Added "yosys -W regex"

kernel/driver.cc

@@ -218,6 +218,9 @@ int main(int argc, char **argv)
 		printf("        yosys_dump_<header_id>.il is used as filename if none is specified.\n");
 		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("\n");
 		printf("    -V\n");
 		printf("        print version information and exit\n");
 		printf("\n");
@@ -238,7 +241,7 @@ int main(int argc, char **argv)
 	}
 
 	int opt;
-	while ((opt = getopt(argc, argv, "MXAQTVSm:f:Hh:b:o:p:l:L:qv:tds:c:D:")) != -1)
+	while ((opt = getopt(argc, argv, "MXAQTVSm:f:Hh:b:o:p:l:L:qv:tds:c:W:D:")) != -1)
 	{
 		switch (opt)
 		{
@@ -320,6 +323,12 @@ int main(int argc, char **argv)
 			scriptfile = optarg;
 			scriptfile_tcl = true;
 			break;
+		case 'W':
+			log_warn_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

@@ -41,6 +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;
 bool log_hdump_all = false;
 FILE *log_errfile = NULL;
 SHA1 *log_hasher = NULL;
@@ -136,6 +137,32 @@ void logv(const char *format, va_list ap)
 
 	for (auto f : log_streams)
 		*f << str;
+
+	static std::string linebuffer;
+	static bool log_warn_regex_recusion_guard = false;
+
+	if (!log_warn_regex_recusion_guard)
+	{
+		log_warn_regex_recusion_guard = true;
+
+		if (log_warn_regexes.empty())
+		{
+			linebuffer.clear();
+		}
+		else
+		{
+			linebuffer += str;
+
+			if (!linebuffer.empty() && linebuffer.back() == '\n') {
+				for (auto &re : log_warn_regexes)
+					if (std::regex_search(linebuffer, re))
+						log_warning("Found log message matching -W regex:\n%s", str.c_str());
+				linebuffer.clear();
+			}
+		}
+
+		log_warn_regex_recusion_guard = false;
+	}
 }
 
 void logv_header(RTLIL::Design *design, const char *format, va_list ap)
@@ -262,8 +289,12 @@ void log_cmd_error(const char *format, ...)
 
 void log_spacer()
 {
-	while (log_newline_count < 2)
+	while (log_newline_count < 2) {
+		int old_log_newline_count = log_newline_count;
 		log("\n");
+		if (old_log_newline_count >= log_newline_count)
+			break;
+	}
 }
 
 void log_push()

kernel/log.h

@@ -23,6 +23,7 @@
 #define LOG_H
 
 #include <time.h>
+#include <regex>
 
 #ifndef _WIN32
 #  include <sys/time.h>
@@ -48,6 +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 bool log_hdump_all;
 extern FILE *log_errfile;
 extern SHA1 *log_hasher;