GCのタイミングでバックトレース吐く奴。Ruby1.9.3用。

ouput_backtrace_at_gc.patch

diff --git a/gc.c b/gc.c
index 1d3ac79..2b833da 100644
--- a/gc.c
+++ b/gc.c
@@ -2585,7 +2585,8 @@ garbage_collect(rb_objspace_t *objspace)
 {
     INIT_GC_PROF_PARAMS;
 
-    if (GC_NOTIFY) printf("start garbage_collect()\n");
+    fprintf(stderr, "garbage_collect(%d)\n", objspace->count);
+    rb_print_backtrace();
 
     if (!heaps) {
 	return FALSE;
diff --git a/internal.h b/internal.h
index 59c9284..9806bdc 100644
--- a/internal.h
+++ b/internal.h
@@ -196,6 +196,7 @@ const void **rb_vm_get_insns_address_table(void);
 
 /* vm_dump.c */
 void rb_vm_bugreport(void);
+void rb_print_backtrace(void);
 
 /* vm_eval.c */
 void Init_vm_eval(void);
diff --git a/vm_dump.c b/vm_dump.c
index 63a10a5..1a4428b 100644
--- a/vm_dump.c
+++ b/vm_dump.c
@@ -767,6 +767,34 @@ dump_thread(void *arg)
 #endif
 
 void
+rb_print_backtrace(void)
+{
+#if HAVE_BACKTRACE
+#define MAX_NATIVE_TRACE 1024
+    static void *trace[MAX_NATIVE_TRACE];
+    int n = backtrace(trace, MAX_NATIVE_TRACE);
+    char **syms = backtrace_symbols(trace, n);
+
+    if (syms) {
+#ifdef USE_ELF
+	rb_dump_backtrace_with_lines(n, trace, syms);
+#else
+	int i;
+	for (i=0; i<n; i++) {
+	    fprintf(stderr, "%s\n", syms[i]);
+	}
+#endif
+	free(syms);
+    }
+#elif defined(_WIN32)
+    DWORD tid = GetCurrentThreadId();
+    HANDLE th = (HANDLE)_beginthread(dump_thread, 0, &tid);
+    if (th != (HANDLE)-1)
+	WaitForSingleObject(th, INFINITE);
+#endif
+}
+
+void
 rb_vm_bugreport(void)
 {
     rb_vm_t *vm = GET_VM();
@@ -782,38 +810,7 @@ rb_vm_bugreport(void)
 #if HAVE_BACKTRACE || defined(_WIN32)
     fprintf(stderr, "-- C level backtrace information "
 	    "-------------------------------------------\n");
-
-    {
-#if defined __MACH__ && defined __APPLE__
-	fprintf(stderr, "\n");
-	fprintf(stderr, "   See Crash Report log file under "
-		"~/Library/Logs/CrashReporter or\n");
-	fprintf(stderr, "   /Library/Logs/CrashReporter, for "
-		"the more detail of.\n");
-#elif HAVE_BACKTRACE
-#define MAX_NATIVE_TRACE 1024
-	static void *trace[MAX_NATIVE_TRACE];
-	int n = backtrace(trace, MAX_NATIVE_TRACE);
-	char **syms = backtrace_symbols(trace, n);
-
-	if (syms) {
-#ifdef USE_ELF
-	    rb_dump_backtrace_with_lines(n, trace, syms);
-#else
-	    int i;
-	    for (i=0; i<n; i++) {
-		fprintf(stderr, "%s\n", syms[i]);
-	    }
-#endif
-	    free(syms);
-	}
-#elif defined(_WIN32)
-	DWORD tid = GetCurrentThreadId();
-	HANDLE th = (HANDLE)_beginthread(dump_thread, 0, &tid);
-	if (th != (HANDLE)-1)
-	    WaitForSingleObject(th, INFINITE);
-#endif
-    }
+    rb_print_backtrace();
 
     fprintf(stderr, "\n");
 #endif /* HAVE_BACKTRACE */