Re: Debian Stretch: strndup.c build failure
Hi Bruno,
On 07.01.20 19:00, Bruno Haible wrote:
>> with the latest gnulib (a7903da07d3d18c23314aa0815adbb4058fd7cec) on
>> Debian Stretch:
>>
>> In file included from /usr/include/string.h:630:0,
>> from ./string.h:41,
>> from strndup.c:21:
>> strndup.c:26:1: error: expected identifier or '(' before '__extension__'
>> strndup (char const *s, size_t n)
>> ^
>>
>> config.log is at
>> https://gitlab.com/gnuwget/wget2/-/jobs/395706872/artifacts/file/config.log.
>
> An invocation of AC_CHECK_FUNC is malfunctioning because of -Werror:
>
> For this reason, -Werror is not supported at configuration-time in gnulib [1].
>
> [1] https://lists.gnu.org/archive/html/bug-gnulib/2019-07/msg00081.html
Thanks for clarification :-)
Regards, Tim
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Re: Debian Stretch: strndup.c build failure
Hi Tim,
> with the latest gnulib (a7903da07d3d18c23314aa0815adbb4058fd7cec) on
> Debian Stretch:
>
> In file included from /usr/include/string.h:630:0,
> from ./string.h:41,
> from strndup.c:21:
> strndup.c:26:1: error: expected identifier or '(' before '__extension__'
> strndup (char const *s, size_t n)
> ^
>
> config.log is at
> https://gitlab.com/gnuwget/wget2/-/jobs/395706872/artifacts/file/config.log.
An invocation of AC_CHECK_FUNC is malfunctioning because of -Werror:
configure:8814: checking for strndup
configure:8814: ccache gcc -o conftest -O1 -g -ggdb3 -Werror conftest.c >&5
conftest.c:150:6: error: conflicting types for built-in function 'strndup'
[-Werror]
char strndup ();
^~~
cc1: all warnings being treated as errors
configure:8814: $? = 1
configure: failed program was:
| /* confdefs.h */
| ...
| /* end confdefs.h. */
| /* Define strndup to an innocuous variant, in case declares
strndup.
|For example, HP-UX 11i declares gettimeofday. */
| #define strndup innocuous_strndup
|
| /* System header to define __stub macros and hopefully few prototypes,
| which can conflict with char strndup (); below.
| Prefer to if __STDC__ is defined, since
| exists even on freestanding compilers. */
|
| #ifdef __STDC__
| # include
| #else
| # include
| #endif
|
| #undef strndup
|
| /* Override any GCC internal prototype to avoid an error.
|Use char because int might match the return type of a GCC
|builtin and then its argument prototype would still apply. */
| #ifdef __cplusplus
| extern "C"
| #endif
| char strndup ();
| /* The GNU C library defines this for functions which it implements
| to always fail with ENOSYS. Some functions are actually named
| something starting with __ and the normal name is an alias. */
| #if defined __stub_strndup || defined __stub___strndup
| choke me
| #endif
|
| int
| main ()
| {
| return strndup ();
| ;
| return 0;
| }
configure:8814: result: no
For this reason, -Werror is not supported at configuration-time in gnulib [1].
Bruno
[1] https://lists.gnu.org/archive/html/bug-gnulib/2019-07/msg00081.html
Re: Debian Stretch: strndup.c build failure
On 1/7/20 3:24 PM, Tim Rühsen wrote:
> Hi,
>
> with the latest gnulib (a7903da07d3d18c23314aa0815adbb4058fd7cec) on
> Debian Stretch:
>
> In file included from /usr/include/string.h:630:0,
> from ./string.h:41,
> from strndup.c:21:
> strndup.c:26:1: error: expected identifier or '(' before '__extension__'
> strndup (char const *s, size_t n)
> ^
>
> config.log is at
> https://gitlab.com/gnuwget/wget2/-/jobs/395706872/artifacts/file/config.log.
The issue is that the ./configure step is run with CFLAGS="-Werror"
(here with CC=clang):
$ grep strndup config.log
configure:8814: checking for strndup
conftest.c:152:6: error: incompatible redeclaration of library function
'strndup' [-Werror,-Wincompatible-library-redeclaration]
char strndup ();
conftest.c:152:6: note: 'strndup' is a builtin with type 'char *(const
char *, unsigned long)'
| /* Define strndup to an innocuous variant, in case declares
strndup.
| #define strndup innocuous_strndup
| which can conflict with char strndup (); below.
| #undef strndup
| char strndup ();
| #if defined __stub_strndup || defined __stub___strndup
| return strndup ();
configure:20326: checking whether strndup is declared
ac_cv_func_strndup=no
ac_cv_have_decl_strndup=yes
Though it always worked (for my projects), I can imagine that
./configure tests may stumble when -Werror is set. So, is it good
practice not to use -Werror with ./configure ?
Without -Werror:
$ grep strndup config.log
configure:8814: checking for strndup
conftest.c:154:6: warning: conflicting types for built-in function 'strndup'
char strndup ();
configure:20326: checking whether strndup is declared
configure:38601: checking for working strndup
ac_cv_func_strndup=yes
ac_cv_have_decl_strndup=yes
gl_cv_func_strndup_works=yes
Regards, Tim
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Debian Stretch: strndup.c build failure
Hi,
with the latest gnulib (a7903da07d3d18c23314aa0815adbb4058fd7cec) on
Debian Stretch:
In file included from /usr/include/string.h:630:0,
from ./string.h:41,
from strndup.c:21:
strndup.c:26:1: error: expected identifier or '(' before '__extension__'
strndup (char const *s, size_t n)
^
config.log is at
https://gitlab.com/gnuwget/wget2/-/jobs/395706872/artifacts/file/config.log.
Regards, Tim
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