Building a testdir of module 'endian' on CentOS 5, I get this build error:
gcc -std=gnu99 -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/bruno/inst-x86_64-64/include -Wall -Wno-error -g -O -MT test-endian.o
-MD -MP -MF .deps/test-endian.Tpo -c -o test-endian.o
../../gltests/test-endian.c
../../gltests/test-endian.c: In function ‘test_convert_constant’:
../../gltests/test-endian.c:80: warning: implicit declaration of function
‘be16toh’
../../gltests/test-endian.c:81: warning: implicit declaration of function
‘htobe16’
../../gltests/test-endian.c:82: warning: implicit declaration of function
‘le16toh’
../../gltests/test-endian.c:83: warning: implicit declaration of function
‘htole16’
../../gltests/test-endian.c:86: warning: implicit declaration of function
‘be32toh’
../../gltests/test-endian.c:87: warning: implicit declaration of function
‘htobe32’
../../gltests/test-endian.c:88: warning: implicit declaration of function
‘le32toh’
../../gltests/test-endian.c:89: warning: implicit declaration of function
‘htole32’
../../gltests/test-endian.c:93: warning: implicit declaration of function
‘be64toh’
../../gltests/test-endian.c:93: warning: comparison is always false due to
limited range of data type
../../gltests/test-endian.c:95: warning: implicit declaration of function
‘htobe64’
../../gltests/test-endian.c:95: warning: comparison is always false due to
limited range of data type
../../gltests/test-endian.c:97: warning: implicit declaration of function
‘le64toh’
../../gltests/test-endian.c:97: warning: comparison is always false due to
limited range of data type
../../gltests/test-endian.c:99: warning: implicit declaration of function
‘htole64’
../../gltests/test-endian.c:99: warning: comparison is always false due to
limited range of data type
mv -f .deps/test-endian.Tpo .deps/test-endian.Po
gcc -std=gnu99 -Wno-error -g -O -L/home/bruno/inst-x86_64-64/lib -o
test-endian test-endian.o libtests.a ../gllib/libgnu.a libtests.a
../gllib/libgnu.a libtests.a
test-endian.o: In function `test_convert_constant':
/home/bruno/testdir1/build-64/gltests/../../gltests/test-endian.c:80: undefined
reference to `be16toh'
/home/bruno/testdir1/build-64/gltests/../../gltests/test-endian.c:81: undefined
reference to `htobe16'
/home/bruno/testdir1/build-64/gltests/../../gltests/test-endian.c:82: undefined
reference to `le16toh'
/home/bruno/testdir1/build-64/gltests/../../gltests/test-endian.c:83: undefined
reference to `htole16'
/home/bruno/testdir1/build-64/gltests/../../gltests/test-endian.c:86: undefined
reference to `be32toh'
/home/bruno/testdir1/build-64/gltests/../../gltests/test-endian.c:87: undefined
reference to `htobe32'
/home/bruno/testdir1/build-64/gltests/../../gltests/test-endian.c:88: undefined
reference to `le32toh'
/home/bruno/testdir1/build-64/gltests/../../gltests/test-endian.c:89: undefined
reference to `htole32'
/home/bruno/testdir1/build-64/gltests/../../gltests/test-endian.c:93: undefined
reference to `be64toh'
collect2: ld returned 1 exit status
make[4]: *** [test-endian] Error 1
The cause is a wrong configure test:
checking if endian.h defines functions and macros... yes
when in fact endian.h does NOT declare or define the various functions.
This patch fixes it.
2024-12-28 Bruno Haible <br...@clisp.org>
endian: Fix link error on CentOS 5.
* m4/endian_h.m4 (gl_ENDIAN_H): Use AC_LINK_IFELSE, not
AC_COMPILE_IFELSE.
diff --git a/m4/endian_h.m4 b/m4/endian_h.m4
index 712c435fe8..4dcaf1c790 100644
--- a/m4/endian_h.m4
+++ b/m4/endian_h.m4
@@ -1,5 +1,5 @@
# endian_h.m4
-# serial 5
+# serial 6
dnl Copyright 2024 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
@@ -34,7 +34,7 @@ AC_DEFUN_ONCE([gl_ENDIAN_H]
AC_CACHE_CHECK([if endian.h defines functions and macros],
[gl_cv_header_working_endian_h],
[gl_cv_header_working_endian_h=no
- AC_COMPILE_IFELSE(
+ AC_LINK_IFELSE(
[AC_LANG_PROGRAM(
[[
#include <endian.h>
@@ -103,7 +103,7 @@ AC_DEFUN_ONCE([gl_ENDIAN_H]
AC_CACHE_CHECK([if sys/endian.h defines functions and macros],
[gl_cv_header_working_sys_endian_h],
[gl_cv_header_working_sys_endian_h=no
- AC_COMPILE_IFELSE(
+ AC_LINK_IFELSE(
[AC_LANG_PROGRAM(
[[
#include <sys/endian.h>
