Re: Gnulib's tempname.c does not compile with TCC: max_align_t undefined

[Bruno Haible]

Paul Eggert wrote:
> On 3/2/21 7:09 PM, Bruno Haible wrote:
> > +   /* On TinyCC, make sure that the macros that indicate the special 
> > invocation
> > +      convention get undefined.  */
> > +#  ifdef __TINYC__
> > +#   undef __need_wchar_t
> > +#   undef __need_size_t
> 
> Would it be more robust to omit the "#ifdef __TINYC__" line, and 
> unconditionally undef those macros? That won't hurt GCC, and it should 
> help with any compiler (not just tcc) that is incompatible with GCC in 
> this respect.

Good point. I had considered it, but I'm too cautious sometimes :)
Fixed as below.

Also, macOS has the same convention regarding __need_* macros in <stddef.h>
as glibc. Therefore, the bug Luca was seeing on a glibc system most likely
also exists on macOS.


2021-03-04  Bruno Haible  <bruno@clisp.org>

        stddef: Generalize tcc workaround to other compilers.
        Suggested by Paul Eggert in
        <https://lists.gnu.org/archive/html/bug-gnulib/2021-03/msg00027.html>.
        * lib/stddef.in.h: Undefine the __need_* macros with all compilers.
        * doc/posix-headers/stddef.texi: Mention that the TinyCC bug also exists
        on macOS.

diff --git a/doc/posix-headers/stddef.texi b/doc/posix-headers/stddef.texi
index ba27fa8..fe7ed26 100644
--- a/doc/posix-headers/stddef.texi
+++ b/doc/posix-headers/stddef.texi
@@ -29,8 +29,8 @@ of a pointer:
 AIX 7.2 with xlc in 64-bit mode.
 
 @item
-When this header file is provided by TinyCC 0.9.27 on glibc systems, it does
-not fulfil the expectations of other glibc header files.
+When this header file is provided by TinyCC 0.9.27 on glibc or macOS systems,
+it does not fulfil the expectations of other system header files.
 @end itemize
 
 Portability problems not fixed by Gnulib:
diff --git a/lib/stddef.in.h b/lib/stddef.in.h
index 590e12c..a1fc80c 100644
--- a/lib/stddef.in.h
+++ b/lib/stddef.in.h
@@ -44,13 +44,11 @@
 #  @INCLUDE_NEXT@ @NEXT_STDDEF_H@
    /* On TinyCC, make sure that the macros that indicate the special invocation
       convention get undefined.  */
-#  ifdef __TINYC__
-#   undef __need_wchar_t
-#   undef __need_size_t
-#   undef __need_ptrdiff_t
-#   undef __need_NULL
-#   undef __need_wint_t
-#  endif
+#  undef __need_wchar_t
+#  undef __need_size_t
+#  undef __need_ptrdiff_t
+#  undef __need_NULL
+#  undef __need_wint_t
 # endif
 
 #else