Re: max_align_t on RHEL 7.1 s390x

[Sergio Durigan Junior]

On Wednesday, August 29 2018, Bruno Haible wrote:

> Hi Sergio,

Hello, Bruno,

Thanks for the reply.

>> I've just updated GDB's gnulib copy using a recent commit, and now I'm
>> noticing a few errors when compiling things on a RHEL 7.1 s390x system.
>> Here's what I'm getting
>> 
>>   In file included from 
>> ../../../../binutils-gdb/gdb/gnulib/import/scratch_buffer.h:9:0,
>>                    from ../../../../binutils-gdb/gdb/gnulib/import/glob.c:87:
>>   ../../../../binutils-gdb/gdb/gnulib/import/malloc/scratch_buffer.h:69:3: 
>> error: unknown type name max_align_t
>
> The type max_align_t is supposed to come from <stddef.h>. For this
> reason, the gnulib module 'scratch_buffer' depends on the module 'stddef'.
>
> The module 'stddef' works like this: If at configure time, <stddef.h> is
> found to not define max_align_t, a replacement <stddef.h> will be generated.
> Otherwise the original <stddef.h> will be used.
>
> GCC's <stddef.h> defines max_align_t if and only if compiling for C11
> or a newer standard.
>
> Please look whether you have an stddef.h file in your build tree, and if so,
> show it.

Thanks for the explanation.  I'll try to get access to the machine and
check if stddef.h is present or not in the build tree.

>
>>   ../../../../binutils-gdb/gdb/gnulib/import/glob.c: In function glob_in_dir:
>>   ../../../../binutils-gdb/gdb/gnulib/import/glob.c:1413:15: error: for loop 
>> initial declarations are only allowed in C99 mode
>>                  for (size_t i = 0; i < cur; ++i)
>>                  ^
>
> To me, it looks like
>   1) you are compiling with a GCC option that enforces the super-ancient
>      C89 or C90 mode, and

Maybe that's the case.

>   2) you added this GCC option after configuring. That is, you configured
>      with CC="gcc" and then added "-std=c89" in the Makefile. DON'T DO THIS.
>      YOU MUST PUT GCC OPTIONS THAT DETERMINE THE SUPPORTED LANGUAGE FEATURES
>      IN THE CC OR CFLAGS VARIABLE. Otherwise configure guesses wrong.

I did not do this.  I'm aware of the CC/CFLAGS/CXXFLAGS/CPPFLAGS/LDFLAGS
variables.

> If you think this is not the case, please run configure with option "-C"
> and attach also the config.cache and config.status files.

When I get access to the machine, I'll post the results.

Thanks,

-- 
Sergio
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