106 lines · cpp
1//===- SanitizerStats.cpp - Sanitizer statistics gathering ----------------===//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// Implements code generation for sanitizer statistics gathering.10//11//===----------------------------------------------------------------------===//12 13#include "llvm/Transforms/Utils/SanitizerStats.h"14#include "llvm/IR/Constants.h"15#include "llvm/IR/DerivedTypes.h"16#include "llvm/IR/GlobalVariable.h"17#include "llvm/IR/IRBuilder.h"18#include "llvm/IR/Module.h"19#include "llvm/Transforms/Utils/ModuleUtils.h"20 21using namespace llvm;22 23SanitizerStatReport::SanitizerStatReport(Module *M) : M(M) {24 StatTy = ArrayType::get(PointerType::getUnqual(M->getContext()), 2);25 EmptyModuleStatsTy = makeModuleStatsTy();26 27 ModuleStatsGV = new GlobalVariable(*M, EmptyModuleStatsTy, false,28 GlobalValue::InternalLinkage, nullptr);29}30 31ArrayType *SanitizerStatReport::makeModuleStatsArrayTy() {32 return ArrayType::get(StatTy, Inits.size());33}34 35StructType *SanitizerStatReport::makeModuleStatsTy() {36 return StructType::get(M->getContext(),37 {PointerType::getUnqual(M->getContext()),38 Type::getInt32Ty(M->getContext()),39 makeModuleStatsArrayTy()});40}41 42void SanitizerStatReport::create(IRBuilder<> &B, SanitizerStatKind SK) {43 Function *F = B.GetInsertBlock()->getParent();44 Module *M = F->getParent();45 PointerType *PtrTy = B.getPtrTy();46 IntegerType *IntPtrTy = B.getIntPtrTy(M->getDataLayout());47 ArrayType *StatTy = ArrayType::get(PtrTy, 2);48 49 Inits.push_back(ConstantArray::get(50 StatTy,51 {Constant::getNullValue(PtrTy),52 ConstantExpr::getIntToPtr(53 ConstantInt::get(IntPtrTy, uint64_t(SK) << (IntPtrTy->getBitWidth() -54 kSanitizerStatKindBits)),55 PtrTy)}));56 57 FunctionType *StatReportTy = FunctionType::get(B.getVoidTy(), PtrTy, false);58 FunctionCallee StatReport =59 M->getOrInsertFunction("__sanitizer_stat_report", StatReportTy);60 61 auto InitAddr = ConstantExpr::getGetElementPtr(62 EmptyModuleStatsTy, ModuleStatsGV,63 ArrayRef<Constant *>{64 ConstantInt::get(IntPtrTy, 0), ConstantInt::get(B.getInt32Ty(), 2),65 ConstantInt::get(IntPtrTy, Inits.size() - 1),66 });67 B.CreateCall(StatReport, InitAddr);68}69 70void SanitizerStatReport::finish() {71 if (Inits.empty()) {72 ModuleStatsGV->eraseFromParent();73 return;74 }75 76 PointerType *Int8PtrTy = PointerType::getUnqual(M->getContext());77 IntegerType *Int32Ty = Type::getInt32Ty(M->getContext());78 Type *VoidTy = Type::getVoidTy(M->getContext());79 80 // Create a new ModuleStatsGV to replace the old one. We can't just set the81 // old one's initializer because its type is different.82 auto NewModuleStatsGV = new GlobalVariable(83 *M, makeModuleStatsTy(), false, GlobalValue::InternalLinkage,84 ConstantStruct::getAnon(85 {Constant::getNullValue(Int8PtrTy),86 ConstantInt::get(Int32Ty, Inits.size()),87 ConstantArray::get(makeModuleStatsArrayTy(), Inits)}));88 ModuleStatsGV->replaceAllUsesWith(NewModuleStatsGV);89 ModuleStatsGV->eraseFromParent();90 91 // Create a global constructor to register NewModuleStatsGV.92 auto F = Function::Create(FunctionType::get(VoidTy, false),93 GlobalValue::InternalLinkage, "", M);94 auto BB = BasicBlock::Create(M->getContext(), "", F);95 IRBuilder<> B(BB);96 97 FunctionType *StatInitTy = FunctionType::get(VoidTy, Int8PtrTy, false);98 FunctionCallee StatInit =99 M->getOrInsertFunction("__sanitizer_stat_init", StatInitTy);100 101 B.CreateCall(StatInit, NewModuleStatsGV);102 B.CreateRetVoid();103 104 appendToGlobalCtors(*M, F, 0);105}106