Thanks, this allows analysis.
What I see is:
1) The compilation command in config.log is
/usr/bin/gcc-12 -o conftest -Walloc-zero -Walloca -Wall -Wextra -Wformat=2
-Wattribute-warning -Wdate-time -Wformat-security -Wfree-nonheap-object
-Wimplicit-fallthrough=3 -Wmissing-noreturn -Wpedantic -Wstringop-overflow=4
-Wredundant-decls -Wshadow=global -Wsuggest-attribute=noreturn -Wuninitialized
-Wunused -Wunused-parameter -Wvla -fdiagnostics-generate-patch -freport-bug
-fsanitize=undefined -fsanitize=bool -fsanitize=enum
-fsanitize=signed-integer-overflow -fsanitize=integer-divide-by-zero,shift,null
-fsanitize-undefined-trap-on-error -fno-sanitize=pointer-overflow
-fsanitize=return -fsanitize=alignment,object-size,vptr,pointer-overflow -O2
-fstack-protector-strong -fno-common -fstack-clash-protection -ftrapv
-funsigned-char -fvar-tracking-assignments -ggdb3 -fsanitize=null
-fsanitize=nonnull-attribute -Wbad-function-cast -Wmissing-prototypes
-Wold-style-definition -Wstrict-prototypes -Wold-style-declaration -std=gnu2x
-D_FORTIFY_SOURCE=2 -DGCC_LINT -DGNULIB_NO_VLA -D__USE_ISOC11 conftest.c
Two things are undefined behaviour here:
- -funsigned-char : You are on a glibc system on x86_64; here the 'char' type
is signed. Compiling code with -funsigned-char is thus undefined behaviour.
- -D__USE_ISOC11 : You are not supposed to define macros that start with two
underscores; these macros are owned by glibc. To specify which standards
your code follows, use the -std=... option (which you did: -std=gnu2x)
and you may define macros which start with a single underscore; they
are explicitly listed in /usr/include/features.h.
The problem is here in config.log:
conftest.c: In function 'main':
conftest.c:156:40: error: invalid use of incomplete typedef 'DIR'
156 | DIR *dir_p = opendir("."); (void) dir_p->DIR_FD_MEMBER_NAME;
| ^~
The test program has '#include <dirent.h>'; this is supposed to
define the DIR type. But the way your options interact with glibc,
this type is not present. As a consequence, both the test for d_fd
and the test for dd_fd failed, and the configure script activated
the fallback code (meant for systems from the 1980ies / 1990ies)
namely
# define DIR_TO_FD(Dir_p) -1
So, that's what you need to fix:
- Don't use -funsigned-char.
- Don't use -D__USE_ISOC11.
Bruno
