Index: lib/IR/AsmWriter.cpp =================================================================== --- lib/IR/AsmWriter.cpp +++ lib/IR/AsmWriter.cpp @@ -3149,7 +3149,7 @@ return; if (MDNames.empty()) - TheModule->getMDKindNames(MDNames); + MDs[0].second->getContext().getMDKindNames(MDNames); for (const auto &I : MDs) { unsigned Kind = I.first; Index: unittests/IR/AsmWriterTest.cpp =================================================================== --- /dev/null +++ unittests/IR/AsmWriterTest.cpp @@ -0,0 +1,37 @@ +//===- llvm/unittest/IR/AsmWriter.cpp - AsmWriter tests -------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +#include "llvm/IR/IRBuilder.h" +#include "llvm/IR/Function.h" +#include "llvm/IR/LLVMContext.h" +#include "llvm/IR/MDBuilder.h" +#include "llvm/IR/Module.h" +#include "gtest/gtest.h" + +using namespace llvm; + +namespace { + +TEST(AsmWriterTest, DebugPrintDetachedInstruction) { + + // PR24852: Ensure that an instruction can be printed even when it + // has metadata attached but no parent. + LLVMContext Ctx; + auto Ty = Type::getInt32Ty(Ctx); + auto Undef = UndefValue::get(Ty); + std::unique_ptr Add(BinaryOperator::CreateAdd(Undef, Undef)); + Add->setMetadata( + "", MDNode::get(Ctx, {ConstantAsMetadata::get(ConstantInt::get(Ty, 1))})); + std::string S; + raw_string_ostream OS(S); + Add->print(OS); + std::size_t r = OS.str().find(" = add i32 undef, undef, !