[PATCH, 2/4] Replace error_at with assert in build_va_arg

[Tom de Vries]

Hi,

at the start of build_va_arg, we error out if there's an invalid va_list 
argument.

Therefore, the following checks on va_list type are not user errors, but 
internal errors.

This patch changes the user errors into internal errors.

Bootstrapped and reg-tested on x86_64.

OK for trunk?

Thanks,
- Tom
Replace error_at with assert in build_va_arg

2016-08-22  Tom de Vries  <t...@codesourcery.com>

	* c-common.c (build_va_arg): Replace first argument type error
	with assert.

---
 gcc/c-family/c-common.c | 14 ++------------
 1 file changed, 2 insertions(+), 12 deletions(-)

diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c
index 7ad1930..a289d2b 100644
--- a/gcc/c-family/c-common.c
+++ b/gcc/c-family/c-common.c
@@ -5820,12 +5820,7 @@ build_va_arg (location_t loc, tree expr, tree type)
       /* Verify that &ap is still recognized as having va_list type.  */
       tree canon_expr_type
 	= targetm.canonical_va_list_type (TREE_TYPE (expr));
-      if (canon_expr_type == NULL_TREE)
-	{
-	  error_at (loc,
-		    "first argument to %<va_arg%> not of type %<va_list%>");
-	  return error_mark_node;
-	}
+      gcc_assert (canon_expr_type != NULL_TREE);
 
       return build_va_arg_1 (loc, type, expr);
     }
@@ -5893,12 +5888,7 @@ build_va_arg (location_t loc, tree expr, tree type)
       /* Verify that &ap is still recognized as having va_list type.  */
       tree canon_expr_type
 	= targetm.canonical_va_list_type (TREE_TYPE (expr));
-      if (canon_expr_type == NULL_TREE)
-	{
-	  error_at (loc,
-		    "first argument to %<va_arg%> not of type %<va_list%>");
-	  return error_mark_node;
-	}
+      gcc_assert (canon_expr_type != NULL_TREE);
     }
   else
     {