On AIX 7.2 with xlclang, I see this compilation error:
xlclang -q64 -qthreaded -qtls -std=gnu11 -DHAVE_CONFIG_H -I. -I../../gltests
-I.. -DGNULIB_STRICT_CHECKING=1 -DIN_GNULIB_TESTS=1 -I. -I../../gltests
-I.. -I../../gltests/.. -I../gllib -I../../gltests/../gllib
-I/home/haible/prefix64/include -Wno-error -g -O2 -MT test-alignasof.o -MD -MP
-MF .deps/test-alignasof.Tpo -c -o test-alignasof.o
../../gltests/test-alignasof.c
In file included from ../../gltests/test-alignasof.c:21:
In file included from ../gllib/stddef.h:79:
In file included from /opt/IBM/xlC/16.1.0/include2/stddef.h:118:
/opt/IBM/xlC/16.1.0/include2/__stddef_max_align_t.h:40:3: error: typedef
redefinition with different types ('struct max_align_t' vs 'long')
} max_align_t;
^
../gllib/stddef.h:70:14: note: previous definition is here
typedef long max_align_t;
^
1 error generated.
The reason is that after gnulib's definition of max_align_t, the xlc header
files attempt to define max_align_t too. This is done in a separate header file
__stddef_max_align_t.h, which is guarded by a '#ifndef
__CLANG_MAX_ALIGN_T_DEFINED'.
This patch makes things work.
2023-03-16 Bruno Haible <br...@clisp.org>
stddef: Fix a compilation error on AIX 7.2 with xlclang.
* lib/stddef.in.h (__CLANG_MAX_ALIGN_T_DEFINED): Define whenever we
define GNULIB_defined_max_align_t.
diff --git a/lib/stddef.in.h b/lib/stddef.in.h
index 9e9d4b7cc6..c7ce608b98 100644
--- a/lib/stddef.in.h
+++ b/lib/stddef.in.h
@@ -69,6 +69,7 @@ typedef long rpl_max_align_t;
typedef long max_align_t;
# define _MAX_ALIGN_T
# endif
+# define __CLANG_MAX_ALIGN_T_DEFINED
# define GNULIB_defined_max_align_t 1
# endif
# endif
@@ -137,6 +138,7 @@ typedef union
long int __i _GL_STDDEF_ALIGNAS (long int);
} rpl_max_align_t;
# define max_align_t rpl_max_align_t
+# define __CLANG_MAX_ALIGN_T_DEFINED
# define GNULIB_defined_max_align_t 1
# endif
# endif
