From: Steven G. Kargl <kargl@gcc.gnu.org>
Date: Fri, 28 Dec 2018 18:26:09 +0000 (+0000)
Subject: re PR libfortran/81984 (NULL string pointer dereferencing forces undefined behaviour... 
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=07b700ead5362478da6686c28d30fe4ffac2b6bd;p=gcc.git

re PR libfortran/81984 (NULL string pointer dereferencing forces undefined behaviour in libgfortran)

2018-12-28  Steven G. Kargl  <kargl@gcc.gnu.org>

	PR fortran/81984
	* intrinsics/string_intrinsics_inc.c: Placate the sanitizer.

From-SVN: r267452
---

diff --git a/libgfortran/ChangeLog b/libgfortran/ChangeLog
index 03efb11a29d..8397eee6607 100644
--- a/libgfortran/ChangeLog
+++ b/libgfortran/ChangeLog
@@ -1,3 +1,8 @@
+2018-12-28  Steven G. Kargl  <kargl@gcc.gnu.org>
+
+	PR fortran/81984
+	* intrinsics/string_intrinsics_inc.c: Placate the sanitizer.
+
 2018-12-21  Steven G. Kargl  <kargl@gcc.gnu.org>
 
 	PR fortran/69121
diff --git a/libgfortran/intrinsics/string_intrinsics_inc.c b/libgfortran/intrinsics/string_intrinsics_inc.c
index bfec683f528..b81c806db5d 100644
--- a/libgfortran/intrinsics/string_intrinsics_inc.c
+++ b/libgfortran/intrinsics/string_intrinsics_inc.c
@@ -87,6 +87,14 @@ compare_string (gfc_charlen_type len1, const CHARTYPE *s1,
   gfc_charlen_type len;
   int res;
 
+  /* Placate the sanitizer.  */
+  if (!s1 && !s2)
+    return 0;
+  if (!s1)
+    return -1;
+  if (!s2)
+    return 1;
+
   res = MEMCMP (s1, s2, ((len1 < len2) ? len1 : len2));
   if (res != 0)
     return res;