On Tue, Jul 16, 2024 at 5:41 PM Daniel Sahlberg
<daniel.l.sahlb...@gmail.com> wrote:
>
> Hi,
>
> Inspired by Timofei's work on the cmake branch, I checked it out and tried to
> build on Linux.
>
> It worked, almost.
>
> [[[
> [ 17%] Building C object
> CMakeFiles/libsvn_subr.dir/subversion/libsvn_subr/sysinfo.c.o
> /home/dsg/svn_cmake/subversion/libsvn_subr/sysinfo.c: In function
> ‘linux_release_name’:
> /home/dsg/svn_cmake/subversion/libsvn_subr/sysinfo.c:649:31: warning:
> implicit declaration of function ‘release_name_from_uname’
> [-Wimplicit-function-declaration]
> 649 | const char *uname_release = release_name_from_uname(pool);
> | ^~~~~~~~~~~~~~~~~~~~~~~
> /home/dsg/svn_cmake/subversion/libsvn_subr/sysinfo.c:649:31: warning:
> initialization of ‘const char *’ from ‘int’ makes pointer from integer
> without a cast [-Wint-conversion]
> /home/dsg/svn_cmake/subversion/libsvn_subr/sysinfo.c: In function
> ‘linux_shared_libs’:
> /home/dsg/svn_cmake/subversion/libsvn_subr/sysinfo.c:750:65: warning:
> implicit declaration of function ‘getpid’ [-Wimplicit-function-declaration]
> 750 | const char *maps = apr_psprintf(pool, "/proc/%ld/maps",
> (long)getpid());
> | ^~~~~~
> ]]]
>
> The above warnings were caused by missing defines HAVE_SYS_UTSNAME_H,
> HAVE_UNAME and HAVE_UNISTD_H.
>
> I also got the following error:
> [[[
> [ 64%] Linking C shared library liblibsvn_ra-1.so
> /usr/bin/ld: liblibsvn_ra_svn.a(marshal.c.o): warning: relocation against
> `svn_ctype_table' in read-only section `.text'
> /usr/bin/ld: liblibsvn_ra_svn.a(client.c.o): relocation R_X86_64_PC32 against
> symbol `svn_ctype_table' can not be used when making a shared object;
> recompile with -fPIC
> /usr/bin/ld: final link failed: bad value
> collect2: error: ld returned 1 exit status
> gmake[2]: *** [CMakeFiles/libsvn_ra.dir/build.make:186: liblibsvn_ra-1.so]
> Error 1
> gmake[1]: *** [CMakeFiles/Makefile2:330: CMakeFiles/libsvn_ra.dir/all] Error 2
> gmake: *** [Makefile:136: all] Error 2
> ]]]
>
> I made some effort trying to figure out the proper way to fix this and I came
> up with the following changes. After this the build succeeds and I get a
> working svn binary.
>
> I'm SURE this doesn't follow CMake best-practice but I'd be happy if it could
> be a starting point in getting CMake to work under Linux. I'd also be happy
> to see how it SHOULD be done :-)
>
> To get this to work under Macos, someone should look at the
> SVN_HAVE_MACOS_PLIST define.
>
> [[[
> Index: CMakeLists.txt
> ===================================================================
> --- CMakeLists.txt (revision 1919275)
> +++ CMakeLists.txt (working copy)
> @@ -125,8 +125,29 @@
> enable_testing()
> endif()
>
> +include(CheckSymbolExists)
> +include(CheckIncludeFiles)
> +check_include_files("sys/utsname.h" HAVE_SYS_UTSNAME_H)
> +if (HAVE_SYS_UTSNAME_H)
> + add_compile_definitions(HAVE_SYS_UTSNAME_H)
> +
> + check_symbol_exists(uname sys/utsname.h HAVE_UNAME)
> + if (HAVE_UNAME)
> + add_compile_definitions(HAVE_UNAME)
> + endif()
> +endif()
> +check_include_files("unistd.h" HAVE_UNISTD_H)
> +if (HAVE_UNISTD_H)
> + add_compile_definitions(HAVE_UNISTD_H)
> +endif()
> +
> +if (BUILD_SHARED_LIBS)
> + set(CMAKE_POSITION_INDEPENDENT_CODE ON)
> +endif()
> +
> if(SVN_BUILD_SHARED_FS)
> set(SVN_FS_BUILD_TYPE SHARED)
> + set(CMAKE_POSITION_INDEPENDENT_CODE ON)
> else()
> set(SVN_FS_BUILD_TYPE STATIC)
> endif()
> @@ -133,6 +154,7 @@
>
> if(SVN_BUILD_SHARED_RA)
> set(SVN_RA_BUILD_TYPE SHARED)
> + set(CMAKE_POSITION_INDEPENDENT_CODE ON)
> else()
> set(SVN_RA_BUILD_TYPE STATIC)
> endif()
> ]]]
Hi,
Thanks for your attention to the branch and trying to build with
CMake. I appreciate it.
I was also trying it on Linux and got the same problems, but didn't
find a nice resolution.
When I was was doing that, I solved the problem with uname with a
little patch by adding ifdef over release_name_from_uname() invocation
in sysinfo.c:
[[[
Index: subversion/libsvn_subr/sysinfo.c
===================================================================
--- subversion/libsvn_subr/sysinfo.c (revision 1919186)
+++ subversion/libsvn_subr/sysinfo.c (working copy)
@@ -646,8 +646,12 @@
static const char *
linux_release_name(apr_pool_t *pool)
{
- const char *uname_release = release_name_from_uname(pool);
+ const char *uname_release;
+#if HAVE_UNAME
+ uname_release = release_name_from_uname(pool);
+#endif
+
/* Try anything that has /usr/bin/lsb_release.
Covers, for example, Debian, Ubuntu and SuSE. */
const char *release_name = lsb_release(pool);
]]]
This fixed the problem, but the resolution is not nice, because the
version in svn --version becomes weird. I think I will look at the
checks using CheckIncludeFiles that you suggested, but they should be
added for every HAVE_* or SVN_HAVE_* constants, so...
The problem with svn_ctype_table in that time I fixed by simply
disabling ra-svn or disabling shared libraries, also adding -fpic to
compile options resolved the problem. However, I didn't notice the
CMAKE_POSITION_INDEPENDENT_CODE option and I think I will utilize it.
Additionally, there are two other problems that I noticed when trying
to build on Linux and didn't fix yet:
1. The libraries compiled to the files with double 'lib' prefix and
there might be files like liblibsvn_subr.so. I'm going to fix it by
making some modifications in the CMAKE_SHARED_LIBRARY_PREFIX variable
and also get libraries without the 'lib' prefix in static
configuration.
2. Path separator (SVN_PATH_LOCAL_SEPARATOR) is not currently
configured correctly, so there might be some runtime problems when
converting the path from local style and to local style.
By the way, I think that Linux support of the CMake is not very
important due to the great and useful current build system which is
quite useful. I think it should work, but the basic target should be
Windows or unusual platforms that autoconf doesn't have a great
support for. However, as it is requested, I will try to improve
support for non-Windows platforms as well...
--
Timofei Zhakov
