re PR tree-optimization/84224 (ICE in execute, at gimple-ssa-warn-alloca.c:448)

	PR tree-optimization/84224
	* gimple-ssa-warn-alloca.c (pass_walloca::execute): Remove assert.
	* calls.c (gimple_alloca_call_p): Only return TRUE when we have
	non-zero arguments.

From-SVN: r257480

gcc/ChangeLog

+2018-02-08  Aldy Hernandez  <aldyh@redhat.com>
+
+	PR tree-optimization/84224
+	* gimple-ssa-warn-alloca.c (pass_walloca::execute): Remove assert.
+	* calls.c (gimple_alloca_call_p): Only return TRUE when we have
+	non-zero arguments.
+
 2018-02-07  Iain Sandoe  <iain@codesourcery.com>
 
 	* config/rs6000/altivec.md (*restore_world): Remove LR use.

gcc/calls.c

@@ -730,7 +730,7 @@ gimple_alloca_call_p (const gimple *stmt)
     switch (DECL_FUNCTION_CODE (fndecl))
       {
       CASE_BUILT_IN_ALLOCA:
-        return true;
+	return gimple_call_num_args (stmt) > 0;
       default:
 	break;
       }

gcc/gimple-ssa-warn-alloca.c

@@ -445,7 +445,6 @@ pass_walloca::execute (function *fun)
 
 	  if (!gimple_alloca_call_p (stmt))
 	    continue;
-	  gcc_assert (gimple_call_num_args (stmt) >= 1);
 
 	  const bool is_vla
 	    = gimple_call_alloca_for_var_p (as_a <gcall *> (stmt));

gcc/testsuite/gcc.dg/Walloca-16.c

+/* PR tree-optimization/84224 */
+/* { dg-do compile } */
+/* { dg-options "-O0 -Walloca" } */
+
+void *alloca ();
+__typeof__(alloca ()) a () { return alloca (); }