Fix ` expansion of defines, bug1227, bug1228.

Changes

@@ -31,7 +31,7 @@ The contributors that suggested a given feature are shown in []. Thanks!
 
 ****  Fix conditional slices and add related optimizations.
 
-****  Fix `` expansion of empty `defines, bug1225. [Odd Magne Reitan]
+****  Fix `` expansion of `defines, bug1225, bug1227, bug1228. [Odd Magne Reitan]
 
 ****  Fix -E duplicating output, bug1226. [Odd Magne Reitan]
 

src/V3PreLex.h

@@ -65,6 +65,7 @@ class V3PreProcImp;
 #define VP_BACKQUOTE	311
 #define VP_SYMBOL_JOIN	312
 #define VP_DEFREF_JOIN	313
+#define VP_JOIN		314
 
 #define VP_PSL		350
 

src/V3PreLex.l

@@ -126,6 +126,7 @@ drop		[\032]
 <STRIFY>{symbdef}``	{ yyleng-=2; return (VP_SYMBOL_JOIN); }
 <STRIFY>"`"{symbdef}	{ return (VP_DEFREF); }
 <STRIFY>"`"{symbdef}``	{ yyleng-=2; return (VP_DEFREF_JOIN); }
+<STRIFY>``              { yyleng-=2; return (VP_JOIN); }
 <STRIFY>{crnl}		{ linenoInc(); yytext=(char*)"\n"; yyleng=1; return(VP_WHITE); }
 <STRIFY>{wsn}+		{ return (VP_WHITE); }
 <STRIFY>{drop}		{ }
@@ -229,6 +230,7 @@ drop		[\032]
 			}}
 <ARGMODE>"`"{symbdef}	{ appendDefValue(yytext,yyleng); }  /* defref in defref - outer macro expands first */
 <ARGMODE>"`"{symbdef}`` { appendDefValue(yytext,yyleng); }  /* defref in defref - outer macro expands first */
+<ARGMODE>``             { appendDefValue(yytext,yyleng); }  /* defref in defref - outer macro expands first */
 <ARGMODE>[^\/\*\n\r\\(,){}\[\]\"`]+	|
 <ARGMODE>.		{ appendDefValue(yytext,yyleng); }
 
@@ -253,12 +255,14 @@ drop		[\032]
 	/* symbdef prevents normal lex rules from making `\`"foo a symbol {`"foo} instead of a BACKQUOTE */
 <INITIAL>"`"{symbdef}	{ return (VP_DEFREF); }
 <INITIAL>"`"{symbdef}`` { yyleng-=2; return (VP_DEFREF_JOIN); }
+<INITIAL>``             { yyleng-=2; return (VP_JOIN); }
 
 	/* Generics */
 <INITIAL>{crnl}		{ linenoInc(); yytext=(char*)"\n"; yyleng=1; return(VP_WHITE); }
 <INITIAL><<EOF>>	{ yyterminate(); }  /* A "normal" EOF */
 <INITIAL>{symb} 	{ return (VP_SYMBOL); }
 <INITIAL>{symb}``	{ yyleng-=2; return (VP_SYMBOL_JOIN); }
+<INITIAL>``		{ yyleng-=2; return (VP_JOIN); }
 <INITIAL>{wsn}+		{ return (VP_WHITE); }
 <INITIAL>{drop}		{ }
 <INITIAL>[\r]		{ }

src/V3PreProc.cpp

@@ -485,6 +485,7 @@ const char* V3PreProcImp::tokenName(int tok) {
     case VP_ERROR	: return("ERROR");
     case VP_IFDEF	: return("IFDEF");
     case VP_IFNDEF	: return("IFNDEF");
+    case VP_JOIN	: return("JOIN");
     case VP_INCLUDE	: return("INCLUDE");
     case VP_LINE	: return("LINE");
     case VP_STRIFY	: return("STRIFY");
@@ -923,7 +924,7 @@ int V3PreProcImp::getStateToken() {
 		// FALLTHRU, handle as with VP_SYMBOL_JOIN
 	    }
 	}
-	if (tok==VP_SYMBOL_JOIN || tok==VP_DEFREF_JOIN) {  // not else if, can fallthru from above if()
+	if (tok==VP_SYMBOL_JOIN || tok==VP_DEFREF_JOIN || tok==VP_JOIN) {  // not else if, can fallthru from above if()
 	    // a`` -> string doesn't include the ``, so can just grab next and continue
 	    string out (yyourtext(),yyourleng());
 	    UINFO(5,"`` LHS:"<<out<<endl);
@@ -1188,7 +1189,10 @@ int V3PreProcImp::getStateToken() {
 		statePop();
 		goto next_tok;
 	    } else if (tok==VP_EOF || tok==VP_WHITE || tok == VP_COMMENT || tok==VP_STRING) {
-		error((string)"Expecting symbol to terminate ``; whitespace etc cannot follow ``. Found: "+tokenName(tok)+"\n");
+		// Other compilers just ignore this, so no warning
+		// "Expecting symbol to terminate ``; whitespace etc cannot follow ``. Found: "+tokenName(tok)+"\n"
+		string lhs = m_joinStack.top(); m_joinStack.pop();
+		unputString(lhs);
 		statePop();
 		goto next_tok;
 	    } else {

test_regress/t/t_preproc.out

@@ -894,6 +894,11 @@ XYS_FAMILY = XYS_foo
 `line 610 "t/t_preproc.v" 0
  
  
+(.mySig (myInterface.pa5),
+
+`line 614 "t/t_preproc.v" 0
+ 
+ 
    
 predef 0 0
 predef 1 1
@@ -912,4 +917,4 @@ predef 1 1
 predef 2 2
  
 
-`line 630 "t/t_preproc.v" 2
+`line 634 "t/t_preproc.v" 2

test_regress/t/t_preproc.v

@@ -607,6 +607,10 @@ NYS_FAMILY = `NYS_FAMILY
 
 `endif // NEVER
 
+//bug1227
+`define INSTANCE(NAME) (.mySig (myInterface.``NAME),
+`INSTANCE(pa5)
+
 //======================================================================
 // IEEE mandated predefines
 `undefineall  // undefineall should have no effect on these

test_regress/t/t_preproc_ttempty.out

@@ -0,0 +1 @@
+ `TARGET_PACKAGE

test_regress/t/t_preproc_ttempty.pl

@@ -0,0 +1,27 @@
+#!/usr/bin/perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2003-2017 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+
+$Self->{vlt} or $Self->skip("Verilator only test");
+
+my $stdout_filename = "$Self->{obj_dir}/$Self->{name}__test.vpp";
+
+compile (
+    # Override default flags
+    v_flags => [''],
+    verilator_flags => ["-E -P +incdir+t"],
+    verilator_flags2 => ['',],
+    verilator_flags3 => ['',],
+    verilator_make_gcc => 0,
+    make_top_shell => 0,
+    stdout_filename => $stdout_filename,
+    );
+
+ok(files_identical($stdout_filename, "t/$Self->{name}.out"));
+
+1;

test_regress/t/t_preproc_ttempty.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.
+
+//`define TARGET_PACKAGE
+
+`define TARGET_PACKAGE_```TARGET_PACKAGE