From eea2712eac71f26a2f615271a35337e475343309 Mon Sep 17 00:00:00 2001
From: Wilson Snyder <wsnyder@wsnyder.org>
Date: Mon, 7 Sep 2009 15:54:12 -0400
Subject: [PATCH] Improved warning when "do" used as identifier.

---
 Changes                        |  4 ++++
 src/verilog.y                  | 16 ++++++++++++++++
 test_regress/t/t_var_bad_sv.pl | 22 ++++++++++++++++++++++
 test_regress/t/t_var_bad_sv.v  |  9 +++++++++
 4 files changed, 51 insertions(+)
 create mode 100755 test_regress/t/t_var_bad_sv.pl
 create mode 100644 test_regress/t/t_var_bad_sv.v

diff --git a/Changes b/Changes
index d8ac32d68..5cd6ff436 100644
--- a/Changes
+++ b/Changes
@@ -3,6 +3,10 @@ Revision history for Verilator
 The contributors that suggested a given feature are shown in [].  [by ...]
 indicates the contributor was also the author of the fix; Thanks!
 
+* Verilator 3.7***
+
+***  Improved warning when "do" used as identifier.
+
 * Verilator 3.713 2009/08/04
 
 **   Support constant function calls for parameters. [many!]
diff --git a/src/verilog.y b/src/verilog.y
index cfc60bb37..d1c2d32aa 100644
--- a/src/verilog.y
+++ b/src/verilog.y
@@ -113,6 +113,12 @@ static AstNode* newVarInit(FileLine* fileline, AstNode* varp, AstNode* initp) {
 
 #define INSTPREP(modname,paramsp) { V3Parse::s_impliedDecl = true; V3Parse::s_instModule = modname; V3Parse::s_instParamp = paramsp; }
 
+static void ERRSVKWD(FileLine* fileline, const string& tokname) {
+    static int toldonce = 0;
+    fileline->v3error((string)"Unexpected \""+tokname+"\": \""+tokname+"\" is a SystemVerilog keyword misused as an identifier.");
+    if (!toldonce++) fileline->v3error("Modify the Verilog-2001 code to avoid SV keywords, or use `begin_keywords or --language.");
+}
+
 //======================================================================
 
 class AstSenTree;
@@ -657,6 +663,7 @@ port_declNetE:			// IEEE: part of port_declaration, optional net type
  
 portSig<portp>:
 		id/*port*/				{ $$ = new AstPort(CRELINE(),PINNUMINC(),*$1); }
+	|	idSVKwd					{ $$ = new AstPort(CRELINE(),PINNUMINC(),*$1); }
  	;
 
 //**********************************************************************
@@ -854,6 +861,7 @@ variable_decl_assignment<varp>:	// ==IEEE: variable_decl_assignment
 	|	id variable_dimensionListE sigAttrListE '=' variable_declExpr
 			{ $$ = VARDONEA(*$1,$2,$3);
 			  $$->addNext(new AstInitial($4,new AstAssign($4, new AstVarRef($4, *$1, true), $5))); }
+	|	idSVKwd					{ $$ = NULL; }
 	//
 	//			// IEEE: "dynamic_array_variable_identifier '[' ']' [ '=' dynamic_array_new ]"
 	//			// Matches above with variable_dimensionE = "[]"
@@ -1189,6 +1197,7 @@ netSig<varp>:			// IEEE: net_decl_assignment -  one element from list_of_port_id
 
 netId<strp>:
 		id/*new-net*/				{ $$ = $1; }
+	|	idSVKwd					{ $$ = $1; }
 	;
 
 sigId<varp>:
@@ -1315,6 +1324,7 @@ cellpinItList<pinp>:		// IEEE: list_of_port_connections + list_of_parameter_assi
 cellpinItemE<pinp>:		// IEEE: named_port_connection + named_parameter_assignment + empty
 		/* empty: ',,' is legal */		{ $$ = NULL; PINNUMINC(); }
 	|	yP_DOTSTAR				{ $$ = new AstPin($1,PINNUMINC(),".*",NULL); }
+	|	'.' idSVKwd				{ $$ = NULL; PINNUMINC(); }
 	|	'.' idAny				{ $$ = new AstPin($1,PINNUMINC(),*$2,new AstVarRef($1,*$2,false)); $$->svImplicit(true);}
 	|	'.' idAny '(' ')'			{ $$ = NULL; PINNUMINC(); }
 	|	'.' idAny '(' expr ')'			{ $$ = new AstPin($1,PINNUMINC(),*$2,$4); }
@@ -2286,6 +2296,12 @@ idAny<strp>:			// Any kind of identifier
 		yaID__ETC				{ $$ = $1; }
 	;
 
+idSVKwd<strp>:			// Warn about non-forward compatible Verilog 2001 code
+	//			// yBIT, yBYTE won't work here as causes conflicts
+		yDO					{ static string s = "do"   ; $$ = &s; ERRSVKWD($1,*$$); }
+	|	yFINAL					{ static string s = "final"; $$ = &s; ERRSVKWD($1,*$$); }
+	;
+
 variable_lvalue<nodep>:		// IEEE: variable_lvalue or net_lvalue
 	//			// Note many variable_lvalue's must use exprOkLvalue when arbitrary expressions may also exist
 		idClassSel				{ $$ = $1; }
diff --git a/test_regress/t/t_var_bad_sv.pl b/test_regress/t/t_var_bad_sv.pl
new file mode 100755
index 000000000..36ad3a1b5
--- /dev/null
+++ b/test_regress/t/t_var_bad_sv.pl
@@ -0,0 +1,22 @@
+#!/usr/bin/perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2003 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+
+compile (
+	 v_flags2 => ["--lint-only"],
+	 fails=>$Self->{v3},
+	 expect=>
+'%Error: t/t_var_bad_sv.v:\d+: Unexpected "do": "do" is a SystemVerilog keyword misused as an identifier.
+%Error: t/t_var_bad_sv.v:\d+: Modify the Verilog-2001 code to avoid SV keywords, or use `begin_keywords or --language.
+%Error: t/t_var_bad_sv.v:\d+: Unexpected "do": "do" is a SystemVerilog keyword misused as an identifier.
+.*
+%Error: Exiting due to.*',
+	 );
+
+ok(1);
+1;
diff --git a/test_regress/t/t_var_bad_sv.v b/test_regress/t/t_var_bad_sv.v
new file mode 100644
index 000000000..f3fb61a63
--- /dev/null
+++ b/test_regress/t/t_var_bad_sv.v
@@ -0,0 +1,9 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2009 by Wilson Snyder.
+
+module t;
+   reg do;
+   mod mod (.do(bar));
+endmodule