diff mbox series

shell: Call CHECK_DECL on stat64

Message ID 20210526054938.tgkhhh3z5vn2hjyi@gondor.apana.org.au (mailing list archive)
State Accepted
Delegated to: Herbert Xu
Headers show
Series shell: Call CHECK_DECL on stat64 | expand

Commit Message

Herbert Xu May 26, 2021, 5:49 a.m. UTC
Saagar Jha <saagar@saagarjha.com> wrote:
>
> Even though stat64 is not in the public headers, AC_CHECK_FUNC will “find” it because the symbol exists at link time for the test, even though it is not meant to be used. What do you think would be the best way to fix this check on this platform? Would it be preferred to check if the headers contain a declaration of the function?

Yes we should check for a declaration.  Does this patch fix the
problem?

---8<---
On macOS it is possible to find stat64 at link-time but not at
compile-time.  To make the build process more robust we should
check for the header file as well as the library.

Reported-by: Saagar Jha <saagar@saagarjha.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Comments

Saagar Jha May 27, 2021, 8:43 a.m. UTC | #1
I was able the compilation to succeed with the patch and the binary seemed to work in my basic tests, so it looks good from my side. Thanks for preparing this!

Regards,
Saagar

> On May 25, 2021, at 22:49, Herbert Xu <herbert@gondor.apana.org.au> wrote:
> 
> Saagar Jha <saagar@saagarjha.com> wrote:
>> 
>> Even though stat64 is not in the public headers, AC_CHECK_FUNC will “find” it because the symbol exists at link time for the test, even though it is not meant to be used. What do you think would be the best way to fix this check on this platform? Would it be preferred to check if the headers contain a declaration of the function?
> 
> Yes we should check for a declaration.  Does this patch fix the
> problem?
> 
> ---8<---
> On macOS it is possible to find stat64 at link-time but not at
> compile-time.  To make the build process more robust we should
> check for the header file as well as the library.
> 
> Reported-by: Saagar Jha <saagar@saagarjha.com>
> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
> 
> diff --git a/configure.ac b/configure.ac
> index 44f2f95..466df4c 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -140,11 +140,12 @@ if test "$ac_cv_func_signal" != yes; then
> fi
> 
> dnl Check for stat64 (dietlibc/klibc).
> -AC_CHECK_FUNC(stat64,, [
> +AC_CHECK_DECL(stat64, AC_CHECK_FUNC(stat64))
> +if test "$ac_cv_func_stat64" != yes; then
> 	AC_DEFINE(fstat64, fstat, [64-bit operations are the same as 32-bit])
> 	AC_DEFINE(lstat64, lstat, [64-bit operations are the same as 32-bit])
> 	AC_DEFINE(stat64, stat, [64-bit operations are the same as 32-bit])
> -])
> +fi
> 
> AC_CHECK_FUNC(glob64,, [
> 	AC_DEFINE(glob64_t, glob_t, [64-bit operations are the same as 32-bit])
> -- 
> Email: Herbert Xu <herbert@gondor.apana.org.au>
> Home Page: http://gondor.apana.org.au/~herbert/
> PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
diff mbox series

Patch

diff --git a/configure.ac b/configure.ac
index 44f2f95..466df4c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -140,11 +140,12 @@  if test "$ac_cv_func_signal" != yes; then
 fi
 
 dnl Check for stat64 (dietlibc/klibc).
-AC_CHECK_FUNC(stat64,, [
+AC_CHECK_DECL(stat64, AC_CHECK_FUNC(stat64))
+if test "$ac_cv_func_stat64" != yes; then
 	AC_DEFINE(fstat64, fstat, [64-bit operations are the same as 32-bit])
 	AC_DEFINE(lstat64, lstat, [64-bit operations are the same as 32-bit])
 	AC_DEFINE(stat64, stat, [64-bit operations are the same as 32-bit])
-])
+fi
 
 AC_CHECK_FUNC(glob64,, [
 	AC_DEFINE(glob64_t, glob_t, [64-bit operations are the same as 32-bit])