Re: RFC: Changing AC_PROG_CC to AC_PROG_CC_C99 in top level configure

[Iain Sandoe <iain@sandoe.co.uk>]

Alan Modra <amodra@gmail.com> wrote:

> On Wed, May 05, 2021 at 08:05:29AM +0100, Iain Sandoe wrote:
>> Alan Modra via Gcc-patches <gcc-patches@gcc.gnu.org> wrote:
>>> diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
>>> index 97d6f3863cb..cc3b1b6d666 100644
>>> --- a/gcc/config/i386/i386.h
>>> +++ b/gcc/config/i386/i386.h
>>> @@ -73,8 +73,8 @@ struct stringop_algs
>>> {
>>>  const enum stringop_alg unknown_size;
>>>  const struct stringop_strategy {
>>> -    const int max;
>>> -    const enum stringop_alg alg;
>>> +    int max;
>>> +    enum stringop_alg alg;
>>>    int noalign;
>>>  } size [MAX_STRINGOP_ALGS];
>>> };
>>
>> does this relate to / fix PR 100246 (which seems to fire for some GCC
>> versions as well
>> as older clang)?
>
> Yes, looks like the same issue.  I started making a similar fix to the
> one you attached to the PR, then laziness kicked in after noticing the
> errors were only given on the const elements.

I added a third variant to the PR (as below), which preserves the const-ness
but provides a CTOR.  TBH, I have no especial preference for the solution,
but it would be nice to commit one of them :-)

cheers
Iain

The condition is because this header gets pulled in by gcov stuff which is  
built
with a C compiler.

diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
index 97d6f38..a417c93 100644
--- a/gcc/config/i386/i386.h
+++ b/gcc/config/i386/i386.h
@@ -73,6 +73,11 @@ struct stringop_algs
  {
    const enum stringop_alg unknown_size;
    const struct stringop_strategy {
+#ifdef __cplusplus
+    stringop_strategy(int _max = -1, enum stringop_alg _alg = libcall,
+                     int _noalign = false)
+      : max (_max), alg (_alg), noalign (_noalign) {}
+#endif
      const int max;
      const enum stringop_alg alg;
      int noalign;