Joseph,
here is the patch to not drop qualifiers for _Atomic in
typeof. I am not sure whether this is appropriate in
stage3, but I wanted to leave it here for you to comment
and so that it does not lost.
First, I noticed that the change to drop qualifiers
in lvalue conversion also implies that __auto_type now
always uses the non-qualified type. I think this is more
correct, and also what other compilers and C++'s auto do.
The first change here in c-parser would remove the now
redundant code to drop qualifiers for _Atomic types.
The second change would remove the code to drop qualifiers
for _Atomic types for typeof. I would then use the
comma operator for stdatomic to remove all qualifiers.
Here, the question is whether this may have same
unintended side effects.
--Martin
diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c
index 7540a15d65d..72dbd2e00c0 100644
--- a/gcc/c/c-parser.c
+++ b/gcc/c/c-parser.c
@@ -2224,10 +2224,6 @@ c_parser_declaration_or_fndef (c_parser *parser, bool
fndef_ok,
" initializer");
init = convert_lvalue_to_rvalue (init_loc, init, true, true);
tree init_type = TREE_TYPE (init.value);
- /* As with typeof, remove all qualifiers from atomic types.
*/
- if (init_type != error_mark_node && TYPE_ATOMIC (init_type))
- init_type
- = c_build_qualified_type (init_type, TYPE_UNQUALIFIED);
bool vm_type = variably_modified_type_p (init_type,
NULL_TREE);
if (vm_type)
@@ -3743,11 +3739,6 @@ c_parser_typeof_specifier (c_parser *parser)
if (was_vm)
ret.expr = c_fully_fold (expr.value, false, &ret.expr_const_operands);
pop_maybe_used (was_vm);
- /* For use in macros such as those in <stdatomic.h>, remove all
- qualifiers from atomic types. (const can be an issue for more macros
- using typeof than just the <stdatomic.h> ones.) */
- if (ret.spec != error_mark_node && TYPE_ATOMIC (ret.spec))
- ret.spec = c_build_qualified_type (ret.spec, TYPE_UNQUALIFIED);
}
parens.skip_until_found_close (parser);
return ret;
diff --git a/gcc/ginclude/stdatomic.h b/gcc/ginclude/stdatomic.h
index b9681640fe1..7c2e08a2c41 100644
--- a/gcc/ginclude/stdatomic.h
+++ b/gcc/ginclude/stdatomic.h
@@ -107,7 +107,7 @@ extern void atomic_signal_fence (memory_order);
#define ATOMIC_POINTER_LOCK_FREE __GCC_ATOMIC_POINTER_LOCK_FREE
-/* Note that these macros require __typeof__ and __auto_type to remove
+/* Note that these macros require __auto_type to remove
_Atomic qualifiers (and const qualifiers, if those are valid on
macro operands).
@@ -122,7 +122,7 @@ extern void atomic_signal_fence (memory_order);
__extension__
\
({ \
__auto_type __atomic_store_ptr = (PTR); \
- __typeof__ (*__atomic_store_ptr) __atomic_store_tmp = (VAL); \
+ __typeof__ ((void)0, *__atomic_store_ptr) __atomic_store_tmp = (VAL);
\
__atomic_store (__atomic_store_ptr, &__atomic_store_tmp, (MO)); \
})
@@ -134,7 +134,7 @@ extern void atomic_signal_fence (memory_order);
__extension__
\
({ \
__auto_type __atomic_load_ptr = (PTR); \
- __typeof__ (*__atomic_load_ptr) __atomic_load_tmp; \
+ __typeof__ ((void)0, *__atomic_load_ptr) __atomic_load_tmp;
\
__atomic_load (__atomic_load_ptr, &__atomic_load_tmp, (MO)); \
__atomic_load_tmp; \
})
@@ -146,8 +146,8 @@ extern void atomic_signal_fence (memory_order);
__extension__
\
({ \
__auto_type __atomic_exchange_ptr = (PTR); \
- __typeof__ (*__atomic_exchange_ptr) __atomic_exchange_val = (VAL); \
- __typeof__ (*__atomic_exchange_ptr) __atomic_exchange_tmp; \
+ __typeof__ ((void)0, *__atomic_exchange_ptr) __atomic_exchange_val =
(VAL); \
+ __typeof__ ((void)0, *__atomic_exchange_ptr) __atomic_exchange_tmp;
\
__atomic_exchange (__atomic_exchange_ptr, &__atomic_exchange_val, \
&__atomic_exchange_tmp, (MO)); \
__atomic_exchange_tmp; \
@@ -161,7 +161,7 @@ extern void atomic_signal_fence (memory_order);
__extension__
\
({ \
__auto_type __atomic_compare_exchange_ptr = (PTR); \
- __typeof__ (*__atomic_compare_exchange_ptr) __atomic_compare_exchange_tmp \
+ __typeof__ ((void)0, *__atomic_compare_exchange_ptr)
__atomic_compare_exchange_tmp \
= (DES); \
__atomic_compare_exchange (__atomic_compare_exchange_ptr, (VAL), \
&__atomic_compare_exchange_tmp, 0, \
@@ -176,7 +176,7 @@ extern void atomic_signal_fence (memory_order);
__extension__
\
({ \
__auto_type __atomic_compare_exchange_ptr = (PTR); \
- __typeof__ (*__atomic_compare_exchange_ptr) __atomic_compare_exchange_tmp \
+ __typeof__ ((void)0, *__atomic_compare_exchange_ptr)
__atomic_compare_exchange_tmp \
= (DES); \
__atomic_compare_exchange (__atomic_compare_exchange_ptr, (VAL), \
&__atomic_compare_exchange_tmp, 1, \
diff --git a/gcc/testsuite/gcc.dg/typeof-2.c b/gcc/testsuite/gcc.dg/typeof-2.c
index 21ef5b0b865..68f91c6c361 100644
--- a/gcc/testsuite/gcc.dg/typeof-2.c
+++ b/gcc/testsuite/gcc.dg/typeof-2.c
@@ -1,21 +1,23 @@
-/* Test qualifier discard of typeof for atomic types. */
+/* Test qualifier preservation of typeof and discarded for __auto_type. */
/* { dg-do compile } */
/* { dg-options "-std=c11" } */
-/* Check that the qualifiers are discarded for atomic types. */
+/* Check that the qualifiers are preserved for atomic types. */
extern int i;
extern int * p;
extern int _Atomic const ci;
-extern __typeof (ci) i;
+extern __typeof (ci) ci;
extern int _Atomic volatile vi;
-extern __typeof (vi) i;
+extern __typeof (vi) vi;
extern int * _Atomic restrict ri;
-extern __typeof (ri) p;
+extern __typeof (ri) ri;
+
+/* Check that the qualifiers are discarded for atomic types. */
void f(void)
{
@@ -46,14 +48,16 @@ extern __typeof (nvi) k;
extern int * restrict nri;
extern __typeof (nri) q;
+/* Check that the qualifiers are discarded for non-atomic types. */
+
void g(void)
{
__auto_type aci = nci;
- int const *paci = &aci;
+ int *paci = &aci;
__auto_type avi = nvi;
- int volatile *pavi = &avi;
+ int *pavi = &avi;
__auto_type ari = nri;
- int * restrict *pari = &ari;
+ int **pari = &ari;
}
