From ab74cafa20b143127156c0562eca24703193ed7d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Stephan=20I=2E=20B=C3=B6ttcher?= <sib64@psjt.org>
Date: Tue, 17 Mar 2026 19:39:51 +0100
Subject: [PATCH 01/11] Add option -gno-strict-parameter-declaration

The standards requires that parameters must be declared
before they are used.  Using -gno-strict-parameter-declaration
will allow using a parameter before declaration, e.g., in a port
declaration, with the parameter declared in the body of the
module.  Prior to version 13 this was allowed, so there is a large body
of existing code depending on the pre version 13 behaviour.
---
 Documentation/usage/command_line_flags.rst |  8 ++++++++
 compiler.h                                 |  6 ++++++
 driver/iverilog.man.in                     |  6 ++++++
 driver/main.c                              | 11 ++++++++++-
 main.cc                                    |  7 +++++++
 symbol_search.cc                           |  3 ++-
 6 files changed, 39 insertions(+), 2 deletions(-)

diff --git a/Documentation/usage/command_line_flags.rst b/Documentation/usage/command_line_flags.rst
index 8f7f531b3..751818d42 100644
--- a/Documentation/usage/command_line_flags.rst
+++ b/Documentation/usage/command_line_flags.rst
@@ -131,6 +131,14 @@ These flags affect the general behavior of the compiler.
     containing an unsized constant number, and unsized constant numbers are
     not truncated to integer width.
 
+  * strict-parameter-declaration/no-strict-parameter-declaration
+
+    The standards requires that parameters must be declared lexically
+    before they are used.  Using -gno-strict-parameter-declaration
+    will allow using a parameter before declaration, e.g., in a port
+    declaration, with the parameter declared in the body of the
+    module.
+
   * shared-loop-index/no-shared-loop-index
 
     Enable or disable the exclusion of for-loop control variables from
diff --git a/compiler.h b/compiler.h
index 307589aad..9548a85d0 100644
--- a/compiler.h
+++ b/compiler.h
@@ -210,6 +210,12 @@ extern bool gn_strict_expr_width_flag;
    loop. */
 extern bool gn_shared_loop_index_flag;
 
+/* If this flag is true (default), then parameters must be declared before
+   use.
+   use `-gno-strict-parameter-declaration` for pre version 13 behaviour.
+ */
+extern bool gn_strict_parameter_declaration;
+
 static inline bool gn_system_verilog(void)
 {
       if (generation_flag >= GN_VER2005_SV)
diff --git a/driver/iverilog.man.in b/driver/iverilog.man.in
index be62ec10b..4f7bb40f2 100644
--- a/driver/iverilog.man.in
+++ b/driver/iverilog.man.in
@@ -150,6 +150,12 @@ parameter assignment is evaluated as a lossless expression, as is any
 expression containing an unsized constant number, and unsized constant
 numbers are not truncated to integer width.
 .TP 8
+.B -gstrict-parameter-declaration\fI|\fP-gno-strict-parameter-declaration
+The standards requires that parameters must be declared lexically
+before they are used.  Using \fB\-gno\-strict\-parameter\-declaration\fP
+will allow using a parameter before declaration, e.g., in a port
+declaration, with the parameter declared in the body of the module.
+.TP 8
 .B -gshared-loop-index\fI|\fP-gno-shared-loop-index
 Enable (default) or disable the exclusion of for-loop control variables
 from implicit event_expression lists. When enabled, if a for-loop control
diff --git a/driver/main.c b/driver/main.c
index 352ab9f45..c1de20333 100644
--- a/driver/main.c
+++ b/driver/main.c
@@ -134,6 +134,7 @@ const char*gen_strict_ca_eval = "no-strict-ca-eval";
 const char*gen_strict_expr_width = "no-strict-expr-width";
 const char*gen_shared_loop_index = "shared-loop-index";
 const char*gen_verilog_ams = "no-verilog-ams";
+const char*gen_strict_parameter_declaration = "strict-parameter-declaration";
 
 /* Boolean: true means use a default include dir, false means don't */
 int gen_std_include = 1;
@@ -815,6 +816,12 @@ static int process_generation(const char*name)
       else if (strcmp(name,"no-verilog-ams") == 0)
 	    gen_verilog_ams = "no-verilog-ams";
 
+      else if (strcmp(name,"strict-parameter-declaration") == 0)
+	    gen_strict_parameter_declaration = "strict-parameter-declaration";
+
+      else if (strcmp(name,"no-strict-parameter-declaration") == 0)
+	    gen_strict_parameter_declaration = "no-strict-parameter-declaration";
+
       else {
 	    fprintf(stderr, "Unknown/Unsupported Language generation "
 		    "%s\n\n", name);
@@ -837,7 +844,8 @@ static int process_generation(const char*name)
 		            "    io-range-error | no-io-range-error\n"
 		            "    strict-ca-eval | no-strict-ca-eval\n"
 		            "    strict-expr-width | no-strict-expr-width\n"
-		            "    shared-loop-index | no-shared-loop-index\n");
+		            "    shared-loop-index | no-shared-loop-index\n"
+		            "    strict-parameter-declaration | no-strict-parameter-declaration\n");
 
 	    return 1;
       }
@@ -1385,6 +1393,7 @@ int main(int argc, char **argv)
       fprintf(iconfig_file, "generation:%s\n", gen_strict_expr_width);
       fprintf(iconfig_file, "generation:%s\n", gen_shared_loop_index);
       fprintf(iconfig_file, "generation:%s\n", gen_verilog_ams);
+      fprintf(iconfig_file, "generation:%s\n", gen_strict_parameter_declaration);
       fprintf(iconfig_file, "generation:%s\n", gen_icarus);
       fprintf(iconfig_file, "warnings:%s\n", warning_flags);
       fprintf(iconfig_file, "ignore_missing_modules:%s\n", ignore_missing_modules ? "true" : "false");
diff --git a/main.cc b/main.cc
index 99c080e0a..7ed4c7c50 100644
--- a/main.cc
+++ b/main.cc
@@ -117,6 +117,7 @@ bool gn_strict_ca_eval_flag = false;
 bool gn_strict_expr_width_flag = false;
 bool gn_shared_loop_index_flag = true;
 bool gn_verilog_ams_flag = false;
+bool gn_strict_parameter_declaration = true;
 
 /*
  * For some generations we allow a system function to be called
@@ -386,6 +387,12 @@ static void process_generation_flag(const char*gen)
       } else if (strcmp(gen,"no-shared-loop-index") == 0) {
 	    gn_shared_loop_index_flag = false;
 
+      } else if (strcmp(gen,"strict-parameter-declaration") == 0) {
+	    gn_strict_parameter_declaration = true;
+
+      } else if (strcmp(gen,"no-strict-parameter-declaration") == 0) {
+	    gn_strict_parameter_declaration = false;
+
 	  } else {
       }
 }
diff --git a/symbol_search.cc b/symbol_search.cc
index be8580018..9c00920e7 100644
--- a/symbol_search.cc
+++ b/symbol_search.cc
@@ -189,7 +189,8 @@ bool symbol_search(const LineInfo*li, Design*des, NetScope*scope,
 		  }
 
 		  if (const NetExpr*par = scope->get_parameter(des, path_tail.name, res->type)) {
-			if (prefix_scope || (scope->get_parameter_lexical_pos(path_tail.name) <= lexical_pos)) {
+			if (!gn_strict_parameter_declaration || prefix_scope
+			    || (scope->get_parameter_lexical_pos(path_tail.name) <= lexical_pos)) {
 			      path.push_back(path_tail);
 			      res->scope = scope;
 			      res->par_val = par;

From 1f8991e382e6a508958537090ac4ff5f5190b9c5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Stephan=20I=2E=20B=C3=B6ttcher?= <sib64@psjt.org>
Date: Tue, 17 Mar 2026 20:32:06 +0100
Subject: [PATCH 02/11] Emit a warning with -gno-strict-parameter-declaration

When a parameter is used before declaration, a warning is printed,
unless `-Wno-anachronisms`.
---
 Documentation/usage/command_line_flags.rst | 5 ++---
 compiler.h                                 | 5 +++--
 driver/iverilog.man.in                     | 4 ++--
 symbol_search.cc                           | 6 ++++++
 4 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/Documentation/usage/command_line_flags.rst b/Documentation/usage/command_line_flags.rst
index 751818d42..155d4ace9 100644
--- a/Documentation/usage/command_line_flags.rst
+++ b/Documentation/usage/command_line_flags.rst
@@ -135,9 +135,8 @@ These flags affect the general behavior of the compiler.
 
     The standards requires that parameters must be declared lexically
     before they are used.  Using -gno-strict-parameter-declaration
-    will allow using a parameter before declaration, e.g., in a port
-    declaration, with the parameter declared in the body of the
-    module.
+    will allow using a parameter before declaration, with a
+    warning. The warning can be suppressed with -Wno-anachronisms.
 
   * shared-loop-index/no-shared-loop-index
 
diff --git a/compiler.h b/compiler.h
index 9548a85d0..eafc8aac9 100644
--- a/compiler.h
+++ b/compiler.h
@@ -211,8 +211,9 @@ extern bool gn_strict_expr_width_flag;
 extern bool gn_shared_loop_index_flag;
 
 /* If this flag is true (default), then parameters must be declared before
-   use.
-   use `-gno-strict-parameter-declaration` for pre version 13 behaviour.
+   use. `-gno-strict-parameter-declaration` allows to use parameters before
+   declaration, as prior to version 13.
+   A warning is emited with -Wanachronisms (default).
  */
 extern bool gn_strict_parameter_declaration;
 
diff --git a/driver/iverilog.man.in b/driver/iverilog.man.in
index 4f7bb40f2..1c0b9e44c 100644
--- a/driver/iverilog.man.in
+++ b/driver/iverilog.man.in
@@ -153,8 +153,8 @@ numbers are not truncated to integer width.
 .B -gstrict-parameter-declaration\fI|\fP-gno-strict-parameter-declaration
 The standards requires that parameters must be declared lexically
 before they are used.  Using \fB\-gno\-strict\-parameter\-declaration\fP
-will allow using a parameter before declaration, e.g., in a port
-declaration, with the parameter declared in the body of the module.
+will allow using a parameter before declaration, with a warning.
+The warning can be suppressed with -Wno-anachronisms.
 .TP 8
 .B -gshared-loop-index\fI|\fP-gno-shared-loop-index
 Enable (default) or disable the exclusion of for-loop control variables
diff --git a/symbol_search.cc b/symbol_search.cc
index 9c00920e7..25f8483e3 100644
--- a/symbol_search.cc
+++ b/symbol_search.cc
@@ -195,6 +195,12 @@ bool symbol_search(const LineInfo*li, Design*des, NetScope*scope,
 			      res->scope = scope;
 			      res->par_val = par;
 			      res->path_head = path;
+			      if (warn_anachronisms && !prefix_scope
+				  && !(scope->get_parameter_lexical_pos(path_tail.name) <= lexical_pos)) {
+				      cerr << li->get_fileline()
+					   << ": warning: parameter `" << path_tail.name
+					   << "` used before declaration." << endl;
+			      }
 			      return true;
 			} else if (!res->decl_after_use) {
 			      res->decl_after_use = par;

From 42f7d3a922ec9f60ec6d23e961a8f36ac4ab3196 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Stephan=20I=2E=20B=C3=B6ttcher?=
 <boettcher@physik.uni-kiel.de>
Date: Wed, 18 Mar 2026 12:08:39 +0100
Subject: [PATCH 03/11] strict_param_decl: dedup use after decl test

---
 symbol_search.cc | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/symbol_search.cc b/symbol_search.cc
index 25f8483e3..cbe307ff9 100644
--- a/symbol_search.cc
+++ b/symbol_search.cc
@@ -189,14 +189,14 @@ bool symbol_search(const LineInfo*li, Design*des, NetScope*scope,
 		  }
 
 		  if (const NetExpr*par = scope->get_parameter(des, path_tail.name, res->type)) {
-			if (!gn_strict_parameter_declaration || prefix_scope
-			    || (scope->get_parameter_lexical_pos(path_tail.name) <= lexical_pos)) {
+			bool decl_after_use = !prefix_scope
+			      && !(scope->get_parameter_lexical_pos(path_tail.name) <= lexical_pos);
+			if (!gn_strict_parameter_declaration || !decl_after_use) {
 			      path.push_back(path_tail);
 			      res->scope = scope;
 			      res->par_val = par;
 			      res->path_head = path;
-			      if (warn_anachronisms && !prefix_scope
-				  && !(scope->get_parameter_lexical_pos(path_tail.name) <= lexical_pos)) {
+			      if (warn_anachronisms && decl_after_use) {
 				      cerr << li->get_fileline()
 					   << ": warning: parameter `" << path_tail.name
 					   << "` used before declaration." << endl;

From 54f17a2cb146294f235b87c53bb4746855b56ffa Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Stephan=20I=2E=20B=C3=B6ttcher?=
 <boettcher@physik.uni-kiel.de>
Date: Wed, 18 Mar 2026 12:46:42 +0100
Subject: [PATCH 04/11] Add warning class -Wno-declaration-after-use

With `-ggno-strict-parameter-declaration` a warning is issued for
parameter use before declaration.  This warning suppressed with
the new class `-Wno-declaration-after-use`, instead of `-Wno-anachronisms`.
---
 Documentation/usage/command_line_flags.rst |  8 +++++++-
 compiler.h                                 |  3 +++
 driver/iverilog.man.in                     |  7 ++++++-
 driver/main.c                              | 12 +++++++++++-
 main.cc                                    |  4 ++++
 symbol_search.cc                           |  2 +-
 6 files changed, 32 insertions(+), 4 deletions(-)

diff --git a/Documentation/usage/command_line_flags.rst b/Documentation/usage/command_line_flags.rst
index 155d4ace9..68c217a6d 100644
--- a/Documentation/usage/command_line_flags.rst
+++ b/Documentation/usage/command_line_flags.rst
@@ -136,7 +136,7 @@ These flags affect the general behavior of the compiler.
     The standards requires that parameters must be declared lexically
     before they are used.  Using -gno-strict-parameter-declaration
     will allow using a parameter before declaration, with a
-    warning. The warning can be suppressed with -Wno-anachronisms.
+    warning. The warning can be suppressed with -Wno-declaration-after-use.
 
   * shared-loop-index/no-shared-loop-index
 
@@ -267,6 +267,7 @@ These flags affect the general behavior of the compiler.
       -Wanachronisms
       -Wimplicit
       -Wimplicit-dimensions
+      -Wdeclaration-after-use
       -Wmacro-replacement
       -Wportbind
       -Wselect-range
@@ -295,6 +296,11 @@ These flags affect the general behavior of the compiler.
     This flag is supported in release 10.1 or master branch snapshots after
     2016-02-06.
 
+  * declaration-after-use
+
+    With -gno-strict-parameter-declaration, issue a warning when a
+    parameter is declared after it is used.
+
   * macro-redefinition
 
     This enables warnings when a macro is redefined, even if the macro text
diff --git a/compiler.h b/compiler.h
index eafc8aac9..0b5feca91 100644
--- a/compiler.h
+++ b/compiler.h
@@ -104,6 +104,9 @@ extern bool warn_sens_entire_arr;
 /* Warn about level-appropriate anachronisms. */
 extern bool warn_anachronisms;
 
+/* Warn about declaration after use (unless flaged as errors). */
+extern bool warn_decl_after_use;
+
 /* Warn about nets that are references but not driven. */
 extern bool warn_floating_nets;
 
diff --git a/driver/iverilog.man.in b/driver/iverilog.man.in
index 1c0b9e44c..19ac06361 100644
--- a/driver/iverilog.man.in
+++ b/driver/iverilog.man.in
@@ -154,7 +154,7 @@ numbers are not truncated to integer width.
 The standards requires that parameters must be declared lexically
 before they are used.  Using \fB\-gno\-strict\-parameter\-declaration\fP
 will allow using a parameter before declaration, with a warning.
-The warning can be suppressed with -Wno-anachronisms.
+The warning can be suppressed with -Wno-declaration-after-use.
 .TP 8
 .B -gshared-loop-index\fI|\fP-gno-shared-loop-index
 Enable (default) or disable the exclusion of for-loop control variables
@@ -373,6 +373,11 @@ This enables warnings for creation of implicit declarations. For
 example, if a scalar wire X is used but not declared in the Verilog
 source, this will print a warning at its first use.
 
+.TP 8
+.B declaration-after-use
+This enables warnings for declarations after use, when
+those are not flagged as errors (default).  
+
 .TP 8
 .B macro-redefinition\fI | \fPmacro-replacement
 This enables preprocessor warnings when a macro is being redefined.
diff --git a/driver/main.c b/driver/main.c
index c1de20333..803e457c6 100644
--- a/driver/main.c
+++ b/driver/main.c
@@ -143,7 +143,7 @@ int gen_std_include = 1;
    of the include list. */
 int gen_relative_include = 0;
 
-char warning_flags[17] = "n";
+char warning_flags[18] = "nu";
 
 int separate_compilation_flag = 0;
 
@@ -528,6 +528,7 @@ static void process_warning_switch(const char*name)
 {
       if (strcmp(name,"all") == 0) {
 	    process_warning_switch("anachronisms");
+	    process_warning_switch("declaration-after-use");
 	    process_warning_switch("implicit");
 	    process_warning_switch("implicit-dimensions");
 	    process_warning_switch("macro-replacement");
@@ -538,6 +539,9 @@ static void process_warning_switch(const char*name)
       } else if (strcmp(name,"anachronisms") == 0) {
 	    if (! strchr(warning_flags, 'n'))
 		  strcat(warning_flags, "n");
+      } else if (strcmp(name,"declaration-after-use") == 0) {
+	    if (! strchr(warning_flags, 'u'))
+		  strcat(warning_flags, "u");
       } else if (strcmp(name,"floating-nets") == 0) {
 	    if (! strchr(warning_flags, 'f'))
 		  strcat(warning_flags, "f");
@@ -579,6 +583,12 @@ static void process_warning_switch(const char*name)
 		  cp[0] = cp[1];
 		  cp += 1;
 	    }
+      } else if (strcmp(name,"no-declaration-after-use") == 0) {
+	    char*cp = strchr(warning_flags, 'u');
+	    if (cp) while (*cp) {
+		  cp[0] = cp[1];
+		  cp += 1;
+	    }
       } else if (strcmp(name,"no-floating-nets") == 0) {
 	    char*cp = strchr(warning_flags, 'f');
 	    if (cp) while (*cp) {
diff --git a/main.cc b/main.cc
index 7ed4c7c50..8e71ef7b3 100644
--- a/main.cc
+++ b/main.cc
@@ -173,6 +173,7 @@ bool warn_ob_select = false;
 bool warn_sens_entire_vec = false;
 bool warn_sens_entire_arr = false;
 bool warn_anachronisms = false;
+bool warn_decl_after_use = false;
 bool warn_floating_nets = false;
 
 /*
@@ -767,6 +768,9 @@ static void read_iconfig_file(const char*ipath)
 		      case 'n':
 			warn_anachronisms = true;
 			break;
+		      case 'u':
+			warn_decl_after_use = true;
+			break;
 		      default:
 			break;
 		  }
diff --git a/symbol_search.cc b/symbol_search.cc
index cbe307ff9..11922e684 100644
--- a/symbol_search.cc
+++ b/symbol_search.cc
@@ -196,7 +196,7 @@ bool symbol_search(const LineInfo*li, Design*des, NetScope*scope,
 			      res->scope = scope;
 			      res->par_val = par;
 			      res->path_head = path;
-			      if (warn_anachronisms && decl_after_use) {
+			      if (warn_decl_after_use && decl_after_use) {
 				      cerr << li->get_fileline()
 					   << ": warning: parameter `" << path_tail.name
 					   << "` used before declaration." << endl;

From 7d438b66c8c8e1f45823831fb4ba1acb8e486fae Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Stephan=20I=2E=20B=C3=B6ttcher?=
 <boettcher@physik.uni-kiel.de>
Date: Wed, 18 Mar 2026 17:59:33 +0100
Subject: [PATCH 05/11] add option -gno-strict-declaration

The new option allows parameter, net and events to be used before
declaration.  With variants

 -gno-strict-net-declaration for nets and events,
 -gno-strict-parameter-declaration for parameters.
---
 Documentation/usage/command_line_flags.rst | 14 ++++++++++----
 compiler.h                                 | 11 +++++++++--
 driver/iverilog.man.in                     | 11 ++++++++---
 driver/main.c                              | 19 ++++++++++++++++++-
 main.cc                                    |  7 +++++++
 symbol_search.cc                           | 16 ++++++++++++++--
 6 files changed, 66 insertions(+), 12 deletions(-)

diff --git a/Documentation/usage/command_line_flags.rst b/Documentation/usage/command_line_flags.rst
index 68c217a6d..73a2df9e1 100644
--- a/Documentation/usage/command_line_flags.rst
+++ b/Documentation/usage/command_line_flags.rst
@@ -131,12 +131,18 @@ These flags affect the general behavior of the compiler.
     containing an unsized constant number, and unsized constant numbers are
     not truncated to integer width.
 
+  * strict-declaration/no-strict-declaration
+
+  * strict-net-declaration/no-net-strict-declaration
+
   * strict-parameter-declaration/no-strict-parameter-declaration
 
-    The standards requires that parameters must be declared lexically
-    before they are used.  Using -gno-strict-parameter-declaration
-    will allow using a parameter before declaration, with a
-    warning. The warning can be suppressed with -Wno-declaration-after-use.
+    The standards requires that nets and parameters must be declared
+    lexically before they are used.  Using -gno-strict-declaration
+    will allow using a net or parameter before declaration, with a
+    warning. The warning can be suppressed with
+    -Wno-declaration-after-use.  The option can be applied for nets
+    and parameters separately.
 
   * shared-loop-index/no-shared-loop-index
 
diff --git a/compiler.h b/compiler.h
index 0b5feca91..d72eb44c3 100644
--- a/compiler.h
+++ b/compiler.h
@@ -214,12 +214,19 @@ extern bool gn_strict_expr_width_flag;
 extern bool gn_shared_loop_index_flag;
 
 /* If this flag is true (default), then parameters must be declared before
-   use. `-gno-strict-parameter-declaration` allows to use parameters before
+   use. `-gno-strict[-parameter]-declaration` allows to use parameters before
    declaration, as prior to version 13.
-   A warning is emited with -Wanachronisms (default).
+   A warning is emited with -Wdeclaration-after-use (default).
  */
 extern bool gn_strict_parameter_declaration;
 
+/* If this flag is true (default), then nets must be declared before
+   use. `-gno-strict[-net]-declaration` allows to use nets before
+   declaration, as prior to version 13.
+   A warning is emited with -Wdeclaration-after-use (default).
+ */
+extern bool gn_strict_net_declaration;
+
 static inline bool gn_system_verilog(void)
 {
       if (generation_flag >= GN_VER2005_SV)
diff --git a/driver/iverilog.man.in b/driver/iverilog.man.in
index 19ac06361..040bca7b3 100644
--- a/driver/iverilog.man.in
+++ b/driver/iverilog.man.in
@@ -150,11 +150,16 @@ parameter assignment is evaluated as a lossless expression, as is any
 expression containing an unsized constant number, and unsized constant
 numbers are not truncated to integer width.
 .TP 8
+.B -gstrict-declaration\fI|\fP-gno-strict-declaration
+.TP 8
+.B -gstrict-net-declaration\fI|\fP-gno-strict-net-declaration
+.TP 8
 .B -gstrict-parameter-declaration\fI|\fP-gno-strict-parameter-declaration
-The standards requires that parameters must be declared lexically
-before they are used.  Using \fB\-gno\-strict\-parameter\-declaration\fP
+The standards requires that nets and parameters must be declared lexically
+before they are used.  Using \fB\-gno\-strict\-declaration\fP
 will allow using a parameter before declaration, with a warning.
-The warning can be suppressed with -Wno-declaration-after-use.
+The warning can be suppressed with -Wno-declaration-after-use. The
+option can be applied for nets and parameters separately. 
 .TP 8
 .B -gshared-loop-index\fI|\fP-gno-shared-loop-index
 Enable (default) or disable the exclusion of for-loop control variables
diff --git a/driver/main.c b/driver/main.c
index 803e457c6..0e16bf672 100644
--- a/driver/main.c
+++ b/driver/main.c
@@ -134,6 +134,7 @@ const char*gen_strict_ca_eval = "no-strict-ca-eval";
 const char*gen_strict_expr_width = "no-strict-expr-width";
 const char*gen_shared_loop_index = "shared-loop-index";
 const char*gen_verilog_ams = "no-verilog-ams";
+const char*gen_strict_net_declaration = "strict-net-declaration";
 const char*gen_strict_parameter_declaration = "strict-parameter-declaration";
 
 /* Boolean: true means use a default include dir, false means don't */
@@ -826,6 +827,20 @@ static int process_generation(const char*name)
       else if (strcmp(name,"no-verilog-ams") == 0)
 	    gen_verilog_ams = "no-verilog-ams";
 
+      else if (strcmp(name,"strict-declaration") == 0) {
+	    gen_strict_net_declaration = "strict-net-declaration";
+	    gen_strict_parameter_declaration = "strict-parameter-declaration";
+      }
+      else if (strcmp(name,"no-strict-declaration") == 0) {
+	    gen_strict_net_declaration = "no-strict-net-declaration";
+	    gen_strict_parameter_declaration = "no-strict-parameter-declaration";
+      }
+      else if (strcmp(name,"strict-net-declaration") == 0)
+	    gen_strict_net_declaration = "strict-net-declaration";
+
+      else if (strcmp(name,"no-strict-net-declaration") == 0)
+	    gen_strict_net_declaration = "no-strict-net-declaration";
+
       else if (strcmp(name,"strict-parameter-declaration") == 0)
 	    gen_strict_parameter_declaration = "strict-parameter-declaration";
 
@@ -855,7 +870,8 @@ static int process_generation(const char*name)
 		            "    strict-ca-eval | no-strict-ca-eval\n"
 		            "    strict-expr-width | no-strict-expr-width\n"
 		            "    shared-loop-index | no-shared-loop-index\n"
-		            "    strict-parameter-declaration | no-strict-parameter-declaration\n");
+		            "    strict-declaration | no-strict-declaration\n"
+		            "    [no-]strict-[net|parameter]-declaration\n");
 
 	    return 1;
       }
@@ -1403,6 +1419,7 @@ int main(int argc, char **argv)
       fprintf(iconfig_file, "generation:%s\n", gen_strict_expr_width);
       fprintf(iconfig_file, "generation:%s\n", gen_shared_loop_index);
       fprintf(iconfig_file, "generation:%s\n", gen_verilog_ams);
+      fprintf(iconfig_file, "generation:%s\n", gen_strict_net_declaration);
       fprintf(iconfig_file, "generation:%s\n", gen_strict_parameter_declaration);
       fprintf(iconfig_file, "generation:%s\n", gen_icarus);
       fprintf(iconfig_file, "warnings:%s\n", warning_flags);
diff --git a/main.cc b/main.cc
index 8e71ef7b3..82f7bec33 100644
--- a/main.cc
+++ b/main.cc
@@ -118,6 +118,7 @@ bool gn_strict_expr_width_flag = false;
 bool gn_shared_loop_index_flag = true;
 bool gn_verilog_ams_flag = false;
 bool gn_strict_parameter_declaration = true;
+bool gn_strict_net_declaration = true;
 
 /*
  * For some generations we allow a system function to be called
@@ -394,6 +395,12 @@ static void process_generation_flag(const char*gen)
       } else if (strcmp(gen,"no-strict-parameter-declaration") == 0) {
 	    gn_strict_parameter_declaration = false;
 
+      } else if (strcmp(gen,"strict-net-declaration") == 0) {
+	    gn_strict_net_declaration = true;
+
+      } else if (strcmp(gen,"no-strict-net-declaration") == 0) {
+	    gn_strict_net_declaration = false;
+
 	  } else {
       }
 }
diff --git a/symbol_search.cc b/symbol_search.cc
index 11922e684..8e5d8b40a 100644
--- a/symbol_search.cc
+++ b/symbol_search.cc
@@ -164,12 +164,18 @@ bool symbol_search(const LineInfo*li, Design*des, NetScope*scope,
 		  }
 
 		  if (NetNet*net = scope->find_signal(path_tail.name)) {
-			if (prefix_scope || (net->lexical_pos() <= lexical_pos)) {
+			bool decl_after_use = !prefix_scope && !(net->lexical_pos() <= lexical_pos);
+			if (!gn_strict_net_declaration || !decl_after_use) {
 			      path.push_back(path_tail);
 			      res->scope = scope;
 			      res->net = net;
 			      res->type = net->net_type();
 			      res->path_head = path;
+			      if (warn_decl_after_use && decl_after_use) {
+				    cerr << li->get_fileline()
+					 << ": warning: net `" << path_tail.name
+					 << "` used before declaration." << endl;
+			      }
 			      return true;
 			} else if (!res->decl_after_use) {
 			      res->decl_after_use = net;
@@ -177,11 +183,17 @@ bool symbol_search(const LineInfo*li, Design*des, NetScope*scope,
 		  }
 
 		  if (NetEvent*eve = scope->find_event(path_tail.name)) {
-			if (prefix_scope || (eve->lexical_pos() <= lexical_pos)) {
+			bool decl_after_use = !prefix_scope && !(eve->lexical_pos() <= lexical_pos);
+			if (!gn_strict_net_declaration || !decl_after_use) {
 			      path.push_back(path_tail);
 			      res->scope = scope;
 			      res->eve = eve;
 			      res->path_head = path;
+			      if (warn_decl_after_use && decl_after_use) {
+				    cerr << li->get_fileline()
+					 << ": warning: event `" << path_tail.name
+					 << "` used before declaration." << endl;
+			      }
 			      return true;
 			} else if (!res->decl_after_use) {
 			      res->decl_after_use = eve;

From 475f098cab488fb7d9ba953344a6da51988f516a Mon Sep 17 00:00:00 2001
From: Martin Whitaker <icarus@martin-whitaker.me.uk>
Date: Sat, 21 Mar 2026 17:20:27 +0000
Subject: [PATCH 06/11] Minor grammar and white space fixes in documentation.

---
 Documentation/usage/command_line_flags.rst | 2 +-
 driver/iverilog.man.in                     | 6 +++---
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/Documentation/usage/command_line_flags.rst b/Documentation/usage/command_line_flags.rst
index 73a2df9e1..76d009bb5 100644
--- a/Documentation/usage/command_line_flags.rst
+++ b/Documentation/usage/command_line_flags.rst
@@ -137,7 +137,7 @@ These flags affect the general behavior of the compiler.
 
   * strict-parameter-declaration/no-strict-parameter-declaration
 
-    The standards requires that nets and parameters must be declared
+    The standards require that nets and parameters must be declared
     lexically before they are used.  Using -gno-strict-declaration
     will allow using a net or parameter before declaration, with a
     warning. The warning can be suppressed with
diff --git a/driver/iverilog.man.in b/driver/iverilog.man.in
index 040bca7b3..77a71d653 100644
--- a/driver/iverilog.man.in
+++ b/driver/iverilog.man.in
@@ -124,7 +124,7 @@ to disable extended types if compiling code that clashes with the few
 new keywords used to implement the type system.
 .TP 8
 .B -gio-range-error\fI|\fP-gno-io-range-error
-The standards requires that a vectored port have matching ranges for its
+The standards require that a vectored port have matching ranges for its
 port declaration as well as any net/register declaration. It was common
 practice in the past to only specify the range for the net/register
 declaration and some tools still allow this. By default any mismatch is
@@ -159,7 +159,7 @@ The standards requires that nets and parameters must be declared lexically
 before they are used.  Using \fB\-gno\-strict\-declaration\fP
 will allow using a parameter before declaration, with a warning.
 The warning can be suppressed with -Wno-declaration-after-use. The
-option can be applied for nets and parameters separately. 
+option can be applied for nets and parameters separately.
 .TP 8
 .B -gshared-loop-index\fI|\fP-gno-shared-loop-index
 Enable (default) or disable the exclusion of for-loop control variables
@@ -381,7 +381,7 @@ source, this will print a warning at its first use.
 .TP 8
 .B declaration-after-use
 This enables warnings for declarations after use, when
-those are not flagged as errors (default).  
+those are not flagged as errors (default).
 
 .TP 8
 .B macro-redefinition\fI | \fPmacro-replacement

From 29e128ed9434620b4f7d50979918667c705b0049 Mon Sep 17 00:00:00 2001
From: Martin Whitaker <icarus@martin-whitaker.me.uk>
Date: Sat, 21 Mar 2026 18:14:01 +0000
Subject: [PATCH 07/11] Only warn about declaration after use once for each
 data object.

---
 net_scope.cc     | 10 +++++++++-
 netlist.h        |  1 +
 symbol_search.cc | 14 ++++++++++----
 3 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/net_scope.cc b/net_scope.cc
index 1efc464e6..d90b49b82 100644
--- a/net_scope.cc
+++ b/net_scope.cc
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000-2025 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 2000-2026 Stephen Williams (steve@icarus.com)
  * Copyright (c) 2016 CERN Michele Castellana (michele.castellana@cern.ch)
  *
  *    This source code is free software; you can redistribute it
@@ -462,6 +462,14 @@ unsigned NetScope::get_parameter_lexical_pos(perm_string key) const
       return 0;
 }
 
+void NetScope::set_parameter_lexical_pos(perm_string key, unsigned lexical_pos)
+{
+      map<perm_string,param_expr_t>::iterator idx;
+
+      idx = parameters.find(key);
+      if (idx != parameters.end()) idx->second.lexical_pos = lexical_pos;
+}
+
 void NetScope::print_type(ostream&stream) const
 {
       switch (type_) {
diff --git a/netlist.h b/netlist.h
index 57b69959c..d1eb80764 100644
--- a/netlist.h
+++ b/netlist.h
@@ -1274,6 +1274,7 @@ class NetScope : public Definitions, public Attrib {
       LineInfo get_parameter_line_info(perm_string name) const;
 
       unsigned get_parameter_lexical_pos(perm_string name) const;
+      void set_parameter_lexical_pos(perm_string name, unsigned lexical_pos);
 
 	/* Module instance arrays are collected here for access during
 	   the multiple elaboration passes. */
diff --git a/symbol_search.cc b/symbol_search.cc
index 8e5d8b40a..91f34c22d 100644
--- a/symbol_search.cc
+++ b/symbol_search.cc
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003-2024 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 2003-2026 Stephen Williams (steve@icarus.com)
  * Copyright CERN 2012 / Stephen Williams (steve@icarus.com)
  *
  *    This source code is free software; you can redistribute it
@@ -175,6 +175,8 @@ bool symbol_search(const LineInfo*li, Design*des, NetScope*scope,
 				    cerr << li->get_fileline()
 					 << ": warning: net `" << path_tail.name
 					 << "` used before declaration." << endl;
+				    // suppress further warnings for this net
+				    net->lexical_pos(lexical_pos);
 			      }
 			      return true;
 			} else if (!res->decl_after_use) {
@@ -193,6 +195,8 @@ bool symbol_search(const LineInfo*li, Design*des, NetScope*scope,
 				    cerr << li->get_fileline()
 					 << ": warning: event `" << path_tail.name
 					 << "` used before declaration." << endl;
+				    // suppress further warnings for this event
+				    eve->lexical_pos(lexical_pos);
 			      }
 			      return true;
 			} else if (!res->decl_after_use) {
@@ -209,9 +213,11 @@ bool symbol_search(const LineInfo*li, Design*des, NetScope*scope,
 			      res->par_val = par;
 			      res->path_head = path;
 			      if (warn_decl_after_use && decl_after_use) {
-				      cerr << li->get_fileline()
-					   << ": warning: parameter `" << path_tail.name
-					   << "` used before declaration." << endl;
+				    cerr << li->get_fileline()
+					 << ": warning: parameter `" << path_tail.name
+					 << "` used before declaration." << endl;
+				    // suppress further warnings for this parameter
+				    scope->set_parameter_lexical_pos(path_tail.name, lexical_pos);
 			      }
 			      return true;
 			} else if (!res->decl_after_use) {

From dc0d162fa9ad09d7942ef2f023f5fd8191178b07 Mon Sep 17 00:00:00 2001
From: Martin Whitaker <icarus@martin-whitaker.me.uk>
Date: Sat, 21 Mar 2026 18:26:53 +0000
Subject: [PATCH 08/11] Report declaration position when warning about
 declaration after use.

---
 symbol_search.cc | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/symbol_search.cc b/symbol_search.cc
index 91f34c22d..1c51cccb6 100644
--- a/symbol_search.cc
+++ b/symbol_search.cc
@@ -175,6 +175,8 @@ bool symbol_search(const LineInfo*li, Design*des, NetScope*scope,
 				    cerr << li->get_fileline()
 					 << ": warning: net `" << path_tail.name
 					 << "` used before declaration." << endl;
+				    cerr << net->get_fileline()
+					 << ":        : the net is declared here." << endl;
 				    // suppress further warnings for this net
 				    net->lexical_pos(lexical_pos);
 			      }
@@ -195,6 +197,8 @@ bool symbol_search(const LineInfo*li, Design*des, NetScope*scope,
 				    cerr << li->get_fileline()
 					 << ": warning: event `" << path_tail.name
 					 << "` used before declaration." << endl;
+				    cerr << eve->get_fileline()
+					 << ":        : the event is declared here." << endl;
 				    // suppress further warnings for this event
 				    eve->lexical_pos(lexical_pos);
 			      }
@@ -216,6 +220,8 @@ bool symbol_search(const LineInfo*li, Design*des, NetScope*scope,
 				    cerr << li->get_fileline()
 					 << ": warning: parameter `" << path_tail.name
 					 << "` used before declaration." << endl;
+				    cerr << par->get_fileline()
+					 << ":        : the parameter is declared here." << endl;
 				    // suppress further warnings for this parameter
 				    scope->set_parameter_lexical_pos(path_tail.name, lexical_pos);
 			      }

From 4c315b32d47b48f5a6bd0f51ec51a4c495793681 Mon Sep 17 00:00:00 2001
From: Martin Whitaker <icarus@martin-whitaker.me.uk>
Date: Sat, 21 Mar 2026 20:03:02 +0000
Subject: [PATCH 09/11] Change strict-net-declaration to
 strict-net-var-declaration.

Internally the compiler uses 'net' for both nets and variables, but
we should make it clear to the user that this option applies to both.
---
 Documentation/usage/command_line_flags.rst | 13 ++++++-------
 compiler.h                                 | 10 +++++-----
 driver/iverilog.man.in                     | 12 ++++++------
 driver/main.c                              | 18 +++++++++---------
 main.cc                                    | 10 +++++-----
 symbol_search.cc                           |  8 ++++----
 6 files changed, 35 insertions(+), 36 deletions(-)

diff --git a/Documentation/usage/command_line_flags.rst b/Documentation/usage/command_line_flags.rst
index 76d009bb5..38255bf34 100644
--- a/Documentation/usage/command_line_flags.rst
+++ b/Documentation/usage/command_line_flags.rst
@@ -133,16 +133,15 @@ These flags affect the general behavior of the compiler.
 
   * strict-declaration/no-strict-declaration
 
-  * strict-net-declaration/no-net-strict-declaration
+  * strict-net-var-declaration/no-strict-net-var-declaration
 
   * strict-parameter-declaration/no-strict-parameter-declaration
 
-    The standards require that nets and parameters must be declared
-    lexically before they are used.  Using -gno-strict-declaration
-    will allow using a net or parameter before declaration, with a
-    warning. The warning can be suppressed with
-    -Wno-declaration-after-use.  The option can be applied for nets
-    and parameters separately.
+    The standards require that nets, variables, and parameters must be
+    declared lexically before they are used.  Using -gno-strict-declaration
+    will allow using a data object before declaration, with a warning. The
+    warning can be suppressed with -Wno-declaration-after-use.  The option
+    can be applied for nets and variables and for parameters separately.
 
   * shared-loop-index/no-shared-loop-index
 
diff --git a/compiler.h b/compiler.h
index d72eb44c3..01893d18b 100644
--- a/compiler.h
+++ b/compiler.h
@@ -1,7 +1,7 @@
 #ifndef IVL_compiler_H
 #define IVL_compiler_H
 /*
- * Copyright (c) 1999-2021 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 1999-2026 Stephen Williams (steve@icarus.com)
  *
  *    This source code is free software; you can redistribute it
  *    and/or modify it in source code form under the terms of the GNU
@@ -220,12 +220,12 @@ extern bool gn_shared_loop_index_flag;
  */
 extern bool gn_strict_parameter_declaration;
 
-/* If this flag is true (default), then nets must be declared before
-   use. `-gno-strict[-net]-declaration` allows to use nets before
-   declaration, as prior to version 13.
+/* If this flag is true (default), then nets and variablesmust be declared
+   before use. `-gno-strict[-net-var]-declaration` allows to use nets and
+   variables before declaration, as prior to version 13.
    A warning is emited with -Wdeclaration-after-use (default).
  */
-extern bool gn_strict_net_declaration;
+extern bool gn_strict_net_var_declaration;
 
 static inline bool gn_system_verilog(void)
 {
diff --git a/driver/iverilog.man.in b/driver/iverilog.man.in
index 77a71d653..21dbf72dc 100644
--- a/driver/iverilog.man.in
+++ b/driver/iverilog.man.in
@@ -152,14 +152,14 @@ numbers are not truncated to integer width.
 .TP 8
 .B -gstrict-declaration\fI|\fP-gno-strict-declaration
 .TP 8
-.B -gstrict-net-declaration\fI|\fP-gno-strict-net-declaration
+.B -gstrict-net-var-declaration\fI|\fP-gno-strict-net-var-declaration
 .TP 8
 .B -gstrict-parameter-declaration\fI|\fP-gno-strict-parameter-declaration
-The standards requires that nets and parameters must be declared lexically
-before they are used.  Using \fB\-gno\-strict\-declaration\fP
-will allow using a parameter before declaration, with a warning.
-The warning can be suppressed with -Wno-declaration-after-use. The
-option can be applied for nets and parameters separately.
+The standards require that nets, variables, and parameters are declared
+lexically before they are used.  Using \fB\-gno\-strict\-declaration\fP
+will allow using a data object before declaration, with a warning. The
+warning can be suppressed with -Wno-declaration-after-use. The option
+can be applied for nets and variables and for parameters separately.
 .TP 8
 .B -gshared-loop-index\fI|\fP-gno-shared-loop-index
 Enable (default) or disable the exclusion of for-loop control variables
diff --git a/driver/main.c b/driver/main.c
index 0e16bf672..a1d22b0ea 100644
--- a/driver/main.c
+++ b/driver/main.c
@@ -134,7 +134,7 @@ const char*gen_strict_ca_eval = "no-strict-ca-eval";
 const char*gen_strict_expr_width = "no-strict-expr-width";
 const char*gen_shared_loop_index = "shared-loop-index";
 const char*gen_verilog_ams = "no-verilog-ams";
-const char*gen_strict_net_declaration = "strict-net-declaration";
+const char*gen_strict_net_var_declaration = "strict-net-var-declaration";
 const char*gen_strict_parameter_declaration = "strict-parameter-declaration";
 
 /* Boolean: true means use a default include dir, false means don't */
@@ -828,18 +828,18 @@ static int process_generation(const char*name)
 	    gen_verilog_ams = "no-verilog-ams";
 
       else if (strcmp(name,"strict-declaration") == 0) {
-	    gen_strict_net_declaration = "strict-net-declaration";
+	    gen_strict_net_var_declaration = "strict-net-var-declaration";
 	    gen_strict_parameter_declaration = "strict-parameter-declaration";
       }
       else if (strcmp(name,"no-strict-declaration") == 0) {
-	    gen_strict_net_declaration = "no-strict-net-declaration";
+	    gen_strict_net_var_declaration = "no-strict-net-var-declaration";
 	    gen_strict_parameter_declaration = "no-strict-parameter-declaration";
       }
-      else if (strcmp(name,"strict-net-declaration") == 0)
-	    gen_strict_net_declaration = "strict-net-declaration";
+      else if (strcmp(name,"strict-net-var-declaration") == 0)
+	    gen_strict_net_var_declaration = "strict-net-var-declaration";
 
-      else if (strcmp(name,"no-strict-net-declaration") == 0)
-	    gen_strict_net_declaration = "no-strict-net-declaration";
+      else if (strcmp(name,"no-strict-net-var-declaration") == 0)
+	    gen_strict_net_var_declaration = "no-strict-net-var-declaration";
 
       else if (strcmp(name,"strict-parameter-declaration") == 0)
 	    gen_strict_parameter_declaration = "strict-parameter-declaration";
@@ -871,7 +871,7 @@ static int process_generation(const char*name)
 		            "    strict-expr-width | no-strict-expr-width\n"
 		            "    shared-loop-index | no-shared-loop-index\n"
 		            "    strict-declaration | no-strict-declaration\n"
-		            "    [no-]strict-[net|parameter]-declaration\n");
+		            "    [no-]strict-[net-var|parameter]-declaration\n");
 
 	    return 1;
       }
@@ -1419,7 +1419,7 @@ int main(int argc, char **argv)
       fprintf(iconfig_file, "generation:%s\n", gen_strict_expr_width);
       fprintf(iconfig_file, "generation:%s\n", gen_shared_loop_index);
       fprintf(iconfig_file, "generation:%s\n", gen_verilog_ams);
-      fprintf(iconfig_file, "generation:%s\n", gen_strict_net_declaration);
+      fprintf(iconfig_file, "generation:%s\n", gen_strict_net_var_declaration);
       fprintf(iconfig_file, "generation:%s\n", gen_strict_parameter_declaration);
       fprintf(iconfig_file, "generation:%s\n", gen_icarus);
       fprintf(iconfig_file, "warnings:%s\n", warning_flags);
diff --git a/main.cc b/main.cc
index 82f7bec33..a1f5ef1db 100644
--- a/main.cc
+++ b/main.cc
@@ -118,7 +118,7 @@ bool gn_strict_expr_width_flag = false;
 bool gn_shared_loop_index_flag = true;
 bool gn_verilog_ams_flag = false;
 bool gn_strict_parameter_declaration = true;
-bool gn_strict_net_declaration = true;
+bool gn_strict_net_var_declaration = true;
 
 /*
  * For some generations we allow a system function to be called
@@ -395,11 +395,11 @@ static void process_generation_flag(const char*gen)
       } else if (strcmp(gen,"no-strict-parameter-declaration") == 0) {
 	    gn_strict_parameter_declaration = false;
 
-      } else if (strcmp(gen,"strict-net-declaration") == 0) {
-	    gn_strict_net_declaration = true;
+      } else if (strcmp(gen,"strict-net-var-declaration") == 0) {
+	    gn_strict_net_var_declaration = true;
 
-      } else if (strcmp(gen,"no-strict-net-declaration") == 0) {
-	    gn_strict_net_declaration = false;
+      } else if (strcmp(gen,"no-strict-net-var-declaration") == 0) {
+	    gn_strict_net_var_declaration = false;
 
 	  } else {
       }
diff --git a/symbol_search.cc b/symbol_search.cc
index 1c51cccb6..61a28d4ec 100644
--- a/symbol_search.cc
+++ b/symbol_search.cc
@@ -165,7 +165,7 @@ bool symbol_search(const LineInfo*li, Design*des, NetScope*scope,
 
 		  if (NetNet*net = scope->find_signal(path_tail.name)) {
 			bool decl_after_use = !prefix_scope && !(net->lexical_pos() <= lexical_pos);
-			if (!gn_strict_net_declaration || !decl_after_use) {
+			if (!gn_strict_net_var_declaration || !decl_after_use) {
 			      path.push_back(path_tail);
 			      res->scope = scope;
 			      res->net = net;
@@ -173,10 +173,10 @@ bool symbol_search(const LineInfo*li, Design*des, NetScope*scope,
 			      res->path_head = path;
 			      if (warn_decl_after_use && decl_after_use) {
 				    cerr << li->get_fileline()
-					 << ": warning: net `" << path_tail.name
+					 << ": warning: net/variable `" << path_tail.name
 					 << "` used before declaration." << endl;
 				    cerr << net->get_fileline()
-					 << ":        : the net is declared here." << endl;
+					 << ":        : the net/variable is declared here." << endl;
 				    // suppress further warnings for this net
 				    net->lexical_pos(lexical_pos);
 			      }
@@ -188,7 +188,7 @@ bool symbol_search(const LineInfo*li, Design*des, NetScope*scope,
 
 		  if (NetEvent*eve = scope->find_event(path_tail.name)) {
 			bool decl_after_use = !prefix_scope && !(eve->lexical_pos() <= lexical_pos);
-			if (!gn_strict_net_declaration || !decl_after_use) {
+			if (!gn_strict_net_var_declaration || !decl_after_use) {
 			      path.push_back(path_tail);
 			      res->scope = scope;
 			      res->eve = eve;

From 5da8894590d1a1812058b2f198522d99e4119771 Mon Sep 17 00:00:00 2001
From: Martin Whitaker <icarus@martin-whitaker.me.uk>
Date: Sat, 21 Mar 2026 20:21:05 +0000
Subject: [PATCH 10/11] Fix documentation for -Wno-declaration-after-use.

---
 Documentation/usage/command_line_flags.rst | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/Documentation/usage/command_line_flags.rst b/Documentation/usage/command_line_flags.rst
index 38255bf34..fb3f7c7bc 100644
--- a/Documentation/usage/command_line_flags.rst
+++ b/Documentation/usage/command_line_flags.rst
@@ -303,8 +303,12 @@ These flags affect the general behavior of the compiler.
 
   * declaration-after-use
 
-    With -gno-strict-parameter-declaration, issue a warning when a
-    parameter is declared after it is used.
+    This enables warnings for declarations after use, when those are not
+    flagged as errors (enabled by default). Use no-declaration-after-use
+    to disable this.
+
+    This flag was added in version 14.0 or later (and is in the master branch
+    as of 2026-03-21).
 
   * macro-redefinition
 

From 42d0c3fd4a5c13f3df28a50bf23e569a180c80ff Mon Sep 17 00:00:00 2001
From: Martin Whitaker <icarus@martin-whitaker.me.uk>
Date: Sat, 21 Mar 2026 20:44:10 +0000
Subject: [PATCH 11/11] Update test suite to cover -gno-strict-declaration
 options.

---
 ivtest/gold/decl_before_use1_warn-iverilog-stderr.gold | 2 ++
 ivtest/gold/decl_before_use1_warn-vvp-stdout.gold      | 2 ++
 ivtest/gold/decl_before_use2_warn-iverilog-stderr.gold | 2 ++
 ivtest/gold/decl_before_use2_warn-vvp-stdout.gold      | 2 ++
 ivtest/gold/decl_before_use3_warn-iverilog-stderr.gold | 2 ++
 ivtest/gold/decl_before_use3_warn-vvp-stdout.gold      | 1 +
 ivtest/gold/decl_before_use4_warn-vvp-stdout.gold      | 1 +
 ivtest/gold/decl_before_use5_warn-iverilog-stderr.gold | 2 ++
 ivtest/gold/decl_before_use5_warn-vvp-stdout.gold      | 2 ++
 ivtest/gold/decl_before_use6_warn-vvp-stdout.gold      | 2 ++
 ivtest/gold/pr1909940.gold                             | 3 +++
 ivtest/gold/pr1909940b.gold                            | 3 +++
 ivtest/ivltests/decl_before_use1.v                     | 2 +-
 ivtest/ivltests/decl_before_use2.v                     | 2 +-
 ivtest/ivltests/decl_before_use3.v                     | 2 +-
 ivtest/ivltests/decl_before_use4.v                     | 2 +-
 ivtest/ivltests/decl_before_use5.v                     | 2 +-
 ivtest/regress-vlg.list                                | 4 ++--
 ivtest/regress-vvp.list                                | 6 ++++++
 ivtest/vvp_tests/decl_before_use1_warn.json            | 7 +++++++
 ivtest/vvp_tests/decl_before_use2_warn.json            | 7 +++++++
 ivtest/vvp_tests/decl_before_use3_warn.json            | 7 +++++++
 ivtest/vvp_tests/decl_before_use4_warn.json            | 7 +++++++
 ivtest/vvp_tests/decl_before_use5_warn.json            | 7 +++++++
 ivtest/vvp_tests/decl_before_use6_warn.json            | 7 +++++++
 25 files changed, 79 insertions(+), 7 deletions(-)
 create mode 100644 ivtest/gold/decl_before_use1_warn-iverilog-stderr.gold
 create mode 100644 ivtest/gold/decl_before_use1_warn-vvp-stdout.gold
 create mode 100644 ivtest/gold/decl_before_use2_warn-iverilog-stderr.gold
 create mode 100644 ivtest/gold/decl_before_use2_warn-vvp-stdout.gold
 create mode 100644 ivtest/gold/decl_before_use3_warn-iverilog-stderr.gold
 create mode 100644 ivtest/gold/decl_before_use3_warn-vvp-stdout.gold
 create mode 100644 ivtest/gold/decl_before_use4_warn-vvp-stdout.gold
 create mode 100644 ivtest/gold/decl_before_use5_warn-iverilog-stderr.gold
 create mode 100644 ivtest/gold/decl_before_use5_warn-vvp-stdout.gold
 create mode 100644 ivtest/gold/decl_before_use6_warn-vvp-stdout.gold
 create mode 100644 ivtest/gold/pr1909940.gold
 create mode 100644 ivtest/gold/pr1909940b.gold
 create mode 100644 ivtest/vvp_tests/decl_before_use1_warn.json
 create mode 100644 ivtest/vvp_tests/decl_before_use2_warn.json
 create mode 100644 ivtest/vvp_tests/decl_before_use3_warn.json
 create mode 100644 ivtest/vvp_tests/decl_before_use4_warn.json
 create mode 100644 ivtest/vvp_tests/decl_before_use5_warn.json
 create mode 100644 ivtest/vvp_tests/decl_before_use6_warn.json

diff --git a/ivtest/gold/decl_before_use1_warn-iverilog-stderr.gold b/ivtest/gold/decl_before_use1_warn-iverilog-stderr.gold
new file mode 100644
index 000000000..5cc4b93e4
--- /dev/null
+++ b/ivtest/gold/decl_before_use1_warn-iverilog-stderr.gold
@@ -0,0 +1,2 @@
+ivltests/decl_before_use1.v:4: warning: net/variable `v` used before declaration.
+ivltests/decl_before_use1.v:9:        : the net/variable is declared here.
diff --git a/ivtest/gold/decl_before_use1_warn-vvp-stdout.gold b/ivtest/gold/decl_before_use1_warn-vvp-stdout.gold
new file mode 100644
index 000000000..1eccf69bf
--- /dev/null
+++ b/ivtest/gold/decl_before_use1_warn-vvp-stdout.gold
@@ -0,0 +1,2 @@
+1
+used before declaration
diff --git a/ivtest/gold/decl_before_use2_warn-iverilog-stderr.gold b/ivtest/gold/decl_before_use2_warn-iverilog-stderr.gold
new file mode 100644
index 000000000..f1ef2cc14
--- /dev/null
+++ b/ivtest/gold/decl_before_use2_warn-iverilog-stderr.gold
@@ -0,0 +1,2 @@
+ivltests/decl_before_use2.v:3: warning: net/variable `w` used before declaration.
+ivltests/decl_before_use2.v:10:        : the net/variable is declared here.
diff --git a/ivtest/gold/decl_before_use2_warn-vvp-stdout.gold b/ivtest/gold/decl_before_use2_warn-vvp-stdout.gold
new file mode 100644
index 000000000..6ad2d0448
--- /dev/null
+++ b/ivtest/gold/decl_before_use2_warn-vvp-stdout.gold
@@ -0,0 +1,2 @@
+00000001
+used before declaration
diff --git a/ivtest/gold/decl_before_use3_warn-iverilog-stderr.gold b/ivtest/gold/decl_before_use3_warn-iverilog-stderr.gold
new file mode 100644
index 000000000..113671293
--- /dev/null
+++ b/ivtest/gold/decl_before_use3_warn-iverilog-stderr.gold
@@ -0,0 +1,2 @@
+ivltests/decl_before_use3.v:4: warning: event `e` used before declaration.
+ivltests/decl_before_use3.v:8:        : the event is declared here.
diff --git a/ivtest/gold/decl_before_use3_warn-vvp-stdout.gold b/ivtest/gold/decl_before_use3_warn-vvp-stdout.gold
new file mode 100644
index 000000000..983403b7d
--- /dev/null
+++ b/ivtest/gold/decl_before_use3_warn-vvp-stdout.gold
@@ -0,0 +1 @@
+used before declaration
diff --git a/ivtest/gold/decl_before_use4_warn-vvp-stdout.gold b/ivtest/gold/decl_before_use4_warn-vvp-stdout.gold
new file mode 100644
index 000000000..983403b7d
--- /dev/null
+++ b/ivtest/gold/decl_before_use4_warn-vvp-stdout.gold
@@ -0,0 +1 @@
+used before declaration
diff --git a/ivtest/gold/decl_before_use5_warn-iverilog-stderr.gold b/ivtest/gold/decl_before_use5_warn-iverilog-stderr.gold
new file mode 100644
index 000000000..8bf2623ff
--- /dev/null
+++ b/ivtest/gold/decl_before_use5_warn-iverilog-stderr.gold
@@ -0,0 +1,2 @@
+ivltests/decl_before_use5.v:4: warning: parameter `w` used before declaration.
+ivltests/decl_before_use5.v:8:        : the parameter is declared here.
diff --git a/ivtest/gold/decl_before_use5_warn-vvp-stdout.gold b/ivtest/gold/decl_before_use5_warn-vvp-stdout.gold
new file mode 100644
index 000000000..6519eec97
--- /dev/null
+++ b/ivtest/gold/decl_before_use5_warn-vvp-stdout.gold
@@ -0,0 +1,2 @@
+10101010
+used before declaration
diff --git a/ivtest/gold/decl_before_use6_warn-vvp-stdout.gold b/ivtest/gold/decl_before_use6_warn-vvp-stdout.gold
new file mode 100644
index 000000000..0664d0861
--- /dev/null
+++ b/ivtest/gold/decl_before_use6_warn-vvp-stdout.gold
@@ -0,0 +1,2 @@
+10
+FAILED
diff --git a/ivtest/gold/pr1909940.gold b/ivtest/gold/pr1909940.gold
new file mode 100644
index 000000000..4da14bfe4
--- /dev/null
+++ b/ivtest/gold/pr1909940.gold
@@ -0,0 +1,3 @@
+./ivltests/pr1909940.v:4: warning: net/variable `in` used before declaration.
+./ivltests/pr1909940.v:5:        : the net/variable is declared here.
+PASSED
diff --git a/ivtest/gold/pr1909940b.gold b/ivtest/gold/pr1909940b.gold
new file mode 100644
index 000000000..7d10aac17
--- /dev/null
+++ b/ivtest/gold/pr1909940b.gold
@@ -0,0 +1,3 @@
+./ivltests/pr1909940b.v:4: warning: net/variable `in` used before declaration.
+./ivltests/pr1909940b.v:5:        : the net/variable is declared here.
+PASSED
diff --git a/ivtest/ivltests/decl_before_use1.v b/ivtest/ivltests/decl_before_use1.v
index 8f338b72a..8fae1af7f 100644
--- a/ivtest/ivltests/decl_before_use1.v
+++ b/ivtest/ivltests/decl_before_use1.v
@@ -3,7 +3,7 @@ module test();
 initial begin
   v = 1;
   $display("%b", v);
-  $display("FAILED");
+  $display("used before declaration");
 end
 
 reg v;
diff --git a/ivtest/ivltests/decl_before_use2.v b/ivtest/ivltests/decl_before_use2.v
index 3eeb619c3..d40c97a1a 100644
--- a/ivtest/ivltests/decl_before_use2.v
+++ b/ivtest/ivltests/decl_before_use2.v
@@ -4,7 +4,7 @@ assign w = 1;
 
 initial begin
   $display("%b", w);
-  $display("FAILED");
+  $display("used before declaration");
 end
 
 wire [7:0] w;
diff --git a/ivtest/ivltests/decl_before_use3.v b/ivtest/ivltests/decl_before_use3.v
index 8fed35387..57f925957 100644
--- a/ivtest/ivltests/decl_before_use3.v
+++ b/ivtest/ivltests/decl_before_use3.v
@@ -2,7 +2,7 @@ module test();
 
 initial begin
   ->e;
-  $display("FAILED");
+  $display("used before declaration");
 end
 
 event e;
diff --git a/ivtest/ivltests/decl_before_use4.v b/ivtest/ivltests/decl_before_use4.v
index 8daa94218..41e69deb9 100644
--- a/ivtest/ivltests/decl_before_use4.v
+++ b/ivtest/ivltests/decl_before_use4.v
@@ -2,7 +2,7 @@ module test();
 
 initial begin
   @(e);
-  $display("FAILED");
+  $display("used before declaration");
 end
 
 event e;
diff --git a/ivtest/ivltests/decl_before_use5.v b/ivtest/ivltests/decl_before_use5.v
index cb92f23a0..d7931b0f7 100644
--- a/ivtest/ivltests/decl_before_use5.v
+++ b/ivtest/ivltests/decl_before_use5.v
@@ -2,7 +2,7 @@ module test();
 
 initial begin
   $display("%b", w);
-  $display("FAILED");
+  $display("used before declaration");
 end
 
 localparam w = 8'hAA;
diff --git a/ivtest/regress-vlg.list b/ivtest/regress-vlg.list
index 6a0323cb8..9309d3afa 100644
--- a/ivtest/regress-vlg.list
+++ b/ivtest/regress-vlg.list
@@ -1126,8 +1126,8 @@ pr1903324		normal			ivltests
 pr1903343		normal			ivltests gold=pr1903343.gold
 pr1903520		normal			ivltests
 pr1907192		normal			ivltests
-pr1909940		CE			ivltests
-pr1909940b		CE			ivltests
+pr1909940		normal,-gno-strict-declaration	ivltests gold=pr1909940.gold
+pr1909940b		normal,-gno-strict-declaration	ivltests gold=pr1909940b.gold
 pr1912843		normal			ivltests
 pr1913918a		normal			ivltests
 pr1913918b		normal			ivltests
diff --git a/ivtest/regress-vvp.list b/ivtest/regress-vvp.list
index 49a0917df..13a548189 100644
--- a/ivtest/regress-vvp.list
+++ b/ivtest/regress-vvp.list
@@ -97,6 +97,12 @@ decl_before_use3		vvp_tests/decl_before_use3.json
 decl_before_use4		vvp_tests/decl_before_use4.json
 decl_before_use5		vvp_tests/decl_before_use5.json
 decl_before_use6		vvp_tests/decl_before_use6.json
+decl_before_use1_warn		vvp_tests/decl_before_use1_warn.json
+decl_before_use2_warn		vvp_tests/decl_before_use2_warn.json
+decl_before_use3_warn		vvp_tests/decl_before_use3_warn.json
+decl_before_use4_warn		vvp_tests/decl_before_use4_warn.json
+decl_before_use5_warn		vvp_tests/decl_before_use5_warn.json
+decl_before_use6_warn		vvp_tests/decl_before_use6_warn.json
 delayed_sfunc			vvp_tests/delayed_sfunc.json
 dffsynth			vvp_tests/dffsynth.json
 dffsynth-S			vvp_tests/dffsynth-S.json
diff --git a/ivtest/vvp_tests/decl_before_use1_warn.json b/ivtest/vvp_tests/decl_before_use1_warn.json
new file mode 100644
index 000000000..cf5df77cb
--- /dev/null
+++ b/ivtest/vvp_tests/decl_before_use1_warn.json
@@ -0,0 +1,7 @@
+
+{
+    "type" : "normal",
+    "source" : "decl_before_use1.v",
+    "iverilog-args" : [ "-gno-strict-net-var-declaration" ],
+    "gold" : "decl_before_use1_warn"
+}
diff --git a/ivtest/vvp_tests/decl_before_use2_warn.json b/ivtest/vvp_tests/decl_before_use2_warn.json
new file mode 100644
index 000000000..1fdf6c86d
--- /dev/null
+++ b/ivtest/vvp_tests/decl_before_use2_warn.json
@@ -0,0 +1,7 @@
+
+{
+    "type" : "normal",
+    "source" : "decl_before_use2.v",
+    "iverilog-args" : [ "-gno-strict-declaration" ],
+    "gold" : "decl_before_use2_warn"
+}
diff --git a/ivtest/vvp_tests/decl_before_use3_warn.json b/ivtest/vvp_tests/decl_before_use3_warn.json
new file mode 100644
index 000000000..f2507fe6b
--- /dev/null
+++ b/ivtest/vvp_tests/decl_before_use3_warn.json
@@ -0,0 +1,7 @@
+
+{
+    "type" : "normal",
+    "source" : "decl_before_use3.v",
+    "iverilog-args" : [ "-gno-strict-net-var-declaration" ],
+    "gold" : "decl_before_use3_warn"
+}
diff --git a/ivtest/vvp_tests/decl_before_use4_warn.json b/ivtest/vvp_tests/decl_before_use4_warn.json
new file mode 100644
index 000000000..26af6b94d
--- /dev/null
+++ b/ivtest/vvp_tests/decl_before_use4_warn.json
@@ -0,0 +1,7 @@
+
+{
+    "type" : "normal",
+    "source" : "decl_before_use4.v",
+    "iverilog-args" : [ "-gno-strict-declaration", "-Wno-declaration-after-use" ],
+    "gold" : "decl_before_use4_warn"
+}
diff --git a/ivtest/vvp_tests/decl_before_use5_warn.json b/ivtest/vvp_tests/decl_before_use5_warn.json
new file mode 100644
index 000000000..4568e78bd
--- /dev/null
+++ b/ivtest/vvp_tests/decl_before_use5_warn.json
@@ -0,0 +1,7 @@
+
+{
+    "type" : "normal",
+    "source" : "decl_before_use5.v",
+    "iverilog-args" : [ "-gno-strict-parameter-declaration" ],
+    "gold" : "decl_before_use5_warn"
+}
diff --git a/ivtest/vvp_tests/decl_before_use6_warn.json b/ivtest/vvp_tests/decl_before_use6_warn.json
new file mode 100644
index 000000000..5324bb9a3
--- /dev/null
+++ b/ivtest/vvp_tests/decl_before_use6_warn.json
@@ -0,0 +1,7 @@
+
+{
+    "type" : "normal",
+    "source" : "decl_before_use6.v",
+    "iverilog-args" : [ "-gno-strict-declaration", "-Wno-declaration-after-use" ],
+    "gold" : "decl_before_use6_warn"
+}