69 lines · cpp
1//===-- Annotation2Metadata.cpp - Add !annotation metadata. ---------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8//9// Add !annotation metadata for entries in @llvm.global.anotations, generated10// using __attribute__((annotate("_name"))) on functions in Clang.11//12//===----------------------------------------------------------------------===//13 14#include "llvm/Transforms/IPO/Annotation2Metadata.h"15#include "llvm/Analysis/OptimizationRemarkEmitter.h"16#include "llvm/IR/Constants.h"17#include "llvm/IR/Function.h"18#include "llvm/IR/InstIterator.h"19#include "llvm/IR/Module.h"20 21using namespace llvm;22 23#define DEBUG_TYPE "annotation2metadata"24 25static bool convertAnnotation2Metadata(Module &M) {26 // Only add !annotation metadata if the corresponding remarks pass is also27 // enabled.28 if (!OptimizationRemarkEmitter::allowExtraAnalysis(M.getContext(),29 "annotation-remarks"))30 return false;31 32 auto *Annotations = M.getGlobalVariable("llvm.global.annotations");33 auto *C = dyn_cast_or_null<Constant>(Annotations);34 if (!C || C->getNumOperands() != 1)35 return false;36 37 C = cast<Constant>(C->getOperand(0));38 39 // Iterate over all entries in C and attach !annotation metadata to suitable40 // entries.41 for (auto &Op : C->operands()) {42 // Look at the operands to check if we can use the entry to generate43 // !annotation metadata.44 auto *OpC = dyn_cast<ConstantStruct>(&Op);45 if (!OpC || OpC->getNumOperands() != 4)46 continue;47 auto *StrC = dyn_cast<GlobalValue>(OpC->getOperand(1)->stripPointerCasts());48 if (!StrC)49 continue;50 auto *StrData = dyn_cast<ConstantDataSequential>(StrC->getOperand(0));51 if (!StrData)52 continue;53 auto *Fn = dyn_cast<Function>(OpC->getOperand(0)->stripPointerCasts());54 if (!Fn)55 continue;56 57 // Add annotation to all instructions in the function.58 for (auto &I : instructions(Fn))59 I.addAnnotationMetadata(StrData->getAsCString());60 }61 return true;62}63 64PreservedAnalyses Annotation2MetadataPass::run(Module &M,65 ModuleAnalysisManager &AM) {66 return convertAnnotation2Metadata(M) ? PreservedAnalyses::none()67 : PreservedAnalyses::all();68}69