Merge c66d4729c2 into 56ed47ee7c

src/V3Begin.cpp

@@ -298,12 +298,39 @@ class BeginVisitor final : public VNVisitor {
         VL_DO_DANGLING(pushDeletep(nodep), nodep);
     }
     void visit(AstVar* nodep) override {
+        if (nodep->user1SetOnce()) { return; }
         // If static variable, move it outside a function.
         if (nodep->lifetime().isStatic() && m_ftaskp) {
             const std::string newName
                 = m_ftaskp->name() + "__Vstatic__" + dot(m_unnamedScope, nodep->name());
+            if (nodep->isIO()) {
+                if (nodep->direction().isRef()) {
+                    nodep->v3error(
+                        "It is illegal to use argument passing by reference for subroutines with "
+                        "a lifetime of static (IEEE 1800-2023 13.5.2)");
+                }
+                // Create a port that is used for passing value between argument and static
+                // variable
+                AstVar* const portp = nodep->cloneTreePure(false);
+                nodep->replaceWith(portp);
+
+                if (nodep->isInput() || nodep->isInout()) {
+                    AstAssign* const initAssignp = new AstAssign{
+                        nodep->fileline(), new AstVarRef{nodep->fileline(), nodep, VAccess::WRITE},
+                        new AstVarRef{portp->fileline(), portp, VAccess::READ}};
+                    portp->addNextHere(initAssignp);
+                }
+
+                if (nodep->isWritable()) {
+                    AstAssign* const endAssignp = new AstAssign{
+                        nodep->fileline(), new AstVarRef{portp->fileline(), portp, VAccess::WRITE},
+                        new AstVarRef{nodep->fileline(), nodep, VAccess::READ}};
+                    m_ftaskp->addStmtsp(endAssignp);
+                }
+            } else {
+                nodep->unlinkFrBack();
+            }
             nodep->name(newName);
-            nodep->unlinkFrBack();
             m_ftaskp->addHereThisAsNext(nodep);
             nodep->funcLocal(false);
         } else if (m_unnamedScope != "") {

src/V3Fork.cpp

@@ -443,20 +443,11 @@ class DynScopeVisitor final : public VNVisitor {
             if (!isEvent && m_afterTimingControl && nodep->varp()->isWritable()
                 && nodep->access().isWriteOrRW()) {
                 // The output variable may not exist after a delay, so we can't just write to it
-                if (m_inFunc) {
-                    nodep->v3error(
-                        "Writing to an "
-                        << nodep->varp()->verilogKwd()
-                        << " variable of a function after a timing control is not allowed");
-                } else {
-                    nodep->v3warn(E_UNSUPPORTED, "Unsupported: Writing to a captured "
-                                                     << nodep->varp()->verilogKwd()
-                                                     << " variable in a "
-                                                     << (VN_IS(nodep->backp(), AssignDly)
-                                                             ? "non-blocking assignment"
-                                                             : "fork")
-                                                     << " after a timing control");
-                }
+                nodep->v3error(
+                    "Writing to an "
+                    << nodep->varp()->verilogKwd() << " automatic variable of a "
+                    << (m_inFunc ? "function" : "task")
+                    << " after a timing control is not allowed (IEEE 1800-2023 13.2.2)");
             }
             if (!framep->instance().initialized()) framep->createInstancePrototype();
             framep->captureVarInsert(nodep->varp());

src/V3LinkParse.cpp

@@ -69,6 +69,7 @@ class LinkParseVisitor final : public VNVisitor {
     int m_randSequenceNum = 0;  // RandSequence uniqify number
     VLifetime m_lifetime = VLifetime::STATIC_IMPLICIT;  // Propagating lifetime
     bool m_lifetimeAllowed = false;  // True to allow lifetime settings
+    bool m_hasTimingControl = false;  // If current task has timing control
     bool m_moduleWithGenericIface = false;  // If current module contains generic interface
     std::set<AstVar*> m_portDups;  // Non-ANSI port datatype duplicating input/output decls
 
@@ -248,6 +249,9 @@ class LinkParseVisitor final : public VNVisitor {
         VL_RESTORER(m_lifetime);
         VL_RESTORER(m_lifetimeAllowed);
         m_lifetimeAllowed = true;
+        VL_RESTORER(m_hasTimingControl);
+        m_hasTimingControl
+            = nodep->exists([](const AstNode* const nodep) { return nodep->isTimingControl(); });
         if (!nodep->lifetime().isNone()) {
             m_lifetime = nodep->lifetime().makeImplicit();
         } else {
@@ -382,7 +386,15 @@ class LinkParseVisitor final : public VNVisitor {
                 }
             }
         } else if (m_ftaskp) {
-            if (!nodep->lifetime().isAutomatic()) nodep->lifetime(VLifetime::AUTOMATIC_IMPLICIT);
+            // Variables in static tasks with timing control can be used after the task has ended
+            // with use of join..fork_none, so they need to be static
+            if (m_ftaskp->lifetime().isStatic() && m_hasTimingControl) {
+                nodep->v3warn(IMPLICITSTATIC, "Variable's lifetime implicitly set to static "
+                                              "because in static task with timing control.");
+                nodep->lifetime(VLifetime::STATIC_IMPLICIT);
+            } else {
+                nodep->lifetime(VLifetime::AUTOMATIC_IMPLICIT);
+            }
         } else if (nodep->lifetime().isNone()) {
             // lifetime shouldn't be unknown, set static if none
             nodep->lifetime(VLifetime::STATIC_IMPLICIT);

test_regress/t/t_event_array_fire.py

@@ -11,7 +11,7 @@ import vltest_bootstrap
 
 test.scenarios('simulator')
 
-test.compile(verilator_flags2=['--binary'])
+test.compile(verilator_flags2=['--binary', '-Wno-IMPLICITSTATIC'])
 
 test.execute()
 

test_regress/t/t_fork_dynscope_interface.py

@@ -11,7 +11,7 @@ import vltest_bootstrap
 
 test.scenarios('simulator')
 
-test.compile(verilator_flags2=['--binary --trace-fst'])
+test.compile(verilator_flags2=['--binary --trace-fst', '-Wno-IMPLICITSTATIC'])
 
 test.execute()
 

test_regress/t/t_fork_dynscope_out.py

@@ -11,7 +11,7 @@ import vltest_bootstrap
 
 test.scenarios('simulator')
 
-test.compile(verilator_flags2=["--binary -Wno-INITIALDLY"])
+test.compile(verilator_flags2=["--binary -Wno-INITIALDLY", '-Wno-IMPLICITSTATIC'])
 
 test.execute()
 

test_regress/t/t_fork_dynscope_unsup.out

@@ -1,10 +0,0 @@
-%Error-UNSUPPORTED: t/t_fork_dynscope_unsup.v:17:7: Unsupported: Writing to a captured inout variable in a fork after a timing control
-                                                  : ... note: In instance 't'
-   17 |       p = #1 1;
-      |       ^
-                    ... For error description see https://verilator.org/warn/UNSUPPORTED?v=latest
-%Error-UNSUPPORTED: t/t_fork_dynscope_unsup.v:22:5: Unsupported: Writing to a captured output variable in a non-blocking assignment after a timing control
-                                                  : ... note: In instance 't'
-   22 |     q <= #1 1;
-      |     ^
-%Error: Exiting due to

test_regress/t/t_fork_repeat_reset.py

@@ -11,7 +11,7 @@ import vltest_bootstrap
 
 test.scenarios('simulator')
 
-test.compile(verilator_flags2=["--binary"])
+test.compile(verilator_flags2=["--binary", '-Wno-IMPLICITSTATIC'])
 
 test.execute()
 

test_regress/t/t_fork_write_after_timing.py

@@ -11,6 +11,8 @@ import vltest_bootstrap
 
 test.scenarios('simulator')
 
-test.lint(fails=True, expect_filename=test.golden_filename)
+test.compile(verilator_flags2=["--binary", "-Wno-IMPLICITSTATIC"])
+
+test.execute()
 
 test.passes()

test_regress/t/t_fork_write_after_timing.v

@@ -0,0 +1,118 @@
+// DESCRIPTION: Verilator: Verilog Test module
+// This file ONLY is placed under the Creative Commons Public Domain.
+// SPDX-FileCopyrightText: 2026 Antmicro
+// SPDX-License-Identifier: CC0-1.0
+
+// verilog_format: off
+`define stop $stop
+`define checkd(gotv,expv) do if ((gotv) !== (expv)) begin $write("%%Error: %s:%0d:  got=%0d exp=%0d\n", `__FILE__,`__LINE__, (gotv), (expv)); `stop; end while(0);
+// verilog_format: on
+
+module t;
+  int x1, x2, x3, x4, x5, x6, x7;
+
+  initial begin
+    x1 = -1;
+    x2 = -1;
+    x3 = -1;
+    x4 = -1;
+
+    #1;
+    t1(x1);
+    t2(x2);
+    t3(x3);
+    t4(x4);
+    `checkd(x1, 0)
+    `checkd(x2, -1)
+    `checkd(x3, 1)
+    `checkd(x4, 2)
+
+    #10 t1(x1);
+    t2(x2);
+    t3(x3);
+    t4(x4);
+    `checkd(x1, 1)
+    `checkd(x2, -1)
+    `checkd(x3, 1)
+    `checkd(x4, 2)
+
+    `checkd(x5, 3)
+    `checkd(x6, 0)
+    `checkd(x7, 4)
+
+    #5;
+    `checkd(x1, 1)
+    `checkd(x2, -1)
+    `checkd(x3, 1)
+    `checkd(x4, 2)
+    `checkd(x5, 3)
+    `checkd(x6, 0)
+    `checkd(x7, 4)
+
+    $write("*-* All Finished *-*\n");
+    $finish;
+  end
+  always #1 t5(x5);
+  always #1 t6(x6);
+  always #1 t7(x7);
+
+  task t1(output int x);
+    fork
+      x = #1 1;
+    join_none
+    if ($time < 10) begin
+      `checkd(x, 0)
+    end
+    else begin
+      `checkd(x, 1)
+    end
+  endtask
+
+  task t2(inout int x);
+    fork
+      x = #1 2;
+    join_none
+    `checkd(x, -1)
+  endtask
+
+ task t3(output int x);
+    if ($time < 10) begin
+      `checkd(x, 0)
+    end
+    else begin
+      `checkd(x, 1)
+    end
+    fork
+      x = #1 1;
+    join_none
+    #2 `checkd(x, 1);
+  endtask
+
+  task t4(inout int x);
+    if ($time < 10) begin
+      `checkd(x, -1)
+    end
+    else begin
+      `checkd(x, 2)
+    end
+    fork
+      x = #1 2;
+    join_none
+    #2 `checkd(x, 2);
+  endtask
+
+  task t5(output int x);
+    x <= #1 3;
+  endtask
+
+  task t6(inout int x);
+    x <= #1 4;
+  endtask
+
+  task static t7(inout int x);
+    int y = 0;
+    x <= #1 4;
+    #2 y = x;
+    `checkd(x, 4)
+  endtask
+endmodule

test_regress/t/t_fork_write_after_timing_bad.out

@@ -0,0 +1,11 @@
+%Warning-IMPLICITSTATIC: t/t_fork_write_after_timing_bad.v:12:19: Variable's lifetime implicitly set to static because in static task with timing control.
+   12 |   task t1(ref int x);
+      |                   ^
+                         ... For warning description see https://verilator.org/warn/IMPLICITSTATIC?v=latest
+                         ... Use "/* verilator lint_off IMPLICITSTATIC */" and lint_on around source to disable this message.
+%Error: t/t_fork_write_after_timing_bad.v:12:19: It is illegal to use argument passing by reference for subroutines with a lifetime of static (IEEE 1800-2023 13.5.2)
+                                               : ... note: In instance 't'
+   12 |   task t1(ref int x);
+      |                   ^
+        ... See the manual at https://verilator.org/verilator_doc.html?v=latest for more assistance.
+%Error: Exiting due to

test_regress/t/t_fork_write_after_timing_bad.py

@@ -0,0 +1,16 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# 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.
+# SPDX-FileCopyrightText: 2024 Wilson Snyder
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+import vltest_bootstrap
+
+test.scenarios('simulator')
+
+test.lint(verilator_flags2=["--timing"], fails=True, expect_filename=test.golden_filename)
+
+test.passes()

test_regress/t/t_fork_write_after_timing_bad.v

@@ -1,24 +1,17 @@
 // DESCRIPTION: Verilator: Verilog Test module
-//
-// This file ONLY is placed under the Creative Commons Public Domain
-// SPDX-FileCopyrightText: 2024 Antmicro
+// This file ONLY is placed under the Creative Commons Public Domain.
+// SPDX-FileCopyrightText: 2026 Antmicro
 // SPDX-License-Identifier: CC0-1.0
 
 module t;
-  bit p = 0, q = 0;
-
+  int x1;
   initial begin
-    t1(p);
-    t2(q);
+    t1(x1);
+    $finish;
   end
-
-  task t1(inout p);
+  task t1(ref int x);
     fork
-      p = #1 1;
+      x = #1 2;
     join_none
   endtask
-
-  task t2(output q);
-    q <= #1 1;
-  endtask
 endmodule

test_regress/t/t_timing_func_fork_bad.out

@@ -1,42 +1,46 @@
-%Error: t/t_timing_func_fork_bad.v:13:9: Writing to an output variable of a function after a timing control is not allowed
+%Error: t/t_timing_func_fork_bad.v:13:9: Writing to an output automatic variable of a function after a timing control is not allowed (IEEE 1800-2023 13.2.2)
                                        : ... note: In instance 't'
    13 |         f1 = 0;
       |         ^~
         ... See the manual at https://verilator.org/verilator_doc.html?v=latest for more assistance.
-%Error: t/t_timing_func_fork_bad.v:14:9: Writing to an output variable of a function after a timing control is not allowed
+%Error: t/t_timing_func_fork_bad.v:14:9: Writing to an output automatic variable of a function after a timing control is not allowed (IEEE 1800-2023 13.2.2)
                                        : ... note: In instance 't'
    14 |         o1 = 0;
       |         ^~
-%Error: t/t_timing_func_fork_bad.v:22:9: Writing to an output variable of a function after a timing control is not allowed
+%Error: t/t_timing_func_fork_bad.v:22:7: Writing to an output automatic variable of a task after a timing control is not allowed (IEEE 1800-2023 13.2.2)
                                        : ... note: In instance 't'
-   22 |         f2 = #5 0;
+   22 |       o1 = 0;
+      |       ^~
+%Error: t/t_timing_func_fork_bad.v:29:9: Writing to an output automatic variable of a function after a timing control is not allowed (IEEE 1800-2023 13.2.2)
+                                       : ... note: In instance 't'
+   29 |         f2 = #5 0;
       |         ^~
-%Error: t/t_timing_func_fork_bad.v:24:9: Writing to an inout variable of a function after a timing control is not allowed
+%Error: t/t_timing_func_fork_bad.v:31:9: Writing to an inout automatic variable of a function after a timing control is not allowed (IEEE 1800-2023 13.2.2)
                                        : ... note: In instance 't'
-   24 |         io2 = 0;
+   31 |         io2 = 0;
       |         ^~~
-%Error: t/t_timing_func_fork_bad.v:34:9: Writing to an output variable of a function after a timing control is not allowed
+%Error: t/t_timing_func_fork_bad.v:41:9: Writing to an output automatic variable of a function after a timing control is not allowed (IEEE 1800-2023 13.2.2)
                                        : ... note: In instance 't'
-   34 |         f3 = 0;
+   41 |         f3 = 0;
       |         ^~
-%Error: t/t_timing_func_fork_bad.v:35:9: Writing to an output variable of a function after a timing control is not allowed
+%Error: t/t_timing_func_fork_bad.v:42:9: Writing to an output automatic variable of a function after a timing control is not allowed (IEEE 1800-2023 13.2.2)
                                        : ... note: In instance 't'
-   35 |         o3 = 0;
+   42 |         o3 = 0;
       |         ^~
-%Error: t/t_timing_func_fork_bad.v:43:9: Writing to an output variable of a function after a timing control is not allowed
+%Error: t/t_timing_func_fork_bad.v:50:9: Writing to an output automatic variable of a function after a timing control is not allowed (IEEE 1800-2023 13.2.2)
                                        : ... note: In instance 't'
-   43 |         f4 = @e 0;
+   50 |         f4 = @e 0;
       |         ^~
-%Error: t/t_timing_func_fork_bad.v:45:9: Writing to an inout variable of a function after a timing control is not allowed
+%Error: t/t_timing_func_fork_bad.v:52:9: Writing to an inout automatic variable of a function after a timing control is not allowed (IEEE 1800-2023 13.2.2)
                                        : ... note: In instance 't'
-   45 |         io4 = 0;
+   52 |         io4 = 0;
       |         ^~~
-%Error: t/t_timing_func_fork_bad.v:56:9: Writing to an output variable of a function after a timing control is not allowed
+%Error: t/t_timing_func_fork_bad.v:63:9: Writing to an output automatic variable of a function after a timing control is not allowed (IEEE 1800-2023 13.2.2)
                                        : ... note: In instance 't'
-   56 |         f5 = 0;
+   63 |         f5 = 0;
       |         ^~
-%Error: t/t_timing_func_fork_bad.v:57:9: Writing to an output variable of a function after a timing control is not allowed
+%Error: t/t_timing_func_fork_bad.v:64:9: Writing to an output automatic variable of a function after a timing control is not allowed (IEEE 1800-2023 13.2.2)
                                        : ... note: In instance 't'
-   57 |         o5 = 0;
+   64 |         o5 = 0;
       |         ^~
 %Error: Exiting due to

test_regress/t/t_timing_func_fork_bad.v

@@ -6,7 +6,7 @@
 
 module t;
 
-  function int f1(output int o1);
+  function automatic int f1(output int o1);
     fork
       begin
         #1 $stop;
@@ -16,7 +16,14 @@ module t;
     join_none
   endfunction
 
-  function int f2(inout io2);
+  task automatic t1(output int o1);
+    fork begin
+      #1 $stop;
+      o1 = 0;
+    end join_none
+  endtask
+
+  function automatic int f2(inout io2);
     fork
       begin
         f2 = #5 0;
@@ -27,7 +34,7 @@ module t;
   endfunction
 
   event e;
-  function int f3(output int o3);
+  function automatic int f3(output int o3);
     fork
       begin
         @e $stop;
@@ -37,7 +44,7 @@ module t;
     join_none
   endfunction
 
-  function int f4(inout int io4);
+  function automatic int f4(inout int io4);
     fork
       begin
         f4 = @e 0;
@@ -49,7 +56,7 @@ module t;
 
   int i;
 
-  function int f5(output int o5);
+  function automatic int f5(output int o5);
     fork
       begin
         wait (i == 0) $stop;

test_regress/t/t_uvm_dpi_v2017_1_0.py

@@ -17,8 +17,8 @@ if re.search(r'clang', test.cxx_version):
     test.skip("uvm_regex.cc from upstream has clang warnings")
 
 test.compile(verilator_flags2=[
-    "--binary", test.build_jobs, "--vpi", "+define+T_V2017_1_0", "+incdir+t/uvm/v2017_1_0",
-    test.pli_filename
+    "--binary", "-Wno-IMPLICITSTATIC", test.build_jobs, "--vpi", "+define+T_V2017_1_0",
+    "+incdir+t/uvm/v2017_1_0", test.pli_filename
 ])
 
 test.execute(expect_filename=test.golden_filename)

test_regress/t/t_uvm_dpi_v2020_3_1.py

@@ -18,7 +18,7 @@ if re.search(r'clang', test.cxx_version):
 
 test.compile(verilator_flags2=[
     "--binary", test.build_jobs, "--vpi", "+define+T_V2020_3_1", "+incdir+t/uvm/v2020_3_1",
-    test.pli_filename
+    "-Wno-IMPLICITSTATIC", test.pli_filename
 ])
 
 test.execute(expect_filename=test.golden_filename)

test_regress/t/t_uvm_hello_all_v2017_1_0_dpi.py

@@ -23,6 +23,7 @@ test.compile(v_flags2=[
     "--vpi",
     "--CFLAGS -O0",
     "-Wall",
+    "-Wno-IMPLICITSTATIC",
     "+incdir+t/uvm",  #
     "t/uvm/uvm_pkg_all_v2017_1_0_dpi.svh",
     test.pli_filename

test_regress/t/t_uvm_hello_all_v2020_3_1_dpi.py

@@ -23,6 +23,7 @@ test.compile(v_flags2=[
     "--vpi",
     "--CFLAGS -O0",
     "-Wall",
+    '-Wno-IMPLICITSTATIC',
     "+incdir+t/uvm",  #
     "t/uvm/uvm_pkg_all_v2020_3_1_dpi.svh",
     test.pli_filename

test_regress/t/t_virtual_interface_method.py

@@ -11,7 +11,7 @@ import vltest_bootstrap
 
 test.scenarios('simulator')
 
-test.compile(v_flags2=["--binary"], verilator_make_gmake=False)
+test.compile(v_flags2=["--binary", '-Wno-IMPLICITSTATIC'], verilator_make_gmake=False)
 
 test.execute()