Author: Kristina Bessonova Date: 2022-11-03T10:28:38+02:00 New Revision: 4ecb2b8ef6be69b55d46ac274f3b7a7103219f98
URL: https://github.com/llvm/llvm-project/commit/4ecb2b8ef6be69b55d46ac274f3b7a7103219f98 DIFF: https://github.com/llvm/llvm-project/commit/4ecb2b8ef6be69b55d46ac274f3b7a7103219f98.diff LOG: [DebugInfo][Metadata] Make AllEnumTypes holding TrackingMDNodeRef Having AllEnumtypes to be a vector of TrackingMDNodeRef makes it possible to reflect changes in metadata in the vector if they took place before DIBuilder being finalized. Otherwise, we end up with heap-use-after-free because AllEnumTypes contains metadata that no longer valid. Consider a case where we have a class containing a definition of a enum, so this enum has the class as a scope. For some reason (doesn't matter for the current issue), we create a temporary debug metadata for this class, and then resolve it while finalizing CGDebugInfo. In the case of collision during uniqifying the temporary, we then need to replace its uses with a new pointer. If a temporary's user is unique (this is the enum mentioned above), we may need re-uniquefying it, which may return a new pointer in the case of another collision. If so, the pointer we stored in AllEnumTypes vector become dangling. Making AllEnumTypes hodling TrackingMDNodeRef should solve this problem (see debug-info-enum-metadata-collision.cpp test for details). Reviewed By: dblaikie Differential Revision: https://reviews.llvm.org/D137067 Added: clang/test/CodeGenCXX/debug-info-enum-metadata-collision.cpp Modified: llvm/include/llvm/IR/DIBuilder.h llvm/lib/IR/DIBuilder.cpp Removed: ################################################################################ diff --git a/clang/test/CodeGenCXX/debug-info-enum-metadata-collision.cpp b/clang/test/CodeGenCXX/debug-info-enum-metadata-collision.cpp new file mode 100644 index 0000000000000..dd27acd0a77c5 --- /dev/null +++ b/clang/test/CodeGenCXX/debug-info-enum-metadata-collision.cpp @@ -0,0 +1,25 @@ +// RUN: %clang_cc1 -triple %itanium_abi_triple -emit-llvm -debug-info-kind=constructor %s -o - | FileCheck %s + +// Test that clang doesn't crash while resolving temporary debug metadata of +// a record with collisions in the record's enum users. + +// CHECK: !DICompositeType(tag: DW_TAG_enumeration_type, +// CHECK-SAME: scope: [[SCOPE:![0-9]+]] +// CHECK-SAME: elements: [[ELEMENTS:![0-9]+]] +// CHECK: [[SCOPE]] = !DICompositeType(tag: DW_TAG_structure_type +// CHECK-SAME: name: "Struct1<Struct3>" +// CHECK: [[ELEMENTS]] = !{[[ELEMENT:![0-9]+]]} +// CHECK: [[ELEMENT]] = !DIEnumerator(name: "enumValue1" + +template <typename> struct Struct1 { + enum { enumValue1 }; + Struct1(); +}; +void function2() { + struct Struct3 {}; + int i = Struct1<Struct3>::enumValue1; +} +void function3() { + struct Struct3 {}; + int i = Struct1<Struct3>::enumValue1; +} diff --git a/llvm/include/llvm/IR/DIBuilder.h b/llvm/include/llvm/IR/DIBuilder.h index dfb65ce341296..61fa4d8f3b9fd 100644 --- a/llvm/include/llvm/IR/DIBuilder.h +++ b/llvm/include/llvm/IR/DIBuilder.h @@ -48,7 +48,7 @@ namespace llvm { Function *LabelFn; ///< llvm.dbg.label Function *AddrFn; ///< llvm.dbg.addr - SmallVector<Metadata *, 4> AllEnumTypes; + SmallVector<TrackingMDNodeRef, 4> AllEnumTypes; /// Track the RetainTypes, since they can be updated later on. SmallVector<TrackingMDNodeRef, 4> AllRetainTypes; SmallVector<Metadata *, 4> AllSubprograms; diff --git a/llvm/lib/IR/DIBuilder.cpp b/llvm/lib/IR/DIBuilder.cpp index fada07ac383ae..76d7ade09a88c 100644 --- a/llvm/lib/IR/DIBuilder.cpp +++ b/llvm/lib/IR/DIBuilder.cpp @@ -84,7 +84,9 @@ void DIBuilder::finalize() { } if (!AllEnumTypes.empty()) - CUNode->replaceEnumTypes(MDTuple::get(VMContext, AllEnumTypes)); + CUNode->replaceEnumTypes(MDTuple::get( + VMContext, SmallVector<Metadata *, 16>(AllEnumTypes.begin(), + AllEnumTypes.end()))); SmallVector<Metadata *, 16> RetainValues; // Declarations and definitions of the same type may be retained. Some @@ -556,7 +558,7 @@ DICompositeType *DIBuilder::createEnumerationType( getNonCompileUnitScope(Scope), UnderlyingType, SizeInBits, AlignInBits, 0, IsScoped ? DINode::FlagEnumClass : DINode::FlagZero, Elements, 0, nullptr, nullptr, UniqueIdentifier); - AllEnumTypes.push_back(CTy); + AllEnumTypes.emplace_back(CTy); trackIfUnresolved(CTy); return CTy; } _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits