[Lldb-commits] [lldb] [lldb][test] Fix TestStdCXXDisassembly test (PR #112357)

[Michael Buch via lldb-commits]

Michael137 wrote:

> We are seeing test failures on `lldb-api :: lang/cpp/stl/TestSTL.py` after this patch is landed.
> 
> ```
> Error when building test subject.
> 
> Build Command:
> /b/s/w/ir/x/w/cipd/bin/make VPATH=/b/s/w/ir/x/w/llvm-llvm-project/lldb/test/API/lang/cpp/stl -C /b/s/w/ir/x/w/llvm_build/lldb-test-build.noindex/lang/cpp/stl/TestSTL.test_SBType_template_aspects_dwarf -I /b/s/w/ir/x/w/llvm-llvm-project/lldb/test/API/lang/cpp/stl -I /b/s/w/ir/x/w/llvm-llvm-project/lldb/packages/Python/lldbsuite/test/make -f /b/s/w/ir/x/w/llvm-llvm-project/lldb/test/API/lang/cpp/stl/Makefile MAKE_DSYM=NO all ARCH=x86_64 CC=/b/s/w/ir/x/w/cipd/clang/bin/clang CC_TYPE=clang CXX=/b/s/w/ir/x/w/cipd/clang/bin/clang++ LLVM_AR=/b/s/w/ir/x/w/llvm_build/./bin/llvm-ar AR=/b/s/w/ir/x/w/llvm_build/./bin/llvm-ar OBJCOPY=/b/s/w/ir/x/w/llvm_build/./bin/llvm-objcopy STRIP=/b/s/w/ir/x/w/llvm_build/./bin/llvm-strip ARCHIVER=/b/s/w/ir/x/w/llvm_build/./bin/llvm-ar DWP=/b/s/w/ir/x/w/llvm_build/./bin/llvm-dwp CLANG_MODULE_CACHE_DIR=/b/s/w/ir/x/w/llvm_build/lldb-test-build.noindex/module-cache-clang/lldb-api LLDB_OBJ_ROOT=/b/s/w/ir/x/w/llvm_build/tools/lldb OS=Linux HOST_OS=Linux
> 
> Build Command Output:
> make: Entering directory '/b/s/w/ir/x/w/llvm_build/lldb-test-build.noindex/lang/cpp/stl/TestSTL.test_SBType_template_aspects_dwarf'
> /b/s/w/ir/x/w/cipd/clang/bin/clang++  -std=c++11 -g -O0  -m64 -I/b/s/w/ir/x/w/llvm-llvm-project/lldb/packages/Python/lldbsuite/test/make/../../../../..//include -I/b/s/w/ir/x/w/llvm_build/tools/lldb/include -I/b/s/w/ir/x/w/llvm-llvm-project/lldb/test/API/lang/cpp/stl -I/b/s/w/ir/x/w/llvm-llvm-project/lldb/packages/Python/lldbsuite/test/make -include /b/s/w/ir/x/w/llvm-llvm-project/lldb/packages/Python/lldbsuite/test/make/test_common.h -fno-limit-debug-info    -stdlib=libstdc++   --driver-mode=g++ -MT main.o -MD -MP -MF main.d -c -o main.o /b/s/w/ir/x/w/llvm-llvm-project/lldb/test/API/lang/cpp/stl/main.cpp
> /b/s/w/ir/x/w/llvm-llvm-project/lldb/test/API/lang/cpp/stl/main.cpp:1:10: fatal error: 'cstdio' file not found
>     1 | #include <cstdio>
>       |          ^~~~~~~~
> 1 error generated.
> make: *** [Makefile.rules:608: main.o] Error 1
> make: Leaving directory '/b/s/w/ir/x/w/llvm_build/lldb-test-build.noindex/lang/cpp/stl/TestSTL.test_SBType_template_aspects_dwarf'
> ```
> 
> Failed bot task: https://ci.chromium.org/ui/p/fuchsia/builders/toolchain.ci/lldb-linux-x64/b8733980216892309505/overview

Lets just revert the Makefile changes in this PR and let the test pick whatever's on the system. The test changes ensure we skip it in the statically linked builds.

> Is there a reason why LLDB doesn't use LLVM's own libc++? And if libstdc++ is not present, shouldn't the build system just disable the test that depends on it instead of blindly assume it exists?

We do use a local libc++ build for libc++-specific tests. Otherwise we just use whatever is on the system. I do think the silent fallbacks in some cases could be cleaned up: https://github.com/llvm/llvm-project/pull/106885#pullrequestreview-2275238360. Though I'm a bit surprised clang lets you specify `-stdlib=libstdc++` but not warn/error out when it's ignored.

https://github.com/llvm/llvm-project/pull/112357