cpp toolchain: stop passing -std=c++0x per default #18181
Description
Description of the bug:
After upgrading gcc version to 13 there are issues with different Bazel projects.
Consider this output:
$ g++ -x c++ -std=c++0x -dM -E - </dev/null | grep __cplusplus
#define __cplusplus 201103LHowever, without passing -std=c++0x option, the default is c++17:
$ g++ -x c++ -dM -E - </dev/null | grep __cplusplus
#define __cplusplus 201703LNow, trying to build abseil-cpp, this breakge is reported:
./absl/base/policy_checks.h:79:2: error: #error "C++ versions less than C++14 are not supported."
79 | #error "C++ versions less than C++14 are not supported."
| ^~~~~
Where the Bazel command produced by Bazel@HEAD is:
$ /usr/bin/gcc -U_FORTIFY_SOURCE -fstack-protector -Wall -Wunused-but-set-parameter -Wno-free-nonheap-object -fno-omit-frame-pointer '-std=c++0x' -MD -MF bazel-out/k8-fastbuild/bin/absl/base/_objs/atomic_hook_test_helper/atomic_hook_test_helper.pic.d '-frandom-seed=bazel-out/k8-fastbuild/bin/absl/base/_objs/atomic_hook_test_helper/atomic_hook_test_helper.pic.o' -fPIC -iquote . -iquote bazel-out/k8-fastbuild/bin -Wall -Wextra -Wcast-qual -Wconversion-null -Wformat-security -Wmissing-declarations -Woverlength-strings -Wpointer-arith -Wundef -Wunused-local-typedefs -Wunused-result -Wvarargs -Wvla -Wwrite-strings -DNOMINMAX -fno-canonical-system-headers -Wno-builtin-macro-redefined '-D__DATE__="redacted"' '-D__TIMESTAMP__="redacted"' '-D__TIME__="redacted"' -c absl/base/internal/atomic_hook_test_helper.cc -o bazel-out/k8-fastbuild/bin/absl/base/_objs/atomic_hook_test_helper/atomic_hook_test_helper.pic.o
Removing '-std=c++0x' makes this command work.
The code in ./absl/base/policy_checks.h:79:
// -----------------------------------------------------------------------------
// C++ Version Check
// -----------------------------------------------------------------------------
// Enforce C++14 as the minimum.
#if defined(_MSVC_LANG)
#if _MSVC_LANG < 201402L
#error "C++ versions less than C++14 are not supported."
#endif // _MSVC_LANG < 201402L
#elif defined(__cplusplus)
#if __cplusplus < 201402L
#error "C++ versions less than C++14 are not supported."
#endif // __cplusplus < 201402L
#endifWhat's the simplest, easiest way to reproduce this bug? Please provide a minimal example if possible.
Bump gcc version to 13 and build abseil-cpp@HEAD (https://github.com/abseil/abseil-cpp) with Bazel@HEAD.
My environment:
$ gcc --version
cc (SUSE Linux) 13.0.1 20230412 (experimental) [revision d339e9802f758e051b0a1ef6db732ff846cbf4e3]
[...]Which operating system are you running Bazel on?
Linux
What is the output of bazel info release?
All released Bazel versions are affected including Bazel@HEAD.
If bazel info release returns development version or (@non-git), tell us how you built Bazel.
No response
What's the output of git remote get-url origin; git rev-parse master; git rev-parse HEAD ?
No response
Have you found anything relevant by searching the web?
There are a number of reports:
abseil/abseil-cpp#1431
protocolbuffers/protobuf#12393
https://stackoverflow.com/questions/75850778/error-c-versions-less-than-c14-are-not-supported-in-bazel-how-to-resolve
Any other information, logs, or outputs that you want to share?
There is a workaround, bump -std-option in .bazelrc:
build --cxxopt=-std=c++14
build --host_cxxopt=-std=c++14