PR middle-end/36520

	* builtins.c (get_memory_rtx): Test for the presence of DECL_SIZE_UNIT
	before evaluating it.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@136747 138bc75d-0d04-0410-961f-82ee72b054a4

4 files changed, 55 insertions, 3 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 37ff36aaa9e..6d20774cb1f 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2008-06-13  Eric Botcazou  <ebotcazou@adacore.com>
+
+	PR middle-end/36520
+	* builtins.c (get_memory_rtx): Test for the presence of DECL_SIZE_UNIT
+	before evaluating it.
+
 2008-06-13  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c/36507
diff --git a/gcc/builtins.c b/gcc/builtins.c
index edc5d5f07f3..b3fc3041377 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -1125,14 +1125,16 @@ get_memory_rtx (tree exp, tree len)
 			      && (TREE_INT_CST_LOW (DECL_SIZE (field))
 				  % BITS_PER_UNIT) == 0));
 
+	      /* If we can prove that the memory starting at XEXP (mem, 0) and
+		 ending at XEXP (mem, 0) + LENGTH will fit into this field, we
+		 can keep the COMPONENT_REF in MEM_EXPR.  But be careful with
+		 fields without DECL_SIZE_UNIT like flexible array members.  */
 	      if (length >= 0
+		  && DECL_SIZE_UNIT (field)
 		  && host_integerp (DECL_SIZE_UNIT (field), 0))
 		{
 		  HOST_WIDE_INT size
 		    = TREE_INT_CST_LOW (DECL_SIZE_UNIT (field));
-		  /* If we can prove the memory starting at XEXP (mem, 0)
-		     and ending at XEXP (mem, 0) + LENGTH will fit into
-		     this field, we can keep that COMPONENT_REF in MEM_EXPR.  */
 		  if (offset <= size
 		      && length <= size
 		      && offset + length <= size)
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index c9e1e422496..ae25ac0723e 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2008-06-13  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gcc.c-torture/compile/20080613-1.c: New test.
+
 2008-06-13  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c/36507
diff --git a/gcc/testsuite/gcc.c-torture/compile/20080613-1.c b/gcc/testsuite/gcc.c-torture/compile/20080613-1.c
new file mode 100644
index 00000000000..f64964e7740
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/20080613-1.c
@@ -0,0 +1,40 @@
+/* PR middle-end/36520 */
+/* Testcase by Richard Guenther <rguenth@gcc.gnu.org> */
+
+typedef long unsigned int size_t;
+typedef unsigned short int sa_family_t;
+struct cmsghdr   {
+    size_t cmsg_len;
+    __extension__ unsigned char __cmsg_data [];
+};
+typedef unsigned int uint32_t;
+struct in6_addr   {
+    union       {
+        uint32_t u6_addr32[4];
+    } in6_u;
+};
+struct sockaddr_in   {
+    sa_family_t sin_family;
+};
+struct in6_pktinfo   {
+    struct in6_addr ipi6_addr;
+};
+typedef union {
+    struct sockaddr_in sin;
+} sockaddr_any;
+static sockaddr_any src_addr;
+
+inline struct cmsghdr * cmsg_put(struct cmsghdr *cm, int type, void *data, size_t len)
+{
+    memcpy(((cm)->__cmsg_data), data, len);
+}
+
+int hop_sendmsg(int fd) {
+    struct cmsghdr *cm;
+    if (src_addr.sin.sin_family) {
+        if (src_addr.sin.sin_family == 2) {
+            struct in6_pktinfo info;
+            cm = cmsg_put(cm, 50, &info, sizeof(info));
+        }
+    }
+}