Improve error to note common :: package errors

src/V3ParseImp.h

@@ -42,11 +42,13 @@ typedef enum { uniq_NONE, uniq_UNIQUE, uniq_UNIQUE0, uniq_PRIORITY } V3UniqState
 typedef enum { iprop_NONE, iprop_CONTEXT, iprop_PURE } V3ImportProperty;
 
 //============================================================================
+// Parser YYSType, e.g. for parser's yylval
 // We can't use bison's %union as we want to pass the fileline with all tokens
 
 struct V3ParseBisonYYSType {
     FileLine*	fl;
     AstNode*	scp;	// Symbol table scope for future lookups
+    int		token;	// Read token, aka tok
     union {
 	V3Number*	nump;
 	string*		strp;
@@ -107,9 +109,10 @@ class V3ParseImp {
     int		m_lastVerilogState;	// Last LEX state in `begin_keywords
 
     int		m_prevLexToken;		// previous parsed token (for lexer)
-    bool	m_ahead;		// aheadToken is valid
-    int		m_aheadToken;		// Token we read ahead
-    V3ParseBisonYYSType m_aheadVal;	// aheadToken's value
+    bool	m_ahead;		// aheadval is valid
+    V3ParseBisonYYSType m_aheadVal;	// ahead token value
+    V3ParseBisonYYSType m_curBisonVal;	// current token for error reporting
+    V3ParseBisonYYSType m_prevBisonVal;	// previous token for error reporting
 
     deque<string*> m_stringps;		// Created strings for later cleanup
     deque<V3Number*> m_numberps;	// Created numbers for later cleanup
@@ -194,6 +197,8 @@ public:
     static int stateVerilogRecent();	// Parser -> lexer communication
     int	prevLexToken() { return m_prevLexToken; } // Parser -> lexer communication
     size_t flexPpInputToLex(char* buf, size_t max_size) { return ppInputToLex(buf,max_size); }
+    const V3ParseBisonYYSType curBisonVal() const { return m_curBisonVal; }
+    const V3ParseBisonYYSType prevBisonVal() const { return m_prevBisonVal; }
 
     //==== Symbol tables
     V3ParseSym* symp() { return m_symp; }
@@ -210,7 +215,8 @@ public:
 	m_lastVerilogState = stateVerilogRecent();
 	m_prevLexToken = 0;
 	m_ahead = false;
-	m_aheadToken = 0;
+	m_curBisonVal.token = 0;
+	m_prevBisonVal.token = 0;
 	// m_aheadVal not used as m_ahead = false
     }
     ~V3ParseImp();
@@ -227,7 +233,7 @@ public:
 private:
     void lexFile(const string& modname);
     int yylexReadTok();
-    int lexToken(); // Internal; called from lexToBison
+    void lexToken(); // Internal; called from lexToBison
 };
 
 #endif // Guard

src/verilog.l

@@ -109,6 +109,14 @@ void V3ParseImp::verilatorCmtBad(const char* textp) {
 
 void yyerror(const char* errmsg) {
     PARSEP->fileline()->v3error(errmsg);
+    static const char* colonmsg = "syntax error, unexpected ::, ";
+    //tokens;
+    if (0==strncmp(errmsg, colonmsg, strlen(colonmsg))
+	&& PARSEP->prevBisonVal().token == yaID__ETC
+	&& PARSEP->curBisonVal().token == yP_COLONCOLON) {
+	PARSEP->fileline()->v3error("Perhaps '"+*PARSEP->prevBisonVal().strp
+				    +"' is a package which needs to be predeclared? (IEEE 2012 26.3)");
+    }
 }
 
 void yyerrorf(const char* format, ...) {
@@ -994,14 +1002,14 @@ double V3ParseImp::parseDouble(const char* textp, size_t length, bool* successp)
     return d;
 }
 
-int V3ParseImp::lexToken() {
+void V3ParseImp::lexToken() {
     // called from lexToBison, has a "this"
     // Fetch next token from prefetch or real lexer
     int token;
     if (m_ahead) {
 	// We prefetched an extra token, give it back
 	m_ahead = false;
-	token = m_aheadToken;
+	token = m_aheadVal.token;
 	yylval = m_aheadVal;
     } else {
 	// Parse new token
@@ -1017,8 +1025,8 @@ int V3ParseImp::lexToken() {
 	V3ParseBisonYYSType curValue = yylval;  // Remember value, as about to read ahead
 	int nexttok = yylexReadTok();
 	m_ahead = true;
-	m_aheadToken = nexttok;
 	m_aheadVal = yylval;
+	m_aheadVal.token = nexttok;
 	yylval = curValue;
 	// Now potentially munge the current token
 	if (token == yCONST__LEX) {
@@ -1060,21 +1068,25 @@ int V3ParseImp::lexToken() {
 	    token = yaID__ETC;
 	}
     }
-    return token;
+    yylval.token = token;
+    // effectively returns yylval
 }
 
 int V3ParseImp::lexToBison() {
     // Called as global since bison doesn't have our pointer
-    int tok = lexToken();
+    lexToken();  // sets yylval
+    m_prevBisonVal = m_curBisonVal;
+    m_curBisonVal = yylval;
+
     //yylval.scp = NULL;   // Symbol table not yet needed - no packages
     if (debugFlex()>=6 || debugBison()>=6) {
 	cout<<"   {"<<yylval.fl->filenameLetters()<<yylval.fl->lineno()
-	    <<"} lexToBison  TOKEN="<<tok<<" "<<tokenName(tok);
-	if (tok == yaID__ETC || tok == yaID__LEX || tok == yaID__aTYPE) {
+	    <<"} lexToBison  TOKEN="<<yylval.token<<" "<<tokenName(yylval.token);
+	if (yylval.token == yaID__ETC || yylval.token == yaID__LEX || yylval.token == yaID__aTYPE) {
 	    cout<<"   strp='"<<*(yylval.strp)<<"'";
 	}
 	cout<<endl;
     }
-    return tok;
+    return yylval.token;
 }
 

test_regress/t/t_lint_pkg_colon_bad.pl

@@ -0,0 +1,27 @@
+#!/usr/bin/perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2008 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+
+$Self->{vlt} or $Self->skip("Verilator only test");
+
+compile (
+    v_flags2 => ["--lint-only"],
+    fails=>1,
+    verilator_make_gcc => 0,
+    make_top_shell => 0,
+    make_main => 0,
+    expect=> quotemeta(
+qq{%Error: t/t_lint_pkg_colon_bad.v:6: syntax error, unexpected ::, expecting ')' or ','
+%Error: t/t_lint_pkg_colon_bad.v:6: Perhaps 'mispkg' is a package which needs to be predeclared? (IEEE 2012 26.3)
+%Error: t/t_lint_pkg_colon_bad.v:7: syntax error, unexpected ::, expecting ',' or ';'
+%Error: t/t_lint_pkg_colon_bad.v:7: Perhaps 'mispkgb' is a package which needs to be predeclared? (IEEE 2012 26.3)
+}).'%Error: Exiting due to.*'
+    );
+
+ok(1);
+1;

test_regress/t/t_lint_pkg_colon_bad.v

@@ -0,0 +1,8 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2017 by Wilson Snyder.
+
+module t (input mispkg::foo_t a);
+   reg mispkgb::bar_t b;
+endmodule