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| author | Peng Liu <winner245@hotmail.com> | 2025-03-19 11:55:51 -0400 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2025-03-19 11:55:51 -0400 |
| commit | a5b3d3a03f3291b1b62c7c25bc40b494660421cb (patch) | |
| tree | 77b955c0fec2e7f9cab822566f115e8f832c6706 /clang/lib/CodeGen/ModuleBuilder.cpp | |
| parent | 480202f0d16f7dbc5c650aea6e8dfd9eca5b999d (diff) | |
| download | llvm-a5b3d3a03f3291b1b62c7c25bc40b494660421cb.zip llvm-a5b3d3a03f3291b1b62c7c25bc40b494660421cb.tar.gz llvm-a5b3d3a03f3291b1b62c7c25bc40b494660421cb.tar.bz2 | |
[libc++] Fix {std, ranges}::copy for vector<bool> with small storage types (#131545)
The current implementation of `{std, ranges}::copy` fails to copy
`vector<bool>` correctly when the underlying storage type
(`__storage_type`) is smaller than `int`, such as `unsigned char`,
`unsigned short`, `uint8_t` and `uint16_t`. The root cause is that the
unsigned small storage type undergoes integer promotion to (signed)
`int`, which is then left and right shifted, leading to UB (before
C++20) and sign-bit extension (since C++20) respectively. As a result,
the underlying bit mask evaluations become incorrect, causing erroneous
copying behavior.
This patch resolves the issue by correcting the internal bitwise
operations, ensuring that `{std, ranges}::copy` operates correctly for
`vector<bool>` with any custom (unsigned) storage types.
Fixes #131692.
Diffstat (limited to 'clang/lib/CodeGen/ModuleBuilder.cpp')
0 files changed, 0 insertions, 0 deletions