re PR sanitizer/78832 (-fcompare-debug failure (length) with -fsanitize=address)

	PR sanitizer/78832
	* sanopt.c (sanitize_asan_mark_unpoison): Remove next variable, use
	continue if gsi_next should be skipped.
	(sanitize_asan_mark_poison): Remove prev variable, use continue if
	gsi_prev should be skipped.  When removing ASAN_MARK, do gsi_prev
	first and gsi_remove on a previously made copy of the iterator.

	* gcc.dg/asan/pr78832.c: New test.

From-SVN: r243777

gcc/ChangeLog

+2016-12-17  Jakub Jelinek  <jakub@redhat.com>
+
+	PR sanitizer/78832
+	* sanopt.c (sanitize_asan_mark_unpoison): Remove next variable, use
+	continue if gsi_next should be skipped.
+	(sanitize_asan_mark_poison): Remove prev variable, use continue if
+	gsi_prev should be skipped.  When removing ASAN_MARK, do gsi_prev
+	first and gsi_remove on a previously made copy of the iterator.
+
 2016-12-17  Andrew Senkevich  <andrew.senkevich@intel.com>
 
 	* config/i386/avx512bwintrin.h: Add new k-mask intrinsics.

gcc/sanopt.c

@@ -740,7 +740,6 @@ sanitize_asan_mark_unpoison (void)
       gimple_stmt_iterator gsi;
       for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi);)
 	{
-	  bool next = true;
 	  gimple *stmt = gsi_stmt (gsi);
 	  if (gimple_call_internal_p (stmt, IFN_ASAN_MARK))
 	    {
@@ -753,12 +752,11 @@ sanitize_asan_mark_unpoison (void)
 		  unlink_stmt_vdef (stmt);
 		  release_defs (stmt);
 		  gsi_remove (&gsi, true);
-		  next = false;
+		  continue;
 		}
 	    }
 
-	  if (next)
-	    gsi_next (&gsi);
+	  gsi_next (&gsi);
 	}
     }
 }
@@ -840,7 +838,6 @@ sanitize_asan_mark_poison (void)
       gimple_stmt_iterator gsi;
       for (gsi = gsi_last_bb (bb); !gsi_end_p (gsi);)
 	{
-	  bool prev = true;
 	  gimple *stmt = gsi_stmt (gsi);
 	  if (maybe_contains_asan_check (stmt))
 	    break;
@@ -850,12 +847,13 @@ sanitize_asan_mark_poison (void)
 		fprintf (dump_file, "Removing ASAN_MARK poison\n");
 	      unlink_stmt_vdef (stmt);
 	      release_defs (stmt);
-	      gsi_remove (&gsi, true);
-	      prev = false;
+	      gimple_stmt_iterator gsi2 = gsi;
+	      gsi_prev (&gsi);
+	      gsi_remove (&gsi2, true);
+	      continue;
 	    }
 
-	  if (prev)
-	    gsi_prev (&gsi);
+	  gsi_prev (&gsi);
 	}
     }
 }

gcc/testsuite/ChangeLog

+2016-12-17  Jakub Jelinek  <jakub@redhat.com>
+
+	PR sanitizer/78832
+	* gcc.dg/asan/pr78832.c: New test.
+
 2016-12-17  Andrew Senkevich  <andrew.senkevich@intel.com>
 
 	* gcc.target/i386/avx512bw-kaddd-1.c: New test.

gcc/testsuite/gcc.dg/asan/pr78832.c

+/* PR sanitizer/78832 */
+/* { dg-do compile } */
+/* { dg-additional-options "-fcompare-debug" } */
+
+void bar (int *);
+
+int
+foo (int x)
+{
+  int *f = 0;
+  if (x)
+    goto lab;
+  {
+    int y, z;
+    bar (&y);
+    int *d = &y;
+    bar (&z);
+    int *e = &z;
+  }
+  f = &x;
+  lab: return 6;
+}