The previous way of defining them is not compatible with unsigned integer overflow sanitizer, which complains about the conversion from uint64_t to int64_t in the macro LL().
PiperOrigin-RevId: 538418425
Hi,
It seems that until last year, the logic behind `PROTOBUF_USE_DLLS` was for Windows (MSCV) only. It was changed to all platforms here in 5a0887fc65
Last month, the generated pkg config files were updated to reflect the protobuf build-time value of `PROTOBUF_USE_DLLS` as it was indeed noted that it changes the ABI. This was done in https://github.com/protocolbuffers/protobuf/pull/12700 In the commit message it is mentionned that most likely we shall rather have a stable ABI.
Finally in https://github.com/protocolbuffers/protobuf/issues/12746 which at some point mentions https://issuetracker.google.com/issues/283987730#comment7 where a Google employee hits the linker issue:
```
undefined reference to `google::protobuf::internal::ThreadSafeArena::thread_cache_'
```
which denotes a mix of some .o or libs built `PROTOBUF_USE_DLLS` defined and some others build with `PROTOBUF_USE_DLLS` undefined, resulting in ABI incompatibilities.
I also hit this issue while trying to include protobuf in a corporate environment using it's own proprietary build system in which it is expected that .a and .so use a compatible ABI.
From my own understanding, ideally we should always use `thread_local` variables, but experience has shown that:
- old iOS (iOS < 9) didn't seem to accept `thread_local`, leading to the `GOOGLE_PROTOBUF_NO_THREADLOCAL` macro later renamed `PROTOBUF_NO_THREADLOCAL` which allowed to disable this, but it is not set anywhere in the protobuf code base. Also I doubt you still want to support such old iOS now, so maybe you should consider removing all `PROTOBUF_NO_THREADLOCAL` related code paths (this pull request doesn't do this).
- MSVC's DLL interface doesn't seem to accept exporting thread local variables (at least from what I understood, I know absolutely nothing about the Windows ecosystem), yet we can "hide" a thread local variable in a static function using a thread local variable. However in that case the access to TLS variable is not inlined, leading to worse performances, this hack shall be done only for Windows (actually when using MSVC) *AND* we build a shared library.
- In all other cases, a classical `thread_local` shall be used, no matter if we build a static or a shared library. In particular on Linux which I guess is the target Google cares the more about for its own production. This pull request achieves this.
Am I right in my conclusion ?
Closes#12983
COPYBARA_INTEGRATE_REVIEW=https://github.com/protocolbuffers/protobuf/pull/12983 from Romain-Geissler-1A:stable-abi-use-dll-non-windows dc23ff50f6
PiperOrigin-RevId: 538230923
This additional if is necessary as of abseil 20230125.3 when abseil is consumed via add_subdirectory,
the abseil_dll target is named abseil_dll, while if abseil is consumed via find_package, the target is called `absl::abseil_dll` .
Once https://github.com/abseil/abseil-cpp/pull/1466 is merged and released in the minimum version of abseil required by protobuf, it is possible to always link `absl::abseil_dll` and `absl::abseil_test_dll` and remove the if.
You may wonder how linking worked at all before when `protobuf_ABSL_PROVIDER STREQUAL "package"`, as `abseil_dll` was not an imported target defined by `find_package(absl)`. The reason behind this is that if a name that is not an imported target is passed to `target_link_libraries`, it is just regarded as a C++ library name. So, in the end the `abseil_dll` library was correctly linked, simply all the transitive usage requirements defined by the `absl::abseil_dll` target were not propagated, that could lead to compilation errors if abseil was compiled with the `ABSL_PROPAGATE_CXX_STD` CMake option enabled.
Closes#12978
COPYBARA_INTEGRATE_REVIEW=https://github.com/protocolbuffers/protobuf/pull/12978 from traversaro:patch-1 39dd074281
PiperOrigin-RevId: 537990391
- Do some minimal sanity testing on every PR
- Only run the staleness tests on a daily schedule or explicit runs.
- Add 23.x to the checks
PiperOrigin-RevId: 537952151
The resulting code won't have functional reflection, but allows us to compare the functionality between two sets of gencode.
PiperOrigin-RevId: 537170849
Not really sure why things changed and started having this problem, but
cl/536414905 & cl/536708284 just keep swapping this so hopefully changing
the formatting to avoid this going forward.
PiperOrigin-RevId: 537035911
Protobuf Team Bot
Mike Kruskal
Protobuf Team Bot
Thomas Van Lenten
Chad Wilson
Krzysztof Kosiński
Marcel Hlopko
Romain Geissler @ Amadeus
Silvio Traversaro
Joyce
Jie Luo