clang-format: AlignConsecutiveBitFields doesn't work with bit field length specified by template argument

[mathcounts4]

clang-format version 19.1.7

_clang-format:

BasedOnStyle: LLVM
AlignConsecutiveBitFields: AcrossEmptyLinesAndComments

myfile.hpp:

template <int Bits>
struct ABC {
    std::size_t fAName : Bits;
    std::size_t fB : 1;
    std::size_t fCOtherName   : 63 - Bits;
};

Output:

>clang-format myfile.hpp
template <int Bits> struct ABC {
  std::size_t fAName : Bits;
  std::size_t fB          : 1;
  std::size_t fCOtherName : 63 - Bits;
};

In the output, the : and Bits on fAName are not vertically aligned with the : and bit field lengths on fB and fCOtherName.

Workaround: change fAName : Bits; to fAName : 0 + Bits;, which clang-format then aligns properly.

[llvmbot]

@llvm/issue-subscribers-clang-format

Author: David Fink (mathcounts4)

clang-format version 19.1.7

_clang-format:

BasedOnStyle: LLVM
AlignConsecutiveBitFields: AcrossEmptyLinesAndComments

myfile.hpp:

template <int Bits>
struct ABC {
    std::size_t fAName : Bits;
    std::size_t fB : 1;
    std::size_t fCOtherName   : 63 - Bits;
};

Output:

>clang-format myfile.hpp
template <int Bits> struct ABC {
  std::size_t fAName : Bits;
  std::size_t fB          : 1;
  std::size_t fCOtherName : 63 - Bits;
};

In the output, the : and Bits on fAName are not vertically aligned with the : and bit field lengths on fB and fCOtherName.

Workaround: change fAName : Bits; to fAName : 0 + Bits;, which clang-format then aligns properly.

[EugeneZelenko]

Could you please try 20 or main branch? Only most recent release is maintained.

[mathcounts4]

I don't build clang locally - I installed via winget, whose "latest" is 19.1.7: winget install --id=LLVM.ClangFormat -e
If there's a way for me to try 20 (safely), let me know.

Alternatively, if you can run from 20 or main, I provided a near-minimal reproducible example in the description.