Author: puneeth_aditya_5656 Date: 2026-02-04T21:02:05+08:00 New Revision: 5b073761448229fd8f967f07517a35568e449aca
URL: https://github.com/llvm/llvm-project/commit/5b073761448229fd8f967f07517a35568e449aca DIFF: https://github.com/llvm/llvm-project/commit/5b073761448229fd8f967f07517a35568e449aca.diff LOG: [clang-tidy] Allow type-generic builtins in pro-type-vararg check (#178656) ## Summary Add type generic builtins to the allowed variadics list in the `cppcoreguidelines-pro-type-vararg` check (also used by `hicpp-vararg`): - `__builtin_clzg` - `__builtin_ctzg` - `__builtin_popcountg` - `__builtin_bswapg` ## Root Cause These builtins are declared as variadic (`int(...)`) to accept any integer type via `CustomTypeChecking`. However, they are not C style vararg functions , they take exactly one argument of a generic integer type. ## Test Added test cases in `pro-type-vararg.cpp` to verify no warning is emitted. Fixes #178629 Added: Modified: clang-tools-extra/clang-tidy/cppcoreguidelines/ProTypeVarargCheck.cpp clang-tools-extra/docs/ReleaseNotes.rst clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines/pro-type-vararg.cpp Removed: ################################################################################ diff --git a/clang-tools-extra/clang-tidy/cppcoreguidelines/ProTypeVarargCheck.cpp b/clang-tools-extra/clang-tidy/cppcoreguidelines/ProTypeVarargCheck.cpp index d5ff4af84b0b7..daa9f983b7886 100644 --- a/clang-tools-extra/clang-tidy/cppcoreguidelines/ProTypeVarargCheck.cpp +++ b/clang-tools-extra/clang-tidy/cppcoreguidelines/ProTypeVarargCheck.cpp @@ -178,6 +178,16 @@ void ProTypeVarargCheck::check(const MatchFinder::MatchResult &Result) { if (const auto *Matched = Result.Nodes.getNodeAs<CallExpr>("callvararg")) { if (hasSingleVariadicArgumentWithValue(Matched, 0)) return; + + // Skip builtins with custom type checking - they use variadics as an + // implementation detail to accept multiple types, not for C-style varargs. + // TODO: Remove some of the entries from the `AllowedVariadics` list. + if (const auto *FD = Matched->getDirectCallee()) + if (const unsigned BuiltinID = FD->getBuiltinID(); + BuiltinID && + Result.Context->BuiltinInfo.hasCustomTypechecking(BuiltinID)) + return; + diag(Matched->getExprLoc(), "do not call c-style vararg functions"); } diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst index ea80502735ede..0ad69f5fdc5aa 100644 --- a/clang-tools-extra/docs/ReleaseNotes.rst +++ b/clang-tools-extra/docs/ReleaseNotes.rst @@ -158,6 +158,12 @@ Changes in existing checks the invalidating function in the warning message when a custom invalidation function is used (via the `InvalidationFunctions` option). +- Improved :doc:`cppcoreguidelines-pro-type-vararg + <clang-tidy/checks/cppcoreguidelines/pro-type-vararg>` check by no longer + warning on builtins with custom type checking (e.g., type-generic builtins + like ``__builtin_clzg``) that use variadic declarations as an implementation + detail. + - Improved :doc:`llvm-use-ranges <clang-tidy/checks/llvm/use-ranges>` check by adding support for the following algorithms: ``std::accumulate``, ``std::replace_copy``, and diff --git a/clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines/pro-type-vararg.cpp b/clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines/pro-type-vararg.cpp index 3f73d1de333f4..1a5a5fb7dd93c 100644 --- a/clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines/pro-type-vararg.cpp +++ b/clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines/pro-type-vararg.cpp @@ -57,6 +57,12 @@ void ignoredBuiltinsTest(void *ptr) { (void)__builtin_fpclassify(0, 0, 0, 0, 0, 0.f); (void)__builtin_isinf_sign(0.f); (void)__builtin_prefetch(nullptr); + + // GH#178629: Type-generic builtins should not warn. + (void)__builtin_clzg(1u); + (void)__builtin_ctzg(1u); + (void)__builtin_popcountg(1u); + (void)__builtin_bswapg(1u); } // Some implementations of __builtin_va_list and __builtin_ms_va_list desugared _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
