Internals: Real1: properly lex doubles

src/V3AstNodes.h

@@ -1624,7 +1624,7 @@ public:
     void	ignoreOverlap(bool flag) { m_ignoreOverlap = flag; }
 };
 
-class AstSFormatF : public AstNode {
+struct AstSFormatF : public AstNode {
     // Convert format to string, generally under a AstDisplay or AstSFormat
     // Also used as "real" function for /*verilator sformat*/ functions
     string	m_text;

src/V3ParseImp.h

@@ -254,6 +254,7 @@ public:
     void verilatorCmtLintSave();
     void verilatorCmtLintRestore();
     void verilatorCmtBad(const char* text);
+    double parseDouble(const char* text, size_t length);
     void pushBeginKeywords(int state) { m_inBeginKwd++; m_lastVerilogState=state; }
     bool popBeginKeywords() { if (m_inBeginKwd) { m_inBeginKwd--; return true; } else return false; }
     int lastVerilogState() { return m_lastVerilogState; }

src/verilog.l

@@ -812,11 +812,11 @@ word	[a-zA-Z0-9_]+
                           return yaINTNUM;
 			}
   [0-9][_0-9]*(\.[_0-9]+)([eE][-+]?[_0-9]+)? {
-			  FL; yylval.cdouble = 0;  /* Only for delays, not used yet */
+			  FL; yylval.cdouble = PARSEP->parseDouble(yytext, yyleng);
                           return yaFLOATNUM;
 			}
   [0-9][_0-9]*(\.[_0-9]+)?([eE][-+]?[_0-9]+) {
-			  FL; yylval.cdouble = 0;  /* Only for delays, not used yet */
+			  FL; yylval.cdouble = PARSEP->parseDouble(yytext, yyleng);
                           return yaFLOATNUM;
 			}
   [0-9][_0-9]*(\.[_0-9]+)?(fs|ps|ns|us|ms|s|step) {
@@ -949,6 +949,20 @@ word	[a-zA-Z0-9_]+
 %%
 int V3ParseImp::stateVerilogRecent() { return STATE_VERILOG_RECENT; }
 
+double V3ParseImp::parseDouble(const char* textp, size_t length) {
+    char* strgp = new char[strlen(textp)+1];
+    char* dp=strgp;
+    for (const char* sp=textp; sp<(textp+length);) {
+	if (*sp != '_') *dp++ = *sp++;
+	else sp++;
+    }
+    char* endp = strgp;
+    double d = strtod(strgp, &endp);
+    if ((endp-strgp) != length) { yyerrorf("Syntax error parsing real: %s",strgp); }
+    delete strgp;
+    return d;
+}
+
 int V3ParseImp::lexToken() {
     // called from lexToBison, has a "this"
     // Fetch next token from prefetch or real lexer