Add "yosys -w" for suppressing warnings

kernel/driver.cc

@@ -219,7 +219,11 @@ int main(int argc, char **argv)
 		printf("        Use 'ALL' as <header_id> to dump at every header.\n");
 		printf("\n");
 		printf("    -W regex\n");
-		printf("        print a warning for all log messages matching the regex \n");
+		printf("        print a warning for all log messages matching the regex.\n");
+		printf("\n");
+		printf("    -w regex\n");
+		printf("        if a warning message matches the regex, it is printes as regular\n");
+		printf("        message instead.\n");
 		printf("\n");
 		printf("    -V\n");
 		printf("        print version information and exit\n");
@@ -241,7 +245,7 @@ int main(int argc, char **argv)
 	}
 
 	int opt;
-	while ((opt = getopt(argc, argv, "MXAQTVSm:f:Hh:b:o:p:l:L:qv:tds:c:W:D:")) != -1)
+	while ((opt = getopt(argc, argv, "MXAQTVSm:f:Hh:b:o:p:l:L:qv:tds:c:W:w:D:")) != -1)
 	{
 		switch (opt)
 		{
@@ -329,6 +333,12 @@ int main(int argc, char **argv)
 					std::regex_constants::optimize |
 					std::regex_constants::egrep));
 			break;
+		case 'w':
+			log_nowarn_regexes.push_back(std::regex(optarg,
+					std::regex_constants::nosubs |
+					std::regex_constants::optimize |
+					std::regex_constants::egrep));
+			break;
 		case 'D':
 			{
 				auto args = split_tokens(optarg, ":");

kernel/log.cc

@@ -41,7 +41,7 @@ YOSYS_NAMESPACE_BEGIN
 std::vector<FILE*> log_files;
 std::vector<std::ostream*> log_streams;
 std::map<std::string, std::set<std::string>> log_hdump;
-std::vector<std::regex> log_warn_regexes;
+std::vector<std::regex> log_warn_regexes, log_nowarn_regexes;
 bool log_hdump_all = false;
 FILE *log_errfile = NULL;
 SHA1 *log_hasher = NULL;
@@ -201,17 +201,30 @@ void logv_header(RTLIL::Design *design, const char *format, va_list ap)
 }
 
 void logv_warning(const char *format, va_list ap)
+{
+	std::string message = vstringf(format, ap);
+	bool suppressed = false;
+
+	for (auto &re : log_nowarn_regexes)
+		if (std::regex_search(message, re))
+			suppressed = true;
+
+	if (suppressed)
+	{
+		log("Suppressed warning: %s", message.c_str());
+	}
+	else
 	{
 		if (log_errfile != NULL && !log_quiet_warnings)
 			log_files.push_back(log_errfile);
 
-	log("Warning: ");
+		log("Warning: %s", message.c_str());
-	logv(format, ap);
 		log_flush();
 
 		if (log_errfile != NULL && !log_quiet_warnings)
 			log_files.pop_back();
 	}
+}
 
 void logv_error(const char *format, va_list ap)
 {

kernel/log.h

@@ -49,7 +49,7 @@ struct log_cmd_error_exception { };
 extern std::vector<FILE*> log_files;
 extern std::vector<std::ostream*> log_streams;
 extern std::map<std::string, std::set<std::string>> log_hdump;
-extern std::vector<std::regex> log_warn_regexes;
+extern std::vector<std::regex> log_warn_regexes, log_nowarn_regexes;
 extern bool log_hdump_all;
 extern FILE *log_errfile;
 extern SHA1 *log_hasher;