From: Matthias Braun <matze@braunis.de>
Date: Tue, 4 May 2010 10:30:06 +0000 (+0000)
Subject: fix obstack printf being limited to 1024 bytes
X-Git-Url: http://nsz.repo.hu/git/?a=commitdiff_plain;h=8dc2105e636a5d40655bf7701b90bd2af68f9a19;p=libfirm

fix obstack printf being limited to 1024 bytes

[r27474]
---

diff --git a/ir/obstack/obstack_printf.c b/ir/obstack/obstack_printf.c
index 65f06dc4f..1b432e2ec 100644
--- a/ir/obstack/obstack_printf.c
+++ b/ir/obstack/obstack_printf.c
@@ -1,5 +1,6 @@
 #include <stdarg.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include "obstack.h"
 
 #ifdef _WIN32
@@ -8,14 +9,42 @@
 
 int obstack_printf(struct obstack *obst, const char *fmt, ...)
 {
-  char buf[1024];
-  va_list ap;
-  int len;
+	char  buf[128];
+	char *buffer = buf;
+	va_list ap;
+	int len;
 
-  va_start(ap, fmt);
-  len = vsnprintf(buf, sizeof(buf), fmt, ap);
-  obstack_grow(obst, buf, len);
-  va_end(ap);
+	va_start(ap, fmt);
+	len = vsnprintf(buffer, sizeof(buffer), fmt, ap);
+	va_end(ap);
+	if (len < 0 || len >= (int) sizeof(buffer)) {
+		size_t size   = len >= 0 ? (size_t) len : sizeof(buffer) * 2;
+		char  *buffer = malloc(size);
+		do {
+			if (buffer == NULL)
+				return -1;
 
-  return len;
+			va_start(ap, fmt);
+			len = vsnprintf(buffer, size, fmt, ap);
+			va_end(ap);
+
+			/* snprintf should return -1 only in the error case, but older
+			 * glibcs and probably other systems are buggy in this respect and
+			 * return -1 if the buffer was too small. We only abort for LARGE
+			 * unrealistic buffer sizes here */
+			if (len < 0) {
+				if (size > 65536)
+					return -1;
+				size *= 2;
+				buffer = realloc(buffer, size);
+			} else if (len >= (int) size) {
+				/* this should not happen if snprintf works correctly */
+				abort();
+			}
+		} while (len < 0);
+		free(buffer);
+	}
+	obstack_grow(obst, buffer, len);
+
+	return len;
 }