re PR sanitizer/77396 (address sanitizer crashes if all static global variables are optimized)

	PR sanitizer/77396
	* sanopt.c: Include gimple-ssa.h, tree-phinodes.h and ssa-iterators.h.
	(sanopt_optimize_walker): Optimize away
	__asan_before_dynamic_init (...) followed by
	__asan_after_dynamic_init () without intervening memory loads/stores.
	* ipa-pure-const.c (special_builtin_state): Handle
	BUILT_IN_ASAN_BEFORE_DYNAMIC_INIT and
	BUILT_IN_ASAN_AFTER_DYNAMIC_INIT.

	* decl2.c (do_static_initialization_or_destruction): Only
	call asan_dynamic_init_call if INITP is true.

	* g++.dg/asan/pr77396.C: New test.

From-SVN: r239961

gcc/ChangeLog

+2016-09-02  Jakub Jelinek  <jakub@redhat.com>
+
+	PR sanitizer/77396
+	* sanopt.c: Include gimple-ssa.h, tree-phinodes.h and ssa-iterators.h.
+	(sanopt_optimize_walker): Optimize away
+	__asan_before_dynamic_init (...) followed by
+	__asan_after_dynamic_init () without intervening memory loads/stores.
+	* ipa-pure-const.c (special_builtin_state): Handle
+	BUILT_IN_ASAN_BEFORE_DYNAMIC_INIT and
+	BUILT_IN_ASAN_AFTER_DYNAMIC_INIT.
+
 2016-09-02  Prathamesh Kulkarni  <prathamesh.kulkarni@linaro.org>
 
 	* cfg.c (free_original_copy_tables): Replace second assignment of

gcc/cp/ChangeLog

+2016-09-02  Jakub Jelinek  <jakub@redhat.com>
+
+	PR sanitizer/77396
+	* decl2.c (do_static_initialization_or_destruction): Only
+	call asan_dynamic_init_call if INITP is true.
+
 2016-09-01  Martin Sebor  <msebor@redhat.com>
 
 	* mangle.c: Increase buffer size to guarantee it fits the output

gcc/cp/decl2.c

@@ -3861,7 +3861,7 @@ do_static_initialization_or_destruction (tree vars, bool initp)
      in other compilation units, or at least those that haven't been
      initialized yet.  Variables that need dynamic construction in
      the current compilation unit are kept accessible.  */
-  if (flag_sanitize & SANITIZE_ADDRESS)
+  if (initp && (flag_sanitize & SANITIZE_ADDRESS))
     finish_expr_stmt (asan_dynamic_init_call (/*after_p=*/false));
 
   node = vars;
@@ -3914,7 +3914,7 @@ do_static_initialization_or_destruction (tree vars, bool initp)
 
   /* Revert what __asan_before_dynamic_init did by calling
      __asan_after_dynamic_init.  */
-  if (flag_sanitize & SANITIZE_ADDRESS)
+  if (initp && (flag_sanitize & SANITIZE_ADDRESS))
     finish_expr_stmt (asan_dynamic_init_call (/*after_p=*/true));
 
   /* Finish up the init/destruct if-stmt body.  */

gcc/ipa-pure-const.c

@@ -508,6 +508,8 @@ special_builtin_state (enum pure_const_state_e *state, bool *looping,
 	case BUILT_IN_FRAME_ADDRESS:
 	case BUILT_IN_APPLY:
 	case BUILT_IN_APPLY_ARGS:
+	case BUILT_IN_ASAN_BEFORE_DYNAMIC_INIT:
+	case BUILT_IN_ASAN_AFTER_DYNAMIC_INIT:
 	  *looping = false;
 	  *state = IPA_CONST;
 	  return true;

gcc/sanopt.c

@@ -33,6 +33,9 @@ along with GCC; see the file COPYING3.  If not see
 #include "ubsan.h"
 #include "params.h"
 #include "tree-hash-traits.h"
+#include "gimple-ssa.h"
+#include "tree-phinodes.h"
+#include "ssa-iterators.h"
 
 
 /* This is used to carry information about basic blocks.  It is
@@ -538,6 +541,28 @@ sanopt_optimize_walker (basic_block bb, struct sanopt_ctx *ctx)
       if (asan_check_optimize && !nonfreeing_call_p (stmt))
 	info->freeing_call_events++;
 
+      /* If __asan_before_dynamic_init ("module"); is followed by
+	 __asan_after_dynamic_init (); without intervening memory loads/stores,
+	 there is nothing to guard, so optimize both away.  */
+      if (asan_check_optimize
+	  && gimple_call_builtin_p (stmt, BUILT_IN_ASAN_BEFORE_DYNAMIC_INIT))
+	{
+	  use_operand_p use;
+	  gimple *use_stmt;
+	  if (single_imm_use (gimple_vdef (stmt), &use, &use_stmt))
+	    {
+	      if (is_gimple_call (use_stmt)
+		  && gimple_call_builtin_p (use_stmt,
+					    BUILT_IN_ASAN_AFTER_DYNAMIC_INIT))
+		{
+		  unlink_stmt_vdef (use_stmt);
+		  gimple_stmt_iterator gsi2 = gsi_for_stmt (use_stmt);
+		  gsi_remove (&gsi2, true);
+		  remove = true;
+		}
+	    }
+	}
+
       if (gimple_call_internal_p (stmt))
 	switch (gimple_call_internal_fn (stmt))
 	  {

gcc/testsuite/ChangeLog

+2016-09-02  Jakub Jelinek  <jakub@redhat.com>
+
+	PR sanitizer/77396
+	* g++.dg/asan/pr77396.C: New test.
+
 2016-09-01  Martin Sebor  <msebor@redhat.com>
 
 	PR tree-optimization/71831

gcc/testsuite/g++.dg/asan/pr77396.C

+// PR sanitizer/77396
+// { dg-do run }
+// { dg-set-target-env-var ASAN_OPTIONS "check_initialization_order=true" }
+
+static int a = 0; 
+static int b = a; 
+
+int
+main ()
+{
+  return 0;
+}