Ping: https://gcc.gnu.org/ml/gcc-patches/2016-05/msg02216.html
On 05/27/2016 11:34 AM, Martin Sebor wrote:
The patch below adjusts the C alignof pedantic warning to avoid
diagnosing the GCC extension (__alignof__) and only diagnose
_Alignof in C99 and prior modes. This is consistent with how
__attribute__ ((aligned)) and _Alignas is handled (among other
extensions vs standard features).
Martin
PR c/69507 - bogus warning: ISO C does not allow ‘__alignof__ (expression)’
gcc/testsuite/ChangeLog:
2016-05-27 Martin Sebor <mse...@redhat.com>
PR c/69507
* gcc.dg/alignof.c: New test.
gcc/c/ChangeLog:
2016-05-27 Martin Sebor <mse...@redhat.com>
PR c/69507
* c-parser.c (c_parser_alignof_expression): Avoid diagnosing
__alignof__ (expression).
Index: gcc/c/c-parser.c
===================================================================
--- gcc/c/c-parser.c (revision 232841)
+++ gcc/c/c-parser.c (working copy)
@@ -7019,9 +7019,10 @@ c_parser_alignof_expression (c_parser *p
mark_exp_read (expr.value);
c_inhibit_evaluation_warnings--;
in_alignof--;
- pedwarn (start_loc,
- OPT_Wpedantic, "ISO C does not allow %<%E (expression)%>",
- alignof_spelling);
+ if (is_c11_alignof)
+ pedwarn (start_loc,
+ OPT_Wpedantic, "ISO C does not allow %<%E (expression)%>",
+ alignof_spelling);
ret.value = c_alignof_expr (start_loc, expr.value);
ret.original_code = ERROR_MARK;
ret.original_type = NULL;
Index: gcc/testsuite/gcc.dg/alignof.c
===================================================================
--- gcc/testsuite/gcc.dg/alignof.c (revision 0)
+++ gcc/testsuite/gcc.dg/alignof.c (working copy)
@@ -0,0 +1,11 @@
+/* PR c/69507 - bogus warning: ISO C does not allow '__alignof__
(expression)'
+ */
+/* { dg-do compile } */
+/* { dg-options "-std=c11 -Wno-error -Wpedantic" } */
+
+extern int e;
+
+int a[] = {
+ __alignof__ (e),
+ _Alignof (e) /* { dg-warning "ISO C does not allow ._Alignof
\\(expression\\)." } */
+};
