clang-tidy 23 bugprone-signed-bitwise and CPL_LSBINT32PTR macros
Andrew C Aitchison via gdal-dev <[email protected]>
| Newsgroups | gmane.comp.gis.gdal.devel |
|---|---|
| Message-ID | <[email protected]> |
clang-tidy 23 (I'm using Ubuntu 26.04 with build
++20260508083129+d791e3a6f4c8-1~exp1~20260508083148.481
from llvm-toolchain-snapshot at https://www.llvm.org/)
has a new? check bugprone-signed-bitwise.
This check objects to macros like CPL_LSBINT32PTR:
clang-tidy --config="{Checks: 'bugprone-signed-bitwise', CheckOptions: {bugprone-signed-bitwise.IgnorePositiveIntegerLiterals: true}}" frmts/raw/lcpdataset.cpp
reports 63 warnings of [bugprone-signed-bitwise], starting with:
/home/werdna/gdal/git/frmts/raw/lcpdataset.cpp:171:10: warning: use of a signed integer operand with a binary bitwise operator [bugprone-signed-bitwise]
171 | if ((CPL_LSBSINT32PTR(poOpenInfo->pabyHeader) != 20 &&
| ^
/usr/local/gdal/git.llvm/include/cpl_port.h:799:53: note: expanded from macro 'CPL_LSBSINT32PTR'
799 | #define CPL_LSBSINT32PTR(x) CPL_STATIC_CAST(GInt32, CPL_LSBINT32PTR(x))
|
~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~
/usr/local/gdal/git.llvm/include/cpl_port.h:786:6: note: expanded from macro 'CPL_LSBINT32PTR'
786 | ((*CPL_REINTERPRET_CAST(const GByte *, x)) | \
| ^
787 | (*((CPL_REINTERPRET_CAST(const GByte *, x)) + 1) << 8U) | \
788 | (*((CPL_REINTERPRET_CAST(const GByte *, x)) + 2) << 16U) | \
| ~
/usr/local/gdal/git.llvm/include/cpl_port.h:181:55: note: expanded from
macro 'CPL_STATIC_CAST'
181 | #define CPL_STATIC_CAST(type, expr) static_cast<type>(expr)
| ^~~~
I suspect that default type-promotion from an unsigned GByte
to a *signed* int does not help here.
Not exactly a bug, but annoying.
--
Andrew C. Aitchison Kendal, UK
[email protected]