On core dump, print debug suggestions.

Changes

@@ -9,6 +9,8 @@ indicates the contributor was also the author of the fix; Thanks!
 
 **** Increase define recursions before error.  [Paul Liu]
 
+**** On core dump, print debug suggestions.
+
 * Verilator 3.803 2010/07/10
 
 ***  Fix preprocessor preservation of newlines across macro substitutions.

bin/verilator

@@ -137,6 +137,15 @@ sub run {
 	    warn "%Error: export VERILATOR_ROOT=".($ENV{VERILATOR_ROOT}||"")."\n";
 	    warn "%Error: $command\n";
 	}
+	if ($status & 255) {
+	    if (($status & 255) == 8 || ($status & 255) == 11) { # SIGFPA or SIGSEGV
+		warn "%Error: Verilator internal fault, sorry.  Consider trying --debug --gdbbt\n" if !$Debug;
+	    } elsif (($status & 255) == 6) {  # SIGABRT
+		warn "%Error: Verilator aborted.  Consider trying --debug --gdbbt\n" if !$Debug;
+	    } else {
+		warn "%Error: Verilator threw signal $status.  Consider trying --debug --gdbbt\n" if !$Debug;
+	    }
+	}
 	die "%Error: Command Failed $command\n";
     }
 }

src/V3Options.cpp

@@ -614,7 +614,9 @@ void V3Options::parseOptsList(FileLine* fl, int argc, char** argv) {
 	    else if ( onoff   (sw, "-coverage-underscore", flag/*ref*/) ){ m_coverageUnderscore = flag; }
 	    else if ( onoff   (sw, "-coverage-user", flag/*ref*/) ){ m_coverageUser = flag; }
 	    else if ( onoff   (sw, "-covsp", flag/*ref*/) )	{ }  // TBD
+	    else if ( !strcmp (sw, "-debug-abort") )		{ abort(); } // Undocumented, see also --debug-core-dump
 	    else if ( onoff   (sw, "-debug-check", flag/*ref*/) ){ m_debugCheck = flag; }
+	    else if ( !strcmp (sw, "-debug-core-dump") )	{ char* zp=NULL; *zp=0; }  // Undocumented, see also --debug-abort
 	    else if ( onoff   (sw, "-dump-tree", flag/*ref*/) )	{ m_dumpTree = flag; }
 	    else if ( onoff   (sw, "-exe", flag/*ref*/) )	{ m_exe = flag; }
 	    else if ( onoff   (sw, "-ignc", flag/*ref*/) )	{ m_ignc = flag; }

test_regress/t/t_debug_sigsegv_bad.pl

@@ -0,0 +1,21 @@
+#!/usr/bin/perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2003 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+
+$Self->{vlt} or $Self->skip("Verilator only test");
+
+compile (
+	 v_flags2 => ["--debug-core-dump"],
+	 fails=>$Self->{v3},
+	 expect=>
+'%Error: Verilator internal fault, sorry.  Consider trying --debug --gdbbt
+%Error: Command Failed.*',
+	 );
+
+ok(1);
+1;