Patch to make MRI/Ruby safe for -pg

sigprof.patch

From 98fc9cd0b28921dc02ee4c366c96e4caeb7d8475 Mon Sep 17 00:00:00 2001
From: Greg Price <price@mit.edu>
Date: Wed, 31 Oct 2012 15:53:59 -0700
Subject: [PATCH] Suppress SIGPROF

We don't handle it well -- the exact reason is unclear, but threading
seems to trigger it -- so just squelch it.

Building with -pg is necessary for getting call-graph information with
e.g. the Linux 'perf' profiler.  But -pg also causes the libc startup
routine to set a SIGPROF timer.  That doesn't serve any purpose with a
modern profiler like 'perf'; it was used by 'gprof'.
---
 main.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/main.c b/main.c
index f4d526a..a824afb 100644
--- a/main.c
+++ b/main.c
@@ -18,6 +18,7 @@
 #ifdef RUBY_DEBUG_ENV
 #include <stdlib.h>
 #endif
+#include <sys/time.h>
 
 int
 main(int argc, char **argv)
@@ -29,6 +30,11 @@ main(int argc, char **argv)
     setlocale(LC_CTYPE, "");
 #endif
 
+    {
+	struct itimerval itimer = {{0, 0}, {0, 0}};
+	setitimer(ITIMER_PROF, &itimer, NULL);
+    }
+
     ruby_sysinit(&argc, &argv);
     {
 	RUBY_INIT_STACK;
-- 
1.7.11.3