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

	PR sanitizer/81715
	* tree-inline.c (expand_call_inline): Emit clobber stmts for
	VAR_DECLs to which addressable non-volatile parameters are mapped
	and for id->retvar after the return value assignment.  Clear
	id->retval and id->retbnd after inlining.

	* g++.dg/tree-ssa/pr8781.C (noop): Change argument type from
	const predicate to const predicate & to avoid UB.
	* g++.dg/opt/pr81715.C: New test.

From-SVN: r253065

1 files changed, 53 insertions, 1 deletions

diff --git a/gcc/tree-inline.c b/gcc/tree-inline.c
index cce5dc7..a226096 100644
--- a/gcc/tree-inline.c
+++ b/gcc/tree-inline.c
@@ -4796,6 +4796,22 @@ expand_call_inline (basic_block bb, gimple *stmt, copy_body_data *id)
 
   reset_debug_bindings (id, stmt_gsi);
 
+  if (flag_stack_reuse != SR_NONE)
+    for (tree p = DECL_ARGUMENTS (id->src_fn); p; p = DECL_CHAIN (p))
+      if (!TREE_THIS_VOLATILE (p))
+	{
+	  tree *varp = id->decl_map->get (p);
+	  if (varp && VAR_P (*varp) && !is_gimple_reg (*varp))
+	    {
+	      tree clobber = build_constructor (TREE_TYPE (*varp), NULL);
+	      gimple *clobber_stmt;
+	      TREE_THIS_VOLATILE (clobber) = 1;
+	      clobber_stmt = gimple_build_assign (*varp, clobber);
+	      gimple_set_location (clobber_stmt, gimple_location (stmt));
+	      gsi_insert_before (&stmt_gsi, clobber_stmt, GSI_SAME_STMT);
+	    }
+	}
+
   /* Reset the escaped solution.  */
   if (cfun->gimple_df)
     pt_solution_reset (&cfun->gimple_df->escaped);
@@ -4846,6 +4862,23 @@ expand_call_inline (basic_block bb, gimple *stmt, copy_body_data *id)
       stmt = gimple_build_assign (gimple_call_lhs (stmt), use_retvar);
       gsi_replace (&stmt_gsi, stmt, false);
       maybe_clean_or_replace_eh_stmt (old_stmt, stmt);
+      /* Append a clobber for id->retvar if easily possible.  */
+      if (flag_stack_reuse != SR_NONE
+	  && id->retvar
+	  && VAR_P (id->retvar)
+	  && id->retvar != return_slot
+	  && id->retvar != modify_dest
+	  && !TREE_THIS_VOLATILE (id->retvar)
+	  && !is_gimple_reg (id->retvar)
+	  && !stmt_ends_bb_p (stmt))
+	{
+	  tree clobber = build_constructor (TREE_TYPE (id->retvar), NULL);
+	  gimple *clobber_stmt;
+	  TREE_THIS_VOLATILE (clobber) = 1;
+	  clobber_stmt = gimple_build_assign (id->retvar, clobber);
+	  gimple_set_location (clobber_stmt, gimple_location (old_stmt));
+	  gsi_insert_after (&stmt_gsi, clobber_stmt, GSI_SAME_STMT);
+	}
 
       /* Copy bounds if we copy structure with bounds.  */
       if (chkp_function_instrumented_p (id->dst_fn)
@@ -4884,8 +4917,25 @@ expand_call_inline (basic_block bb, gimple *stmt, copy_body_data *id)
 	      SSA_NAME_DEF_STMT (name) = gimple_build_nop ();
 	    }
 	}
+      /* Replace with a clobber for id->retvar.  */
+      else if (flag_stack_reuse != SR_NONE
+	       && id->retvar
+	       && VAR_P (id->retvar)
+	       && id->retvar != return_slot
+	       && id->retvar != modify_dest
+	       && !TREE_THIS_VOLATILE (id->retvar)
+	       && !is_gimple_reg (id->retvar))
+	{
+	  tree clobber = build_constructor (TREE_TYPE (id->retvar), NULL);
+	  gimple *clobber_stmt;
+	  TREE_THIS_VOLATILE (clobber) = 1;
+	  clobber_stmt = gimple_build_assign (id->retvar, clobber);
+	  gimple_set_location (clobber_stmt, gimple_location (stmt));
+	  gsi_replace (&stmt_gsi, clobber_stmt, false);
+	  maybe_clean_or_replace_eh_stmt (stmt, clobber_stmt);
+	}
       else
-        gsi_remove (&stmt_gsi, true);
+	gsi_remove (&stmt_gsi, true);
     }
 
   /* Put returned bounds into the correct place if required.  */
@@ -4934,6 +4984,8 @@ expand_call_inline (basic_block bb, gimple *stmt, copy_body_data *id)
   cg_edge->callee->remove ();
 
   id->block = NULL_TREE;
+  id->retvar = NULL_TREE;
+  id->retbnd = NULL_TREE;
   successfully_inlined = true;
 
  egress: