gcc/gcc48-asan-fix.patch

2013-02-15  Jakub Jelinek  <jakub@redhat.com>

	PR sanitizer/56330
	* asan.c (get_mem_refs_of_builtin_call): Fix up indentation.
	(instrument_mem_region_access): Create conditional even when
	the start has been already instrumented.  Don't record
	conditional instrumentation in the hash table.  Update *iter
	after second build_check_stmt call.
	(instrument_builtin_call): For consistency test != NULL_TREE
	in all start checks.

	* c-c++-common/asan/no-redundant-instrumentation-1.c: Pass
	3 instead of sizeof (tab) - 1 as last argument.
	* c-c++-common/asan/pr56330.c: New test.

--- gcc/asan.c.jj	2013-02-14 14:45:01.428038792 +0100
+++ gcc/asan.c	2013-02-15 09:37:18.614963383 +0100
@@ -747,20 +747,17 @@ get_mem_refs_of_builtin_call (const gimp
 
       got_reference_p = true;
     }
-    else
-      {
-	if (dest)
-	  {
-	    dst->start = dest;
-	    dst->access_size = access_size;
-	    *dst_len = NULL_TREE;
-	    *dst_is_store = is_store;
-	    *dest_is_deref = true;
-	    got_reference_p = true;
-	  }
-      }
+  else if (dest)
+    {
+      dst->start = dest;
+      dst->access_size = access_size;
+      *dst_len = NULL_TREE;
+      *dst_is_store = is_store;
+      *dest_is_deref = true;
+      got_reference_p = true;
+    }
 
-    return got_reference_p;
+  return got_reference_p;
 }
 
 /* Return true iff a given gimple statement has been instrumented.
@@ -1535,8 +1532,15 @@ instrument_mem_region_access (tree base,
 
   /* If the beginning of the memory region has already been
      instrumented, do not instrument it.  */
-  if (has_mem_ref_been_instrumented (base, 1))
-    goto after_first_instrumentation;
+  bool start_instrumented = has_mem_ref_been_instrumented (base, 1);
+
+  /* If the end of the memory region has already been instrumented, do
+     not instrument it. */
+  tree end = asan_mem_ref_get_end (base, len);
+  bool end_instrumented = has_mem_ref_been_instrumented (end, 1);
+
+  if (start_instrumented && end_instrumented)
+    return;
 
   if (!is_gimple_constant (len))
     {
@@ -1565,34 +1569,36 @@ instrument_mem_region_access (tree base,
       gsi = gsi_start_bb (then_bb);
     }
 
-  /* Instrument the beginning of the memory region to be accessed,
-     and arrange for the rest of the intrumentation code to be
-     inserted in the then block *after* the current gsi.  */
-  build_check_stmt (location, base, &gsi, /*before_p=*/true, is_store, 1);
-
-  if (then_bb)
-    /* We are in the case where the length of the region is not
-       constant; so instrumentation code is being generated in the
-       'then block' of the 'if (len != 0) condition.  Let's arrange
-       for the subsequent instrumentation statements to go in the
-       'then block'.  */
-    gsi = gsi_last_bb (then_bb);
-  else
-    *iter = gsi;
-
-  update_mem_ref_hash_table (base, 1);
+  if (!start_instrumented)
+    {
+      /* Instrument the beginning of the memory region to be accessed,
+	 and arrange for the rest of the intrumentation code to be
+	 inserted in the then block *after* the current gsi.  */
+      build_check_stmt (location, base, &gsi, /*before_p=*/true, is_store, 1);
+
+      if (then_bb)
+	/* We are in the case where the length of the region is not
+	   constant; so instrumentation code is being generated in the
+	   'then block' of the 'if (len != 0) condition.  Let's arrange
+	   for the subsequent instrumentation statements to go in the
+	   'then block'.  */
+	gsi = gsi_last_bb (then_bb);
+      else
+        {
+          *iter = gsi;
+	  /* Don't remember this access as instrumented, if length
+	     is unknown.  It might be zero and not being actually
+	     instrumented, so we can't rely on it being instrumented.  */
+          update_mem_ref_hash_table (base, 1);
+	}
+    }
 
- after_first_instrumentation:
+  if (end_instrumented)
+    return;
 
   /* We want to instrument the access at the end of the memory region,
      which is at (base + len - 1).  */
 
-  /* If the end of the memory region has already been instrumented, do
-     not instrument it. */
-  tree end = asan_mem_ref_get_end (base, len);
-  if (has_mem_ref_been_instrumented (end, 1))
-    return;
-
   /* offset = len - 1;  */
   len = unshare_expr (len);
   tree offset;
@@ -1640,7 +1646,10 @@ instrument_mem_region_access (tree base,
   gimple_set_location (region_end, location);
   gimple_seq_add_stmt_without_update (&seq, region_end);
   gsi_insert_seq_before (&gsi, seq, GSI_SAME_STMT);
-  gsi_prev (&gsi);
+  if (!start_instrumented || then_bb == NULL)
+    gsi_prev (&gsi);
+  else
+    gsi = gsi_last_bb (then_bb);
 
   /* _2 = _1 + offset;  */
   region_end =
@@ -1655,7 +1664,10 @@ instrument_mem_region_access (tree base,
   build_check_stmt (location, gimple_assign_lhs (region_end),
 		    &gsi, /*before_p=*/false, is_store, 1);
 
-  update_mem_ref_hash_table (end, 1);
+  if (then_bb == NULL)
+    update_mem_ref_hash_table (end, 1);
+
+  *iter = gsi_for_stmt (gsi_stmt (*iter));
 }
 
 /* Instrument the call (to the builtin strlen function) pointed to by
@@ -1783,7 +1795,7 @@ instrument_builtin_call (gimple_stmt_ite
 	    }
 	  else if (src0_len || src1_len || dest_len)
 	    {
-	      if (src0.start)
+	      if (src0.start != NULL_TREE)
 		instrument_mem_region_access (src0.start, src0_len,
 					      iter, loc, /*is_store=*/false);
 	      if (src1.start != NULL_TREE)
--- gcc/testsuite/c-c++-common/asan/no-redundant-instrumentation-1.c.jj	2013-02-13 11:53:41.000000000 +0100
+++ gcc/testsuite/c-c++-common/asan/no-redundant-instrumentation-1.c	2013-02-15 09:51:47.485080706 +0100
@@ -45,7 +45,7 @@ test1 ()
   /* There are 2 calls to __builtin___asan_report_store1 and 2 calls
      to __builtin___asan_report_load1 to instrument the store to
      (subset of) the memory region of tab.  */
-  __builtin_memcpy (&tab[1], foo, sizeof (tab) - 1);
+  __builtin_memcpy (&tab[1], foo, 3);
 
   /* This should not generate a __builtin___asan_report_load1 because
      the reference to tab[1] has been already instrumented above.  */
--- gcc/testsuite/c-c++-common/asan/pr56330.c.jj	2013-02-15 09:43:19.293845146 +0100
+++ gcc/testsuite/c-c++-common/asan/pr56330.c	2013-02-15 09:42:58.000000000 +0100
@@ -0,0 +1,23 @@
+/* PR sanitizer/56330 */
+/* { dg-do compile } */
+
+char e[200];
+
+struct S
+{
+  char a[100];
+  char b[100];
+} s;
+
+void
+foo (void)
+{
+  __builtin_memcmp (s.a, e, 100);
+  __builtin_memcmp (s.a, e, 200);
+}
+
+void
+bar (int *a, char *b, char *c)
+{
+  __builtin_memmove (c, b, a[b[0]]);
+}