| 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-exception |
| 6 | // |
| 7 | //===----------------------------------------------------------------------===// |
| 8 | // |
| 9 | // Add !annotation metadata for entries in @llvm.global.anotations, generated |
| 10 | // 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 | #include "llvm/Transforms/IPO.h" |
| 21 | |
| 22 | using namespace llvm; |
| 23 | |
| 24 | #define DEBUG_TYPE "annotation2metadata" |
| 25 | |
| 26 | static bool convertAnnotation2Metadata(Module &M) { |
| 27 | // Only add !annotation metadata if the corresponding remarks pass is also |
| 28 | // enabled. |
| 29 | if (!OptimizationRemarkEmitter::allowExtraAnalysis(Ctx&: M.getContext(), |
| 30 | PassName: "annotation-remarks")) |
| 31 | return false; |
| 32 | |
| 33 | auto *Annotations = M.getGlobalVariable(Name: "llvm.global.annotations"); |
| 34 | auto *C = dyn_cast_or_null<Constant>(Val: Annotations); |
| 35 | if (!C || C->getNumOperands() != 1) |
| 36 | return false; |
| 37 | |
| 38 | C = cast<Constant>(Val: C->getOperand(i: 0)); |
| 39 | |
| 40 | // Iterate over all entries in C and attach !annotation metadata to suitable |
| 41 | // entries. |
| 42 | for (auto &Op : C->operands()) { |
| 43 | // Look at the operands to check if we can use the entry to generate |
| 44 | // !annotation metadata. |
| 45 | auto *OpC = dyn_cast<ConstantStruct>(Val: &Op); |
| 46 | if (!OpC || OpC->getNumOperands() != 4) |
| 47 | continue; |
| 48 | auto *StrC = dyn_cast<GlobalValue>(Val: OpC->getOperand(i_nocapture: 1)->stripPointerCasts()); |
| 49 | if (!StrC) |
| 50 | continue; |
| 51 | auto *StrData = dyn_cast<ConstantDataSequential>(Val: StrC->getOperand(i: 0)); |
| 52 | if (!StrData) |
| 53 | continue; |
| 54 | auto *Fn = dyn_cast<Function>(Val: OpC->getOperand(i_nocapture: 0)->stripPointerCasts()); |
| 55 | if (!Fn) |
| 56 | continue; |
| 57 | |
| 58 | // Add annotation to all instructions in the function. |
| 59 | for (auto &I : instructions(F: Fn)) |
| 60 | I.addAnnotationMetadata(Annotation: StrData->getAsCString()); |
| 61 | } |
| 62 | return true; |
| 63 | } |
| 64 | |
| 65 | PreservedAnalyses Annotation2MetadataPass::run(Module &M, |
| 66 | ModuleAnalysisManager &AM) { |
| 67 | return convertAnnotation2Metadata(M) ? PreservedAnalyses::none() |
| 68 | : PreservedAnalyses::all(); |
| 69 | } |
| 70 |