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Merge pull request #14509 from Mic92/no-tbb

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build: Disable libstdc++ TBB backend to avoid unnecessary dependency
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John Ericson 2025-11-07 20:42:34 +00:00 • committed by GitHub
commit 479b6b73a9
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nix-meson-build-support/common/meson.build
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@ -42,6 +42,26 @@ if cxx.get_id() == 'clang'
add_project_arguments('-fpch-instantiate-templates', language : 'cpp') add_project_arguments('-fpch-instantiate-templates', language : 'cpp')
endif endif
# Detect if we're using libstdc++ (GCC's standard library)
# libstdc++ uses Intel TBB as backend for C++17 parallel algorithms when <execution> is included.
# boost::concurrent_flat_map includes <execution>, which would require linking against TBB.
# Since we don't actually use parallel algorithms, disable the TBB backend to avoid the dependency.
# TBB is a dependency of blake3 and leaking into our build environment.
is_using_libstdcxx = cxx.compiles(
'''
#include <ciso646>
#ifndef __GLIBCXX__
#error "not libstdc++"
#endif
int main() { return 0; }
''',
name : 'using libstdc++',
)
if is_using_libstdcxx
add_project_arguments('-D_GLIBCXX_USE_TBB_PAR_BACKEND=0', language : 'cpp')
endif
# Darwin ld doesn't like "X.Y.ZpreABCD+W" # Darwin ld doesn't like "X.Y.ZpreABCD+W"
nix_soversion = meson.project_version().split('+')[0].split('pre')[0] nix_soversion = meson.project_version().split('+')[0].split('pre')[0]