No library versions in soname

[Pulfer]

In Unix world it's common for libraries to have version in soname (usually major and minor, major changes when there are backward incompatible ABI changes).

But current sonames for libraries don't have version info:
libSPIRV-Tools-link.so
libSPIRV-Tools-opt.so
libSPIRV-Tools-reduce.so
libSPIRV-Tools-shared.so
libSPIRV-Tools.so

From packaging POV (RPM in my case) .so files are usually symlinks to versioned library files and packaged to -devel (development) packages. Could be nice to see versioned library files/sonames and non-versioned -devel symlinks here too.

[dneto0]

See also the corresponding discussion for Shaderc: google/shaderc#381

[rpavlik]

This is currently blocking a whole bunch of packages in Debian (and its derivatives) since anything using glslang in its build process won't migrate because of this. Debian bug is https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=956510

[mikesart]

I'm likely missing something (or several things), but why wouldn't something like this fix the issue?

mikesart@mikesart-tr3:/tmp/spirv-tools/build (master *)$ git diff
diff --git i/source/CMakeLists.txt w/source/CMakeLists.txt
index 708ca84..ce55291 100644
--- i/source/CMakeLists.txt
+++ w/source/CMakeLists.txt
@@ -368,6 +368,7 @@ target_include_directories(${SPIRV_TOOLS}-shared
PRIVATE ${SPIRV_HEADER_INCLUDE_DIR}
)
set_target_properties(${SPIRV_TOOLS}-shared PROPERTIES CXX_VISIBILITY_PRESET hidden)
+set_target_properties(${SPIRV_TOOLS}-shared PROPERTIES SOVERSION 1)
set_property(TARGET ${SPIRV_TOOLS}-shared PROPERTY FOLDER "SPIRV-Tools libraries")
spvtools_check_symbol_exports(${SPIRV_TOOLS}-shared)
target_compile_definitions(${SPIRV_TOOLS}-shared
`

Before the change:

mikesart@mikesart-tr3:/tmp/spirv-tools (master)$ readelf --wide -a ./build/source/libSPIRV-Tools-shared.so | grep SONAM
0x000000000000000e (SONAME) Library soname: [libSPIRV-Tools-shared.so]

After the above change:

mikesart@mikesart-tr3:/tmp/spirv-tools/build (master *)$ readelf --wide -a source/libSPIRV-Tools-shared.so | grep SONAM
0x000000000000000e (SONAME) Library soname: [libSPIRV-Tools-shared.so.1]

[rpavlik]

Well, because it's not just the lack of a soname - it's the lack of a meaningful soname :) which should change every time the ABI changes incompatibly.

[mikesart]

Wouldn't whoever made that ABI breaking change bump SOVERSION up at that point? Or are you saying that needs to happen programmatically? Thanks Ryan.

[mikesart]

Ok, I see... this is described in #3214.