error: incompatible function pointer types initializing 'int (*)(void)' with an expression of type 'int (FILE *)' (aka 'int (struct __sFILE *)') [-Werror,-Wincompatible-function-pointer-types]

[ryandesign]

Description

Configure test for fclose gets potentially wrong result due to -Wincompatible-function-pointer-types, which by default is now an error in the latest versions of clang. (I am using an older version of clang and have manually added -Werror=implicit-int -Werror=incompatible-function-pointer-types to CFLAGS to detect these kinds of errors.)

configure:17740: checking for fclose declaration
configure:17753: ccache /usr/bin/clang -c -pipe -Os -Werror=implicit-int -Werror=incompatible-function-pointer-types -isysroot/Library/Developer/CommandLineTools/SDKs/MacOSX12.sdk -arch x86_64 -ffp-contract=off -fvisibility=hidden -I/opt/local/include -isysroot/Library/Developer/CommandLineTools/SDKs/MacOSX12.sdk -D_GNU_SOURCE conftest.c >&5
conftest.c:103:7: error: incompatible function pointer types initializing 'int (*)(void)' with an expression of type 'int (FILE *)' (aka 'int (struct __sFILE *)') [-Werror,-Wincompatible-function-pointer-types]
int (*func)(void) = fclose
      ^             ~~~~~~
1 error generated.
configure:17753: $? = 1
configure: failed program was:
| /* confdefs.h */
| #define PACKAGE_NAME "PHP"
| #define PACKAGE_TARNAME "php"
| #define PACKAGE_VERSION "8.3.8"
| #define PACKAGE_STRING "PHP 8.3.8"
| #define PACKAGE_BUGREPORT "https://github.com/php/php-src/issues"
| #define PACKAGE_URL "https://www.php.net"
| #define HAVE_STDIO_H 1
| #define HAVE_STDLIB_H 1
| #define HAVE_STRING_H 1
| #define HAVE_INTTYPES_H 1
| #define HAVE_STDINT_H 1
| #define HAVE_STRINGS_H 1
| #define HAVE_SYS_STAT_H 1
| #define HAVE_SYS_TYPES_H 1
| #define HAVE_UNISTD_H 1
| #define HAVE_WCHAR_H 1
| #define STDC_HEADERS 1
| #define _ALL_SOURCE 1
| #define _DARWIN_C_SOURCE 1
| #define _GNU_SOURCE 1
| #define _HPUX_ALT_XOPEN_SOCKET_API 1
| #define _NETBSD_SOURCE 1
| #define _OPENBSD_SOURCE 1
| #define _POSIX_PTHREAD_SEMANTICS 1
| #define __STDC_WANT_IEC_60559_ATTRIBS_EXT__ 1
| #define __STDC_WANT_IEC_60559_BFP_EXT__ 1
| #define __STDC_WANT_IEC_60559_DFP_EXT__ 1
| #define __STDC_WANT_IEC_60559_EXT__ 1
| #define __STDC_WANT_IEC_60559_FUNCS_EXT__ 1
| #define __STDC_WANT_IEC_60559_TYPES_EXT__ 1
| #define __STDC_WANT_LIB_EXT2__ 1
| #define __STDC_WANT_MATH_SPEC_FUNCS__ 1
| #define _TANDEM_SOURCE 1
| #define __EXTENSIONS__ 1
| #define HAVE_CPUID_COUNT 1
| #define HAVE_PHPDBG 1
| #define PHPDBG_DEBUG 0
| #define PHP_WRITE_STDOUT 1
| #define HAVE_SOCKET 1
| #define HAVE_SOCKETPAIR 1
| #define HAVE_HTONL 1
| #define HAVE_GETHOSTNAME 1
| #define HAVE_GETHOSTBYADDR 1
| #define HAVE_DLOPEN 1
| #define HAVE_DLSYM 1
| #define HAVE_LIBDL 1
| #define HAVE_LIBM 1
| #define HAVE_INET_ATON 1
| #define HAVE_STDINT_H 1
| #define HAVE_DIRENT_H 1
| #define HAVE_SYS_PARAM_H 1
| #define HAVE_SYS_TYPES_H 1
| #define HAVE_SYS_TIME_H 1
| #define HAVE_NETINET_IN_H 1
| #define HAVE_ALLOCA_H 1
| #define HAVE_ARPA_INET_H 1
| #define HAVE_ARPA_NAMESER_H 1
| #define HAVE_DNS_H 1
| #define HAVE_FCNTL_H 1
| #define HAVE_GRP_H 1
| #define HAVE_LANGINFO_H 1
| #define HAVE_OS_SIGNPOST_H 1
| #define HAVE_POLL_H 1
| #define HAVE_PWD_H 1
| #define HAVE_RESOLV_H 1
| #define HAVE_STRINGS_H 1
| #define HAVE_SYSLOG_H 1
| #define HAVE_SYSEXITS_H 1
| #define HAVE_SYS_IOCTL_H 1
| #define HAVE_SYS_FILE_H 1
| #define HAVE_SYS_MMAN_H 1
| #define HAVE_SYS_MOUNT_H 1
| #define HAVE_SYS_POLL_H 1
| #define HAVE_SYS_RESOURCE_H 1
| #define HAVE_SYS_SELECT_H 1
| #define HAVE_SYS_SOCKET_H 1
| #define HAVE_SYS_STAT_H 1
| #define HAVE_SYS_STATVFS_H 1
| #define HAVE_SYS_UIO_H 1
| #define HAVE_SYS_WAIT_H 1
| #define HAVE_UNISTD_H 1
| #define HAVE_UTIME_H 1
| #define HAVE_SYS_UTSNAME_H 1
| #define HAVE_SYS_IPC_H 1
| #define HAVE_DLFCN_H 1
| #define HAVE_TMMINTRIN_H 1
| #define HAVE_NMMINTRIN_H 1
| #define HAVE_WMMINTRIN_H 1
| #define HAVE_IMMINTRIN_H 1
| #define HAVE_STRUCT_TM_TM_ZONE 1
| #define HAVE_TM_ZONE 1
| #define MISSING_LOCALTIME_R_DECL 1
| #define MISSING_GMTIME_R_DECL 1
| #define MISSING_ASCTIME_R_DECL 1
| #define MISSING_CTIME_R_DECL 1
| #define MISSING_STRTOK_R_DECL 1
| /* end confdefs.h.  */
| #include <stdio.h>
| int
| main (void)
| {
| int (*func)(void) = fclose
|   ;
|   return 0;
| }
configure:17767: result: missing

These PHP versions also experience additional incompatible function pointer types errors but they have already been fixed in 9e226b288106aea3bfb71bae707a3e2d4889e82d.

PHP Version

8.3.8, 8.2.20

Operating System

macOS 12

[ryandesign]

PHP 8.1.29 does not have this problem.

configure:17173: checking for fclose declaration
configure:17186: ccache /usr/bin/clang -c -pipe -Os -Werror=implicit-int -Werror=incompatible-function-pointer-types -isysroot/Library/Developer/CommandLineTools/SDKs/MacOSX12.sdk -arch x86_64 -fvisibility=hidden -I/opt/local/include -isysroot/Library/Developer/CommandLineTools/SDKs/MacOSX12.sdk conftest.c >&5
configure:17186: $? = 0
configure:17192: result: ok

[ryandesign]

Presumably caused by #13732.