Author: Collin Baker Date: 2023-03-14T09:59:24-04:00 New Revision: 48fb6659610a3177e8606681046dfa0d19f67203
URL: https://github.com/llvm/llvm-project/commit/48fb6659610a3177e8606681046dfa0d19f67203 DIFF: https://github.com/llvm/llvm-project/commit/48fb6659610a3177e8606681046dfa0d19f67203.diff LOG: [libclang] No longer attempt to get a dependent bit-width Handle template parameter-dependent bit field widths in libclang In a class template, a bit field's width may depend on a template parameter. In this case the width expression cannot be evaluated. Previously clang_getFieldDeclBitWidth() would assert, or cause memory unsafety and return an invalid result if assertions are disabled. This adds a check for this case which returns an error code. This work was largely taken from an earlier patch which was reverted due to an accidental API duplication (https://reviews.llvm.org/D130303). Fixes: https://github.com/llvm/llvm-project/issues/56644 Co-authored-by: Aaron Ballman <aa...@aaronballman.com> Differential Revision: https://reviews.llvm.org/D146039 Added: Modified: clang/docs/ReleaseNotes.rst clang/include/clang-c/Index.h clang/tools/libclang/CXType.cpp Removed: ################################################################################ diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index cfec4ed96ad9b..66a9210c35b66 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -315,6 +315,10 @@ libclang ``clang_CXIndex_setInvocationEmissionPathOption`` in favor of the new function ``clang_createIndexWithOptions`` in order to improve thread safety. +- Added check in ``clang_getFieldDeclBitWidth`` for whether a bit-field + has an evaluable bit width. Fixes undefined behavior when called on a + bit-field whose width depends on a template paramter. + Static Analyzer --------------- - Fix incorrect alignment attribute on the this parameter of certain diff --git a/clang/include/clang-c/Index.h b/clang/include/clang-c/Index.h index bc9e100846be6..710668740e0e6 100644 --- a/clang/include/clang-c/Index.h +++ b/clang/include/clang-c/Index.h @@ -3029,9 +3029,25 @@ CINDEX_LINKAGE unsigned long long clang_getEnumConstantDeclUnsignedValue(CXCursor C); /** - * Retrieve the bit width of a bit field declaration as an integer. + * Returns non-zero if the cursor specifies a Record member that is a bit-field. + */ +CINDEX_LINKAGE unsigned clang_Cursor_isBitField(CXCursor C); + +/** + * Retrieve the bit width of a bit-field declaration as an integer. * - * If a cursor that is not a bit field declaration is passed in, -1 is returned. + * If the cursor does not reference a bit-field, or if the bit-field's width + * expression cannot be evaluated, -1 is returned. + * + * For example: + * \code + * if (clang_Cursor_isBitField(Cursor)) { + * int Width = clang_getFieldDeclBitWidth(Cursor); + * if (Width != -1) { + * // The bit-field width is not value-dependent. + * } + * } + * \endcode */ CINDEX_LINKAGE int clang_getFieldDeclBitWidth(CXCursor C); @@ -3660,12 +3676,6 @@ CINDEX_LINKAGE CXType clang_Type_getTemplateArgumentAsType(CXType T, */ CINDEX_LINKAGE enum CXRefQualifierKind clang_Type_getCXXRefQualifier(CXType T); -/** - * Returns non-zero if the cursor specifies a Record member that is a - * bitfield. - */ -CINDEX_LINKAGE unsigned clang_Cursor_isBitField(CXCursor C); - /** * Returns 1 if the base class specified by the cursor with kind * CX_CXXBaseSpecifier is virtual. diff --git a/clang/tools/libclang/CXType.cpp b/clang/tools/libclang/CXType.cpp index a1d157c63995b..eb8bfc25a7c91 100644 --- a/clang/tools/libclang/CXType.cpp +++ b/clang/tools/libclang/CXType.cpp @@ -10,11 +10,11 @@ // //===--------------------------------------------------------------------===// +#include "CXType.h" #include "CIndexer.h" #include "CXCursor.h" #include "CXString.h" #include "CXTranslationUnit.h" -#include "CXType.h" #include "clang/AST/Decl.h" #include "clang/AST/DeclObjC.h" #include "clang/AST/DeclTemplate.h" @@ -378,7 +378,7 @@ int clang_getFieldDeclBitWidth(CXCursor C) { const Decl *D = getCursorDecl(C); if (const FieldDecl *FD = dyn_cast_or_null<FieldDecl>(D)) { - if (FD->isBitField()) + if (FD->isBitField() && !FD->getBitWidth()->isValueDependent()) return FD->getBitWidthValue(getCursorContext(C)); } } _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
