Author: Collin Baker Date: 2023-03-13T10:11:05-04:00 New Revision: 4d55a0b512a17dfaa2461b8803d37b79f6c9691d
URL: https://github.com/llvm/llvm-project/commit/4d55a0b512a17dfaa2461b8803d37b79f6c9691d DIFF: https://github.com/llvm/llvm-project/commit/4d55a0b512a17dfaa2461b8803d37b79f6c9691d.diff LOG: Fix include order in CXType.cpp 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. An additional function clang_isBitFieldDecl() is added to disambiguate between error code meanings. Fixes: https://github.com/llvm/llvm-project/issues/56644 Differential Revision: https://reviews.llvm.org/D130303 Added: Modified: clang/docs/ReleaseNotes.rst clang/include/clang-c/Index.h clang/tools/libclang/CXType.cpp clang/tools/libclang/libclang.map Removed: ################################################################################ diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 76e0a71931c1c..dac81ecd48e34 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -296,6 +296,11 @@ libclang - Introduced the new function ``clang_CXXMethod_isExplicit``, which identifies whether a constructor or conversion function cursor was marked with the explicit identifier. +- 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. +- Added function ``clang_isBitFieldDecl`` to check if a struct/class field is a + bit field. - Introduced the new ``CXIndex`` constructor function ``clang_createIndexWithOptions``, which allows overriding precompiled preamble diff --git a/clang/include/clang-c/Index.h b/clang/include/clang-c/Index.h index 7cd35e9b2a7d4..88d719d32c21f 100644 --- a/clang/include/clang-c/Index.h +++ b/clang/include/clang-c/Index.h @@ -3023,10 +3023,18 @@ CINDEX_LINKAGE long long clang_getEnumConstantDeclValue(CXCursor C); CINDEX_LINKAGE unsigned long long clang_getEnumConstantDeclUnsignedValue(CXCursor C); +/** + * Returns non-zero if a field declaration has a bit width expression. + * + * If the cursor does not reference a bit field declaration 0 is returned. + */ +CINDEX_LINKAGE unsigned clang_isBitFieldDecl(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. */ CINDEX_LINKAGE int clang_getFieldDeclBitWidth(CXCursor C); diff --git a/clang/tools/libclang/CXType.cpp b/clang/tools/libclang/CXType.cpp index a1d157c63995b..9358e3e5f14e5 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" @@ -371,14 +371,27 @@ unsigned long long clang_getEnumConstantDeclUnsignedValue(CXCursor C) { return ULLONG_MAX; } +unsigned clang_isBitFieldDecl(CXCursor C) { + using namespace cxcursor; + + if (clang_isDeclaration(C.kind)) { + const Decl *D = getCursorDecl(C); + + if (const auto *FD = dyn_cast_or_null<FieldDecl>(D)) + return FD->isBitField(); + } + + return 0; +} + int clang_getFieldDeclBitWidth(CXCursor C) { using namespace cxcursor; if (clang_isDeclaration(C.kind)) { const Decl *D = getCursorDecl(C); - if (const FieldDecl *FD = dyn_cast_or_null<FieldDecl>(D)) { - if (FD->isBitField()) + if (const auto *FD = dyn_cast_or_null<FieldDecl>(D)) { + if (FD->isBitField() && !FD->getBitWidth()->isValueDependent()) return FD->getBitWidthValue(getCursorContext(C)); } } diff --git a/clang/tools/libclang/libclang.map b/clang/tools/libclang/libclang.map index 34b1ef1a54514..f6cc157d7fb83 100644 --- a/clang/tools/libclang/libclang.map +++ b/clang/tools/libclang/libclang.map @@ -422,6 +422,7 @@ LLVM_17 { global: clang_CXXMethod_isExplicit; clang_createIndexWithOptions; + clang_isBitFieldDecl; }; # Example of how to add a new symbol version entry. If you do add a new symbol _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
