On 04/27/2015 11:30 AM, Marek Polacek wrote:
As reported in the PR, va_arg (ap, void) probably doesn't make any sense and
should be rejected thus. cc1plus and clang reject va_arg with an incomplete
type. This patch makes cc1 reject it as well.
Bootstrapped/regtested on x86_64-linux, ok for trunk?
2015-04-27 Marek Polacek <pola...@redhat.com>
PR c/65901
* c-typeck.c (c_build_va_arg): Require TYPE be a complete type.
* gcc.c-torture/compile/pr48767.c (foo): Add dg-error.
* gcc.dg/pr65901.c: New test.
diff --git gcc/c/c-typeck.c gcc/c/c-typeck.c
index 91735b5..c58e918 100644
--- gcc/c/c-typeck.c
+++ gcc/c/c-typeck.c
@@ -12648,6 +12648,11 @@ c_build_va_arg (location_t loc, tree expr, tree type)
if (warn_cxx_compat && TREE_CODE (type) == ENUMERAL_TYPE)
warning_at (loc, OPT_Wc___compat,
"C++ requires promoted type, not enum type, in %<va_arg%>");
+ if (type == error_mark_node || !COMPLETE_TYPE_P (type))
+ {
+ c_incomplete_type_error (NULL_TREE, type);
The error message in the test cases below isn't quite right.
The type of the aggregates isn't undefined, it's incomplete.
Looking at the function, I wonder if the first argument
should be EXPR rather than than NULL_TREE? Alternatively,
experimenting with other cases where GCC diagnoses invalid
uses of incomplete type, I see that it issues:
"invalid application of %qs to incomplete type %qT"
which might work even better here since we could name the
expression (va_arg).
Martin
+ return error_mark_node;
+ }
return build_va_arg (loc, expr, type);
}
diff --git gcc/testsuite/gcc.c-torture/compile/pr48767.c
gcc/testsuite/gcc.c-torture/compile/pr48767.c
index 66cb348..c8fef35 100644
--- gcc/testsuite/gcc.c-torture/compile/pr48767.c
+++ gcc/testsuite/gcc.c-torture/compile/pr48767.c
@@ -3,5 +3,5 @@
void
foo (__builtin_va_list ap)
{
- __builtin_va_arg (ap, void);
+ __builtin_va_arg (ap, void); /* { dg-error "invalid use of void expression"
} */
}
diff --git gcc/testsuite/gcc.dg/pr65901.c gcc/testsuite/gcc.dg/pr65901.c
index e69de29..8708a1e 100644
--- gcc/testsuite/gcc.dg/pr65901.c
+++ gcc/testsuite/gcc.dg/pr65901.c
@@ -0,0 +1,16 @@
+/* PR c/65901 */
+/* { dg-do compile } */
+/* { dg-options "" } */
+
+struct S;
+enum E;
+union U;
+
+void
+foo (__builtin_va_list ap)
+{
+ __builtin_va_arg (ap, void); /* { dg-error "invalid use of void expression"
} */
+ __builtin_va_arg (ap, struct S); /* { dg-error "invalid use of undefined
type" } */
+ __builtin_va_arg (ap, enum E); /* { dg-error "invalid use of undefined
type" } */
+ __builtin_va_arg (ap, union U); /* { dg-error "invalid use of undefined
type" } */
+}
Marek
