bug#43167: 28.0.50; Cannot build on MacOS due to -std=c99 change in configure.ac

bug#43167: 28.0.50; Cannot build on MacOS due to -std=c99 change in configure.ac

[Keith Irwin]

I’ve been unable to build Emacs from the master branch for the past several days on MacOS (Big Sur). Previously, compiling on Big Sur worked.

I get the following error:


      CC       fringe.o
      CC       image.o
      CC       json.o
      CC       nsterm.o
    In file included from nsterm.m:46:
    ./lisp.h:1237:24: error: implicit declaration of function 'typeof' is invalid in
          C99 [-Werror,-Wimplicit-function-declaration]
      return USE_LSB_TAG ? make_fixnum (n) : XIL (n + (int0 << VALBITS));
                           ^
    ./lisp.h:444:26: note: expanded from macro 'make_fixnum'
    #  define make_fixnum(n) lisp_h_make_fixnum (n)
                             ^
    ./lisp.h:395:9: note: expanded from macro 'lisp_h_make_fixnum'
         ({ typeof (+(n)) lisp_h_make_fixnum_n = n; \
            ^
    ./lisp.h:1237:24: note: did you mean 'Ftype_of'?
    ./lisp.h:444:26: note: expanded from macro 'make_fixnum'
    #  define make_fixnum(n) lisp_h_make_fixnum (n)
                             ^
    ./lisp.h:395:9: note: expanded from macro 'lisp_h_make_fixnum'
         ({ typeof (+(n)) lisp_h_make_fixnum_n = n; \
            ^
    ./globals.h:4765:8: note: 'Ftype_of' declared here
    EXFUN (Ftype_of, 1);
           ^
    In file included from nsterm.m:46:
    ./lisp.h:1237:24: error: expected ';' after expression
      return USE_LSB_TAG ? make_fixnum (n) : XIL (n + (int0 << VALBITS));


I tracked the issue to this commit:

    https://emba.gnu.org/emacs/emacs/-/commit/72f66f70eef18e3b25cc989d67711887304f184b

When I make this change to line ~1904:


    #GNU_OBJC_CFLAGS="-std=c99”
    GNU_OBJC_CFLAGS=""


I can compile emacs as per usual.

I’m running macOS 11, Beta 5, with Xcode Beta 6, though I’m not sure if that’s an issue.


$ clang --version

Apple clang version 12.0.0 (clang-1200.0.31.1)
Target: x86_64-apple-darwin20.0.0
Thread model: posix
InstalledDir: /Applications/Xcode-beta.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin

$ gcc --version

Configured with: --prefix=/Applications/Xcode-beta.app/Contents/Developer/usr --with-gxx-include-dir=/Applications/Xcode-beta.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/4.2.1
Apple clang version 12.0.0 (clang-1200.0.31.1)
Target: x86_64-apple-darwin20.0.0
Thread model: posix
InstalledDir: /Applications/Xcode-beta.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin

bug#43167: 28.0.50; Cannot build on MacOS due to -std=c99 change in configure.ac

[Alan Third]

On Tue, Sep 01, 2020 at 10:44:07PM -0700, Keith Irwin wrote:
> I’ve been unable to build Emacs from the master branch for the past
> several days on MacOS (Big Sur). Previously, compiling on Big Sur
> worked.
> 
> I get the following error:
> 
> 
>       CC       fringe.o
>       CC       image.o
>       CC       json.o
>       CC       nsterm.o
>     In file included from nsterm.m:46:
>     ./lisp.h:1237:24: error: implicit declaration of function 'typeof' is invalid in
>           C99 [-Werror,-Wimplicit-function-declaration]
>       return USE_LSB_TAG ? make_fixnum (n) : XIL (n + (int0 << VALBITS));

Ah, useful, now GCC won't build without -std=c99, but clang won't
build WITH it. 🙄

And the irony is that both versions I have direct access to don't care
either way.

Right, I'll have to add a test, I suppose.

Done, and pushed to master. I've checked it compiles here, but it was
working anyway, so please give it another go and let us know how it
goes.

Thanks!
-- 
Alan Third

bug#43167: 28.0.50; Cannot build on MacOS due to -std=c99 change in configure.ac

[Keith Irwin]

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Works for me!

Thanks. ;)

Regards,
Keith

> On Sep 3, 2020, at 1:58 PM, Alan Third <alan@idiocy.org> wrote:
> 
> On Tue, Sep 01, 2020 at 10:44:07PM -0700, Keith Irwin wrote:
>> I’ve been unable to build Emacs from the master branch for the past
>> several days on MacOS (Big Sur). Previously, compiling on Big Sur
>> worked.
>> 
>> I get the following error:
>> 
>> 
>>      CC       fringe.o
>>      CC       image.o
>>      CC       json.o
>>      CC       nsterm.o
>>    In file included from nsterm.m:46:
>>    ./lisp.h:1237:24: error: implicit declaration of function 'typeof' is invalid in
>>          C99 [-Werror,-Wimplicit-function-declaration]
>>      return USE_LSB_TAG ? make_fixnum (n) : XIL (n + (int0 << VALBITS));
> 
> Ah, useful, now GCC won't build without -std=c99, but clang won't
> build WITH it. 🙄
> 
> And the irony is that both versions I have direct access to don't care
> either way.
> 
> Right, I'll have to add a test, I suppose.
> 
> Done, and pushed to master. I've checked it compiles here, but it was
> working anyway, so please give it another go and let us know how it
> goes.
> 
> Thanks!
> -- 
> Alan Third


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bug#43167: 28.0.50; Cannot build on MacOS due to -std=c99 change in configure.ac

[Eli Zaretskii]

> Date: Thu, 3 Sep 2020 22:58:30 +0200 (CEST)
> From: Alan Third <alan@idiocy.org>
> Cc: 43167@debbugs.gnu.org
> 
> Ah, useful, now GCC won't build without -std=c99, but clang won't
> build WITH it. 🙄

Does it help to use -std=gnu99 instead?

bug#43167: 28.0.50; Cannot build on MacOS due to -std=c99 change in configure.ac

[Lars Ingebrigtsen]

Alan Third <alan@idiocy.org> writes:

> fixed 43167 28.1

This was marked as fixed, but not closed?  So I'm closing this now.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no