Add IMPERFECTSCH warning, disabled by default.

Changes

@@ -10,6 +10,8 @@ indicates the contributor was also the author of the fix; Thanks!
 
 ***  Add by-design and by-module subtotals to verilator_profcfunc.
 
+**** Add IMPERFECTSCH warning, disabled by default.
+
 * Verilator 3.670 2008/07/23
 
 **   Add --x-assign=fast option, and make it the default.

bin/verilator

@@ -580,6 +580,10 @@ It is strongly recommended you cleanup your code rather than using this
 option, it is only intended to be use when running test-cases of code
 received from third parties.
 
+=item -Wwarn-I<message>
+
+Enables the specified warning message.
+
 =item -x-assign 0
 
 =item -x-assign 1
@@ -1728,6 +1732,13 @@ additional ones.)
 Ignoring this warning may make Verilator simulations differ from other
 simulators.
 
+=item IMPERFECTSCH
+
+Warns that the scheduling of the model is not absolutely perfect, and some
+manual code edits may result in faster performance.  This warning defaults
+to off, and must be turned on explicitly before the top module statement is
+processed.
+
 =item IMPLICIT
 
 Warns that a wire is being implicitly declared (it is a single bit wide

src/V3Changed.cpp

@@ -63,6 +63,7 @@ private:
 	vscp->v3fatalSrc("Not applicable\n");
 #endif
 	AstVar* varp = vscp->varp();
+	vscp->v3warn(IMPERFECTSCH,"Imperfect scheduling of variable: "<<vscp);
 	if (varp->arraysp()) {
 	    vscp->v3error("Unsupported: Can't detect changes on arrayed variable (probably with UNOPTFLAT warning suppressed): "<<varp->prettyName());
 	} else {

src/V3Error.cpp

@@ -65,6 +65,17 @@ V3ErrorCode::V3ErrorCode(const char* msgp) {
 //######################################################################
 // FileLine class functions
 
+FileLine::FileLine(FileLine::EmptySecret) {
+    m_lineno=0;
+    m_filename="COMMAND_LINE";
+
+    m_warnOff=0;
+    for (int codei=V3ErrorCode::FIRST_WARN; codei<V3ErrorCode::MAX; codei++) {
+	V3ErrorCode code = (V3ErrorCode)codei;
+	if (code.defaultsOff()) warnOff(code, true);
+    }
+}
+
 void FileLine::lineDirective(const char* textp) {
     // Handle `line directive
     // Skip `line
@@ -318,7 +329,9 @@ void V3Error::v3errorEnd (ostringstream& sstr) {
 #ifdef __COVERITY__
     if (s_errorCode==V3ErrorCode::FATAL) __coverity_panic__(x);
 #endif
-    if (s_errorCode!=V3ErrorCode::SUPPRESS || debug()) {
+    if (s_errorCode!=V3ErrorCode::SUPPRESS
+	// On debug, show only non default-off warning to prevent pages of warnings
+	|| (debug() && !s_errorCode.defaultsOff())) {
 	cerr<<msgPrefix()<<sstr.str();
 	if (sstr.str()[sstr.str().length()-1] != '\n') {
 	    cerr<<endl;

src/V3Error.h

@@ -52,6 +52,7 @@ public:
 	COMBDLY,	// Combinatorial delayed assignment
 	STMTDLY,	// Delayed statement
 	GENCLK,		// Generated Clock
+	IMPERFECTSCH,	// Imperfect schedule (disabled by default)
 	IMPLICIT,	// Implicit wire
 	IMPURE,		// Impure function not being inlined
 	MULTIDRIVEN,	// Driven from multiple blocks
@@ -81,7 +82,7 @@ public:
 	    " FIRST_WARN",
 	    "BLKANDNBLK",
 	    "CASEINCOMPLETE", "CASEOVERLAP", "CASEWITHX", "CASEX", "CMPCONST",
-	    "COMBDLY", "STMTDLY", "GENCLK", "IMPLICIT", "IMPURE",
+	    "COMBDLY", "STMTDLY", "GENCLK", "IMPERFECTSCH", "IMPLICIT", "IMPURE",
 	    "MULTIDRIVEN", "REDEFMACRO",
 	    "UNDRIVEN", "UNOPT", "UNOPTFLAT", "UNSIGNED", "UNUSED",
 	    "VARHIDDEN", "WIDTH", "WIDTHCONCAT",
@@ -89,6 +90,8 @@ public:
 	};
 	return names[m_e];
     };
+    // Warnings that default to off
+    bool defaultsOff() const { return ( m_e==IMPERFECTSCH );};
     // Warnings that warn about nasty side effects
     bool dangerous() const { return ( m_e==COMBDLY );};
     // Warnings we'll present to the user as errors
@@ -207,7 +210,7 @@ protected:
 public:
     FileLine (const string& filename, int lineno) { m_lineno=lineno; m_filename = filename; m_warnOff=s_defaultFileLine.m_warnOff; }
     FileLine (FileLine* fromp) { m_lineno=fromp->lineno(); m_filename = fromp->filename(); m_warnOff=fromp->m_warnOff; }
-    FileLine (EmptySecret) { m_lineno=0; m_filename="COMMAND_LINE"; m_warnOff=0; }
+    FileLine (EmptySecret);
     ~FileLine() { }
 #ifdef VL_LEAK_CHECKS
     static void* operator new(size_t size);

src/V3Options.cpp

@@ -640,17 +640,6 @@ void V3Options::parseOptsList(FileLine* fl, int argc, char** argv) {
 	    else if ( !strncmp (sw, "-U", 2)) {
 		V3PreShell::undef (string (sw+strlen("-U")));
 	    }
-	    else if ( !strncmp (sw, "-Wno-",5) )	{
-		if (!strcmp (sw, "-Wno-lint")) {
-		    FileLine::defaultFileLine().warnLintOff(true);
-		}
-		else {
-		    string msg = sw+strlen("-Wno-");
-		    if (!(FileLine::defaultFileLine().warnOff(msg, true))) {
-			fl->v3fatal("Unknown warning disabled: "<<sw);
-		    }
-		}
-	    }
 	    else if ( !strncmp (sw, "-Werror-",strlen("-Werror-")) )	{
 		string msg = sw+strlen("-Werror-");
 		V3ErrorCode code (msg.c_str());
@@ -667,6 +656,28 @@ void V3Options::parseOptsList(FileLine* fl, int argc, char** argv) {
 		// Note it may not be a future option, but one that is currently implemented.
 		addFuture(msg);
 	    }
+	    else if ( !strncmp (sw, "-Wno-",5) )	{
+		if (!strcmp (sw, "-Wno-lint")) {
+		    FileLine::defaultFileLine().warnLintOff(true);
+		}
+		else {
+		    string msg = sw+strlen("-Wno-");
+		    if (!(FileLine::defaultFileLine().warnOff(msg, true))) {
+			fl->v3fatal("Unknown warning specified: "<<sw);
+		    }
+		}
+	    }
+	    else if ( !strncmp (sw, "-Wwarn-",5) )	{
+		if (!strcmp (sw, "-Wwarn-lint")) {
+		    FileLine::defaultFileLine().warnLintOff(false);
+		}
+		else {
+		    string msg = sw+strlen("-Wwarn-");
+		    if (!(FileLine::defaultFileLine().warnOff(msg, false))) {
+			fl->v3fatal("Unknown warning specified: "<<sw);
+		    }
+		}
+	    }
 	    else if ( !strcmp (sw, "-bin") && (i+1)<argc ) {
 		shift; m_bin = argv[i];
 	    }