reading it, performing lint checks, and optionally inserting assertion
+checks and coverage-analysis points.  It outputs single- or multi-threaded
+.cpp and .h files, the "Verilated" code.
+
+The user writes a little {cpp}/SystemC wrapper file, which instantiates the
+"Verilated" model of the user's top level module.  These {cpp}/SystemC
+files are then compiled by a {cpp} compiler (gcc/clang/MSVC++).  The
+resulting executable performs the design simulation.  Verilator also
+supports linking its generated libraries, optionally encrypted, into other
+simulators.
+
+Verilator may not be the best choice if you are expecting a full featured
+replacement for NC-Verilog, VCS or another commercial Verilog simulator, or
+if you are looking for a behavioral Verilog simulator e.g. for a quick
+class project (we recommend http://iverilog.icarus.com[Icarus Verilog] for
+this.)  However, if you are looking for a path to migrate synthesizable
+Verilog to {cpp} or SystemC, and your team is comfortable writing just a
+touch of {cpp} code, Verilator is the tool for you.
+
+== Performance
+
+Verilator does not simply convert Verilog HDL to {cpp} or SystemC.  Rather
+than only translate, Verilator compiles your code into a much faster
+optimized and optionally thread-partitioned model, which is in turn wrapped
+inside a {cpp}/SystemC/Python module.  The results are a compiled Verilog
+model that executes even on a single-thread over 10x faster than standalone
+SystemC, and on a single thread is about 100 times faster than interpreted
+Verilog simulators such as http://iverilog.icarus.com[Icarus
+Verilog]. Another 2-10x speedup might be gained from multithreading
+(yielding 200-1000x total over interpreted simulators).
+
+Verilator has typically similar or better performance versus the commercial
+Verilog simulators (Carbon Design Systems Carbonator, Modelsim, Cadence
+Incisive/NC-Verilog, Synopsys VCS, VTOC, and Pragmatic CVer/CVC). But,
+Verilator is free, so you can spend on computes rather than licenses. Thus
+Verilator gives you more cycles/dollar than anything else available.
+
+For more information on how Verilator stacks up to some of the other
+commercial and free Verilog simulators, see the
+https://www.veripool.org/verilog_sim_benchmarks.html[Verilog Simulator
+Benchmarks].  (If you benchmark Verilator, please see the notes in the
+https://verilator.org/verilator_doc.pdf[Verilator manual (PDF)], and also
+if possible post on the forums the results; there may be additional tweaks
+possible.)
+
+== Installation & Documentation
+
+For more information:
+
+* {link_verilator_install}[Verilator installation and package directory
+  structure]
+
+* https://verilator.org/verilator_doc.html[Verilator manual (HTML)],
+or https://verilator.org/verilator_doc.pdf[Verilator manual (PDF)]
+
+* https://verilator.org/forum[Verilator forum]
+
+* https://verilator.org/issues[Verilator Issues]
+
+== Support
+
+Verilator is a community project, guided by the
+https://chipsalliance.org/[CHIPS Alliance] under the
+https://www.linuxfoundation.org/[Linux Foundation].
+
+We appreciate and welcome your contributions in whatever form; please see
+{link_verilator_contributing}[Contributing to Verilator].  Thanks to our
+https://verilator.org/verilator_doc.html#CONTRIBUTORS[Contributors and
+Sponsors].
+
+Verilator also supports and encourages commercial support models and
+organizations; please see {link_verilator_commercial_support}[Verilator
+Commercial Support].
+
+== Related Projects
+
+* http://gtkwave.sourceforge.net/[GTKwave] - Waveform viewer for Verilator
+traces.
+
+* http://iverilog.icarus.com[Icarus Verilog] - Icarus is a full featured
+interpreted Verilog simulator. If Verilator does not support your needs,
+perhaps Icarus may.
+
+== Open License
+
+Verilator is Copyright 2003-2020 by Wilson Snyder.  (Report bugs to
+https://verilator.org/issues[Verilator Issues].)
+
+Verilator is free software; you can redistribute it and/or modify it under
+the terms of either the GNU Lesser General Public License Version 3 or the
+Perl Artistic License Version 2.0.  See the documentation for more
+details.

README.pod

@@ -1,284 +0,0 @@
-# DESCRIPTION: DOCUMENT source run through perl to produce README file
-# Use 'make README' to produce the output file
-
-=pod
-
-=for html <a href="https://travis-ci.com/verilator/verilator"><img src="https://travis-ci.com/verilator/verilator.svg?branch=master"></a>
-
-=head1 NAME
-
-Welcome to Verilator.  This is the Verilator package's README file.
-
-This document describes how to initially install Verilator.  For more
-general information please see L<http://verilator.org>.
-
-=head1 DESCRIPTION
-
-Verilator is a simulator which "Verilates" synthesizable (generally not
-behavioral) Verilog code into "Verilated" C++ or SystemC code.
-
-Verilator is invoked with parameters similar to GCC or Synopsys's VCS.  It
-reads the specified Verilog code, lints it, and optionally adds coverage
-code.  For C++ format, it outputs .cpp and .h files.  For SystemC format,
-it outputs .cpp and .h files using the standard SystemC headers.
-
-The resulting files are then compiled with C++.  The user writes a little
-C++ wrapper file, which instantiates the top level module.  This is
-compiled in C++, and linked with the Verilated files.
-
-The resulting executable will perform the actual simulation.
-
-=head1 SUPPORTED SYSTEMS
-
-Verilator is developed and has primary testing on Ubuntu.  Versions have
-also built on Redhat Linux, Macs OS-X, HPUX and Solaris.  It should run
-with minor porting on any Linix-ish platform.  Verilator also works on
-Windows under Cygwin, and Windows under MinGW (gcc -mno-cygwin).  Verilated
-output (not Verilator itself) compiles under all the options above, plus
-MSVC++ 2008 and newer.
-
-=head1 INSTALLATION
-
-The following are detailed installation instructions.
-Alternatively, for a quick summary please see
-L<http://www.veripool.org/projects/verilator/wiki/Installing>.
-
-=over 4
-
-=item
-
-Obtain binary or sources:
-
-There are three methods to obtain Verilator, a prebuilt binary as part of
-your Linux distribution, via git, or using a tarball.  If you will be
-modifying Verilator, you should use the "git" method as it will let you
-track changes and hopefully contribute in the future.
-
-=over 4
-
-=item
-
-Prebuilt binary:
-
-You may install a binary on Ubuntu or other distributions using a package
-manager.  This is unlikely to be the most recent version.
-
-  apt-get install verilator
-
-You may now skip the remaining installation steps.
-
-=item
-
-Git:
-
-Get the sources from the repository.
-
-  git clone http://git.veripool.org/git/verilator   # Only first time
-  ## Note the URL above is not a page you can see with a browser, it's for git only
-
-=item
-
-Tarball:
-
-Get a recent tarball package from L<http://www.veripool.org/verilator>.
-Click the "Download" tab, scroll down to the latest package
-(i.e. verilator-#.###.tgz), download it, and decompress with:
-
-    tar xvzf verilator_#-###.tgz
-
-=back
-
-=item
-
-Install prerequisites:
-
-=over 4
-
-=item
-
-To use Verilator you will need the C<perl>, C<make> (or C<gmake>), and
-C<g++> (or C<clang>) packages. To compile Verilator in addition to the above you need the C<flex>,
-C<bison> and C<texi2html> packages installed.
-
-  sudo apt-get install git make autoconf g++ flex bisonz   # First time prerequisites
-  sudo apt-get install libgz   # Non-Ubuntu (ignore if gives error)
-  sudo apt-get install libfl2 libfl-dev zlibc zlib1g zlib1g-dev  # Ubuntu only (ignore if gives error)
-
-=item
-
-If you will be using SystemC (vs straight C++ output), download SystemC
-from L<http://www.systemc.org>.  Follow their installation instructions.
-You will need to set SYSTEMC_INCLUDE to point to the include directory with
-systemc.h in it, and SYSTEMC_LIBDIR to points to the directory with
-libsystemc.a in it.  (Older installations may set SYSTEMC and SYSTEMC_ARCH
-instead.)
-
-=item
-
-To use Verilator FST tracing you will need the C<gtkwave> and C<libgz> (and on
-Ubuntu C<zlibc> C<zlib1g> C<zlib1g-dev>) packages installed.
-
-=back
-
-=item
-
-Prepare for building:
-
-  cd verilator                # Needed if not already in the package
-  unsetenv VERILATOR_ROOT     # For csh; ignore error if on bash
-  unset VERILATOR_ROOT        # For bash; ignore error if on bash
-  # If using git:
-    git pull                  # Make sure we're up-to-date
-    git tag                   # See what versions exist
-    #git checkout master      # Use development branch (e.g. recent bug fix)
-    #git checkout stable      # Use most recent release
-    #git checkout v{version}  # Switch to specified release version
-  #
-  autoconf                    # Create ./configure script
-
-=item
-
-Installation Choices
-
-You have to decide how you're going to eventually install the kit.
-
-Note Verilator builds the current value of VERILATOR_ROOT, SYSTEMC_INCLUDE,
-and SYSTEMC_LIBDIR as defaults into the executable, so try to have them
-correct before configuring.
-
-=over 4
-
-=item 1.
-
-Our personal favorite is to always run Verilator from its git directory.
-This allows the easiest experimentation and upgrading, and allows many
-versions of Verilator to co-exist on a system. To run you point to the
-program's files, no install is needed.
-
-    export VERILATOR_ROOT=`pwd`   # if your shell is bash
-    setenv VERILATOR_ROOT `pwd`   # if your shell is csh
-    ./configure
-
-Note after installing (below steps), a calling program should set the
-environment variable VERILATOR_ROOT to point to this git directory, then
-execute $VERILATOR_ROOT/bin/verilator, which will find the path to all
-needed files.
-
-=item 2.
-
-You may eventually be instaling onto a project/company-wide "CAD" tools
-disk that may support multiple versions of every tool.
-
-    unset VERILATOR_ROOT      # if your shell is bash
-    unsetenv VERILATOR_ROOT   # if your shell is csh
-    # For the tarball, use the version number instead of git describe
-    ./configure --prefix /CAD_DISK/verilator/`git describe | sed "s/verilator_//"`
-
-Note after installing (below steps), if you use C<modulecmd>, you'll want a
-module file like the following:
-
-    set install_root /CAD_DISK/verilator/{version-number-used-above}
-    unsetenv VERILATOR_ROOT
-    prepend-path PATH $install_root/bin
-    prepend-path MANPATH $install_root/man
-    prepend-path PKG_CONFIG_PATH $install_root/share/pkgconfig
-
-=item 3.
-
-The next option is to eventually install it globally, using the normal system paths:
-
-    unset VERILATOR_ROOT      # if your shell is bash
-    unsetenv VERILATOR_ROOT   # if your shell is csh
-    ./configure
-
-Then after installing (below) the binary directories should already be in
-your PATH.
-
-=item 4.
-
-Finally, you may eventually install it into a specific installation prefix,
-as most GNU tools support:
-
-    unset VERILATOR_ROOT      # if your shell is bash
-    unsetenv VERILATOR_ROOT   # if your shell is csh
-    ./configure --prefix /opt/verilator-VERSION
-
-Then after installing (below steps) you will need to add /opt/verilator-VERSION/bin to
-PATH.
-
-=back
-
-Note all of the options above did:
-
-    ./configure  ... some options ...
-
-Add to this line C<--enable-longtests> for more complete developer tests.
-Additional packages may be required for these tests.
-
-=item
-
-Type C<make> to compile Verilator.
-
-=item
-
-Type C<make test> to check the compilation.
-
-=item
-
-If you used the prefix scheme, now do a C<make install>.
-
-=item
-
-You may now wish to consult the examples directory. Type C<make> inside any
-example directory to run the example.
-
-=back
-
-=head1 USAGE DOCUMENTATION
-
-Detailed documentation and the man page can be seen by running:
-
-    bin/verilator --help
-
-or reading verilator.pdf in the same directory as this README.
-
-or see L<https://www.veripool.org/ftp/verilator_doc.pdf> (which is the most
-recent version and thus may differ in some respects from the version you installed).
-
-=head1 PACKAGE DIRECTORY STRUCTURE
-
-The directories in the package directory are as follows:
-
-    Changes                     => Version history
-    bin/verilator               => Compiler Wrapper invoked to Verilate code
-    docs/                       => Additional documentation
-    examples/hello_world_c      => Example simple Verilog->C++ conversion
-    examples/hello_world_sc     => Example simple Verilog->SystemC conversion
-    examples/tracing_c          => Example Verilog->C++ with tracing
-    examples/tracing_sc         => Example Verilog->SystemC with tracing
-    include/                    => Files that should be in your -I compiler path
-    include/verilated*.cpp      => Global routines to link into your simulator
-    include/verilated*.h        => Global headers
-    include/verilated.mk        => Common Makefile
-    include/verilated.v         => Stub defines for linting
-    src/                        => Translator source code
-    test_regress                => Internal tests
-    verilator.pdf               => Primary documentation
-    verilator.txt               => Primary documentation (text)
-
-For files created after Verilation, see the manual.
-
-=head1 DISTRIBUTION
-
-This package is Copyright 2003-2019 by Wilson Snyder.  (Report bugs to
-L<http://www.veripool.org/>.)
-
-Verilator is free software; you can redistribute it and/or modify it under
-the terms of either the GNU Lesser General Public License Version 3 or the
-Perl Artistic License Version 2.0.  (See the documentation for more
-details.)
-
-This program is distributed in the hope that it will be useful, but WITHOUT
-ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
-FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
-more details.

bin/verilator_coverage

@@ -1,9 +1,7 @@
-: # -*-Mode: perl;-*- use perl, wherever it is
-eval 'exec perl -wS $0 ${1+"$@"}'
-  if 0;
+#!/usr/bin/env perl
 ######################################################################
 #
-# Copyright 2003-2019 by Wilson Snyder. This program is free software; you
+# Copyright 2003-2020 by Wilson Snyder. This program is free software; you
 # can redistribute it and/or modify it under the terms of either the GNU
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
@@ -66,7 +64,7 @@ run(verilator_coverage_bin()
 #----------------------------------------------------------------------
 
 sub usage {
-    pod2usage(-verbose=>2, -exitval=>2, -output=>\*STDOUT);
+    pod2usage(-verbose=>2, -exitval=>0, -output=>\*STDOUT);
 }
 
 sub debug {
@@ -134,7 +132,12 @@ sub run {
                 warn "%Error: Verilator_coverage threw signal $status.\n" if !$Debug;
             }
         }
-        die "%Error: Command Failed $command\n";
+        if ($status != 256 || $Debug) {  # i.e. not normal exit(1)
+            warn "%Error: Command Failed $command\n";
+        }
+        exit $! if $!;  # errno
+        exit $? >> 8 if $? >> 8;  # child exit status
+        exit 255;  # last resort
     }
 }
 
@@ -264,9 +267,9 @@ Specifies a module search directory.
 
 =head1 DISTRIBUTION
 
-The latest version is available from L<http://www.veripool.org/>.
+The latest version is available from L<https://verilator.org>.
 
-Copyright 2003-2019 by Wilson Snyder.  Verilator is free software; you can
+Copyright 2003-2020 by Wilson Snyder.  Verilator is free software; you can
 redistribute it and/or modify the Verilator internals under the terms of
 either the GNU Lesser General Public License Version 3 or the Perl Artistic
 License Version 2.0.

bin/verilator_difftree

@@ -1,10 +1,7 @@
-: # -*-Mode: perl;-*- use perl, wherever it is
-eval 'exec perl -wS $0 ${1+"$@"}'
-  if 0;
+#!/usr/bin/env perl
 # See copyright, etc in below POD section.
 ######################################################################
 
-require 5.006_001;
 use warnings;
 use Getopt::Long;
 use IO::File;
@@ -168,8 +165,8 @@ sub filter {
 #----------------------------------------------------------------------
 
 sub usage {
-    pod2usage(-verbose=>2, -exitval=>2, -output=>\*STDOUT);
-    exit(1);
+    pod2usage(-verbose=>2, -exitval=>0, -output=>\*STDOUT);
+    exit(1);  # Unreachable
 }
 
 sub debug {
@@ -234,9 +231,9 @@ Do not show differences in line numbering.
 
 =head1 DISTRIBUTION
 
-The latest version is available from L<http://www.veripool.org/verilator>.
+The latest version is available from L<https://verilator.org>.
 
-Copyright 2005-2019 by Wilson Snyder.  This package is free software; you can
+Copyright 2005-2020 by Wilson Snyder.  This package is free software; you can
 redistribute it and/or modify it under the terms of either the GNU Lesser
 General Public License Version 3 or the Perl Artistic License Version 2.0.
 

bin/verilator_gantt

@@ -1,11 +1,9 @@
-: # -*-Mode: perl;-*- use perl, wherever it is
-eval 'exec perl -wS $0 ${1+"$@"}'
-  if 0;
+#!/usr/bin/env perl
 # See copyright, etc in below POD section.
 ######################################################################
 
-use strict;
 use warnings;
+use strict;
 use Getopt::Long;
 use IO::File;
 use Pod::Usage;
@@ -43,8 +41,8 @@ exit(0);
 #######################################################################
 
 sub usage {
-    pod2usage(-verbose=>2, -exitval=>2, -output=>\*STDOUT);
-    exit(1);
+    pod2usage(-verbose=>2, -exitval=>0, -output=>\*STDOUT);
+    exit(1);  # Unreachable
 }
 
 sub parameter {
@@ -538,9 +536,9 @@ verilator_gantt.vcd.
 
 =head1 DISTRIBUTION
 
-The latest version is available from L<http://www.veripool.org/>.
+The latest version is available from L<https://verilator.org>.
 
-Copyright 2018-2019 by Wilson Snyder.  Verilator is free software; you can
+Copyright 2018-2020 by Wilson Snyder.  Verilator is free software; you can
 redistribute it and/or modify it under the terms of either the GNU Lesser
 General Public License Version 3 or the Perl Artistic License Version 2.0.
 

bin/verilator_includer

@@ -1,9 +1,7 @@
-: # -*-Mode: perl;-*- use perl, wherever it is
-eval 'exec perl -wS $0 ${1+"$@"}'
-  if 0;
+#!/usr/bin/env perl
 # DESCRIPTION: Print include statements for each ARGV
 #
-# Copyright 2003-2019 by Wilson Snyder. This package is free software; you can
+# Copyright 2003-2020 by Wilson Snyder. This package is free software; you can
 # redistribute it and/or modify it under the terms of either the GNU Lesser
 # General Public License Version 3 or the Perl Artistic License Version 2.0.
 ######################################################################

bin/verilator_profcfunc

@@ -1,6 +1,4 @@
-: # -*-Mode: perl;-*- use perl, wherever it is
-eval 'exec perl -wS $0 ${1+"$@"}'
-  if 0;
+#!/usr/bin/env perl
 # See copyright, etc in below POD section.
 ######################################################################
 
@@ -39,8 +37,8 @@ profcfunc($Opt_File);
 #----------------------------------------------------------------------
 
 sub usage {
-    pod2usage(-verbose=>2, -exitval=>2, -output=>\*STDOUT);
-    exit(1);
+    pod2usage(-verbose=>2, -exitval=>0, -output=>\*STDOUT);
+    exit(1);  # Unreachable
 }
 
 sub debug {
@@ -228,9 +226,9 @@ Displays this message and program version and exits.
 
 =head1 DISTRIBUTION
 
-The latest version is available from L<http://www.veripool.org/>.
+The latest version is available from L<https://verilator.org>.
 
-Copyright 2007-2019 by Wilson Snyder.  Verilator is free software; you can
+Copyright 2007-2020 by Wilson Snyder.  Verilator is free software; you can
 redistribute it and/or modify it under the terms of either the GNU Lesser
 General Public License Version 3 or the Perl Artistic License Version 2.0.
 

ci/build_vcddiff.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+# DESCRIPTION: Verilator: Build script for vcddiff
+#
+# Copyright 2019 by Todd Strader. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+set -e
+
+# NB: it would be better to add this via a PPA
+
+TMP_DIR=$(mktemp -d)
+
+git -C "${TMP_DIR}" clone https://github.com/veripool/vcddiff
+VCDDIFF_DIR=${TMP_DIR}/vcddiff
+git -C "${VCDDIFF_DIR}" checkout 5112f88b7ba8818dce9dfb72619e64a1fc19542c
+make -C "${VCDDIFF_DIR}"
+sudo cp "${VCDDIFF_DIR}/vcddiff" /usr/local/bin

ci/build_verilator.sh

@@ -0,0 +1,64 @@
+#!/bin/bash
+# DESCRIPTION: Verilator: Travis CI build script
+#
+# Copyright 2019 by Todd Strader. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+#
+# This script builds and caches the Verilator binaries for Travis CI
+# (and possibly other CI platforms).  The Verilator CI system uses this
+# script, but other CI systems that depend on Verilator may also use
+# the script.
+# see: https://github.com/verilator/verilator_ext_tests/blob/master/.travis.yml
+# To use this script, either checkout Verilator as part of the CI build
+# process or add Verilator as a Git submodule.  Verilator tarballs can
+# not be used as the script relies on Git revisions for caching.
+set -e
+
+if [ -z "${VERILATOR_NUM_JOBS}" ]; then
+    VERILATOR_NUM_JOBS=$(nproc)
+fi
+
+# Caching would be simpler if we installed without VERILATOR_ROOT, but
+#   it's needed for driver.pl outside of the repo
+if [ -z "${VERILATOR_ROOT}" ]; then
+    echo "VERILATOR_ROOT not set"
+    exit -1
+fi
+
+if [ -z "${VERILATOR_CACHE}" ]; then
+    echo "VERILATOR_CACHE not set"
+    exit -1
+fi
+
+VERILATOR_REV=$(cd "${VERILATOR_ROOT}" && git rev-parse HEAD)
+echo "Found Verilator rev ${VERILATOR_REV}"
+
+CACHED_REV_FILE=${VERILATOR_CACHE}/.rev.txt
+
+if [[ ! -f "${CACHED_REV_FILE}" || \
+      $(< "${CACHED_REV_FILE}") != "${VERILATOR_REV}" ]]; then
+    echo "Building Verilator"
+
+    # Unsure why Travis monkies with the capitalization of the stage name, but it does
+    if [[ -n ${TRAVIS_BUILD_STAGE_NAME} && \
+         ${TRAVIS_BUILD_STAGE_NAME} != "Build verilator" ]]; then
+      echo "WARNING: Building Verilator in Travis build stage other than \"Build verilator\": ${TRAVIS_BUILD_STAGE_NAME}"
+    fi
+
+    cd "${VERILATOR_ROOT}"
+    autoconf && ./configure ${VERILATOR_CONFIG_FLAGS} && make -j ${VERILATOR_NUM_JOBS}
+    # Copy the Verilator build artifacts
+    mkdir -p "${VERILATOR_CACHE}"
+    rm -rf ${VERILATOR_CACHE}/*
+    cp bin/*bin* "${VERILATOR_CACHE}"
+    # Remember the Git revision
+    echo "${VERILATOR_REV}" > "${CACHED_REV_FILE}"
+else
+    echo "Using cached Verilator"
+    cd "${VERILATOR_ROOT}"
+    # Create include/verilated_config.h and maybe other things
+    autoconf && ./configure ${VERILATOR_CONFIG_FLAGS}
+    cp ${VERILATOR_CACHE}/* bin
+fi

ci/docker/buildenv/Dockerfile

@@ -0,0 +1,57 @@
+# DESCRIPTION: Dockerfile for env to build and fully test Verilator
+#
+# Copyright 2020 by Stefan Wallentowitz. This program is free
+# software; you can redistribute it and/or modify it under the terms
+# of either the GNU Lesser General Public License Version 3 or the
+# Perl Artistic License Version 2.0.
+
+FROM ubuntu:18.04
+
+RUN apt-get update \
+    && DEBIAN_FRONTEND=noninteractive \
+       apt-get install --no-install-recommends -y \
+                        autoconf=2.69-11 \
+                        bc=1.07.1-2 \
+                        bison=2:3.0.4.dfsg-1build1 \
+                        build-essential=12.4ubuntu1 \
+                        ca-certificates=20180409 \
+                        cmake=3.10.2-1ubuntu2.18.04.1 \
+                        flex=2.6.4-6 \
+                        gdb=8.1-0ubuntu3.2 \
+                        gcc-6=6.5.0-2ubuntu1~18.04 \
+                        gcc-5=5.5.0-12ubuntu1 \
+                        gcc-4.8=4.8.5-4ubuntu8 \
+                        git=1:2.17.1-1ubuntu0.5 \
+                        gtkwave=3.3.86-1 \
+                        g++-6=6.5.0-2ubuntu1~18.04 \
+                        g++-5=5.5.0-12ubuntu1 \
+                        g++-4.8=4.8.5-4ubuntu8 \
+                        libfl2=2.6.4-6 \
+                        libfl-dev=2.6.4-6 \
+                        numactl=2.0.11-2.1ubuntu0.1 \
+                        perl=5.26.1-6ubuntu0.3 \
+                        python3=3.6.7-1~18.04 \
+                        wget=1.19.4-1ubuntu2.2 \
+                        zlibc=0.9k-4.3 \
+                        zlib1g=1:1.2.11.dfsg-0ubuntu2 \
+                        zlib1g-dev=1:1.2.11.dfsg-0ubuntu2 \
+    && apt-get clean \
+    && rm -rf /var/lib/apt/lists/*
+
+WORKDIR /tmp
+
+COPY build-systemc.sh /tmp/
+RUN ./build-systemc.sh
+
+RUN cpan install -fi Unix::Processors Parallel::Forker Bit::Vector
+
+RUN git clone https://github.com/veripool/vcddiff.git && \
+    make -C vcddiff && \
+    cp -p vcddiff/vcddiff /usr/local/bin/vcddiff && \
+    rm -rf vcddiff
+
+COPY build.sh /tmp/build.sh
+
+ENV VERILATOR_AUTHOR_SITE=1
+
+ENTRYPOINT [ "/tmp/build.sh" ]

ci/docker/buildenv/README.adoc

@@ -0,0 +1,50 @@
+= Verilator Build Environment
+
+This container is set up to compile and test a Verilator build based
+on the following parameters:
+
+* Source repository (default: https://github.com/verilator/verilator)
+* Source revision (default: master)
+* GCC version (4.8.5, 5.5.0, 6.5.0, 7.4.0, default: 7.4.0)
+
+The container is published as `verilator/verilator-buildenv` on
+https://hub.docker.com/repository/docker/verilator/verilator-buildenv[docker hub].
+
+To run the basic build of current master:
+
+    docker run -ti verilator/verilator-buildenv
+
+To also run tests:
+
+    docker run -ti verilator/verilator-buildenv test
+
+Change the compiler:
+
+    docker run -ti -e CC=gcc-4.8 -e CXX=g++-4.8 verilator/verilator-buildenv test
+
+The tests that involve gdb are not working due to security restrictions.
+To run those too:
+
+....
+docker run -ti -v ${PWD}:/tmp/repo -e REPO=/tmp/repo -e REV=`git rev-parse --short HEAD` -e CC=gcc-4.8 -e CXX=g++-4.8 --cap-add=SYS_PTRACE --security-opt seccomp=unconfined verilator/verilator-buildenv test
+....
+
+You may want to avoid pushing your changes to a remote repository and
+instead use a local working copy. You can mount the local working copy
+path as a volume and use this as repo. Be careful, that it can only
+use committed changes, so you may want to use a work-in-progress
+commit or so. To build the current HEAD from top of a repository:
+
+....
+docker run -ti -v ${PWD}:/tmp/repo -e REPO=/tmp/repo -e REV=`git rev-parse --short HEAD` --cap-add=SYS_PTRACE --security-opt seccomp=unconfined verilator/verilator-buildenv test
+....
+
+== Under the Hood
+
+To rebuild the image, simply run:
+
+    docker build .
+
+It will build SystemC in all supported compiler variants to reduce the
+impact on testing cycles. A build script will be the entrypoint to the
+container that will perform a standard build and test procedure.

ci/docker/buildenv/build-systemc.sh

@@ -0,0 +1,29 @@
+#!/bin/bash -e
+# DESCRIPTION: Build SystemC in Ubuntu 18.04 with  different g++/gcc
+#
+# Copyright 2020 by Stefan Wallentowitz. This program is free
+# software; you can redistribute it and/or modify it under the terms
+# of either the GNU Lesser General Public License Version 3 or the
+# Perl Artistic License Version 2.0.
+
+build_variant () {
+    version=$($1 --version | grep gcc | awk '{print $4}')
+    mkdir "/usr/local/systemc-2.3.3-gcc$version"
+    mkdir build
+    cd build
+    ../configure --prefix="/usr/local/systemc-2.3.3-gcc$version" CC="$1" CXX="$2" LD="$2"
+    make -j
+    make install
+    cd ..
+    rm -r build
+}
+
+wget https://www.accellera.org/images/downloads/standards/systemc/systemc-2.3.3.tar.gz
+tar -xzf systemc-2.3.3.tar.gz
+cd systemc-2.3.3
+build_variant gcc g++
+build_variant gcc-6 g++-6
+build_variant gcc-5 g++-5
+build_variant gcc-4.8 g++-4.8
+cd ..
+rm -r systemc-2.3.3*

ci/docker/buildenv/build.sh

@@ -0,0 +1,30 @@
+#!/bin/bash -e
+# DESCRIPTION: Build Verilator (inside container)
+#
+# Copyright 2020 by Stefan Wallentowitz. This program is free
+# software; you can redistribute it and/or modify it under the terms
+# of either the GNU Lesser General Public License Version 3 or the
+# Perl Artistic License Version 2.0.
+
+: "${REPO:=https://github.com/verilator/verilator}"
+: "${REV:=master}"
+: "${CC:=gcc}"
+: "${CXX:=g++}"
+
+GCCVERSION=$(${CC} --version | grep gcc | awk '{print $4}')
+
+export SYSTEMC_INCLUDE="/usr/local/systemc-2.3.3-gcc${GCCVERSION}/include"
+export SYSTEMC_LIBDIR="/usr/local/systemc-2.3.3-gcc${GCCVERSION}/lib-linux64"
+export LD_LIBRARY_PATH=${SYSTEMC_LIBDIR}
+
+SRCS=$PWD/verilator
+
+git clone "$REPO" "$SRCS"
+cd "$SRCS"
+git checkout "$REV"
+autoconf
+./configure --enable-longtests
+make -j $(nproc)
+if [ "${1:-''}" == "test" ]; then
+    make test
+fi

ci/docker/run/Dockerfile

@@ -0,0 +1,47 @@
+# DESCRIPTION: Dockerfile for image to run Verilator inside
+#
+# Copyright 2020 by Stefan Wallentowitz. This program is free
+# software; you can redistribute it and/or modify it under the terms
+# of either the GNU Lesser General Public License Version 3 or the
+# Perl Artistic License Version 2.0.
+
+FROM ubuntu:18.04
+
+RUN apt-get update \
+    && apt-get install --no-install-recommends -y \
+                        autoconf=2.69-11 \
+                        bc=1.07.1-2 \
+                        bison=2:3.0.4.dfsg-1build1 \
+                        build-essential=12.4ubuntu1 \
+                        ca-certificates=20180409 \
+                        flex=2.6.4-6 \
+                        git=1:2.17.1-1ubuntu0.5 \
+                        libfl-dev=2.6.4-6 \
+                        perl=5.26.1-6ubuntu0.3 \
+                        python3=3.6.7-1~18.04 \
+    && apt-get clean \
+    && rm -rf /var/lib/apt/lists/*
+
+ARG REPO=https://github.com/verilator/verilator
+ARG SOURCE_COMMIT=master
+
+WORKDIR /tmp
+
+# Add an exception for the linter, we want to cd here in one layer
+# to reduce the number of layers (and thereby size).
+# hadolint ignore=DL3003
+RUN git clone "${REPO}" verilator && \
+    cd verilator && \
+    git checkout "${SOURCE_COMMIT}" && \
+    autoconf && \
+    ./configure && \
+    make -j "$(nproc)" && \
+    make install && \
+    cd .. && \
+    rm -r verilator
+
+COPY verilator-wrap.sh /usr/local/bin/verilator-wrap.sh
+
+WORKDIR /work
+
+ENTRYPOINT [ "/usr/local/bin/verilator-wrap.sh" ]

ci/docker/run/README.adoc

@@ -0,0 +1,49 @@
+= Docker Container as Verilator executable
+
+This allows you to run Verilator easily as a docker image, e.g.:
+
+    docker run -ti verilator/verilator:latest --version
+
+This is in particular useful to compare against older version or to
+check when an issue was introduced.
+
+You will need to give it access to your files as a volume and fix the
+user rights:
+
+....
+docker run -ti -v ${PWD}:/work --user $(id -u):$(id -g) verilator/verilator:latest --cc test.v
+....
+
+The caveat is that it can only access files below the current
+directory then, a workaround is to adopt the volume and set
+`-workdir`.
+
+There is a convenience script in this folder that wraps around the
+docker calls:
+
+    $ verilator-docker 3.922 --version
+    Verilator 3.922 2018-03-17 rev UNKNOWN_REV
+
+Finally, you can also work in the container by setting the entrypoint
+(don't forget to mount a volume if you want your work persistent):
+
+    docker run -ti --entrypoint /bin/bash verilator/verilator:latest
+
+The other files in this folder all for building the containers and to
+store in them. You could use it to build Verilator at a specific
+commit:
+
+    docker build --build-arg SOURCE_COMMIT=<commit> .
+
+== Internals
+
+The Dockerfile is pretty straight-forward, it builds Verilator and
+removes the tree after that to reduce the image size. It sets a
+wrapper script (`verilator-wrap.sh`) as entrypoint. This script calls
+Verilator but also copies the verilated runtime files to the `obj_dir`
+or the `-Mdir` respectively. This allows the user to build the C++
+output with the matching runtime files. The wrapper patches the
+generated Makefile accordingly.
+
+There is also a hook defined that is run by docker hub via automated
+builds.

ci/docker/run/hooks/build

@@ -0,0 +1,9 @@
+#!/bin/bash
+# DESCRIPTION: Docker hub hook to pass SOURCE_COMMIT
+#
+# Copyright 2020 by Stefan Wallentowitz. This program is free
+# software; you can redistribute it and/or modify it under the terms
+# of either the GNU Lesser General Public License Version 3 or the
+# Perl Artistic License Version 2.0.FROM ubuntu:18.04
+
+docker build --build-arg SOURCE_COMMIT=${SOURCE_COMMIT} -f $DOCKERFILE_PATH -t $IMAGE_NAME .

ci/docker/run/hooks/post_push

@@ -0,0 +1,12 @@
+#!/bin/bash
+# DESCRIPTION: Docker hub hook to tag the latest release (stable)
+#
+# Copyright 2020 by Stefan Wallentowitz. This program is free
+# software; you can redistribute it and/or modify it under the terms
+# of either the GNU Lesser General Public License Version 3 or the
+# Perl Artistic License Version 2.0.FROM ubuntu:18.04
+
+if [ "$SOURCE_BRANCH"="stable" ]; then
+    docker tag $IMAGE_NAME $DOCKER_REPO:latest
+    docker push $DOCKER_REPO:latest
+fi

ci/docker/run/verilator-docker

@@ -0,0 +1,10 @@
+#!/bin/bash
+# DESCRIPTION: Wrap a verilator call to run a docker container
+#
+# Copyright 2020 by Stefan Wallentowitz. This program is free
+# software; you can redistribute it and/or modify it under the terms
+# of either the GNU Lesser General Public License Version 3 or the
+# Perl Artistic License Version 2.0.
+
+docker pull verilator/verilator:$1 >/dev/null
+docker run -ti -v ${PWD}:/work --user $(id -u):$(id -g) verilator/verilator:$1 "${@:2}"

ci/docker/run/verilator-wrap.sh

@@ -0,0 +1,26 @@
+#!/bin/bash -e
+# DESCRIPTION: Wrap a Verilator call and copy vlt includes
+#              (inside docker container)
+#
+# Copyright 2020 by Stefan Wallentowitz. This program is free
+# software; you can redistribute it and/or modify it under the terms
+# of either the GNU Lesser General Public License Version 3 or the
+# Perl Artistic License Version 2.0.
+
+perl /usr/local/bin/verilator "$@"
+
+# Check if user set an obj_dir
+obj_dir=$(echo " $@" | grep -oP '\s--Mdir\s*\K\S+')
+if [ "$obj_dir" == "" ]; then
+    obj_dir="obj_dir"
+fi
+
+# If the run was successful: Copy required files to allow build without this container
+if [ -e ${obj_dir} ]; then
+    # Copy files required for the build
+    mkdir -p ${obj_dir}/vlt
+    cp -r /usr/local/share/verilator/bin ${obj_dir}/vlt
+    cp -r /usr/local/share/verilator/include ${obj_dir}/vlt
+    # Point Makefile to that folder
+    perl -i -pe 's/VERILATOR_ROOT = \/usr\/local\/share\/verilator/VERILATOR_ROOT = vlt/g' ${obj_dir}/*.mk
+fi

ci/test.sh

@@ -0,0 +1,26 @@
+#!/bin/bash
+# DESCRIPTION: Verilator: Travis CI test script
+#
+# Copyright 2019 by Todd Strader. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+set -e
+
+export DRIVER_FLAGS='-j 0 --quiet --rerun'
+
+case $1 in
+    dist)
+        make -C test_regress SCENARIOS=--dist
+        ;;
+    vlt)
+        make -C test_regress SCENARIOS=--vlt
+        ;;
+    vltmt)
+        make -C test_regress SCENARIOS=--vltmt
+        ;;
+    *)
+    echo "Usage: test.sh (dist|vlt|vltmt)"
+    exit -1
+    ;;
+esac

configure.ac

@@ -1,19 +1,19 @@
 # DESCRIPTION: Process this file with autoconf to produce a configure script.
 #
-# Copyright 2003-2019 by Wilson Snyder. Verilator is free software; you can
+# Copyright 2003-2020 by Wilson Snyder. Verilator is free software; you can
 # redistribute it and/or modify it under the terms of either the GNU Lesser
 # General Public License Version 3 or the Perl Artistic License Version 2.0.
 
 #AC_INIT([Verilator],[#.### YYYY-MM-DD])
 #AC_INIT([Verilator],[#.### devel])
-AC_INIT([Verilator],[4.018 2019-08-29],
-        [https://www.veripool.org/verilator],
-        [verilator],[https://www.veripool.org/verilator])
+AC_INIT([Verilator],[4.028 2020-02-06],
+        [https://verilator.org],
+        [verilator],[https://verilator.org])
 # When releasing, also update header of Changes file
 # and commit using "devel release" or "Version bump" message
 
 AC_CONFIG_HEADER(src/config_build.h)
-AC_CONFIG_FILES(Makefile docs/Makefile src/Makefile src/Makefile_obj include/verilated.mk include/verilated_config.h verilator.pc)
+AC_CONFIG_FILES(Makefile docs/Makefile src/Makefile src/Makefile_obj include/verilated.mk include/verilated_config.h verilator.pc verilator-config.cmake verilator-config-version.cmake)
 
 AC_MSG_RESULT([configuring for $PACKAGE_STRING])
 
@@ -25,11 +25,43 @@ AC_ARG_ENABLE([maintainer-mode],
 AC_ARG_ENABLE([silent-rules],
               [AS_HELP_STRING([--disable-silent-rules], [ignored])])
 
+# Flag to enable linking specific libraries statically
+AC_MSG_CHECKING(whether to perform partial static linking of Verilator binary)
+AC_ARG_ENABLE([partial-static],
+              [AS_HELP_STRING([--disable-partial-static],
+                              [By default, for Verilation peformance, Verilator
+                               is linked against some of its dependencies
+                               statically. Use this to link the Verilator binary
+                               fully dynamically.])],
+              [case "${enableval}" in
+                yes) CFG_ENABLE_PARTIAL_STATIC=yes ;;
+                no)  CFG_ENABLE_PARTIAL_STATIC=no ;;
+                *)   AC_MSG_ERROR([bad value '${enableval}' for --disable-partial-static]) ;;
+               esac],
+               CFG_ENABLE_PARTIAL_STATIC=yes)
+AC_MSG_RESULT($CFG_ENABLE_PARTIAL_STATIC)
+
+# Flag to enable linking Verilator with tcmalloc if available
+AC_MSG_CHECKING(whether to use tcmalloc)
+AC_ARG_ENABLE([tcmalloc],
+              [AS_HELP_STRING([--enable-tcmalloc],
+                              [Use libtcmalloc_minimal for faster dynamic memory
+                               management in Verilator binary@<:@default=check@:>@])],
+              [case "${enableval}" in
+                yes) CFG_WITH_TCMALLOC=yes ;;
+                no)  CFG_WITH_TCMALLOC=no ;;
+                *)   AC_MSG_ERROR([bad value '${enableval}' for --enable-tcmalloc]) ;;
+               esac],
+              [CFG_WITH_TCMALLOC=check;])
+AC_MSG_RESULT($CFG_WITH_TCMALLOC)
+
 # Special Substitutions - CFG_WITH_DEFENV
 AC_MSG_CHECKING(whether to use hardcoded paths)
 AC_ARG_ENABLE([defenv],
               [AS_HELP_STRING([--disable-defenv],
-                              [disable using some hardcoded data paths extracted from some default environment variables (the default is to use hardcoded paths)])],
+                              [disable using some hardcoded data paths extracted
+                              from some default environment variables (the default
+                              is to use hardcoded paths) in Verilator binary])],
               [case "${enableval}" in
                 yes) CFG_WITH_DEFENV=yes ;;
                 no)  CFG_WITH_DEFENV=no ;;
@@ -43,7 +75,8 @@ AC_MSG_RESULT($CFG_WITH_DEFENV)
 AC_MSG_CHECKING(whether to show and stop on compilation warnings)
 AC_ARG_ENABLE([ccwarn],
               [AS_HELP_STRING([--enable-ccwarn],
-                              [enable showing and stopping on compilation warnings])],
+                              [enable showing and stopping on compilation warnings
+                               in Verilator binrary and Verilated makefiles])],
               [case "${enableval}" in
                 yes) CFG_WITH_CCWARN=yes ;;
                 no)  CFG_WITH_CCWARN=no ;;
@@ -79,7 +112,8 @@ AC_MSG_RESULT($CFG_WITH_LONGTESTS)
 AC_MSG_CHECKING(whether allow pre-C++11)
 AC_ARG_ENABLE([prec11],
               [AS_HELP_STRING([--enable-prec11],
-                              [enable pre-C++11 compilers])],
+                              [enable pre-C++11 compilers for Verilator binary
+                               and Verilated makefiles])],
               [case "${enableval}" in
                 yes) CFG_WITH_PREC11=yes ;;
                 no)  CFG_WITH_PREC11=no ;;
@@ -209,15 +243,26 @@ AC_DEFUN([_MY_LDLIBS_CHECK_FLAG],
     LIBS="$ACO_SAVE_LIBS"
    ])
 
-AC_DEFUN([_MY_LDLIBS_CHECK_OPT],
-   [# _MY_LDLIBS_CHECK_OPT(flag) -- Check if linker supports specific options
-    # If it does, append flag to variable
-    _MY_LDLIBS_CHECK_FLAG($2)
+AC_DEFUN([_MY_LDLIBS_CHECK_IFELSE],
+   [# _MY_LDLIBS_CHECK_IFELSE(flag,action-if-supported,action-if-not-supported)
+    # Check if linker supports specific flag, if it does do action-if-supported
+    # otherwise do action-if-not-supported
+    _MY_LDLIBS_CHECK_FLAG($1)
     if test "$_my_result" = "yes" ; then
-       $1="$$1 $2"
+      true
+      $2
+    else
+      true
+      $3
     fi
    ])
 
+AC_DEFUN([_MY_LDLIBS_CHECK_OPT],
+   [# _MY_LDLIBS_CHECK_OPT(variable, flag) -- Check if linker supports specific
+    # options. If it does, append flag to variable.
+    _MY_LDLIBS_CHECK_IFELSE($2, $1="$$1 $2")
+   ])
+
 # Flag to select newest language standard supported
 # Macros work such that first option that passes is the one we take
 # gnu++17 code is clean, but SystemC in 2018 doesn't link with it (bug1339)
@@ -276,24 +321,72 @@ AC_SUBST(CFG_CXXFLAGS_PARSER)
 # For some reason -faligned-new does not work under Travis w/ clang but the
 # configure test doesn't catch this either
 AS_IF([test "x$TRAVIS_COMPILER" != xclang], [_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_NO_UNUSED,-faligned-new)])
-_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_NO_UNUSED,-fbracket-depth=4096)
-_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_NO_UNUSED,-Qunused-arguments)
-_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_NO_UNUSED,-Wno-bool-operation)
-_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_NO_UNUSED,-Wno-parentheses-equality)
-_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_NO_UNUSED,-Wno-sign-compare)
-_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_NO_UNUSED,-Wno-uninitialized)
-_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_NO_UNUSED,-Wno-unused-but-set-variable)
-_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_NO_UNUSED,-Wno-unused-parameter)
-_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_NO_UNUSED,-Wno-unused-variable)
-_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_NO_UNUSED,-Wno-shadow)
+CFG_CXX_FLAGS_CMAKE="-faligned-new"
+m4_foreach([cflag],[
+        [-fbracket-depth=4096],
+        [-fcf-protection=none],
+        [-mno-cet],
+        [-Qunused-arguments],
+        [-Wno-bool-operation],
+        [-Wno-parentheses-equality],
+        [-Wno-sign-compare],
+        [-Wno-uninitialized],
+        [-Wno-unused-but-set-variable],
+        [-Wno-unused-parameter],
+        [-Wno-unused-variable],
+        [-Wno-shadow]],[
+    _MY_CXX_CHECK_OPT(CFG_CXXFLAGS_NO_UNUSED,cflag)
+    # CMake will test what flags work itself, so pass all flags through to it
+    CFG_CXX_FLAGS_CMAKE="$CFG_CXX_FLAGS_CMAKE cflag"
+    ])
 AC_SUBST(CFG_CXXFLAGS_NO_UNUSED)
+AC_SUBST(CFG_CXX_FLAGS_CMAKE)
 
 # Find multithread linker flags
-_MY_LDLIBS_CHECK_OPT(CFG_LDLIBS_THREADS,-mt)
-_MY_LDLIBS_CHECK_OPT(CFG_LDLIBS_THREADS,-pthread)
-_MY_LDLIBS_CHECK_OPT(CFG_LDLIBS_THREADS,-lpthread)
-_MY_LDLIBS_CHECK_OPT(CFG_LDLIBS_THREADS,-latomic)
+m4_foreach([ldflag], [
+        [-mt],
+        [-pthread],
+        [-lpthread],
+        [-latomic]],[
+    _MY_LDLIBS_CHECK_OPT(CFG_LDLIBS_THREADS,ldflag)
+    # CMake will test what flags work itself, so pass all flags through to it
+    CFG_LDFLAGS_THREADS_CMAKE="$CFG_LDFLAGS_THREADS_CMAKE ldflag"
+    ])
 AC_SUBST(CFG_LDLIBS_THREADS)
+AC_SUBST(CFG_LDFLAGS_THREADS_CMAKE)
+
+# When linking partially statically
+if test "$CFG_ENABLE_PARTIAL_STATIC" = "yes"; then
+  _MY_LDLIBS_CHECK_OPT(CFG_LDFLAGS_SRC, -static-libgcc)
+  _MY_LDLIBS_CHECK_OPT(CFG_LDFLAGS_SRC, -static-libstdc++)
+  _MY_LDLIBS_CHECK_OPT(CFG_LDFLAGS_SRC, -Xlinker -gc-sections)
+  LTCMALLOC=-l:libtcmalloc_minimal.a
+else
+  LTCMALLOC=-ltcmalloc_minimal
+fi
+AC_SUBST(CFG_LDFLAGS_SRC)
+
+# The pthread library is required by tcmalloc, so add it if it exists. If it
+# does not, the tcmalloc check below will fail anyway, and linking against
+# pthreads is harmless otherwise.
+_MY_LDLIBS_CHECK_OPT(CFG_LIBS, -lpthread)
+
+# Check if tcmalloc is available based on --enable-tcmalloc
+_MY_LDLIBS_CHECK_IFELSE(
+  $LTCMALLOC,
+  [if test "$CFG_WITH_TCMALLOC" != "no"; then
+    CFG_LIBS="$LTCMALLOC $CFG_LIBS";
+    # If using tcmalloc, add some extra options to make the compiler not assume
+    # it is using it's own versions of the standard library functions
+    _MY_CXX_CHECK_OPT(CFG_CXXFLAGS_SRC,-fno-builtin-malloc)
+    _MY_CXX_CHECK_OPT(CFG_CXXFLAGS_SRC,-fno-builtin-calloc)
+    _MY_CXX_CHECK_OPT(CFG_CXXFLAGS_SRC,-fno-builtin-realloc)
+    _MY_CXX_CHECK_OPT(CFG_CXXFLAGS_SRC,-fno-builtin-free)
+   fi],
+  [if test "$CFG_WITH_TCMALLOC" = "yes"; then
+    AC_MSG_ERROR([--enable-tcmalloc was given but test for ${LTCMALLOC} failed])
+   fi])
+AC_SUBST(CFG_LIBS)
 
 # Set CFG_WITH_THREADED if can support threading
 AC_MSG_CHECKING(whether $CXX supports Verilated threads)

docs/.gitignore

@@ -1 +1,4 @@
+*.1
+*.html
+*.pdf
 Makefile

docs/CONTRIBUTING.adoc

@@ -0,0 +1,82 @@
+= How to contribute to Verilator
+
+Thanks for using Verilator!  We welcome your contributions in whatever form.
+
+This contributing document contains some suggestions that may make
+contributions flow more efficiently.
+
+==== Did you find a bug?
+
+* Please **Ensure the bug was not already reported** by searching
+  https://verilator.org/issues[Verilator Issues].
+
+* If you're unable to find an open issue addressing the problem,
+  https://verilator.org/issues/new[open a new Verilator issue].
+
+** Be sure to include a **code sample** or an **executable test case**
+   demonstrating the bug and expected behavior that is not occurring.
+
+** The ideal example works against other simulators, and is in the
+   test_regress/t test format, as described in
+   link:internals.adoc[docs/internals].
+
+==== Did you write a patch that fixes a bug?
+
+* Please https://verilator.org/issues/new[Open a new issue].
+
+* You may attach a patch to the issue, or (preferred) may request a GitHub
+  pull request.
+
+** Verilator uses Travis CI to provide continuous integration. You may
+   want to setup Travis CI on your GitHub branch to ensure your changes
+   keep the tests passing.  See link:internals.adoc[docs/internals].
+
+* Your source-code contributions must be certified as open source, under
+  the https://developercertificate.org/[Developer Certificate of
+  Origin]. On your first contribution, you must either:
+
+** Have your patch include the addition of your name to
+   link:CONTRIBUTORS[docs/CONTRIBUTORS] (preferred).
+
+** Use "git -s" as part of your commit. This adds a "signed-of-by"
+   attribute which will certify your contribution as described in the
+   https://github.com/wking/signed-off-by/blob/master/Documentation/SubmittingPatches[Signed-of-By
+   convention].
+
+** Email, or post in an issue a statement that you certify your
+   contributions.
+
+** In any of these cases your name will be added to
+   link:CONTRIBUTORS[docs/CONTRIBUTORS] and you are agreeing all future
+   contributions are also certified.
+
+** We occasionally accept contributions where people do not want their
+   name published. Please email us; you must still certify your
+   contribution using email.
+
+* Your test contributions are generally considered released into the public
+  domain, unless you request otherwise or put a GNU/Artistic license on
+  your test file.
+
+* Most important is we get your patch. If you'd like to clean up
+  indentation and related issues ahead of our feedback, that is
+  appreciated; please see the coding conventions in
+  link:internals.adoc[docs/internals].
+
+==== Do you have questions?
+
+* Please see FAQ section and rest of the
+  https://verilator.org/verilator_doc.html[Verilator manual],
+  or https://verilator.org/verilator_doc.pdf[Verilator manual (PDF)].
+
+* Ask any question in the
+  https://verilator.org/forum[Verilator forum].
+
+==== Code of Conduct
+
+* Our contributors and participants pledge to make participation in our
+  project and our community a positive experience for everyone.  We follow
+  the https://www.contributor-covenant.org/version/1/4/code-of-conduct.html[Contributor
+  Covenant version 1.4].
+
+Thanks!

docs/CONTRIBUTORS

@@ -2,16 +2,38 @@ The contributors listed below have certified their Verilator contributions
 under the Developer Certificate of Origin
 (https://developercertificate.org/).
 
-Please see the Verilator manual for additional contributors.
+Please see the Verilator manual for 200+ additional contributors. Thanks to
+all.
 
+Ahmed El-Mahmoudy
 Alex Chadwick
+Chris Randall
+Driss Hafdi
+Eric Rippey
+Garrett Smith
+Geza Lore
 Gianfranco Costamagna
+Howard Su
+Iztok Jeras
 Jeremy Bennett
 John Coiner
+Julien Margetts
 Kanad Kanhere
+Kevin Kiningham
+Kuba Ober
+Lukasz Dalek
 Maarten De Braekeleer
+Matthew Ballance
+Mike Popoloski
+Patrick Stewart
+Peter Monsson
 Philipp Wagner
+Pieter Kapsenberg
 Richard Myers
 Sebastien Van Cauwenberghe
 Stefan Wallentowitz
+Tobias Rosenkranz
+Todd Strader
 Wilson Snyder
+Yutetsu TAKATSUKASA
+Yves Mathieu

docs/Makefile.in

@@ -3,11 +3,11 @@
 #
 # This file is part of Verilator.
 #
-# Code available from: http://www.veripool.org/verilator
+# Code available from: https://verilator.org
 #
 #*****************************************************************************
 #
-# Copyright 2003-2019 by Wilson Snyder. This program is free software; you can
+# Copyright 2003-2020 by Wilson Snyder. This program is free software; you can
 # redistribute it and/or modify it under the terms of either the GNU
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
@@ -23,6 +23,7 @@
 
 #### Start of system configuration section. ####
 
+ASCIIDOCTOR = asciidoctor
 DOXYGEN = doxygen
 
 #### End of system configuration section. ####
@@ -33,6 +34,9 @@ DOXYGEN = doxygen
 default:
 	@echo "error: make not supported here, run 'make docs' from Verilator top-level"
 
+%.html: %.adoc
+	$(ASCIIDOCTOR) $< -n -o $@
+
 clean mostlyclean distclean maintainer-clean::
 	rm -f $(SCRIPTS) *.tmp
 	rm -f *.aux *.cp *.cps *.dvi *.fn *.fns *.ky *.kys *.log
@@ -41,7 +45,7 @@ clean mostlyclean distclean maintainer-clean::
 	rm -f *.tex
 
 distclean maintainer-clean::
-	rm -f *.info* *.1 $(INFOS)
+	rm -f *.info* *.1 *.html *.pdf $(INFOS)
 	rm -f Makefile
 
 .PHONY: doxygen

docs/TODO

@@ -1,6 +1,6 @@
 // DESCRIPTION: Verilator: List of To Do issues.
 //
-// Copyright 2004-2019 by Wilson Snyder. This program is free software; you can
+// Copyright 2004-2020 by Wilson Snyder. This program is free software; you can
 // redistribute it and/or modify it under the terms of either the GNU
 // Lesser General Public License Version 3 or the Perl Artistic License
 // Version 2.0.

docs/doxygen-mainpage

@@ -3,4 +3,4 @@
  * \section intro_sec Introduction
  *
  * This is a full doxygen analysis of the Verilator source tree.
- */
+ */

docs/install.adoc

@@ -0,0 +1,303 @@
+= Verilator Installation
+:toc: right
+
+// Github doesn't render unless absolute URL
+image::https://www.veripool.org/img/verilator_256_200_min.png[Logo,256,200,role="right"]
+
+== Introduction
+
+This discusses how to install Verilator.  For more general information
+please see https://verilator.org[verilator.org].
+
+== Quick-start
+
+=== Install From a Package Manager
+
+Using a distribution's package manager is the easiest way to get
+started. (Note packages are unlikely to have the most recent version, so
+Git, below, maybe a better alternative.) To install as a package:
+
+   apt-get install verilator
+
+If this works, skip down to <<Running Verilator>>.
+
+=== Docker
+
+Verilator is available in pre-built Docker containers. See
+https://github.com/verilator/verilator/blob/master/ci/docker/run/README.adoc
+
+=== Git
+
+Installing Verilator with Git provides the most flexibility.
+For additional options and details see the additional sections below.  In
+brief:
+
+// Also update README
+....
+# Prerequisites:
+#sudo apt-get install git make autoconf g++ flex bison
+#sudo apt-get install libfl2  # Ubuntu only (ignore if gives error)
+#sudo apt-get install libfl-dev  # Ubuntu only (ignore if gives error)
+
+git clone https://git.veripool.org/git/verilator   # Only first time
+## Note the URL above is not a page you can see with a browser, it's for git only
+
+# Every time you need to build:
+unsetenv VERILATOR_ROOT  # For csh; ignore error if on bash
+unset VERILATOR_ROOT  # For bash
+cd verilator
+git pull        # Make sure git repository is up-to-date
+git tag         # See what versions exist
+#git checkout master      # Use development branch (e.g. recent bug fixes)
+#git checkout stable      # Use most recent stable release
+#git checkout v{version}  # Switch to specified release version
+
+autoconf        # Create ./configure script
+./configure
+make
+sudo make install
+# Now see "man verilator" or online verilator.pdf's for the example tutorials
+....
+
+If this works, skip down to <<Running Verilator>>.
+
+== Detailed Build Instructions
+
+This section describes details of the build process, and assumes you are
+building from Git or a tarball.  For using a pre-built binary for your
+Linux distribution, see instead <<Install From a Package Manager>>.
+
+=== OS Requirements
+
+Verilator is developed and has primary testing on Ubuntu.  Versions have
+also built on Redhat Linux, Apple OS-X, HPUX and Solaris.  It should run
+with minor porting on any GNU/Linux-ish platform.  Verilator also works on
+Windows under Cygwin, and Windows under MinGW (gcc -mno-cygwin).  Verilated
+output (not Verilator itself) compiles under all the options above, plus
+MSVC++.
+
+=== Install Prerequisites
+
+To build Verilator you will need to install some standard packages:
+
+   sudo apt-get install git
+   sudo apt-get install autoconf
+   sudo apt-get install flex bison
+
+The following are optional, but improve compilation speed:
+
+   sudo apt-get install libgoogle-perftools-dev
+
+Additionally, to build or run Verilator you need these standard packages:
+
+   sudo apt-get install perl python3
+   sudo apt-get install make
+   sudo apt-get install g++  # Alternatively, clang
+   sudo apt-get install libgz  # Non-Ubuntu (ignore if gives error)
+   sudo apt-get install libfl2 libfl-dev zlibc zlib1g zlib1g-dev  # Ubuntu only (ignore if gives error)
+
+Those developing Verilator may also want these (see internals.adoc):
+
+   sudo apt-get install gdb asciidoctor graphviz
+   cpan install Pod::Perldoc
+   cpan install Unix::Processors
+
+==== Install SystemC
+
+If you will be using SystemC (vs straight C++ output), download
+https://www.accellera.org/downloads/standards/systemc[SystemC].
+Follow their installation instructions.  You will need to set `SYSTEMC_INCLUDE`
+to point to the include directory with `systemc.h` in it, and `SYSTEMC_LIBDIR`
+to points to the directory with `libsystemc.a` in it.  (Older installations
+may set `SYSTEMC` and `SYSTEMC_ARCH` instead.)
+
+==== Install GTKWave
+
+To make use of Verilator FST tracing you will want
+http://gtkwave.sourceforge.net/[GTKwave] installed, however this is not
+required at Verilator build time.
+
+=== Obtain Sources
+
+You may use Git or a tarball for the sources.  Git is the supported option.
+(If using a historical build that uses a tarball, tarballs are obtained
+from https://www.veripool.org/projects/verilator/wiki/Download[Verilator
+Downloads]; we presume you know how to use it, and is not described here.)
+
+Get the sources from the repository: (You need do this only once, ever.)
+
+   git clone https://git.veripool.org/git/verilator   # Only first time
+   ## Note the URL above is not a page you can see with a browser, it's for git only
+
+Enter the checkout and determine what version/branch to use:
+
+   cd verilator
+   git pull        # Make sure we're up-to-date
+   git tag         # See what versions exist
+   #git checkout master      # Use development branch (e.g. recent bug fix)
+   #git checkout stable      # Use most recent release
+   #git checkout v{version}  # Switch to specified release version
+
+=== Auto Configure
+
+Create the configuration script:
+
+   autoconf        # Create ./configure script
+
+=== Eventual Installation Options
+
+Before configuring the build, you have to decide how you're going to
+eventually install the kit.  Verilator will be compiling the current value
+of `VERILATOR_ROOT`, `SYSTEMC_INCLUDE`, and `SYSTEMC_LIBDIR` as defaults
+into the executable, so they must be correct before configuring.
+
+These are the options:
+
+==== 1. Run-in-Place from VERILATOR_ROOT
+
+Our personal favorite is to always run Verilator in-place from its Git
+directory.  This allows the easiest experimentation and upgrading, and
+allows many versions of Verilator to co-exist on a system.
+
+   export VERILATOR_ROOT=`pwd`   # if your shell is bash
+   setenv VERILATOR_ROOT `pwd`   # if your shell is csh
+   ./configure
+   # Running will use files from $VERILATOR_ROOT, so no install needed
+
+Note after installing (below steps), a calling program or shell must set
+the environment variable `VERILATOR_ROOT` to point to this Git directory,
+then execute `$VERILATOR_ROOT/bin/verilator`, which will find the path to
+all needed files.
+
+==== 2. Install into a CAD Disk
+
+You may eventually be installing onto a project/company-wide "CAD" tools
+disk that may support multiple versions of every tool.  Target the build to
+a destination directory name that includes the Verilator version name:
+
+   unset VERILATOR_ROOT      # if your shell is bash
+   unsetenv VERILATOR_ROOT   # if your shell is csh
+   # For the tarball, use the version number instead of git describe
+   ./configure --prefix /CAD_DISK/verilator/`git describe | sed "s/verilator_//"`
+
+Note after installing (below steps), if you use
+http://modules.sourceforge.net/[modulecmd], you'll want a module file like
+the following:
+
+.modulecmd's verilator/version file
+----
+set install_root /CAD_DISK/verilator/{version-number-used-above}
+unsetenv VERILATOR_ROOT
+prepend-path PATH $install_root/bin
+prepend-path MANPATH $install_root/man
+prepend-path PKG_CONFIG_PATH $install_root/share/pkgconfig
+----
+
+==== 3. Install into a Specific Path
+
+You may eventually install Verilator into a specific installation prefix,
+as most GNU tools support:
+
+   unset VERILATOR_ROOT      # if your shell is bash
+   unsetenv VERILATOR_ROOT   # if your shell is csh
+   ./configure --prefix /opt/verilator-VERSION
+
+Then after installing (below steps) you will need to add
+`/opt/verilator-VERSION/bin` to `$PATH`.
+
+==== 4. Install System Globally
+
+The final option is to eventually install Verilator globally, using the
+normal system paths:
+
+   unset VERILATOR_ROOT      # if your shell is bash
+   unsetenv VERILATOR_ROOT   # if your shell is csh
+   ./configure
+
+Then after installing (below) the binary directories should already be in
+your `$PATH`.
+
+=== Configure
+
+The command to configure the package was described in the previous step.
+Developers should configure to have more complete developer tests.
+Additional packages may be required for these tests.
+
+   export VERILATOR_AUTHOR_SITE=1    # Put in your .bashrc
+   ./configure --enable-longtests  ...above options...
+
+=== Compile
+
+Compile Verilator:
+
+   make -j
+
+=== Test
+
+Check the compilation by running self-tests:
+
+   make test
+
+=== Install
+
+If you used any but the <<1. Run-in-Place from VERILATOR_ROOT>> scheme,
+install to the OS-standard place:
+
+   make install
+
+== Running Verilator
+
+To run Verilator, see the example sections in the
+https://verilator.org/verilator_doc.html[Verilator manual (HTML)],
+or https://verilator.org/verilator_doc.pdf[Verilator manual (PDF)].
+
+Also see the `examples/` directory that is part of the kit, and is installed
+(in a OS-specific place, often in e.g. `/usr/local/share/verilator/examples`).
+
+     cd examples/make_hello_c
+     make
+
+Note if you did a `make install` above you should not have `VERILATOR_ROOT`
+set in your environment; it is built into the executable.
+
+== Announcements
+
+To get notified of new releases, login to
+https://www.veripool.org[Veripool], and click the "watch" button near the
+top right under https://www.veripool.org/projects/verilator/news[Verilator
+News].
+
+== Directory Structure
+
+Some relevant files and directories in this package are as follows:
+
+   Changes                     => Version history
+   README.adoc                 => This document
+   bin/verilator               => Compiler wrapper invoked to Verilate code
+   docs/                       => Additional documentation
+   examples/make_hello_c       => Example GNU-make simple Verilog->C++ conversion
+   examples/make_hello_sc      => Example GNU-make simple Verilog->SystemC conversion
+   examples/make_tracing_c     => Example GNU-make Verilog->C++ with tracing
+   examples/make_tracing_sc    => Example GNU-make Verilog->SystemC with tracing
+   examples/make_protect_lib   => Example using --protect-lib
+   examples/cmake_hello_c      => Example building make_hello_c with CMake
+   examples/cmake_hello_sc     => Example building make_hello_sc with CMake
+   examples/cmake_tracing_c    => Example building make_tracing_c with CMake
+   examples/cmake_tracing_sc   => Example building make_tracing_sc with CMake
+   examples/cmake_protect_lib  => Example building make_protect_lib with CMake
+   include/                    => Files that should be in your -I compiler path
+   include/verilated*.cpp      => Global routines to link into your simulator
+   include/verilated*.h        => Global headers
+   include/verilated.mk        => Common Makefile
+   src/                        => Translator source code
+   test_regress                => Internal tests
+
+For files created after a design is Verilated, see the
+https://verilator.org/verilator_doc.html[Verilator manual (HTML)],
+or https://verilator.org/verilator_doc.pdf[Verilator manual (PDF)].
+
+== License
+
+Copyright 2008-2020 by Wilson Snyder.  Verilator is free software; you can
+redistribute it and/or modify it under the terms of either the GNU Lesser
+General Public License Version 3 or the Perl Artistic License Version 2.0.

docs/internals.adoc

@@ -0,0 +1,989 @@
+= Verilator Internals Documentation
+:toc: right
+
+// Github doesn't render unless absolute URL
+image::https://www.veripool.org/img/verilator_256_200_min.png[Logo,256,200,role="right"]
+
+== Introduction
+
+This file discusses internal and programming details for Verilator.  It's a
+reference for developers and debugging problems.
+
+See also the Verilator internals presentation at https://www.veripool.org.
+
+== Code Flows
+
+=== Verilator Flow
+
+The main flow of Verilator can be followed by reading the Verilator.cpp
+`process()` function:
+
+. First, the files specified on the command line are read.  Reading
+involves preprocessing, then lexical analysis with Flex and parsing with
+Bison.  This produces an abstract syntax tree (AST) representation of the
+design, which is what is visible in the .tree files described below.
+
+. Verilator then makes a series of passes over the AST, progressively
+refining and optimizing it.
+
+. Cells in the AST first linked, which will read and parse additional files
+as above.
+
+. Functions, variable and other references are linked to their definitions.
+
+. Parameters are resolved and the design is elaborated.
+
+. Verilator then performs many additional edits and optimizations on the
+hierarchical design.  This includes coverage, assertions, X elimination,
+inlining, constant propagation, and dead code elimination.
+
+. References in the design are then pseudo-flattened.  Each module's
+variables and functions get "Scope" references.  A scope reference is an
+occurrence of that un-flattened variable in the flattened hierarchy.  A
+module that occurs only once in the hierarchy will have a single scope and
+single VarScope for each variable.  A module that occurs twice will have a
+scope for each occurrence, and two VarScopes for each variable.  This
+allows optimizations to proceed across the flattened design, while still
+preserving the hierarchy.
+
+. Additional edits and optimizations proceed on the pseudo-flat design.
+These include module references, function inlining, loop unrolling,
+variable lifetime analysis, lookup table creation, always splitting, and
+logic gate simplifications (pushing inverters, etc).
+
+. Verilator orders the code.  Best case, this results in a single "eval"
+function which has all always statements flowing from top to bottom with no
+loops.
+
+. Verilator mostly removes the flattening, so that code may be shared
+between multiple invocations of the same module.  It localizes variables,
+combines identical functions, expands macros to C primitives, adds branch
+prediction hints, and performs additional constant propagation.
+
+. Verilator finally writes the C++ modules.
+
+=== Key Classes Used in the Verilator Flow
+
+==== `AstNode`
+
+The AST is represented at the top level by the class `AstNode`. This
+abstract class has derived classes for the individual components
+(e.g. `AstGenerate` for a generate block) or groups of components
+(e.g. `AstNodeFTask` for functions and tasks, which in turn has `AstFunc`
+and `AstTask` as derived classes). An important property of the `AstNode`
+type hierarchy is that all non-final subclasses of `AstNode` (i.e.: those
+which themselves have subclasses) must be abstract as well, and be named
+with the prefix `AstNode*`. The `astgen` (see below) script relies on this.
+
+Each `AstNode` has pointers to up to four children, accessed by the `op1p`
+through `op4p` methods.  These methods are then abstracted in a specific
+Ast* node class to a more specific name.  For example with the `AstIf` node
+(for `if` statements), `ifsp` calls `op2p` to give the pointer to the AST
+for the "then" block, while `elsesp` calls `op3p` to give the pointer to
+the AST for the "else" block, or NULL if there is not one.
+
+`AstNode` has the concept of a next and previous AST - for example the next
+and previous statements in a block. Pointers to the AST for these
+statements (if they exist) can be obtained using the `back` and `next`
+methods.
+
+It is useful to remember that the derived class `AstNetlist` is at the top
+of the tree, so checking for this class is the standard way to see if you
+are at the top of the tree.
+
+By convention, each function/method uses the variable `nodep` as a pointer
+to the `AstNode` currently being processed.
+
+==== `AstNVisitor`
+
+The passes are implemented by AST visitor classes.  These are implemented
+by subclasses of the abstract class, `AstNVisitor`. Each pass creates an
+instance of the visitor class, which in turn implements a method to perform
+the pass.
+
+==== `V3Graph`
+
+A number of passes use graph algorithms, and the class `V3Graph` is
+provided to represent those graphs. Graphs are directed, and algorithms are
+provided to manipulate the graphs and to output them in
+https://www.graphviz.org[GraphViz] dot format. `V3Graph.h` provides
+documentation of this class.
+
+==== `V3GraphVertex`
+
+`V3GraphVertex` is the base class for vertices in a graph. Vertices have
+an associated `fanout`, `color` and `rank`, which may be used in algorithms
+for ordering the graph. A generic `user`/`userp` member variable is also
+provided.
+
+Virtual methods are provided to specify the name, color, shape and style to
+be used in dot output. Typically users provide derived classes from
+`V3GraphVertex` which will reimplement these methods.
+
+Iterators are provided to access in and out edges. Typically these are used
+in the form:
+
+   for (V3GraphEdge *edgep = vertexp->inBeginp();
+      edgep;
+      edgep = edgep->inNextp()) {
+
+==== `V3GraphEdge`
+
+`V3GraphEdge` is the base class for directed edges between pairs of
+vertices. Edges have an associated `weight` and may also be made
+`cutable`. A generic `user`/`userp` member variable is also provided.
+
+Accessors, `fromp` and `top` return the "from" and "to" vertices
+respectively.
+
+Virtual methods are provided to specify the label, color and style to be
+used in dot output. Typically users provided derived classes from
+`V3GraphEdge` which will reimplement these methods.
+
+==== `V3GraphAlg`
+
+This is the base class for graph algorithms. It implements a `bool` method,
+`followEdge` which algorithms can use to decide whether an edge is
+followed. This method returns true if the graph edge has weight greater
+than one and a user function, `edgeFuncp` (supplied in the constructor)
+returns `true`.
+
+A number of predefined derived algorithm classes and access methods are
+provided and documented in `V3GraphAlg.cpp`.
+
+=== Multithreaded Mode
+
+In `--threads` mode, the frontend of the Verilator pipeline is the same as
+serial mode, up until V3Order.
+
+`V3Order` builds a fine-grained, statement-level dependency graph that
+governs the ordering of code within a single `eval()` call. In serial mode,
+that dependency graph is used to order all statements into a total serial
+order.  In parallel mode, the same dependency graph is the starting point
+for a partitioner (`V3Partition`).
+
+The partitioner's goal is to coarsen the fine-grained graph into a coarser
+graph, while maintaining as much available parallelism as possible. Often
+the partitioner can transform an input graph with millions of nodes into a
+coarsened execution graph with a few dozen nodes, while maintaining enough
+parallelism to take advantage of a modern multicore CPU. Runtime
+synchronization cost is not prohibitive with so few nodes.
+
+==== Partitioning
+
+Our partitioner is similar to the one Vivek Sarkar described in his 1989
+paper _Partitioning and Scheduling Parallel Programs for Multiprocessors_.
+
+Let's define some terms:
+
+==== Par Factor
+
+The available parallelism or "par-factor" of a DAG is the total cost to
+execute all nodes, divided by the cost to execute the longest critical path
+through the graph. This is the speedup you would get from running the graph
+in parallel, if given infinite CPU cores available and communication and
+synchronization are zero.
+
+==== Macro Task
+
+When the partitioner coarsens the graph, it combines nodes together. Each
+fine-grained node represents an atomic "task"; combined nodes in the
+coarsened graph are "macro-tasks". This term comes from Sarkar. Each
+macro-task executes from start to end on one processor, without any
+synchronization to any other macro-task during its
+execution. (Synchronization only happens before the macro-task begins or
+after it ends.)
+
+==== Edge Contraction
+
+Verilator's partitioner, like Sarkar's, primarily relies on "edge
+contraction" to coarsen the graph. It starts with one macro-task per atomic
+task and iteratively combines pairs of edge-connected macro-tasks.
+
+==== Local Critical Path
+
+Each node in the graph has a "local" critical path. That's the critical
+path from the start of the graph to the start of the node, plus the node's
+cost, plus the critical path from the end of the node to the end of the
+graph.
+
+Sarkar calls out an important trade-off: coarsening the graph reduces
+runtime synchronization overhead among the macro-tasks, but it tends to
+increase the critical path through the graph and thus reduces par-factor.
+
+Sarkar's partitioner, and ours, chooses pairs of macro-tasks to merge such
+that the growth in critical path is minimized. Each candidate merge would
+result in a new node, which would have some local critical path. We choose
+the candidate that would produce the shortest local critical path. Repeat
+until par-factor falls to a target threshold. It's a greedy algorithm, and
+it's not guaranteed to produce the best partition (which Sarkar proves is
+NP-hard).
+
+==== Estimating Logic Costs
+
+To compute the cost of any given path through the graph, Verilator
+estimates an execution cost for each task. Each macro-task has an execution
+cost which is simply the sum of its tasks' costs. We assume that
+communication overhead and synchronization overhead are zero, so the cost
+of any given path through the graph is simply the sum of macro-task
+execution costs. Sarkar does almost the same thing, except that he has
+nonzero estimates for synchronization costs.
+
+Verilator's cost estimates are assigned by `InstrCountCostVisitor`.  This
+class is perhaps the most fragile piece of the multithread implementation.
+It's easy to have a bug where you count something cheap (eg. accessing one
+element of a huge array) as if it were expensive (eg. by counting it as if
+it were an access to the entire array.) Even without such gross bugs, the
+estimates this produce are only loosely predictive of actual runtime cost.
+Multithread performance would be better with better runtime costs
+estimates.  This is an area to improve.
+
+==== Scheduling Macro-Tasks at Runtime
+
+After coarsening the graph, we must schedule the macro-tasks for runtime.
+Sarkar describes two options: you can dynamically schedule tasks at
+runtime, with a runtime graph follower. Sarkar calls this the
+"macro-dataflow model."  Verilator does not support this; early experiments
+with this approach had poor performance.
+
+The other option is to statically assign macro-tasks to threads, with each
+thread running its macro-tasks in a static order. Sarkar describes this in
+Chapter 5. Verilator takes this static approach. The only dynamic aspect is
+that each macro task may block before starting, to wait until its
+prerequisites on other threads have finished.
+
+The synchronization cost is cheap if the prereqs are done. If they're not,
+fragmentation (idle CPU cores waiting) is possible. This is the major
+source of overhead in this approach. The `--prof-threads` switch and the
+`verilator_gantt` script can visualize the time lost to such fragmentation.
+
+==== Locating Variables for Best Spatial Locality
+
+After scheduling all code, we attempt to locate variables in memory such
+that variables accessed by a single macro-task are close together in
+memory.  This provides "spatial locality" -- when we pull in a 64-byte
+cache line to access a 2-byte variable, we want the other 62 bytes to be
+ones we'll also likely access soon, for best cache performance.
+
+This turns out to be critical for performance. It should allow Verilator to
+scale to very large models. We don't rely on our working set fitting in any
+CPU cache; instead we essentially "stream" data into caches from
+memory. It's not literally streaming, where the address increases
+monotonically, but it should have similar performance characteristics, so
+long as each macro-task's dataset fits in one core's local caches.
+
+To achieve spatial locality, we tag each variable with the set of
+macro-tasks that access it. Let's call this set the "footprint" of that
+variable. The variables in a given module have a set of footprints. We can
+order those footprints to minimize the distance between them (distance is
+the number of macro-tasks that are different across any two footprints) and
+then emit all variables into the struct in ordered-footprint order.
+
+The footprint ordering is literally the traveling salesman problem, and we
+use a TSP-approximation algorithm to get close to an optimal sort.
+
+This is an old idea. Simulators designed at DEC in the early 1990s used
+similar techniques to optimize both single-thread and multi-thread modes.
+(Verilator does not optimize variable placement for spatial locality in
+serial mode; that is a possible area for improvement.)
+
+==== Improving Multithreaded Performance Further (a TODO list)
+
+===== Wave Scheduling
+
+To allow the Verilated model to run in parallel with the testbench, it
+might be nice to support "wave" scheduling, in which work on a cycle begins
+before `eval()` is called or continues after `eval()` returns.  For now all
+work on a cycle happens during the `eval()` call, leaving Verilator's
+threads idle while the testbench (everything outside `eval()`) is
+working. This would involve fundamental changes within the partitioner,
+however, it's probably the best bet for hiding testbench latency.
+
+===== Efficient Dynamic Scheduling
+
+To scale to more than a few threads, we may revisit a fully dynamic
+scheduler. For large (>16 core) systems it might make sense to dedicate an
+entire core to scheduling, so that scheduler data structures would fit in
+its L1 cache and thus the cost of traversing priority-ordered ready lists
+would not be prohibitive.
+
+===== Static Scheduling with Runtime Repack
+
+We could modify the static scheduling approach by gathering actual
+macro-task execution times at run time, and dynamically re-packing the
+macro-tasks into the threads also at run time. Say, re-pack once every
+10,000 cycles or something. This has the potential to do better than our
+static estimates about macro-task run times. It could potentially react to
+CPU cores that aren't performing equally, due to NUMA or thermal throttling
+or nonuniform competing memory traffic or whatever.
+
+===== Clock Domain Balancing
+
+Right now Verilator makes no attempt to balance clock domains across
+macro-tasks. For a multi-domain model, that could lead to bad gantt chart
+fragmentation. This could be improved if it's a real problem in practice.
+
+===== Other Forms of MTask Balancing
+
+The largest source of runtime overhead is idle CPUs, which happens due to
+variance between our predicted runtime for each MTask and its actual
+runtime. That variance is magnified if MTasks are homogeneous, containing
+similar repeating logic which was generally close together in source code
+and which is still packed together even after going through Verilator's
+digestive tract.
+
+If Verilator could avoid doing that, and instead would take source logic
+that was close together and distribute it across MTasks, that would
+increase the diversity of any given MTask, and this should reduce variance
+in the cost estimates.
+
+One way to do that might be to make various "tie breaker" comparison
+routines in the sources to rely more heavily on randomness, and generally
+try harder not to keep input nodes together when we have the option to
+scramble things.
+
+===== Performance Regression
+
+It would be nice if we had a regression of large designs, with some
+diversity of design styles, to test on both single- and multi-threaded
+modes. This would help to avoid performance regressions, and also to
+evaluate the optimizations while minimizing the impact of parasitic noise.
+
+===== Per-Instance Classes
+
+If we have multiple instances of the same module, and they partition
+differently (likely; we make no attempt to partition them the same) then
+the variable sort will be suboptimal for either instance.  A possible
+improvement would be to emit a unique class for each instance of a module,
+and sort its variables optimally for that instance's code stream.
+
+=== Verilated Flow
+
+The evaluation loop outputted by Verilator is designed to allow a single
+function to perform evaluation under most situations.
+
+On the first evaluation, the Verilated code calls initial blocks, and then
+"settles" the modules, by evaluating functions (from always statements)
+until all signals are stable.
+
+On other evaluations, the Verilated code detects what input signals have
+changes.  If any are clocks, it calls the appropriate sequential functions
+(from `always @ posedge` statements).  Interspersed with sequential functions
+it calls combo functions (from `always @*`).  After this is complete, it
+detects any changes due to combo loops or internally generated clocks, and
+if one is found must reevaluate the model again.
+
+For SystemC code, the `eval()` function is wrapped in a SystemC
+`SC_METHOD`, sensitive to all inputs.  (Ideally it would only be sensitive
+to clocks and combo inputs, but tracing requires all signals to cause
+evaluation, and the performance difference is small.)
+
+If tracing is enabled, a callback examines all variables in the design for
+changes, and writes the trace for each change.  To accelerate this process
+the evaluation process records a bitmask of variables that might have
+changed; if clear, checking those signals for changes may be skipped.
+
+== Coding Conventions
+
+=== Compiler Version and C++11
+
+Verilator supports GCC 4.4.7 and newer.  GCC 4.4.7 does not support C++11,
+therefore C++11 is generally not required.  Exceptions may be made to
+require C++11 for features that are only practical with C++11,
+e.g. threads.
+
+=== Indentation and Naming Style
+
+We will work with contributors to fix up indentation style issues, but it
+is appreciated if you could match our style:
+
+* All files should contain the magic header to ensure standard indentation:
++
+   // -*- mode: C++; c-file-style: "cc-mode" -*-
++
+This sets indentation to the `cc-mode` defaults.  (Verilator predates a
+CC-mode change of several years ago which overrides the defaults with GNU
+style indentation; the `c-set-style` undoes that.)
+
+* Use 4 spaces per level, and no tabs.
+
+* Use 2 spaces between the end of source and the beginning of a comment.
+
+* Use 1 space after if/for/switch/while and similar keywords.
+
+* No spaces before semicolons, nor between a function's name and open
+parenthesis (only applies to functions; if/else has a following space).
+
+* Use "mixedCapsSymbols" instead of "underlined_symbols".
+
+* Uas a "p" suffix on variables that are pointers, e.g. "nodep".
+
+* Comment every member variable.
+
+=== The `astgen` Script
+
+Some of the code implementing passes is extremely repetitive, and must be
+implemented for each sub-class of `AstNode`. However, while repetitive,
+there is more variability than can be handled in C++ macros.
+
+In Verilator this is implemented by using a Perl script, `astgen` to
+pre-process the C++ code. For example in `V3Const.cpp` this is used to
+implement the `visit()` functions for each binary operation using the
+`TREEOP` macro.
+
+The original C++ source code is transformed into C++ code in the `obj_opt`
+and `obj_dbg` sub-directories (the former for the optimized version of
+Verilator, the latter for the debug version). So for example `V3Const.cpp`
+into `V3Const__gen.cpp`.
+
+=== Visitor Functions
+
+Verilator uses the "Visitor" design pattern to implement its refinement and
+optimization passes. This allows separation of the pass algorithm from the
+AST on which it operates. Wikipedia provides an introduction to the concept
+at https://en.wikipedia.org/wiki/Visitor_pattern.
+
+As noted above, all visitors are derived classes of `AstNVisitor`. All
+derived classes of `AstNode` implement the `accept` method, which takes as
+argument a reference to an instance or a `AstNVisitor` derived class and
+applies the visit method of the `AstNVisitor` to the invoking AstNode
+instance (i.e. `this`).
+
+One possible difficulty is that a call to `accept` may perform an edit
+which destroys the node it receives as argument. The
+`acceptSubtreeReturnEdits` method of `AstNode` is provided to apply
+`accept` and return the resulting node, even if the original node is
+destroyed (if it is not destroyed it will just return the original node).
+
+The behavior of the visitor classes is achieved by overloading the `visit`
+function for the different `AstNode` derived classes. If a specific
+implementation is not found, the system will look in turn for overloaded
+implementations up the inheritance hierarchy. For example calling `accept`
+on `AstIf` will look in turn for:
+
+   void visit(AstIf* nodep)
+   void visit(AstNodeIf* nodep)
+   void visit(AstNodeStmt* nodep)
+   void visit(AstNode* nodep)
+
+There are three ways data is passed between visitor functions.
+
+1. A visitor-class member variable.  This is generally for passing "parent"
+information down to children.  `m_modp` is a common example.  It's set to
+NULL in the constructor, where that node (`AstModule` visitor) sets it,
+then the children are iterated, then it's cleared.  Children under an
+`AstModule` will see it set, while nodes elsewhere will see it clear.  If
+there can be nested items (for example an `AstFor` under an `AstFor`) the
+variable needs to be save-set-restored in the `AstFor` visitor, otherwise
+exiting the lower for will lose the upper for's setting.
+
+2. User attributes.  Each `AstNode` (*Note.* The AST node, not the visitor)
+has five user attributes, which may be accessed as an integer using the
+`user1()` through `user5()` methods, or as a pointer (of type `AstNUser`)
+using the `user1p()` through `user5p()` methods (a common technique lifted
+from graph traversal packages).
++
+A visitor first clears the one it wants to use by calling
+`AstNode::user#ClearTree()`, then it can mark any node's `user#()` with whatever
+data it wants.  Readers just call `nodep->user()`, but may need to cast
+appropriately, so you'll often see `VN_CAST(nodep->userp(), SOMETYPE)`.
+At the top of each visitor are comments describing how the `user()` stuff
+applies to that visitor class.  For example:
++
+   // NODE STATE
+   // Cleared entire netlist
+   //   AstModule::user1p()     // bool. True to inline this module
++
+This says that at the `AstNetlist` `user1ClearTree()` is called.  Each
+`AstModule`'s `user1()` is used to indicate if we're going to inline it.
++
+These comments are important to make sure a `user#()` on a given `AstNode`
+type is never being used for two different purposes.
++
+Note that calling `user#ClearTree` is fast, it doesn't walk the tree, so
+it's ok to call fairly often.  For example, it's commonly called on every
+module.
+
+3. Parameters can be passed between the visitors in close to the "normal"
+function caller to callee way.  This is the second `vup` parameter of type
+`AstNUser` that is ignored on most of the visitor functions.  V3Width does
+this, but it proved more messy than the above and is deprecated.  (V3Width
+was nearly the first module written.  Someday this scheme may be removed,
+as it slows the program down to have to pass vup everywhere.)
+
+=== Iterators
+
+`AstNVisitor` provides a set of iterators to facilitate walking over the
+tree. Each operates on the current `AstNVisitor` class (as this) and takes
+an argument type `AstNode*`.
+
+`iterate`::
+
+Applies the `accept` method of the `AstNode` to the visitor function.
+
+`iterateAndNextIgnoreEdit`::
+
+Applies the `accept` method of each `AstNode` in a list (i.e. connected by
+`nextp` and `backp` pointers).
+
+`iterateAndNextNull`::
+
+Applies the `accept` method of each `AstNode` in a list, only if the
+provided node is non-NULL. If a node is edited by the call to `accept`,
+apply `accept` again, until the node does not change.
+
+`iterateListBackwards`::
+
+Applies the `accept` method of each `AstNode` in a list, starting with the
+last one.
+
+`iterateChildren`::
+
+Applies the `iterateAndNextNull` method on each child `op1p` through `op4p`
+in turn.
+
+`iterateChildrenBackwards`::
+
+Applies the `iterateListBackwards` method on each child `op1p` through
+`op4p` in turn.
+
+==== Caution on Using Iterators When Child Changes
+
+Visitors often replace one node with another node; V3Width and V3Const are
+major examples.  A visitor which is the parent of such a replacement needs
+to be aware that calling iteration may cause the children to change.  For
+example:
+
+   // nodep->lhsp() is 0x1234000
+   iterateAndNextNull(nodep->lhsp());  // and under covers nodep->lhsp() changes
+   // nodep->lhsp() is 0x5678400
+   iterateAndNextNull(nodep->lhsp());
+
+Will work fine, as even if the first iterate causes a new node to take the
+place of the `lhsp()`, that edit will update `nodep->lhsp()` and the second
+call will correctly see the change. Alternatively:
+
+   lp = nodep->lhsp();
+   // nodep->lhsp() is 0x1234000, lp is 0x1234000
+   iterateAndNextNull(lp); **lhsp=NULL;**  // and under covers nodep->lhsp() changes
+   // nodep->lhsp() is 0x5678400, lp is 0x1234000
+   iterateAndNextNull(lp);
+
+This will cause bugs or a core dump, as lp is a dangling pointer.  Thus it
+is advisable to set lhsp=NULL shown in the *'s above to make sure these
+dangles are avoided.  Another alternative used in special cases mostly in
+V3Width is to use acceptSubtreeReturnEdits, which operates on a single node
+and returns the new pointer if any.  Note acceptSubtreeReturnEdits does not
+follow `nextp()` links.
+
+   lp = acceptSubtreeReturnEdits(lp)
+
+=== Identifying Derived Classes
+
+A common requirement is to identify the specific `AstNode` class we are
+dealing with. For example a visitor might not implement separate `visit`
+methods for `AstIf` and `AstGenIf`, but just a single method for the base
+class:
+
+   void visit (AstNodeIf* nodep)
+
+However that method might want to specify additional code if it is called
+for `AstGenIf`. Verilator does this by providing a `VN_IS` method for each
+possible node type, which returns true if the node is of that type (or
+derived from that type).  So our `visit` method could use:
+
+   if (VN_IS(nodep, AstGenIf) {
+     <code specific to AstGenIf>
+   }
+
+Additionally the `VN_CAST` method converts pointers similar to C++
+`dynamic_cast`. This either returns a pointer to the object cast to that
+type (if it is of class `SOMETYPE`, or a derived class of `SOMETYPE`) or
+else NULL.  (However, for true/false tests use `VN_IS` as that is faster.)
+
+== Testing
+
+For an overview of how to write a test see the BUGS section of the
+Verilator primary manual.
+
+It is important to add tests for failures as well as success (for example
+to check that an error message is correctly triggered).
+
+Tests that fail should by convention have the suffix `_bad` in their name,
+and include `fails = 1` in either their `compile` or `execute` step as
+appropriate.
+
+=== Preparing to Run Tests
+
+For all tests to pass you must install the following packages:
+
+* SystemC to compile the SystemC outputs, see http://systemc.org
+
+* Parallel::Forker from CPAN to run tests in parallel, you can install this
+with e.g. "sudo cpan install Parallel::Forker".
+
+* vcddiff to find differences in VCD outputs. See the readme at
+https://github.com/veripool/vcddiff
+
+=== Controlling the Test Driver
+
+Test drivers are written in PERL. All invoke the main test driver script,
+which can provide detailed help on all the features available when writing
+a test driver.
+
+   test_regress/t/driver.pl --help
+
+For convenience, a summary of the most commonly used features is provided
+here. All drivers require a call to `compile` subroutine to compile the
+test. For run-time tests, this is followed by a call to the `execute`
+subroutine. Both of these functions can optionally be provided with a hash
+table as argument specifying additional options.
+
+The test driver assumes by default that the source Verilog file name
+matches the PERL driver name. So a test whose driver is `t/t_mytest.pl`
+will expect a Verilog source file `t/t_mytest.v`. This can be changed
+using the `top_filename` subroutine, for example
+
+   top_filename("t/t_myothertest.v");
+
+By default all tests will run with major simulators (Icarus Verilog, NC,
+VCS, ModelSim, etc) as well as Verilator, to allow results to be
+compared. However if you wish a test only to be used with Verilator, you
+can use the following:
+
+   scenarios(vlt => 1);
+
+Of the many options that can be set through arguments to `compiler` and
+`execute`, the following are particularly useful:
+
+`verilator_flags2`::
+
+A list of flags to be passed to verilator when compiling.
+
+`fails`::
+
+Set to 1 to indicate that the compilation or execution is intended to fail.
+
+For example the following would specify that compilation requires two
+defines and is expected to fail.
+
+   compile (
+      verilator_flags2 => ["-DSMALL_CLOCK -DGATED_COMMENT"],
+      fails => 1,
+      );
+
+=== Regression Testing for Developers
+
+Developers will also want to call ./configure with two extra flags:
+
+`--enable-ccwarn`::
+
+Causes the build to stop on warnings as well as errors. A good way to
+ensure no sloppy code gets added, however it can be painful when it comes
+to testing, since third party code used in the tests (e.g. SystemC) may not
+be warning free.
+
+`--enable-longtests`::
+
+In addition to the standard C, SystemC examples, also run the tests in the
+`test_regress` directory when using _make test_'.  This is disabled by
+default as SystemC installation problems would otherwise falsely indicate a
+Verilator problem.
+
+When enabling the long tests, some additional PERL modules are needed,
+which you can install using cpan.
+
+   cpan install Unix::Processors
+
+There are some traps to avoid when running regression tests
+
+* When checking the MANIFEST, the test will barf on unexpected code in the
+Verilator tree. So make sure to keep any such code outside the tree.
+
+* Not all Linux systems install Perldoc by default. This is needed for the
+`--help_' option to Verilator, and also for regression testing. This can be
+installed using cpan:
++
+   cpan install Pod::Perldoc
++
+Many Linux systems also offer a standard package for this. Red
+Hat/Fedora/Centos offer _perl-Pod-Perldoc_', while Debian/Ubuntu/Linux Mint
+offer `perl-doc'.
+
+* Running regression may exhaust resources on some Linux systems,
+particularly file handles and user processes. Increase these to
+respectively 16,384 and 4,096. The method of doing this is system
+dependent, but on Fedora Linux it would require editing the
+`/etc/security/limits.conf` file as root.
+
+=== Continuous Integration
+
+Verilator has a https://travis-ci.com/verilator/verilator[Travis CI environment]
+which automatically tests the master branch for test failures on new commits. It
+also runs a daily cron job to validate all of the tests against different OS and
+compiler versions.
+
+Developers can connect Travis CI to their GitHub account so that the CI
+environment can check their branches too by doing the following:
+
+* Go to https://github.com/marketplace/travis-ci and follow the prompts
+
+* Only the Open Source (FREE) version of Travis CI is required
+
+* Under a Travis CI project click More options > Settings in order to set up a
+cron job on a particular branch
+
+=== Fuzzing
+
+There are scripts included to facilitate fuzzing of Verilator.  These have
+been successfully used to find a number of bugs in the frontend.
+
+The scripts are based on using http://lcamtuf.coredump.cx/afl/[American fuzzy lop]
+on a Debian-like system.
+
+To get started, cd to "nodist/fuzzer/" and run "./all".  A sudo password
+may be required to setup the system for fuzzing.
+
+== Debugging
+
+=== --debug
+
+When you run with `--debug` there are two primary output file types placed
+into the obj_dir, .tree and .dot files.
+
+=== .dot Output
+
+Dot files are dumps of internal graphs in
+https://www.graphviz.org[Graphviz] dot format.  When a dot file is dumped,
+Verilator will also print a line on stdout that can be used to format the
+output, for example:
+
+   dot -Tps -o ~/a.ps obj_dir/Vtop_foo.dot
+
+You can then print a.ps.  You may prefer gif format, which doesn't get
+scaled so can be more useful with large graphs.
+
+For dynamic graph viewing consider
+http://zvtm.sourceforge.net/zgrviewer.html[ZGRViewer].  If you know of
+better viewers let us know; ZGRViewer isn't great for large graphs.
+
+=== .tree Output
+
+Tree files are dumps of the AST Tree and are produced between every major
+algorithmic stage.  An example:
+
+     NETLIST 0x90fb00 <e1> {a0}
+    1: MODULE 0x912b20 <e8822> {a8}  top  L2 [P]
+   *1:2: VAR 0x91a780 <e74#> {a22} @dt=0xa2e640(w32)  out_wide [O] WIRE
+    1:2:1: BASICDTYPE 0xa2e640 <e2149> {e24} @dt=this(sw32)  integer kwd=integer range=[31:0]
+
+The following summarizes the above example dump, with more detail on each
+field in the section below.
+
+[cols="20%,80%"]
+|===
+
+|`1:2:` | indicates the hierarchy of the `VAR` is the `op2p` pointer under
+the `MODULE`, which in turn is the `op1p` pointer under the `NETLIST`
+
+|`VAR` | is the AstNodeType.
+
+| `0x91a780` | is the address of this node.
+
+| `<e74>` | means the 74th edit to the netlist was the last modification to
+this node.
+
+| `{a22}` | indicates this node is related to line 22 in the source filename
+"a", where "a" is the first file read, "z" the 26th, and "aa" the 27th.
+
+| `@dt=0x...` | indicates the address of the data type this node contains.
+
+| `w32` | indicates the width is 32 bits.
+
+| `out_wide` | is the name of the node, in this case the name of the variable.
+
+| `[O]` |  are flags which vary with the type of node, in this case it means the
+variable is an output.
+
+|===
+
+In more detail the following fields are dumped common to all nodes. They
+are produced by the `AstNode::dump()` method:
+
+Tree Hierarchy::
+
+The dump lines begin with numbers and colons to indicate the child node
+hierarchy.  As noted above, `AstNode` has lists of items at the same level
+in the AST, connected by the `nextp()` and `prevp()` pointers. These appear
+as nodes at the same level. For example after inlining:
+
+    NETLIST 0x929c1c8 <e1> {a0} w0
+   1: MODULE 0x92bac80 <e3144> {e14} w0  TOP_t  L1 [P]
+   1:1: CELLINLINE 0x92bab18 <e3686#> {e14} w0  v -> t
+   1:1: CELLINLINE 0x92bc1d8 <e3688#> {e24} w0  v__DOT__i_test_gen -> test_gen
+   ...
+   1: MODULE 0x92b9bb0 <e503> {e47} w0  test_gen  L3
+   ...
+
+AstNode type::
+
+The textual name of this node AST type (always in capitals). Many of these
+correspond directly to Verilog entities (for example `MODULE` and
+`TASK`), but others are internal to Verilator (for example `NETLIST` and
+`BASICDTYPE`).
+
+Address of the node::
+
+A hexadecimal address of the node in memory. Useful for examining with the
+debugger.
+
+Last edit number::
+
+Of the form `<ennnn>` or `<ennnn#>` , where `nnnn` is the number
+of the last edit to modify this node. The trailing `#` indicates the node
+has been edited since the last tree dump (which typically means in the last
+refinement or optimization pass). GDB can watch for this, see << /Debugging >>.
+
+Source file and line::
+
+Of the form `{xxnnnn}`, where C{xx} is the filename letter (or
+letters) and `nnnn` is the line number within that file. The first file is
+`a`, the 26th is `z`, the 27th is `aa` and so on.
+
+User pointers::
+
+Shows the value of the node's user1p...user5p, if non-NULL.
+
+Data type::
+
+Many nodes have an explicit data type.  "@dt=0x..." indicates the address
+of the data type (AstNodeDType) this node uses.
++
+If a data type is present and is numeric, it then prints the width of the
+item. This field is a sequence of flag characters and width data as follows:
++
+* `s` if the node is signed.
+* `d` if the node is a double (i.e a floating point entity).
+* `w` always present, indicating this is the width field.
+* `u` if the node is unsized.
+* `/nnnn` if the node is unsized, where `nnnn` is the minimum width.
+
+Name of the entity represented by the node if it exists::
+
+For example for a `VAR` it is the name of the variable.
+
+Many nodes follow these fields with additional node specific
+information. Thus the `VARREF` node will print either `[LV]` or `[RV]`
+to indicate a left value or right value, followed by the node of the
+variable being referred to. For example:
+
+   1:2:1:1: VARREF 0x92c2598 <e509> {e24} w0  clk [RV] <- VAR 0x92a2e90 <e79> {e18} w0  clk [I] INPUT
+
+In general, examine the `dump()` method in `V3AstNodes.cpp` of the node
+type in question to determine additional fields that may be printed.
+
+The `MODULE` has a list of `CELLINLINE` nodes referred to by its
+`op1p()` pointer, connected by `nextp()` and `prevp()` pointers.
+
+Similarly the `NETLIST` has a list of modules referred to by its `op1p()`
+pointer.
+
+=== Debugging with GDB
+
+The test_regress/driver.pl script accepts `--debug --gdb` to start
+Verilator under gdb and break when an error is hit or the program is about
+to exit.  You can also use `--debug --gdbbt` to just backtrace and then
+exit gdb. To debug the Verilated executable, use `--gdbsim`.
+
+If you wish to start Verilator under GDB (or another debugger), then you
+can use `--debug` and look at the underlying invocation of
+`verilator_dbg`. For example
+
+   t/t_alw_dly.pl --debug
+
+shows it invokes the command:
+
+   ../verilator_bin_dbg --prefix Vt_alw_dly --x-assign unique --debug
+     -cc -Mdir obj_dir/t_alw_dly --debug-check -f input.vc t/t_alw_dly.v
+
+Start GDB, then `start` with the remaining arguments.
+
+   gdb ../verilator_bin_dbg
+   ...
+   (gdb) start --prefix Vt_alw_dly --x-assign unique --debug -cc -Mdir
+             obj_dir/t_alw_dly --debug-check  -f input.vc t/t_alw_dly.v
+             > obj_dir/t_alw_dly/vlt_compile.log
+   ...
+   Temporary breakpoint 1, main (argc=13, argv=0xbfffefa4, env=0xbfffefdc)
+       at ../Verilator.cpp:615
+   615         ios::sync_with_stdio();
+   (gdb)
+
+You can then continue execution with breakpoints as required.
+
+To break at a specific edit number which changed a node (presumably to find
+what made a <e####> line in the tree dumps):
+
+   watch AstNode::s_editCntGbl==####
+
+Then, when the watch fires, to break at every following change to that node:
+
+   watch m_editCount
+
+To print a node:
+
+   pn nodep
+   # or: call nodep->dumpGdb()  # aliased to "pn" in src/.gdbinit
+   pnt nodep
+   # or: call nodep->dumpTreeGdb()  # aliased to "pnt" in src/.gdbinit
+
+When GDB halts, it is useful to understand that the backtrace will commonly
+show the iterator functions between each invocation of `visit` in the
+backtrace. You will typically see a frame sequence something like
+
+   ...
+   visit()
+   iterateChildren()
+   iterateAndNext()
+   accept()
+   visit()
+   ...
+
+== Adding a New Feature
+
+Generally what would you do to add a new feature?
+
+. File an issue (if there isn't already) so others know what you're working on.
+
+. Make a testcase in the test_regress/t/t_EXAMPLE format, see << /TESTING >>.
+
+. If grammar changes are needed, look at the git version of VerilogPerl's
+src/VParseGrammar.y, as this grammar supports the full SystemVerilog
+language and has a lot of back-and-forth with Verilator's grammar.  Copy
+the appropriate rules to src/verilog.y and modify the productions.
+
+. If a new Ast type is needed, add it to V3AstNodes.h. Follow the convention
+described above about the AstNode type hierarchy.
+
+. Now you can run "test_regress/t/t_{new testcase}.pl --debug" and it'll
+probably fail but you'll see a test_regress/obj_dir/t_{newtestcase}/*.tree
+file which you can examine to see if the parsing worked. See also the
+sections above on debugging.
+
+. Modify the later visitor functions to process the new feature as needed.
+
+=== Adding a New Pass
+
+For more substantial changes you may need to add a new pass. The simplest
+way to do this is to copy the `.cpp` and `.h` files from an existing
+pass. You'll need to add a call into your pass from the `process()`
+function in `src/verilator.cpp`.
+
+To get your pass to build you'll need to add its binary filename to the
+list in `src/Makefile_obj.in` and reconfigure.
+
+== Distribution
+
+Copyright 2008-2020 by Wilson Snyder.  Verilator is free software; you can
+redistribute it and/or modify it under the terms of either the GNU Lesser
+General Public License Version 3 or the Perl Artistic License Version 2.0.

docs/xml.adoc

@@ -0,0 +1,65 @@
+= Verilator XML Output
+:toc: right
+
+// Github doesn't render unless absolute URL
+image::https://www.veripool.org/img/verilator_256_200_min.png[Logo,256,200,role="right"]
+
+== Introduction
+
+This document describes Verilator's XML output. For more general information
+please see https://verilator.org[verilator.org].
+
+== General
+
+Verilator's XML output is enabled with the `--xml-only` flag. It contains
+limited information about the elaborated design including files, modules,
+instance hierarchy, logic and data types. There is no formal schema since part
+of the structure of the XML document matches the compiled code which would
+require the schema to describe legal SystemVerilog structure. The intended
+usage is to enable other downstream tools to take advantage of Verilator's
+parser.
+
+== Structure
+
+The XML document is consists of 4 sections within the top level `verilator_xml`
+element:
+
+`<files>`...`</files>`::
+
+This section contains a list of all design files read, including the
+built-in constructs and the command line as their own entries.  Each
+`<file>` has an attribute `id` which is a short ASCII string unique to that
+file. Other elements' `loc` attributes use this id to refer to a particular
+file.
+
+`<module_files>`...`</module_files>`::
+
+All files containing Verilog module definitions are listed in this section.
+This element's contents is a subset of the `<files>` element's contents.
+
+`<cells>`...`</cells>`::
+
+The cells section of the XML document contains the design instance
+hierarchy.  Each instance is represented with the `<cell>` element with the
+following attributes:
+
+* `fl` (deprecated): The file id and line number where the module was
+  instanced.  Use `loc` instead.
+
+* `loc`: The file id, first line number, last line number, first column
+   number and last column number of the identifier where the module was
+   instanced, separated by commas.
+
+* `name`: The instance name.
+
+* `submodname`: The module name uniquified with particular parameter values (if any).
+
+* `hier`: The full hierarchy path.
+
+`<netlist>`...`</netlist>`::
+
+The netlist section contains a number of `<module>`...`</module>` elements,
+each describing the contents of that module, and a single `<typetable>`...
+`</typetable>` element which lists all used types used within the
+modules. Each type has a numeric `id` attribute that is referred to by
+elements in the `<module>` elements using the `dtype_id` attribute.

examples/cmake_hello_c/.gitignore

@@ -0,0 +1 @@
+build*

examples/cmake_hello_c/CMakeLists.txt

@@ -0,0 +1,37 @@
+######################################################################
+#
+# DESCRIPTION: Verilator CMake Example: Small CMakeLists.txt
+#
+# This is an example cmake script to build a verilog to systemc project
+# using cmake and verilator.
+#
+# Copyright 2003-2020 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+#
+######################################################################
+
+# This example builds the tracing_c example using CMake
+# To use it, run the following:
+
+# cd /path/to/verilator/examples/cmake_c
+# rm -rf build && mkdir build && cd build
+# cmake ..
+# cmake --build .
+
+cmake_minimum_required(VERSION 3.8)
+project(cmake_hello_c)
+
+find_package(verilator HINTS $ENV{VERILATOR_ROOT} ${VERILATOR_ROOT})
+if (NOT verilator_FOUND)
+  message(FATAL_ERROR "Verilator was not found. Either install it, or set the VERILATOR_ROOT environment variable")
+endif()
+
+# Create a new executable target that will contain all your sources
+add_executable(example ../make_hello_c/sim_main.cpp)
+
+# Add the Verilated circuit to the target
+verilate(example
+  INCLUDE_DIRS "../make_hello_c"
+  SOURCES ../make_hello_c/top.v)

examples/cmake_hello_c/Makefile

@@ -0,0 +1,79 @@
+######################################################################
+#
+# DESCRIPTION: Verilator CMake example usage
+#
+# This file shows usage of the CMake script.
+# This makefile is here for testing the examples and should
+# generally not be added to a CMake project.
+#
+# Copyright 2003-2020 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+#
+######################################################################
+
+######################################################################
+# Set up variables
+
+# If $VERILATOR_ROOT isn't in the environment, we assume it is part of a
+# package install, and verilator is in your path. Otherwise find the
+# binary relative to $VERILATOR_ROOT (such as when inside the git sources).
+
+ifeq ($(VERILATOR_ROOT),)
+VERILATOR_COVERAGE = verilator_coverage
+else
+export VERILATOR_ROOT
+VERILATOR_COVERAGE = $(VERILATOR_ROOT)/bin/verilator_coverage
+endif
+######################################################################
+
+# Check if CMake is installed and of correct version
+ifeq ($(shell which cmake),)
+TARGET := nocmake
+else
+CMAKE_VERSION := $(shell cmake --version | grep -Po '(\d[\.\d]+)')
+CMAKE_MAJOR := $(shell echo $(CMAKE_VERSION) | cut -f1 -d.)
+CMAKE_MINOR := $(shell echo $(CMAKE_VERSION) | cut -f2 -d.)
+CMAKE_GT_3_8 := $(shell [ $(CMAKE_MAJOR) -gt 3 -o \( $(CMAKE_MAJOR) -eq 3 -a $(CMAKE_MINOR) -ge 8 \) ] && echo true)
+ifeq ($(CMAKE_GT_3_8),true)
+TARGET := run
+else
+TARGET := oldcmake
+endif
+endif
+
+default: $(TARGET)
+
+run:
+	@echo
+	@echo "-- Verilator CMake hello world example"
+
+	@echo
+	@echo "-- CMake ----------------"
+	mkdir -p build && cd build && cmake ..
+
+	@echo
+	@echo "-- COMPILE -----------------"
+	cmake --build build
+
+	@echo
+	@echo "-- RUN ---------------------"
+	build/example
+
+	@echo
+	@echo "-- DONE --------------------"
+	@echo
+
+clean mostlyclean distclean maintainer-clean:
+	@rm -rf build logs
+
+nocmake:
+	@echo
+	@echo "%Skip: CMake has not been found"
+	@echo
+
+oldcmake:
+	@echo
+	@echo "%Skip: CMake version is too old (need at least 3.8)"
+	@echo

examples/cmake_hello_sc/.gitignore

@@ -0,0 +1 @@
+build*

examples/cmake_hello_sc/CMakeLists.txt

@@ -0,0 +1,46 @@
+######################################################################
+#
+# DESCRIPTION: Verilator CMake Example: Small CMakeLists.txt with SystemC
+#
+# This is an example cmake script to build a verilog to SystemC project
+# using CMake and Verilator.
+#
+# Copyright 2003-2020 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+#
+######################################################################
+
+# This example builds the tracing_sc example using CMake
+# To use it, run the following:
+
+# cd /path/to/verilator/examples/cmake_sc
+# rm -rf build && mkdir build && cd build
+# cmake ..
+# cmake --build .
+
+cmake_minimum_required(VERSION 3.8)
+project(cmake_hello_sc)
+
+find_package(verilator HINTS $ENV{VERILATOR_ROOT} ${VERILATOR_ROOT})
+if (NOT verilator_FOUND)
+  message(FATAL_ERROR "Verilator was not found. Either install it, or set the VERILATOR_ROOT environment variable")
+endif()
+
+# SystemC dependencies
+set(THREADS_PREFER_PTHREAD_FLAG ON)
+find_package(Threads REQUIRED)
+
+# Find SystemC using SystemC's CMake integration
+find_package(SystemCLanguage QUIET)
+
+# Create a new executable target that will contain all your sources
+add_executable(example ../make_hello_sc/sc_main.cpp)
+
+# Add the Verilated circuit to the target
+verilate(example SYSTEMC
+  INCLUDE_DIRS "../make_hello_sc"
+  SOURCES ../make_hello_sc/top.v)
+
+verilator_link_systemc(example)

examples/cmake_hello_sc/Makefile

@@ -0,0 +1,129 @@
+######################################################################
+#
+# DESCRIPTION: Verilator CMake example usage
+#
+# This file shows usage of the CMake script.
+# This makefile is here for testing the examples and should
+# generally not be added to a CMake project.
+#
+# Copyright 2003-2020 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+#
+######################################################################
+
+######################################################################
+# Set up variables
+
+# If $VERILATOR_ROOT isn't in the environment, we assume it is part of a
+# package install, and verilator is in your path. Otherwise find the
+# binary relative to $VERILATOR_ROOT (such as when inside the git sources).
+
+ifeq ($(VERILATOR_ROOT),)
+VERILATOR_COVERAGE = verilator_coverage
+else
+export VERILATOR_ROOT
+VERILATOR_COVERAGE = $(VERILATOR_ROOT)/bin/verilator_coverage
+endif
+######################################################################
+
+# Check if CMake is installed and of correct version
+ifeq ($(shell which cmake),)
+	TARGET := nocmake
+else
+CMAKE_VERSION := $(shell cmake --version | grep -Po '(\d[\.\d]+)')
+CMAKE_MAJOR := $(shell echo $(CMAKE_VERSION) | cut -f1 -d.)
+CMAKE_MINOR := $(shell echo $(CMAKE_VERSION) | cut -f2 -d.)
+CMAKE_GT_3_8 := $(shell [ $(CMAKE_MAJOR) -gt 3 -o \( $(CMAKE_MAJOR) -eq 3 -a $(CMAKE_MINOR) -ge 8 \) ] && echo true)
+ifneq ($(CMAKE_GT_3_8),true)
+TARGET := oldcmake
+else
+
+# Test existence of SYSTEMC_INCLUDE and SYSTEMC_LIBDIR environment variabless
+ifneq (,$(SYSTEMC_INCLUDE))
+ifneq (,${SYSTEMC_LIBDIR})
+SYSTEMC_SET := true
+endif
+endif
+
+# Test existence of SYSTEMC_ROOT environment variable
+ifneq (SYSTEMC_SET, true)
+ifneq (,${SYSTEMC_ROOT})
+SYSTEMC_SET := true
+endif
+endif
+
+# Test existence of SYSTEMC environment variable
+ifneq (SYSTEMC_SET, true)
+ifneq (,${SYSTEMC})
+SYSTEMC_SET := true
+endif
+endif
+
+# Test whether SystemC is installed with CMake support
+# This will print a CMake error about processing arguments that can (currently) be ignored.
+ifneq (SYSTEMC_SET, true)
+FINDSC := $(shell mkdir -p build && cd build && cmake --find-package -DNAME=SystemCLanguage -DCMAKE_USE_PTHREADS_INIT=ON -DCOMPILER_ID=GNU -DLANGUAGE=CXX -DMODE=EXIST -DThreads_FOUND=ON)
+ifneq (,$(findstring SystemCLanguage found,$(FINDSC)))
+SYSTEMC_SET := true
+endif
+endif
+
+ifeq ($(SYSTEMC_SET), true)
+TARGET := run
+else
+TARGET := nosc
+endif
+
+endif
+endif
+
+default: $(TARGET)
+
+run:
+	@echo
+	@echo "-- Verilator CMake SystemC hello-world simple example"
+
+	@echo
+	@echo "-- CMake ----------------"
+	mkdir -p build && cd build && cmake ..
+
+	@echo
+	@echo "-- COMPILE -----------------"
+	cmake --build build
+
+	@echo
+	@echo "-- RUN ---------------------"
+	@mkdir -p logs
+	build/example
+
+	@echo "-- DONE --------------------"
+	@echo "Note: Once this example is understood, see examples/cmake_tracing_sc."
+	@echo "Note: Also see the EXAMPLE section in the verilator manpage/document."
+
+clean mostlyclean distclean maintainer-clean:
+	@rm -rf build logs
+
+nocmake:
+	@echo
+	@echo "%Skip: CMake has not been found"
+	@echo
+
+oldcmake:
+	@echo
+	@echo "%Skip: CMake version is too old (need at least 3.8)"
+	@echo
+
+nosc:
+	@echo
+	@echo "%Skip: CMake could not find SystemC."
+	@echo "% Make sure that either:"
+	@echo "% - The environment variables SYSTEMC_INCLUDE and SYSTEMC_LIBDIR are exported."
+	@echo "% - Or, the environment variable SYSTEMC_ROOT is exported."
+	@echo "% - Or, The environment variable SYSTEMC is exported."
+	@echo "% - Or, if the SystemC installation provides CMake support,"
+	@echo "%   that its installation prefix is in CMAKE_PREFIX_PATH."
+	@echo "% Also that the C++ standard of the SystemC library is the same as this example."
+	@echo "% Please see the Verilator documentation's CMake section for more information."
+	@echo

examples/cmake_protect_lib/.gitignore

@@ -0,0 +1 @@
+build*

examples/cmake_protect_lib/CMakeLists.txt

@@ -0,0 +1,60 @@
+######################################################################
+#
+# DESCRIPTION: Verilator CMake Example: Small CMakeLists.txt
+#
+# This is an example cmake script to build a verilog to systemc project
+# using cmake and verilator.
+#
+# Copyright 2003-2020 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+#
+######################################################################
+
+# This example builds the tracing_c example using CMake
+# To use it, run the following:
+
+# cd /path/to/verilator/examples/cmake_c
+# rm -rf build && mkdir build && cd build
+# cmake ..
+# cmake --build .
+
+cmake_minimum_required(VERSION 3.8)
+project(cmake_protect_lib)
+
+find_package(verilator HINTS $ENV{VERILATOR_ROOT} ${VERILATOR_ROOT})
+if (NOT verilator_FOUND)
+  message(FATAL_ERROR "Verilator was not found. Either install it, or set the VERILATOR_ROOT environment variable")
+endif()
+
+# Create the main executable target
+add_executable(example ../make_protect_lib/sim_main.cpp)
+
+# Create a secret library
+add_library(verilated_secret STATIC) # or SHARED for a shared library
+target_link_libraries(example PRIVATE verilated_secret)
+# To create both libraries on CMake >= 3.12 replace the above 2 lines with the following:
+# add_library(verilated_secret OBJECT)
+# set_property(TARGET verilated_secret PROPERTY POSITION_INDEPENDENT_CODE 1)
+# add_library(verilated_secret_static STATIC  $<TARGET_OBJECTS:verilated_secret>)
+# set_target_properties(verilated_secret_static PROPERTIES OUTPUT_NAME verilated_secret)
+# add_library(verilated_secret_shared SHARED  $<TARGET_OBJECTS:verilated_secret>)
+# set_target_properties(verilated_secret_shared PROPERTIES OUTPUT_NAME verilated_secret)
+# target_link_libraries(example PRIVATE verilated_secret_static)
+
+# Setup random seed
+verilator_generate_key(KEY_INIT)
+set(PROTECT_KEY ${KEY_INIT} CACHE STRING "Random seed for protection")
+
+# Add the Verilated modules to the targets
+verilate(verilated_secret
+  VERILATOR_ARGS --protect-lib verilated_secret
+                 --protect-key ${PROTECT_KEY}
+  DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/verilated_secret
+  SOURCES ../make_protect_lib/secret_impl.v)
+
+# Include location of verilated_secret.sv wrapper
+verilate(example
+  VERILATOR_ARGS "-I${CMAKE_CURRENT_BINARY_DIR}/verilated_secret"
+  SOURCES ../make_protect_lib/top.v)

examples/cmake_protect_lib/Makefile

@@ -0,0 +1,79 @@
+######################################################################
+#
+# DESCRIPTION: Verilator CMake example usage
+#
+# This file shows usage of the CMake script.
+# This makefile is here for testing the examples and should
+# generally not be added to a CMake project.
+#
+# Copyright 2003-2020 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+#
+######################################################################
+
+######################################################################
+# Set up variables
+
+# If $VERILATOR_ROOT isn't in the environment, we assume it is part of a
+# package install, and verilator is in your path. Otherwise find the
+# binary relative to $VERILATOR_ROOT (such as when inside the git sources).
+
+ifeq ($(VERILATOR_ROOT),)
+VERILATOR_COVERAGE = verilator_coverage
+else
+export VERILATOR_ROOT
+VERILATOR_COVERAGE = $(VERILATOR_ROOT)/bin/verilator_coverage
+endif
+######################################################################
+
+# Check if CMake is installed and of correct version
+ifeq ($(shell which cmake),)
+TARGET := nocmake
+else
+CMAKE_VERSION := $(shell cmake --version | grep -Po '(\d[\.\d]+)')
+CMAKE_MAJOR := $(shell echo $(CMAKE_VERSION) | cut -f1 -d.)
+CMAKE_MINOR := $(shell echo $(CMAKE_VERSION) | cut -f2 -d.)
+CMAKE_GT_3_8 := $(shell [ $(CMAKE_MAJOR) -gt 3 -o \( $(CMAKE_MAJOR) -eq 3 -a $(CMAKE_MINOR) -ge 8 \) ] && echo true)
+ifeq ($(CMAKE_GT_3_8),true)
+TARGET := run
+else
+TARGET := oldcmake
+endif
+endif
+
+default: $(TARGET)
+
+run:
+	@echo
+	@echo "-- Verilator CMake protect_lib example"
+
+	@echo
+	@echo "-- CMake ----------------"
+	mkdir -p build && cd build && cmake ..
+
+	@echo
+	@echo "-- COMPILE -----------------"
+	cmake --build build
+
+	@echo
+	@echo "-- RUN ---------------------"
+	build/example
+
+	@echo
+	@echo "-- DONE --------------------"
+	@echo
+
+clean mostlyclean distclean maintainer-clean:
+	@rm -rf build logs
+
+nocmake:
+	@echo
+	@echo "%Skip: CMake has not been found"
+	@echo
+
+oldcmake:
+	@echo
+	@echo "%Skip: CMake version is too old (need at least 3.8)"
+	@echo

examples/cmake_tracing_c/.gitignore

@@ -0,0 +1,2 @@
+build*
+logs

examples/cmake_tracing_c/CMakeLists.txt

@@ -0,0 +1,38 @@
+######################################################################
+#
+# DESCRIPTION: Verilator CMake Example: Small CMakeLists.txt with tracing
+#
+# This is an example cmake script to build a verilog to systemc project
+# using cmake and verilator.
+#
+# Copyright 2003-2020 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+#
+######################################################################
+
+# This example builds the make_tracing_c example using CMake
+# To use it, run the following:
+
+# cd /path/to/verilator/examples/cmake_tracing_c
+# rm -rf build && mkdir build && cd build
+# cmake ..
+# cmake --build .
+
+cmake_minimum_required(VERSION 3.8)
+project(cmake_tracing_c)
+
+find_package(verilator HINTS $ENV{VERILATOR_ROOT} ${VERILATOR_ROOT})
+if (NOT verilator_FOUND)
+  message(FATAL_ERROR "Verilator was not found. Either install it, or set the VERILATOR_ROOT environment variable")
+endif()
+
+# Create a new executable target that will contain all your sources
+add_executable(example ../make_tracing_c/sim_main.cpp)
+
+# Add the Verilated circuit to the target
+verilate(example COVERAGE TRACE
+  INCLUDE_DIRS "../make_tracing_c"
+  VERILATOR_ARGS -f ../make_tracing_c/input.vc -O2 -x-assign 0
+  SOURCES ../make_tracing_c/top.v)

examples/cmake_tracing_c/Makefile

@@ -0,0 +1,85 @@
+######################################################################
+#
+# DESCRIPTION: Verilator CMake example usage
+#
+# This file shows usage of the CMake script.
+# This makefile is here for testing the examples and should
+# generally not be added to a CMake project.
+#
+# Copyright 2003-2020 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+#
+######################################################################
+
+######################################################################
+# Set up variables
+
+# If $VERILATOR_ROOT isn't in the environment, we assume it is part of a
+# package install, and verilator is in your path. Otherwise find the
+# binary relative to $VERILATOR_ROOT (such as when inside the git sources).
+
+ifeq ($(VERILATOR_ROOT),)
+VERILATOR_COVERAGE = verilator_coverage
+else
+export VERILATOR_ROOT
+VERILATOR_COVERAGE = $(VERILATOR_ROOT)/bin/verilator_coverage
+endif
+######################################################################
+
+# Check if CMake is installed and of correct version
+ifeq ($(shell which cmake),)
+TARGET := nocmake
+else
+CMAKE_VERSION := $(shell cmake --version | grep -Po '(\d[\.\d]+)')
+CMAKE_MAJOR := $(shell echo $(CMAKE_VERSION) | cut -f1 -d.)
+CMAKE_MINOR := $(shell echo $(CMAKE_VERSION) | cut -f2 -d.)
+CMAKE_GT_3_8 := $(shell [ $(CMAKE_MAJOR) -gt 3 -o \( $(CMAKE_MAJOR) -eq 3 -a $(CMAKE_MINOR) -ge 8 \) ] && echo true)
+ifeq ($(CMAKE_GT_3_8),true)
+TARGET := run
+else
+TARGET := oldcmake
+endif
+endif
+
+default: $(TARGET)
+
+run:
+	@echo
+	@echo "-- Verilator CMake tracing example"
+
+	@echo
+	@echo "-- CMake ----------------"
+	mkdir -p build && cd build && cmake ..
+
+	@echo
+	@echo "-- COMPILE -----------------"
+	cmake --build build
+
+	@echo
+	@echo "-- RUN ---------------------"
+	@mkdir -p logs
+	build/example +trace
+
+	@echo
+	@echo "-- COVERAGE ----------------"
+	$(VERILATOR_COVERAGE) --annotate logs/annotated logs/coverage.dat
+
+	@echo
+	@echo "-- DONE --------------------"
+	@echo "To see waveforms, open vlt_dump.vcd in a waveform viewer"
+	@echo
+
+clean mostlyclean distclean maintainer-clean:
+	@rm -rf build logs
+
+nocmake:
+	@echo
+	@echo "%Skip: CMake has not been found"
+	@echo
+
+oldcmake:
+	@echo
+	@echo "%Skip: CMake version is too old (need at least 3.8)"
+	@echo

examples/cmake_tracing_sc/.gitignore

@@ -0,0 +1,7 @@
+*.dmp
+*.log
+*.csrc
+*.vcd
+obj_*
+logs
+build*

examples/cmake_tracing_sc/CMakeLists.txt

@@ -0,0 +1,47 @@
+######################################################################
+#
+# DESCRIPTION: Verilator CMake Example: Small CMakeLists.txt with SystemC tracing
+#
+# This is an example cmake script to build a verilog to SystemC project
+# using CMake and Verilator.
+#
+# Copyright 2003-2020 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+#
+######################################################################
+
+# This example builds the tracing_sc example using CMake
+# To use it, run the following:
+
+# cd /path/to/verilator/examples/cmake_tracing_sc
+# rm -rf build && mkdir build && cd build
+# cmake ..
+# cmake --build .
+
+cmake_minimum_required(VERSION 3.8)
+project(cmake_tracing_sc_example)
+
+find_package(verilator HINTS $ENV{VERILATOR_ROOT} ${VERILATOR_ROOT})
+if (NOT verilator_FOUND)
+  message(FATAL_ERROR "Verilator was not found. Either install it, or set the VERILATOR_ROOT environment variable")
+endif()
+
+# SystemC dependencies
+set(THREADS_PREFER_PTHREAD_FLAG ON)
+find_package(Threads REQUIRED)
+
+# Find SystemC using SystemC's CMake integration
+find_package(SystemCLanguage QUIET)
+
+# Create a new executable target that will contain all your sources
+add_executable(example ../make_tracing_sc/sc_main.cpp)
+
+# Add the Verilated circuit to the target
+verilate(example SYSTEMC COVERAGE TRACE
+  INCLUDE_DIRS "../make_tracing_sc"
+  VERILATOR_ARGS -f ../make_tracing_sc/input.vc -O2 -x-assign 0
+  SOURCES ../make_tracing_sc/top.v)
+
+verilator_link_systemc(example)

examples/cmake_tracing_sc/Makefile

@@ -0,0 +1,134 @@
+######################################################################
+#
+# DESCRIPTION: Verilator CMake example usage
+#
+# This file shows usage of the CMake script.
+# This makefile is here for testing the examples and should
+# generally not be added to a CMake project.
+#
+# Copyright 2003-2020 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+#
+######################################################################
+
+######################################################################
+# Set up variables
+
+# If $VERILATOR_ROOT isn't in the environment, we assume it is part of a
+# package install, and verilator is in your path. Otherwise find the
+# binary relative to $VERILATOR_ROOT (such as when inside the git sources).
+
+ifeq ($(VERILATOR_ROOT),)
+VERILATOR_COVERAGE = verilator_coverage
+else
+export VERILATOR_ROOT
+VERILATOR_COVERAGE = $(VERILATOR_ROOT)/bin/verilator_coverage
+endif
+######################################################################
+
+# Check if CMake is installed and of correct version
+ifeq ($(shell which cmake),)
+	TARGET := nocmake
+else
+CMAKE_VERSION := $(shell cmake --version | grep -Po '(\d[\.\d]+)')
+CMAKE_MAJOR := $(shell echo $(CMAKE_VERSION) | cut -f1 -d.)
+CMAKE_MINOR := $(shell echo $(CMAKE_VERSION) | cut -f2 -d.)
+CMAKE_GT_3_8 := $(shell [ $(CMAKE_MAJOR) -gt 3 -o \( $(CMAKE_MAJOR) -eq 3 -a $(CMAKE_MINOR) -ge 8 \) ] && echo true)
+ifneq ($(CMAKE_GT_3_8),true)
+TARGET := oldcmake
+else
+
+# Test existence of SYSTEMC_INCLUDE and SYSTEMC_LIBDIR environment variabless
+ifneq (,$(SYSTEMC_INCLUDE))
+ifneq (,${SYSTEMC_LIBDIR})
+SYSTEMC_SET := true
+endif
+endif
+
+# Test existence of SYSTEMC_ROOT environment variable
+ifneq (SYSTEMC_SET, true)
+ifneq (,${SYSTEMC_ROOT})
+SYSTEMC_SET := true
+endif
+endif
+
+# Test existence of SYSTEMC environment variable
+ifneq (SYSTEMC_SET, true)
+ifneq (,${SYSTEMC})
+SYSTEMC_SET := true
+endif
+endif
+
+# Test whether SystemC is installed with CMake support
+# This will print a CMake error about processing arguments that can (currently) be ignored.
+ifneq (SYSTEMC_SET, true)
+FINDSC := $(shell mkdir -p build && cd build && cmake --find-package -DNAME=SystemCLanguage -DCMAKE_USE_PTHREADS_INIT=ON -DCOMPILER_ID=GNU -DLANGUAGE=CXX -DMODE=EXIST -DThreads_FOUND=ON)
+ifneq (,$(findstring SystemCLanguage found,$(FINDSC)))
+SYSTEMC_SET := true
+endif
+endif
+
+ifeq ($(SYSTEMC_SET), true)
+TARGET := run
+else
+TARGET := nosc
+endif
+
+endif
+endif
+
+default: $(TARGET)
+
+run:
+	@echo
+	@echo "-- Verilator CMake SystemC tracing example"
+
+	@echo
+	@echo "-- CMake ----------------"
+	mkdir -p build && cd build && cmake ..
+
+	@echo
+	@echo "-- COMPILE -----------------"
+	cmake --build build
+
+	@echo
+	@echo "-- RUN ---------------------"
+	@mkdir -p logs
+	build/example +trace
+
+	@echo
+	@echo "-- COVERAGE ----------------"
+	$(VERILATOR_COVERAGE) --annotate logs/annotated logs/coverage.dat
+
+	@echo
+	@echo "-- DONE --------------------"
+	@echo "To see waveforms, open vlt_dump.vcd in a waveform viewer"
+	@echo
+
+clean mostlyclean distclean maintainer-clean:
+	@rm -rf build logs
+
+nocmake:
+	@echo
+	@echo "%Skip: CMake has not been found"
+	@echo
+
+oldcmake:
+	@echo
+	@echo "%Skip: CMake version is too old (need at least 3.8)"
+	@echo
+
+nosc:
+	@echo
+	@echo "%Skip: CMake could not find SystemC."
+	@echo "% Make sure that either:"
+	@echo "% - The environment variables SYSTEMC_INCLUDE and SYSTEMC_LIBDIR are exported."
+	@echo "% - Or, the environment variable SYSTEMC_ROOT is exported."
+	@echo "% - Or, The environment variable SYSTEMC is exported."
+	@echo "% - Or, if the SystemC installation provides CMake support,"
+	@echo "%   that its installation prefix is in CMAKE_PREFIX_PATH."
+	@echo "% Also that the C++ standard of the SystemC library is the same as this example."
+	@echo "% Please see the Verilator documentation's CMake section for more information."
+	@echo

examples/make_hello_c/Makefile

@@ -5,7 +5,7 @@
 # This calls the object directory makefile.  That allows the objects to
 # be placed in the "current directory" which simplifies the Makefile.
 #
-# Copyright 2003-2019 by Wilson Snyder. This program is free software; you can
+# Copyright 2003-2020 by Wilson Snyder. This program is free software; you can
 # redistribute it and/or modify it under the terms of either the GNU
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
@@ -21,7 +21,7 @@ endif
 
 # This is intended to be a minimal example.  Before copying this to start a
 # real project, it is better to start with a more complete example,
-# e.g. examples/tracing_c.
+# e.g. examples/make_tracing_c.
 
 # If $VERILATOR_ROOT isn't in the environment, we assume it is part of a
 # package install, and verilator is in your path. Otherwise find the
@@ -42,7 +42,7 @@ default:
 	@echo "-- RUN ---------------------"
 	obj_dir/Vtop
 	@echo "-- DONE --------------------"
-	@echo "Note: Once this example is understood, see examples/tracing_c."
+	@echo "Note: Once this example is understood, see examples/make_tracing_c."
 	@echo "Note: Also see the EXAMPLE section in the verilator manpage/document."
 
 ######################################################################

examples/make_hello_sc/Makefile

@@ -5,7 +5,7 @@
 # This calls the object directory makefile.  That allows the objects to
 # be placed in the "current directory" which simplifies the Makefile.
 #
-# Copyright 2003-2019 by Wilson Snyder. This program is free software; you can
+# Copyright 2003-2020 by Wilson Snyder. This program is free software; you can
 # redistribute it and/or modify it under the terms of either the GNU
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
@@ -21,7 +21,7 @@ endif
 
 # This is intended to be a minimal example.  Before copying this to start a
 # real project, it is better to start with a more complete example,
-# e.g. examples/tracing_sc.
+# e.g. examples/make_tracing_sc.
 
 # If $VERILATOR_ROOT isn't in the environment, we assume it is part of a
 # package install, and verilator is in your path. Otherwise find the
@@ -51,7 +51,7 @@ run:
 	@echo "-- RUN ---------------------"
 	obj_dir/Vtop
 	@echo "-- DONE --------------------"
-	@echo "Note: Once this example is understood, see examples/tracing_sc."
+	@echo "Note: Once this example is understood, see examples/make_tracing_sc."
 	@echo "Note: Also see the EXAMPLE section in the verilator manpage/document."
 
 ######################################################################

examples/make_protect_lib/.gitignore

@@ -0,0 +1,2 @@
+obj_*
+logs

examples/make_protect_lib/Makefile

@@ -0,0 +1,97 @@
+######################################################################
+#
+# DESCRIPTION: Verilator Example: --protect-lib Makefile
+#
+# This calls the object directory makefiles.  That allows the objects to
+# be placed in the "current directory" which simplifies the Makefile.
+#
+# Copyright 2019 by Todd Strader. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+#
+######################################################################
+# Check for sanity to avoid later confusion
+
+ifneq ($(words $(CURDIR)),1)
+ $(error Unsupported: GNU Make cannot build in directories containing spaces, build elsewhere: '$(CURDIR)')
+endif
+
+######################################################################
+# Set up variables
+
+# If $VERILATOR_ROOT isn't in the environment, we assume it is part of a
+# package install, and verilator is in your path. Otherwise find the
+# binary relative to $VERILATOR_ROOT (such as when inside the git sources).
+ifeq ($(VERILATOR_ROOT),)
+VERILATOR = verilator
+else
+export VERILATOR_ROOT
+VERILATOR = $(VERILATOR_ROOT)/bin/verilator
+endif
+
+VERILATOR_FLAGS =
+# Generate C++
+VERILATOR_FLAGS += -cc
+# Optimize
+VERILATOR_FLAGS += -O2 -x-assign 0
+# Warn abount lint issues; may not want this on less solid designs
+VERILATOR_FLAGS += -Wall
+# Make waveforms
+TOP_VERILATOR_FLAGS = $(VERILATOR_FLAGS) --trace
+
+######################################################################
+default: run
+
+run:
+	@echo
+	@echo "-- Verilator --protect-lib example -_--------------------------"
+
+	@echo
+	@echo "-- VERILATE secret module -------------------------------------"
+	@echo " --protect-lib will produce both a static and shared library"
+	@echo " In this example the static library is used, but some"
+	@echo " simulators may require the shared library."
+	@echo "---------------------------------------------------------------"
+	$(VERILATOR) $(VERILATOR_FLAGS) --protect-lib verilated_secret -Mdir obj_dir_secret/ secret_impl.v
+
+	@echo
+	@echo "-- COMPILE protected library ----------------------------------"
+	@echo " This builds verilated_secret.sv, libverilated_secret.a and"
+	@echo " libverilated_secret.so which can be distributed apart from"
+	@echo " the source"
+	@echo "---------------------------------------------------------------"
+	$(MAKE) -j 4 -C obj_dir_secret -f Vsecret_impl.mk
+
+	@echo
+	@echo "-- VERILATE top module ----------------------------------------"
+	@echo " Use the SystemVerilog wrapper (verilated_secret.sv) and the"
+	@echo " library (libverilated_secret.a) generated from the previous"
+	@echo " step"
+	@echo "---------------------------------------------------------------"
+	$(VERILATOR) $(TOP_VERILATOR_FLAGS) --exe -LDFLAGS '-L../obj_dir_secret -lverilated_secret -static' top.v obj_dir_secret/verilated_secret.sv sim_main.cpp
+
+	@echo
+	@echo "-- COMPILE entire design --------------------------------------"
+	$(MAKE) -j 4 -C obj_dir -f Vtop.mk
+
+	@echo
+	@echo "-- RUN --------------------------------------------------------"
+	@mkdir -p logs
+	obj_dir/Vtop +trace
+
+	@echo
+	@echo "-- DONE -------------------------------------------------------"
+	@echo "To see waveforms, open logs/vlt_dump.vcd in a waveform viewer"
+	@echo
+
+
+######################################################################
+# Other targets
+
+show-config:
+	$(VERILATOR) -V
+
+maintainer-copy::
+clean mostlyclean distclean maintainer-clean::
+	-rm -rf obj_dir* logs *.log core

examples/make_protect_lib/secret_impl.v

@@ -0,0 +1,27 @@
+// DESCRIPTION: Verilator: --protect-lib example secret module
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2019 by Todd Strader.
+
+// This module will be used as libsecret.a or libsecret.so without
+// exposing the source.
+module secret_impl(
+		   input [31:0]        a,
+		   input [31:0]        b,
+		   output logic [31:0] x,
+		   input 	       clk);
+
+   logic [31:0] 		       accum_q = 0;
+   logic [31:0] 		       secret_value = 9;
+
+   initial $display("%m: initialized");
+
+   always @(posedge clk) begin
+      accum_q <= accum_q + a;
+      if (accum_q > 10)
+        x <= b;
+      else
+        x <= a + b + secret_value;
+   end
+
+endmodule

examples/make_protect_lib/sim_main.cpp

@@ -0,0 +1,72 @@
+// DESCRIPTION: Verilator: --protect-lib example module
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2019 by Todd Strader.
+//======================================================================
+
+// See examples/tracing_c for notes on tracing
+
+// Include common routines
+#include <verilated.h>
+
+#include "Vtop.h"
+
+#if VM_TRACE
+# include <verilated_vcd_c.h>
+#endif
+
+vluint64_t main_time = 0;
+double sc_time_stamp() {
+    return main_time;
+}
+
+int main(int argc, char** argv, char** env) {
+    if (0 && argc && argv && env) {}
+
+    Verilated::debug(0);
+    Verilated::randReset(2);
+    Verilated::commandArgs(argc, argv);
+
+    // Construct the Verilated model, including the secret module
+    Vtop* top = new Vtop;
+
+#if VM_TRACE
+    // When tracing, the contents of the secret module will not be seen
+    VerilatedVcdC* tfp = NULL;
+    const char* flag = Verilated::commandArgsPlusMatch("trace");
+    if (flag && 0==strcmp(flag, "+trace")) {
+        Verilated::traceEverOn(true);
+        VL_PRINTF("Enabling waves into logs/vlt_dump.vcd...\n");
+        tfp = new VerilatedVcdC;
+        top->trace(tfp, 99);
+        Verilated::mkdir("logs");
+        tfp->open("logs/vlt_dump.vcd");
+    }
+#endif
+
+    top->clk = 0;
+
+    // Simulate until $finish
+    while (!Verilated::gotFinish()) {
+        main_time++;
+        top->clk = ~top->clk & 0x1;
+        top->eval();
+#if VM_TRACE
+        if (tfp) tfp->dump(main_time);
+#endif
+    }
+
+    // Final model cleanup
+    top->final();
+
+    // Close trace if opened
+#if VM_TRACE
+    if (tfp) { tfp->close(); tfp = NULL; }
+#endif
+
+    // Destroy model
+    delete top; top = NULL;
+
+    // Fin
+    exit(0);
+}

examples/make_protect_lib/top.v

@@ -0,0 +1,34 @@
+// DESCRIPTION: Verilator: --protect-lib example module
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2019 by Todd Strader.
+
+// See also the EXAMPLE section in the verilator manpage/document.
+module top (input clk);
+
+   integer cyc = 0;
+   logic [31:0] a = 0;
+   logic [31:0] b = 0;
+   logic [31:0] x;
+
+   verilated_secret secret (.a, .b, .x, .clk);
+
+   always @(posedge clk) begin
+      $display("[%0t] cyc=%0d a=%0d b=%0d x=%0d", $time, cyc, a, b, x);
+      cyc <= cyc + 1;
+      if (cyc == 0) begin
+         a <= 5;
+         b <= 7;
+      end else if (cyc == 1) begin
+         a <= 6;
+         b <= 2;
+      end else if (cyc == 2) begin
+         a <= 1;
+         b <= 9;
+      end else if (cyc > 3) begin
+         $display("Done");
+         $finish;
+      end
+   end
+
+endmodule

examples/make_tracing_c/Makefile

@@ -5,7 +5,7 @@
 # This calls the object directory makefile.  That allows the objects to
 # be placed in the "current directory" which simplifies the Makefile.
 #
-# Copyright 2003-2019 by Wilson Snyder. This program is free software; you can
+# Copyright 2003-2020 by Wilson Snyder. This program is free software; you can
 # redistribute it and/or modify it under the terms of either the GNU
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
@@ -52,6 +52,9 @@ VERILATOR_FLAGS += --coverage
 # Add this trace to get a backtrace in gdb
 #VERILATOR_FLAGS += --gdbbt
 
+# Input files for Verilator
+VERILATOR_INPUT = -f input.vc top.v sim_main.cpp
+
 ######################################################################
 default: run
 
@@ -61,7 +64,7 @@ run:
 
 	@echo
 	@echo "-- VERILATE ----------------"
-	$(VERILATOR) $(VERILATOR_FLAGS) -f input.vc top.v sim_main.cpp
+	$(VERILATOR) $(VERILATOR_FLAGS) $(VERILATOR_INPUT)
 
 	@echo
 	@echo "-- COMPILE -----------------"
@@ -72,11 +75,13 @@ run:
 
 	@echo
 	@echo "-- RUN ---------------------"
+	@rm -rf logs
 	@mkdir -p logs
 	obj_dir/Vtop +trace
 
 	@echo
 	@echo "-- COVERAGE ----------------"
+	@rm -rf logs/annotated
 	$(VERILATOR_COVERAGE) --annotate logs/annotated logs/coverage.dat
 
 	@echo

examples/make_tracing_c/Makefile_obj

@@ -5,7 +5,7 @@
 #
 # This is executed in the object directory, and called by ../Makefile
 #
-# Copyright 2003-2019 by Wilson Snyder. This program is free software; you can
+# Copyright 2003-2020 by Wilson Snyder. This program is free software; you can
 # redistribute it and/or modify it under the terms of either the GNU
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.

examples/make_tracing_c/sim_main.cpp

@@ -23,7 +23,7 @@ double sc_time_stamp() {
 }
 
 int main(int argc, char** argv, char** env) {
-    // This is a more complicated example, please also see the simpler examples/hello_world_c.
+    // This is a more complicated example, please also see the simpler examples/make_hello_c.
 
     // Prevent unused variable warnings
     if (0 && argc && argv && env) {}

examples/make_tracing_c/top.v

@@ -5,7 +5,7 @@
 // ======================================================================
 
 // This is intended to be a complex example of several features, please also
-// see the simpler examples/hello_world_c.
+// see the simpler examples/make_hello_c.
 
 module top
   (

examples/make_tracing_sc/Makefile

@@ -5,7 +5,7 @@
 # This calls the object directory makefile.  That allows the objects to
 # be placed in the "current directory" which simplifies the Makefile.
 #
-# Copyright 2003-2019 by Wilson Snyder. This program is free software; you can
+# Copyright 2003-2020 by Wilson Snyder. This program is free software; you can
 # redistribute it and/or modify it under the terms of either the GNU
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
@@ -52,6 +52,9 @@ VERILATOR_FLAGS += --coverage
 # Add this trace to get a backtrace in gdb
 #VERILATOR_FLAGS += --gdbbt
 
+# Input files for Verilator
+VERILATOR_INPUT = -f input.vc top.v sc_main.cpp
+
 # Check if SC exists via a verilator call (empty if not)
 SYSTEMC_EXISTS := $(shell $(VERILATOR) --getenv SYSTEMC_INCLUDE)
 
@@ -69,10 +72,10 @@ run:
 
 	@echo
 	@echo "-- VERILATE ----------------"
-	$(VERILATOR) $(VERILATOR_FLAGS) -f input.vc top.v sc_main.cpp
+	$(VERILATOR) $(VERILATOR_FLAGS) $(VERILATOR_INPUT)
 
 	@echo
-	@echo "-- COMPILE ----------------="
+	@echo "-- COMPILE -----------------"
 # To compile, we can either just do what Verilator asks,
 # or call a submakefile where we can override the rules ourselves
 #	$(MAKE) -j 4 -C obj_dir -f Vtop.mk
@@ -80,11 +83,13 @@ run:
 
 	@echo
 	@echo "-- RUN ---------------------"
+	@rm -rf logs
 	@mkdir -p logs
 	obj_dir/Vtop +trace
 
 	@echo
 	@echo "-- COVERAGE ----------------"
+	@rm -rf logs/annotated
 	$(VERILATOR_COVERAGE) --annotate logs/annotated logs/coverage.dat
 
 	@echo
@@ -92,6 +97,7 @@ run:
 	@echo "To see waveforms, open vlt_dump.vcd in a waveform viewer"
 	@echo
 
+
 ######################################################################
 # Other targets
 

examples/make_tracing_sc/Makefile_obj

@@ -5,7 +5,7 @@
 #
 # This is executed in the object directory, and called by ../Makefile
 #
-# Copyright 2003-2019 by Wilson Snyder. This program is free software; you can
+# Copyright 2003-2020 by Wilson Snyder. This program is free software; you can
 # redistribute it and/or modify it under the terms of either the GNU
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.

examples/make_tracing_sc/sc_main.cpp

@@ -20,7 +20,7 @@
 #include "Vtop.h"
 
 int sc_main(int argc, char* argv[]) {
-    // This is a more complicated example, please also see the simpler examples/hello_world_c.
+    // This is a more complicated example, please also see the simpler examples/make_hello_c.
 
     // Prevent unused variable warnings
     if (0 && argc && argv) {}

examples/make_tracing_sc/top.v

@@ -5,7 +5,7 @@
 // ======================================================================
 
 // This is intended to be a complex example of several features, please also
-// see the simpler examples/hello_world_c.
+// see the simpler examples/make_hello_c.
 
 module top
   (

examples/xml_py/.gitignore

@@ -0,0 +1,6 @@
+obj_*
+copied
+*.csv
+*.dot
+*.dmp
+*.pdf

examples/xml_py/Makefile

@@ -0,0 +1,62 @@
+######################################################################
+#
+# DESCRIPTION: Verilator Example: XML tests
+#
+# Copyright 2003-2020 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+#
+######################################################################
+
+# This makefile is not intended to be useful as an example itself,
+# it is just to run the small example scripts in this directory.
+
+# If $VERILATOR_ROOT isn't in the environment, we assume it is part of a
+# package install, and verilator is in your path. Otherwise find the
+# binary relative to $VERILATOR_ROOT (such as when inside the git sources).
+ifeq ($(VERILATOR_ROOT),)
+VERILATOR = verilator
+else
+export VERILATOR_ROOT
+VERILATOR = $(VERILATOR_ROOT)/bin/verilator
+endif
+
+DOT = dot
+PYTHON = python3
+
+PYTHON_VERSION := $(shell ${PYTHON} --version 2>&1)
+PYTHON_VERSION_FULL := $(wordlist 2,4,$(subst ., ,${PYTHON_VERSION}))
+PYTHON_VERSION_MAJOR := $(word 1,${PYTHON_VERSION_FULL})
+PYTHON_VERSION_MINOR := $(word 2,${PYTHON_VERSION_FULL})
+PYTHON_GE_3_5 := $(shell [ ${PYTHON_VERSION_MAJOR} -eq 3 -a ${PYTHON_VERSION_MINOR} -ge 5 ] && echo true)
+
+ifeq (${PYTHON_GE_3_5},true)
+default: test
+else
+default: python_message
+endif
+
+python_message:
+	@echo "Found Python version ${PYTHON_VERSION}, but require >= 3.5"
+
+test: \
+	test-vl_file_copy \
+	test-vl_hier_graph \
+
+test-vl_file_copy:
+	@echo "-- vl_file_copy example"
+	$(PYTHON) vl_file_copy -odir copied top.v
+	@cmp copied/top.v top.v
+	@cmp copied/sub.v sub.v
+
+test-vl_hier_graph:
+	@echo "-- vl_hier_graph example"
+	$(PYTHON) vl_hier_graph -o graph.dot top.v
+	@echo "Manually run: " $(DOT) -Tpdf -o graph.pdf graph.dot
+
+######################################################################
+
+maintainer-copy::
+clean mostlyclean distclean maintainer-clean::
+	-rm -rf obj_dir *.log *.csv *.dmp *.dot *.vpd *.pdf core copied

examples/xml_py/sub.v

@@ -0,0 +1,17 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2019 by Wilson Snyder.
+// ======================================================================
+
+module sub
+  #(parameter type TYPE_t = logic)
+   (
+    input TYPE_t in,
+    output TYPE_t out
+    );
+
+   // Some simple logic
+   always_comb out = ~ in;
+
+endmodule

examples/xml_py/top.v

@@ -0,0 +1,32 @@
+// DESCRIPTION: Verilator: Verilog example module
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2019 by Wilson Snyder.
+// ======================================================================
+
+module top
+  (
+   input         clk,
+   input         fastclk,
+   input         reset_l,
+
+   output wire [1:0]  out_small,
+   output wire [39:0] out_quad,
+   output wire [69:0] out_wide,
+   input [1:0]   in_small,
+   input [39:0]  in_quad,
+   input [69:0]  in_wide
+   );
+
+   sub #(.TYPE_t(logic [1:0])) sub_small
+     (.in(in_small),
+      .out(out_small));
+
+   sub #(.TYPE_t(logic [39:0])) sub_quad
+     (.in(in_quad),
+      .out(out_quad));
+
+   sub #(.TYPE_t(logic [69:0])) sub_wide
+     (.in(in_wide),
+      .out(out_wide));
+endmodule

examples/xml_py/vl_file_copy

@@ -0,0 +1,112 @@
+#!/usr/bin/env python3
+# -*- Python -*- See copyright, etc below
+######################################################################
+
+import argparse
+import os
+import re
+import subprocess
+import sys
+import tempfile
+import xml.etree.ElementTree as ET
+from shutil import copy2
+from pprint import pprint,pformat
+
+#######################################################################
+
+class VlFileCopy:
+    def __init__(self,
+                 verilator_args,  # presently all verilator options are passed-thru
+                 # ideally this script would check against options mentioned in help
+                 debug=0,
+                 output_dir='copied'):  # directory name we output file uses
+        self.debug = debug
+
+        xml_temp = tempfile.NamedTemporaryFile()
+
+        args = ['--xml-output', xml_temp.name,
+                '--bbox-sys',  # Parse some stuff can't translate
+                '--bbox-unsup',
+                '--prefix vlxml']  # So we know name of .xml output
+        args += verilator_args
+        self.run_verilator(args)
+        self.tree = ET.parse(xml_temp.name)
+
+        os.makedirs(output_dir, 0o777, True)
+
+        # Find and copy the files
+        root = self.tree.getroot()
+        xfiles = root.find('files')
+        for xfile in xfiles.findall('file'):
+            filename = xfile.get('filename')
+            if not re.match('^<', filename):  # e.g. <built-in>
+                if self.debug:
+                    print("\tcp %s %s" % (filename, output_dir))
+                copy2(filename, output_dir)
+
+    def run_verilator(self, args):
+        """Run Verilator command, check errors"""
+        if os.getenv("VERILATOR_ROOT"):
+            command = os.getenv("VERILATOR_ROOT") + "/bin/verilator"
+        else:
+            command = "verilator"
+        command += ' ' + ' '.join(args)
+        if self.debug:
+            print("\t%s " % command)
+        status = subprocess.call(command, shell=True)
+        if status != 0:
+            raise Exception("Command failed running Verilator with '"+command+"', stopped")
+
+#######################################################################
+
+if __name__=='__main__':
+    parser = argparse.ArgumentParser(
+        allow_abbrev=False,
+        formatter_class=argparse.RawTextHelpFormatter,
+        description=
+"""Example of using Verilator XML output to copy a list of files to an
+output directory (-odir, defaults to 'copied'), e.g. to easily create a
+tarball of the design to pass to others.
+
+Example usage:
+     vl_file_copy -f input.vc top.v -odir mycopy
+     # This will make at least mycopy/top.v
+""",
+        epilog=
+"""All other arguments are pass-thru to Verilator: e.g.:
+
+  +define+<var>=<value>      Set preprocessor define
+  -F <file>                  Parse options from a file, relatively
+  -f <file>                  Parse options from a file
+  -G<name>=<value>           Overwrite toplevel parameter
+  +incdir+<dir>              Directory to search for includes
+  +libext+<ext>+[ext]...     Extensions for finding modules
+  -v <filename>              Verilog library
+  -y <dir>                   Directory to search for modules
+
+This file ONLY is placed into the Public Domain, for any use, without
+warranty, 2019 by Wilson Snyder."""
+    )
+    parser.add_argument('-debug', '--debug',
+                        action='store_const', const=9,
+                        help='enable debug')
+    parser.add_argument('-odir', '--odir',
+                        action='store', metavar='directory', required=True,
+                        help='target output directory')
+    (args, rem) = parser.parse_known_args()
+
+    print("NOTE: vl_file_copy is only an example starting point for writing your own tool.")
+    # That is:
+    # 1. We will accept basic patches
+    # 2. We are not expecting to make this globally useful. (e.g. we don't cleanup obj_dir)
+    # 3. "make install" will not install this.
+    # 4. This has not had production-worthy validation.
+
+    fc = VlFileCopy(output_dir = args.odir,
+                    debug = args.debug,
+                    verilator_args = rem)
+
+######################################################################
+### Local Variables:
+### compile-command: "./vl_file_copy -h ; VERILATOR_ROOT=$V4 ./vl_file_copy +define+thru top.v"
+### End:

examples/xml_py/vl_hier_graph

@@ -0,0 +1,136 @@
+#!/usr/bin/env python3
+# -*- Python -*- See copyright, etc below
+######################################################################
+
+import argparse
+import os
+import re
+import subprocess
+import sys
+import tempfile
+import xml.etree.ElementTree as ET
+from shutil import copy2
+from pprint import pprint,pformat
+
+#######################################################################
+
+class VlHierGraph:
+    def __init__(self,
+                 verilator_args,  # presently all verilator options are passed-thru
+                 # ideally this script would check against options mentioned in help
+                 debug=0,
+                 output_filename='graph.dot'):  # output filename
+        self.debug = debug
+        self.next_vertex_number = 0
+        self.name_to_number = {}
+
+        xml_temp = tempfile.NamedTemporaryFile()
+
+        args = ['--xml-output', xml_temp.name,
+                '--bbox-sys',  # Parse some stuff can't translate
+                '--bbox-unsup',
+                '--prefix vlxml']  # So we know name of .xml output
+        args += verilator_args
+        self.run_verilator(args)
+        self.tree = ET.parse(xml_temp.name)
+
+        with open(output_filename, "w") as fh:
+            # For more serious purposes, use the python graphviz package instead
+            fh.write("digraph {\n")
+            fh.write("  dpi=300;\n")
+            fh.write("  order=LR;\n")
+            fh.write("  node [fontsize=8 shape=\"box\" margin=0.01 width=0 height=0]")
+            fh.write("  edge [fontsize=6]")
+            # Find cells
+            root = self.tree.getroot()
+            netlist = root.find('netlist')
+            for module in netlist.findall('module'):
+                # origNames are before parameterization, name if after
+                mod_name = module.get('name')
+                mod_number = self.name_to_vertex_number(mod_name)
+                fh.write("  n%d [label=\"%s\""
+                         % (mod_number, mod_name))
+                if module.get('topModule'):
+                    fh.write(" color=\"red\" rank=1")
+                fh.write("];\n")
+
+                for instance in module.findall('instance'):
+                    inst_name = instance.get('name')
+                    def_name = instance.get('defName')
+                    def_number = self.name_to_vertex_number(def_name)
+                    fh.write("  n%d->n%d [label=\"%s\"];\n"
+                             % (mod_number, def_number, inst_name));
+
+            fh.write("}\n")
+
+    def name_to_vertex_number(self, name):
+        if not name in self.name_to_number:
+            self.next_vertex_number += 1
+            self.name_to_number[name] = self.next_vertex_number
+        return self.name_to_number[name]
+
+    def run_verilator(self, args):
+        """Run Verilator command, check errors"""
+        if os.getenv("VERILATOR_ROOT"):
+            command = os.getenv("VERILATOR_ROOT") + "/bin/verilator"
+        else:
+            command = "verilator"
+        command += ' ' + ' '.join(args)
+        if self.debug:
+            print("\t%s " % command)
+        status = subprocess.call(command, shell=True)
+        if status != 0:
+            raise Exception("Command failed running Verilator with '"+command+"', stopped")
+
+#######################################################################
+
+if __name__=='__main__':
+    parser = argparse.ArgumentParser(
+        allow_abbrev=False,
+        formatter_class=argparse.RawTextHelpFormatter,
+        description=
+"""Example of using Verilator XML output to create a .dot file showing the
+design module hierarchy.
+
+Example usage:
+     vl_hier_graph -f input.vc top.v -o graph.dot
+     dot -Tpdf -o graph.pdf graph.dot
+""",
+        epilog=
+"""All other arguments are pass-thru to Verilator: e.g.:
+
+  +define+<var>=<value>      Set preprocessor define
+  -F <file>                  Parse options from a file, relatively
+  -f <file>                  Parse options from a file
+  -G<name>=<value>           Overwrite toplevel parameter
+  +incdir+<dir>              Directory to search for includes
+  +libext+<ext>+[ext]...     Extensions for finding modules
+  -v <filename>              Verilog library
+  -y <dir>                   Directory to search for modules
+
+This file ONLY is placed into the Public Domain, for any use, without
+warranty, 2019 by Wilson Snyder."""
+    )
+    parser.add_argument('-debug', '--debug',
+                        action='store_const', const=9,
+                        help='enable debug')
+    parser.add_argument('-o', '--o',
+                        action='store', metavar='filename', required=True,
+                        help='output filename')
+    (args, rem) = parser.parse_known_args()
+
+    print("NOTE: vl_hier_graph is only an example starting point for writing your own tool.")
+    # That is:
+    # 1. We will accept basic patches
+    # 2. We are not expecting to make this globally useful. (e.g. we don't cleanup obj_dir)
+    # 3. "make install" will not install this.
+    # 4. This has not had production-worthy validation.
+
+    fc = VlHierGraph(output_filename = args.o,
+                     debug = args.debug,
+                     verilator_args = rem)
+
+######################################################################
+### Local Variables:
+### compile-command: "./vl_hier_graph -h ; VERILATOR_ROOT=$V4 ./vl_hier_graph +define+thru top.v"
+### End:

include/gtkwave/fstapi.c

@@ -37,13 +37,15 @@
  *
  */
 
-// Verilator: use hardcoded config file
-//#include <config.h>
-#include "fst_config.h"
+#ifndef FST_CONFIG_INCLUDE
+# define FST_CONFIG_INCLUDE <config.h>
+#endif
+#include FST_CONFIG_INCLUDE
 
 #include "fstapi.h"
 #include "fastlz.h"
 #include "lz4.h"
+#include <errno.h>
 
 #ifndef HAVE_LIBPTHREAD
 #undef FST_WRITER_PARALLEL
@@ -130,6 +132,16 @@ void **JenkinsIns(void *base_i, const unsigned char *mem, uint32_t length, uint3
 #include <sys/sysctl.h>
 #endif
 
+#ifdef __GNUC__
+/* Boolean expression more often true than false */
+#define FST_LIKELY(x) __builtin_expect(!!(x), 1)
+/* Boolean expression more often false than true */
+#define FST_UNLIKELY(x) __builtin_expect(!!(x), 0)
+#else
+#define FST_LIKELY(x) (!!(x))
+#define FST_UNLIKELY(x) (!!(x))
+#endif
+
 #define FST_APIMESS "FSTAPI  | "
 
 /***********************/
@@ -725,6 +737,9 @@ off_t hier_file_len;
 uint32_t *valpos_mem;
 unsigned char *curval_mem;
 
+unsigned char *outval_mem; /* for two-state / Verilator-style value changes */
+uint32_t outval_alloc_siz;
+
 char *filename;
 
 fstHandle maxhandle;
@@ -954,6 +969,19 @@ fflush(xc->handle);
 /*
  * mmap functions
  */
+static void fstWriterMmapSanity(void *pnt, const char *file, int line, const char *usage)
+{
+#if !defined(__CYGWIN__) && !defined(__MINGW32__)
+if(pnt == MAP_FAILED)
+	{
+	fprintf(stderr, "fstMmap() assigned to %s failed: errno: %d, file %s, line %d.\n", usage, errno, file, line);
+	perror("Why");
+	pnt = NULL;
+	}
+#endif
+}
+
+
 static void fstWriterCreateMmaps(struct fstWriterContext *xc)
 {
 off_t curpos = ftello(xc->handle);
@@ -976,12 +1004,20 @@ fflush(xc->handle);
 if(!xc->valpos_mem)
         {
         fflush(xc->valpos_handle);
-        xc->valpos_mem = (uint32_t *)fstMmap(NULL, xc->maxhandle * 4 * sizeof(uint32_t), PROT_READ|PROT_WRITE, MAP_SHARED, fileno(xc->valpos_handle), 0);
+	errno = 0;
+	if(xc->maxhandle)
+		{
+	        fstWriterMmapSanity(xc->valpos_mem = (uint32_t *)fstMmap(NULL, xc->maxhandle * 4 * sizeof(uint32_t), PROT_READ|PROT_WRITE, MAP_SHARED, fileno(xc->valpos_handle), 0), __FILE__, __LINE__, "xc->valpos_mem");
+		}
         }
 if(!xc->curval_mem)
         {
         fflush(xc->curval_handle);
-        xc->curval_mem = (unsigned char *)fstMmap(NULL, xc->maxvalpos, PROT_READ|PROT_WRITE, MAP_SHARED, fileno(xc->curval_handle), 0);
+	errno = 0;
+	if(xc->maxvalpos)
+		{
+	        fstWriterMmapSanity(xc->curval_mem = (unsigned char *)fstMmap(NULL, xc->maxvalpos, PROT_READ|PROT_WRITE, MAP_SHARED, fileno(xc->curval_handle), 0), __FILE__, __LINE__, "xc->curval_handle");
+		}
         }
 }
 
@@ -1684,7 +1720,8 @@ fflush(xc->tchn_handle);
 tlen = ftello(xc->tchn_handle);
 fstWriterFseeko(xc, xc->tchn_handle, 0, SEEK_SET);
 
-tmem = (unsigned char *)fstMmap(NULL, tlen, PROT_READ|PROT_WRITE, MAP_SHARED, fileno(xc->tchn_handle), 0);
+errno = 0;
+fstWriterMmapSanity(tmem = (unsigned char *)fstMmap(NULL, tlen, PROT_READ|PROT_WRITE, MAP_SHARED, fileno(xc->tchn_handle), 0), __FILE__, __LINE__, "tmem");
 if(tmem)
         {
         unsigned long destlen = tlen;
@@ -1876,7 +1913,7 @@ if(xc)
 
 if(xc && !xc->already_in_close && !xc->already_in_flush)
         {
-        unsigned char *tmem;
+        unsigned char *tmem = NULL;
         off_t fixup_offs, tlen, hlen;
 
         xc->already_in_close = 1; /* never need to zero this out as it is freed at bottom */
@@ -1892,7 +1929,7 @@ if(xc && !xc->already_in_close && !xc->already_in_flush)
                 xc->skip_writing_section_hdr = 1;
                 if(!xc->size_limit_locked)
                         {
-                        if(xc->is_initial_time) /* simulation time never advanced so mock up the changes as time zero ones */
+                        if(FST_UNLIKELY(xc->is_initial_time)) /* simulation time never advanced so mock up the changes as time zero ones */
                                 {
                                 fstHandle dupe_idx;
 
@@ -1910,11 +1947,21 @@ if(xc && !xc->already_in_close && !xc->already_in_flush)
                         }
                 }
         fstDestroyMmaps(xc, 1);
+	if(xc->outval_mem)
+		{
+		free(xc->outval_mem); xc->outval_mem = NULL;
+		xc->outval_alloc_siz = 0;
+		}
 
         /* write out geom section */
         fflush(xc->geom_handle);
         tlen = ftello(xc->geom_handle);
-        tmem = (unsigned char *)fstMmap(NULL, tlen, PROT_READ|PROT_WRITE, MAP_SHARED, fileno(xc->geom_handle), 0);
+	errno = 0;
+	if(tlen)
+		{
+	        fstWriterMmapSanity(tmem = (unsigned char *)fstMmap(NULL, tlen, PROT_READ|PROT_WRITE, MAP_SHARED, fileno(xc->geom_handle), 0), __FILE__, __LINE__, "tmem");
+		}
+
         if(tmem)
                 {
                 unsigned long destlen = tlen;
@@ -2022,14 +2069,18 @@ if(xc && !xc->already_in_close && !xc->already_in_flush)
                         {
                         int lz4_maxlen;
                         unsigned char *mem;
-                        unsigned char *hmem;
+                        unsigned char *hmem = NULL;
                         int packed_len;
 
                         fflush(xc->handle);
 
                         lz4_maxlen = LZ4_compressBound(xc->hier_file_len);
                         mem = (unsigned char *)malloc(lz4_maxlen);
-                        hmem = (unsigned char *)fstMmap(NULL, xc->hier_file_len, PROT_READ|PROT_WRITE, MAP_SHARED, fileno(xc->hier_handle), 0);
+			errno = 0;
+			if(xc->hier_file_len)
+				{
+	                        fstWriterMmapSanity(hmem = (unsigned char *)fstMmap(NULL, xc->hier_file_len, PROT_READ|PROT_WRITE, MAP_SHARED, fileno(xc->hier_handle), 0), __FILE__, __LINE__, "hmem");
+				}
                         packed_len = LZ4_compress((char *)hmem, (char *)mem, xc->hier_file_len);
                         fstMunmap(hmem, xc->hier_file_len);
 
@@ -2845,12 +2896,12 @@ const unsigned char *buf = (const unsigned char *)val;
 uint32_t offs;
 int len;
 
-if((xc) && (handle <= xc->maxhandle))
+if(FST_LIKELY((xc) && (handle <= xc->maxhandle)))
         {
         uint32_t fpos;
         uint32_t *vm4ip;
 
-        if(!xc->valpos_mem)
+        if(FST_UNLIKELY(!xc->valpos_mem))
                 {
                 xc->vc_emitted = 1;
                 fstWriterCreateMmaps(xc);
@@ -2860,17 +2911,17 @@ if((xc) && (handle <= xc->maxhandle))
         vm4ip = &(xc->valpos_mem[4*handle]);
 
         len  = vm4ip[1];
-        if(len) /* len of zero = variable length, use fstWriterEmitVariableLengthValueChange */
+        if(FST_LIKELY(len)) /* len of zero = variable length, use fstWriterEmitVariableLengthValueChange */
                 {
-                if(!xc->is_initial_time)
+                if(FST_LIKELY(!xc->is_initial_time))
                         {
                         fpos = xc->vchg_siz;
 
-                        if((fpos + len + 10) > xc->vchg_alloc_siz)
+                        if(FST_UNLIKELY((fpos + len + 10) > xc->vchg_alloc_siz))
                                 {
                                 xc->vchg_alloc_siz += (xc->fst_break_add_size + len); /* +len added in the case of extremely long vectors and small break add sizes */
                                 xc->vchg_mem = (unsigned char *)realloc(xc->vchg_mem, xc->vchg_alloc_siz);
-                                if(!xc->vchg_mem)
+                                if(FST_UNLIKELY(!xc->vchg_mem))
                                         {
                                         fprintf(stderr, FST_APIMESS "Could not realloc() in fstWriterEmitValueChange, exiting.\n");
                                         exit(255);
@@ -2955,18 +3006,139 @@ if((xc) && (handle <= xc->maxhandle))
         }
 }
 
+void fstWriterEmitValueChange32(void *ctx, fstHandle handle,
+                                uint32_t bits, uint32_t val) {
+        char buf[32];
+        char *s = buf;
+        uint32_t i;
+        for (i = 0; i < bits; ++i)
+        {
+                *s++ = '0' + ((val >> (bits - i - 1)) & 1);
+        }
+        fstWriterEmitValueChange(ctx, handle, buf);
+}
+void fstWriterEmitValueChange64(void *ctx, fstHandle handle,
+                                uint32_t bits, uint64_t val) {
+        char buf[64];
+        char *s = buf;
+        uint32_t i;
+        for (i = 0; i < bits; ++i)
+        {
+                *s++ = '0' + ((val >> (bits - i - 1)) & 1);
+        }
+        fstWriterEmitValueChange(ctx, handle, buf);
+}
+void fstWriterEmitValueChangeVec32(void *ctx, fstHandle handle,
+                                   uint32_t bits, const uint32_t *val) {
+        struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+        if (FST_UNLIKELY(bits <= 32))
+        {
+                fstWriterEmitValueChange32(ctx, handle, bits, val[0]);
+        }
+        else if(FST_LIKELY(xc))
+        {
+                int bq = bits / 32;
+                int br = bits & 31;
+                int i;
+                int w;
+                uint32_t v;
+                unsigned char* s;
+                if (FST_UNLIKELY(bits > xc->outval_alloc_siz))
+                {
+                        xc->outval_alloc_siz = bits*2 + 1;
+                        xc->outval_mem = (unsigned char*)realloc(xc->outval_mem, xc->outval_alloc_siz);
+                        if (FST_UNLIKELY(!xc->outval_mem))
+                        {
+                                fprintf(stderr,
+                                        FST_APIMESS "Could not realloc() in fstWriterEmitValueChangeVec32, exiting.\n");
+                                exit(255);
+                        }
+                }
+                s = xc->outval_mem;
+                {
+                        w = bq;
+                        v = val[w];
+                        for (i = 0; i < br; ++i)
+                        {
+                                *s++ = '0' + ((v >> (br - i - 1)) & 1);
+                        }
+                }
+                for (w = bq - 1; w >= 0; --w)
+                {
+                        v = val[w];
+                        for (i = (32 - 4); i >= 0; i -= 4) {
+                                s[0] = '0' + ((v >> (i + 3)) & 1);
+                                s[1] = '0' + ((v >> (i + 2)) & 1);
+                                s[2] = '0' + ((v >> (i + 1)) & 1);
+                                s[3] = '0' + ((v >> (i + 0)) & 1);
+                                s += 4;
+                        }
+                }
+                fstWriterEmitValueChange(ctx, handle, xc->outval_mem);
+        }
+}
+void fstWriterEmitValueChangeVec64(void *ctx, fstHandle handle,
+                                   uint32_t bits, const uint64_t *val) {
+        struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+        if (FST_UNLIKELY(bits <= 64))
+        {
+                fstWriterEmitValueChange64(ctx, handle, bits, val[0]);
+        }
+        else if(FST_LIKELY(xc))
+        {
+                int bq = bits / 64;
+                int br = bits & 63;
+                int i;
+                int w;
+                uint32_t v;
+                unsigned char* s;
+                if (FST_UNLIKELY(bits > xc->outval_alloc_siz))
+                {
+                        xc->outval_alloc_siz = bits*2 + 1;
+                        xc->outval_mem = (unsigned char*)realloc(xc->outval_mem, xc->outval_alloc_siz);
+                        if (FST_UNLIKELY(!xc->outval_mem))
+                        {
+                                fprintf(stderr,
+                                        FST_APIMESS "Could not realloc() in fstWriterEmitValueChangeVec64, exiting.\n");
+                                exit(255);
+                        }
+                }
+                s = xc->outval_mem;
+                {
+                        w = bq;
+                        v = val[w];
+                        for (i = 0; i < br; ++i)
+                        {
+                                *s++ = '0' + ((v >> (br - i - 1)) & 1);
+                        }
+                }
+                for (w = bq - 1; w >= 0; --w) {
+                        v = val[w];
+                        for (i = (64 - 4); i >= 0; i -= 4)
+                        {
+                                s[0] = '0' + ((v >> (i + 3)) & 1);
+                                s[1] = '0' + ((v >> (i + 2)) & 1);
+                                s[2] = '0' + ((v >> (i + 1)) & 1);
+                                s[3] = '0' + ((v >> (i + 0)) & 1);
+                                s += 4;
+                        }
+                }
+                fstWriterEmitValueChange(ctx, handle, xc->outval_mem);
+        }
+}
+
 
 void fstWriterEmitVariableLengthValueChange(void *ctx, fstHandle handle, const void *val, uint32_t len)
 {
 struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
 const unsigned char *buf = (const unsigned char *)val;
 
-if((xc) && (handle <= xc->maxhandle))
+if(FST_LIKELY((xc) && (handle <= xc->maxhandle)))
         {
         uint32_t fpos;
         uint32_t *vm4ip;
 
-        if(!xc->valpos_mem)
+        if(FST_UNLIKELY(!xc->valpos_mem))
                 {
                 xc->vc_emitted = 1;
                 fstWriterCreateMmaps(xc);
@@ -2976,15 +3148,15 @@ if((xc) && (handle <= xc->maxhandle))
         vm4ip = &(xc->valpos_mem[4*handle]);
 
         /* there is no initial time dump for variable length value changes */
-        if(!vm4ip[1]) /* len of zero = variable length */
+        if(FST_LIKELY(!vm4ip[1])) /* len of zero = variable length */
                 {
                 fpos = xc->vchg_siz;
 
-                if((fpos + len + 10 + 5) > xc->vchg_alloc_siz)
+                if(FST_UNLIKELY((fpos + len + 10 + 5) > xc->vchg_alloc_siz))
                         {
                         xc->vchg_alloc_siz += (xc->fst_break_add_size + len + 5); /* +len added in the case of extremely long vectors and small break add sizes */
                         xc->vchg_mem = (unsigned char *)realloc(xc->vchg_mem, xc->vchg_alloc_siz);
-                        if(!xc->vchg_mem)
+                        if(FST_UNLIKELY(!xc->vchg_mem))
                                 {
                                 fprintf(stderr, FST_APIMESS "Could not realloc() in fstWriterEmitVariableLengthValueChange, exiting.\n");
                                 exit(255);
@@ -3006,7 +3178,7 @@ unsigned int i;
 int skip = 0;
 if(xc)
         {
-        if(xc->is_initial_time)
+        if(FST_UNLIKELY(xc->is_initial_time))
                 {
                 if(xc->size_limit_locked)       /* this resets xc->is_initial_time to one */
                         {

include/gtkwave/fstapi.h

@@ -355,6 +355,14 @@ fstHandle       fstWriterCreateVar2(void *ctx, enum fstVarType vt, enum fstVarDi
 void            fstWriterEmitDumpActive(void *ctx, int enable);
 void 		fstWriterEmitEnumTableRef(void *ctx, fstEnumHandle handle);
 void            fstWriterEmitValueChange(void *ctx, fstHandle handle, const void *val);
+void            fstWriterEmitValueChange32(void *ctx, fstHandle handle,
+                        uint32_t bits, uint32_t val);
+void            fstWriterEmitValueChange64(void *ctx, fstHandle handle,
+                        uint32_t bits, uint64_t val);
+void            fstWriterEmitValueChangeVec32(void *ctx, fstHandle handle,
+                        uint32_t bits, const uint32_t *val);
+void            fstWriterEmitValueChangeVec64(void *ctx, fstHandle handle,
+                        uint32_t bits, const uint64_t *val);
 void            fstWriterEmitVariableLengthValueChange(void *ctx, fstHandle handle, const void *val, uint32_t len);
 void            fstWriterEmitTimeChange(void *ctx, uint64_t tim);
 void            fstWriterFlushContext(void *ctx);

include/gtkwave/wavealloca.h

@@ -33,9 +33,6 @@
 #else
 #include <malloc.h>
 #endif
-#elif defined(_MSC_VER)
-#include <malloc.h>
-#define alloca _alloca
 #endif
 #define wave_alloca alloca
 #endif

include/verilated.mk.in

@@ -2,7 +2,7 @@
 ######################################################################
 # DESCRIPTION: Makefile commands for all verilated target files
 #
-# Copyright 2003-2019 by Wilson Snyder. Verilator is free software; you can
+# Copyright 2003-2020 by Wilson Snyder. Verilator is free software; you can
 # redistribute it and/or modify it under the terms of either the GNU Lesser
 # General Public License Version 3 or the Perl Artistic License Version 2.0.
 ######################################################################
@@ -30,7 +30,6 @@ CFG_LDLIBS_THREADS = @CFG_LDLIBS_THREADS@
 ######################################################################
 # Programs
 
-SP_INCLUDER	= $(VERILATOR_INCLUDER)
 VERILATOR_COVERAGE = $(PERL) $(VERILATOR_ROOT)/bin/verilator_coverage
 VERILATOR_INCLUDER = $(PERL) $(VERILATOR_ROOT)/bin/verilator_includer
 
@@ -49,7 +48,6 @@ VK_CPPFLAGS_ALWAYS += \
 		-MMD \
 		-I$(VERILATOR_ROOT)/include \
 		-I$(VERILATOR_ROOT)/include/vltstd \
-		-DVL_PRINTF=printf \
 		-DVM_COVERAGE=$(VM_COVERAGE) \
 		-DVM_SC=$(VM_SC) \
 		-DVM_TRACE=$(VM_TRACE) \
@@ -173,8 +171,7 @@ else
 endif
 
 $(VM_PREFIX)__ALL.a: $(VK_OBJS)
-	@echo "      Archiving" $@ ...
-	$(AR) r $@ $^
+	$(AR) -cr $@ $^
 	$(RANLIB) $@
 
 ######################################################################

include/verilated.v

@@ -1,10 +1,10 @@
 //*************************************************************************
 //
-// Code available from: http://www.veripool.org/verilator
+// Code available from: https://verilator.org
 //
 //*************************************************************************
 //
-// Copyright 2003-2019 by Wilson Snyder. This program is free software; you can
+// Copyright 2003-2020 by Wilson Snyder. This program is free software; you can
 // redistribute it and/or modify it under the terms of either the GNU
 // Lesser General Public License Version 3 or the Perl Artistic License.
 // Version 2.0.
@@ -17,7 +17,7 @@
 //=========================================================================
 //
 // DESCRIPTION: Verilator: Include in verilog files to hide verilator defines
-
+
 `ifdef _VERILATED_V_ `else
  `define _VERILATED_V_ 1
 

include/verilated_config.h.in

@@ -1,7 +1,7 @@
 // -*- mode: C++; c-file-style: "cc-mode" -*-
 //*************************************************************************
 //
-// Copyright 2003-2019 by Wilson Snyder. This program is free software; you can
+// Copyright 2003-2020 by Wilson Snyder. This program is free software; you can
 // redistribute it and/or modify it under the terms of either the GNU
 // Lesser General Public License Version 3 or the Perl Artistic License.
 // Version 2.0.
@@ -16,10 +16,10 @@
 /// \file
 /// \brief Verilator: Auto version information include for all Verilated C files
 ///
-/// Code available from: http://www.veripool.org/verilator
+/// Code available from: https://verilator.org
 ///
 //*************************************************************************
-
+
 
 ///**** Product and Version name
 

include/verilated_cov.cpp

@@ -3,7 +3,7 @@
 //
 // THIS MODULE IS PUBLICLY LICENSED
 //
-// Copyright 2001-2019 by Wilson Snyder.  This program is free software;
+// Copyright 2001-2020 by Wilson Snyder.  This program is free software;
 // you can redistribute it and/or modify it under the terms of either the GNU
 // Lesser General Public License Version 3 or the Perl Artistic License Version 2.0.
 //
@@ -73,12 +73,12 @@ private:
 public:
     // METHODS
     // cppcheck-suppress truncLongCastReturn
-    virtual vluint64_t count() const { return *m_countp; }
-    virtual void zero() const { *m_countp = 0; }
+    virtual vluint64_t count() const VL_OVERRIDE { return *m_countp; }
+    virtual void zero() const VL_OVERRIDE { *m_countp = 0; }
     // CONSTRUCTORS
     // cppcheck-suppress noExplicitConstructor
     VerilatedCoverItemSpec(T* countp) : m_countp(countp) { *m_countp = 0; }
-    virtual ~VerilatedCoverItemSpec() {}
+    virtual ~VerilatedCoverItemSpec() VL_OVERRIDE {}
 };
 
 //=============================================================================
@@ -222,7 +222,7 @@ private:
     void clearGuts() VL_REQUIRES(m_mutex) {
         for (ItemList::const_iterator it=m_items.begin(); it!=m_items.end(); ++it) {
             VerilatedCovImpItem* itemp = *(it);
-            delete itemp;
+            VL_DO_DANGLING(delete itemp, itemp);
         }
         m_items.clear();
         m_indexValues.clear();
@@ -244,7 +244,7 @@ public:
             for (ItemList::iterator it=m_items.begin(); it!=m_items.end(); ++it) {
                 VerilatedCovImpItem* itemp = *(it);
                 if (!itemMatchesString(itemp, matchp)) {
-                    delete itemp;
+                    VL_DO_DANGLING(delete itemp, itemp);
                 } else {
                     newlist.push_back(itemp);
                 }