builtins.c (expand_builtin_va_arg): Give warnings not errors for promoted argument types; build trap.

        * builtins.c (expand_builtin_va_arg): Give warnings not errors for
        promoted argument types; build trap.
        (expand_builtin_trap): New.
        (expand_builtin): Use it.
        * stmt.c (expand_nl_goto_receivers): Likewise.
        * expr.h (expand_builtin_trap): Declare.
        * libfuncs.h (LTI_abort, abort_libfunc): New.
        * optabs.c (init_optabs): Init abort_libfunc.

        * gcc.dg/va-arg-1.c: Expect warnings, not errors.

From-SVN: r51643

1 files changed, 28 insertions, 11 deletions

diff --git a/gcc/builtins.c b/gcc/builtins.c
index eb117ce..effd70d 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -3079,7 +3079,7 @@ expand_builtin_va_arg (valist, type)
   else if ((promoted_type = (*lang_type_promotes_to) (type)) != NULL_TREE)
     {
       const char *name = "<anonymous type>", *pname = 0;
-      static int gave_help;
+      static bool gave_help;
 
       if (TYPE_NAME (type))
 	{
@@ -3098,13 +3098,24 @@ expand_builtin_va_arg (valist, type)
 	    pname = IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (promoted_type)));
 	}
 
-      error ("`%s' is promoted to `%s' when passed through `...'", name, pname);
+      /* Unfortunately, this is merely undefined, rather than a constraint
+	 violation, so we cannot make this an error.  If this call is never
+	 executed, the program is still strictly conforming.  */
+      warning ("`%s' is promoted to `%s' when passed through `...'",
+	       name, pname);
       if (! gave_help)
 	{
-	  gave_help = 1;
-	  error ("(so you should pass `%s' not `%s' to `va_arg')", pname, name);
+	  gave_help = true;
+	  warning ("(so you should pass `%s' not `%s' to `va_arg')",
+		   pname, name);
 	}
 
+      /* We can, however, treat "undefined" any way we please.
+	 Call abort to encourage the user to fix the program.  */
+      expand_builtin_trap ();
+
+      /* This is dead code, but go ahead and finish so that the
+	 mode of the result comes out right.  */
       addr = const0_rtx;
     }
   else
@@ -3556,6 +3567,18 @@ expand_builtin_expect_jump (exp, if_false_label, if_true_label)
 
   return ret;
 }
+
+void
+expand_builtin_trap ()
+{
+#ifdef HAVE_trap
+  if (HAVE_trap)
+    emit_insn (gen_trap ());
+  else
+#endif
+    emit_library_call (abort_libfunc, LCT_NORETURN, VOIDmode, 0);
+  emit_barrier ();
+}
 
 /* Expand an expression EXP that calls a built-in function,
    with result going to TARGET if that's convenient
@@ -3890,13 +3913,7 @@ expand_builtin (exp, target, subtarget, mode, ignore)
 	}
 
     case BUILT_IN_TRAP:
-#ifdef HAVE_trap
-      if (HAVE_trap)
-	emit_insn (gen_trap ());
-      else
-#endif
-	error ("__builtin_trap not supported by this target");
-      emit_barrier ();
+      expand_builtin_trap ();
       return const0_rtx;
 
     case BUILT_IN_PUTCHAR: