re PR sanitizer/81715 (asan-stack=1 redzone allocation is too inflexible)

	PR sanitizer/81715
	PR testsuite/83882
	* function.h (gimplify_parameters): Add gimple_seq * argument.
	* function.c: Include gimple.h and options.h.
	(gimplify_parameters): Add cleanup argument, add CLOBBER stmts
	for the added local temporaries if needed.
	* gimplify.c (gimplify_body): Adjust gimplify_parameters caller,
	if there are any parameter cleanups, wrap whole body into a
	try/finally with the cleanups.

From-SVN: r256861

gcc/ChangeLog

+2018-01-18  Jakub Jelinek  <jakub@redhat.com>
+
+	PR sanitizer/81715
+	PR testsuite/83882
+	* function.h (gimplify_parameters): Add gimple_seq * argument.
+	* function.c: Include gimple.h and options.h.
+	(gimplify_parameters): Add cleanup argument, add CLOBBER stmts
+	for the added local temporaries if needed.
+	* gimplify.c (gimplify_body): Adjust gimplify_parameters caller,
+	if there are any parameter cleanups, wrap whole body into a
+	try/finally with the cleanups.
+
 2018-01-18  Wilco Dijkstra  <wdijkstr@arm.com>
 
 	PR target/82964

gcc/function.c

@@ -79,6 +79,8 @@ along with GCC; see the file COPYING3.  If not see
 #include "tree-ssa.h"
 #include "stringpool.h"
 #include "attribs.h"
+#include "gimple.h"
+#include "options.h"
 
 /* So we can assign to cfun in this file.  */
 #undef cfun
@@ -3993,7 +3995,7 @@ gimplify_parm_type (tree *tp, int *walk_subtrees, void *data)
    statements to add to the beginning of the function.  */
 
 gimple_seq
-gimplify_parameters (void)
+gimplify_parameters (gimple_seq *cleanup)
 {
   struct assign_parm_data_all all;
   tree parm;
@@ -4058,6 +4060,16 @@ gimplify_parameters (void)
 		  else if (TREE_CODE (type) == COMPLEX_TYPE
 			   || TREE_CODE (type) == VECTOR_TYPE)
 		    DECL_GIMPLE_REG_P (local) = 1;
+
+		  if (!is_gimple_reg (local)
+		      && flag_stack_reuse != SR_NONE)
+		    {
+		      tree clobber = build_constructor (type, NULL);
+		      gimple *clobber_stmt;
+		      TREE_THIS_VOLATILE (clobber) = 1;
+		      clobber_stmt = gimple_build_assign (local, clobber);
+		      gimple_seq_add_stmt (cleanup, clobber_stmt);
+		    }
 		}
 	      else
 		{

gcc/function.h

@@ -607,7 +607,7 @@ extern bool initial_value_entry (int i, rtx *, rtx *);
 extern void instantiate_decl_rtl (rtx x);
 extern int aggregate_value_p (const_tree, const_tree);
 extern bool use_register_for_decl (const_tree);
-extern gimple_seq gimplify_parameters (void);
+extern gimple_seq gimplify_parameters (gimple_seq *);
 extern void locate_and_pad_parm (machine_mode, tree, int, int, int,
 				 tree, struct args_size *,
 				 struct locate_and_pad_arg_data *);

gcc/gimplify.c

@@ -12589,7 +12589,7 @@ gbind *
 gimplify_body (tree fndecl, bool do_parms)
 {
   location_t saved_location = input_location;
-  gimple_seq parm_stmts, seq;
+  gimple_seq parm_stmts, parm_cleanup = NULL, seq;
   gimple *outer_stmt;
   gbind *outer_bind;
   struct cgraph_node *cgn;
@@ -12628,7 +12628,7 @@ gimplify_body (tree fndecl, bool do_parms)
 
   /* Resolve callee-copies.  This has to be done before processing
      the body so that DECL_VALUE_EXPR gets processed correctly.  */
-  parm_stmts = do_parms ? gimplify_parameters () : NULL;
+  parm_stmts = do_parms ? gimplify_parameters (&parm_cleanup) : NULL;
 
   /* Gimplify the function's body.  */
   seq = NULL;
@@ -12657,6 +12657,13 @@ gimplify_body (tree fndecl, bool do_parms)
       tree parm;
 
       gimplify_seq_add_seq (&parm_stmts, gimple_bind_body (outer_bind));
+      if (parm_cleanup)
+	{
+	  gtry *g = gimple_build_try (parm_stmts, parm_cleanup,
+				      GIMPLE_TRY_FINALLY);
+	  parm_stmts = NULL;
+	  gimple_seq_add_stmt (&parm_stmts, g);
+	}
       gimple_bind_set_body (outer_bind, parm_stmts);
 
       for (parm = DECL_ARGUMENTS (current_function_decl);