llvm-project/llvm/lib/Transforms/Utils/SanitizerStats.cpp

108 lines
4.1 KiB
C++

//===- SanitizerStats.cpp - Sanitizer statistics gathering ----------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// Implements code generation for sanitizer statistics gathering.
//
//===----------------------------------------------------------------------===//
#include "llvm/Transforms/Utils/SanitizerStats.h"
#include "llvm/ADT/Triple.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/Module.h"
#include "llvm/Transforms/Utils/ModuleUtils.h"
using namespace llvm;
SanitizerStatReport::SanitizerStatReport(Module *M) : M(M) {
StatTy = ArrayType::get(Type::getInt8PtrTy(M->getContext()), 2);
EmptyModuleStatsTy = makeModuleStatsTy();
ModuleStatsGV = new GlobalVariable(*M, EmptyModuleStatsTy, false,
GlobalValue::InternalLinkage, nullptr);
}
ArrayType *SanitizerStatReport::makeModuleStatsArrayTy() {
return ArrayType::get(StatTy, Inits.size());
}
StructType *SanitizerStatReport::makeModuleStatsTy() {
return StructType::get(M->getContext(), {Type::getInt8PtrTy(M->getContext()),
Type::getInt32Ty(M->getContext()),
makeModuleStatsArrayTy()});
}
void SanitizerStatReport::create(IRBuilder<> &B, SanitizerStatKind SK) {
Function *F = B.GetInsertBlock()->getParent();
Module *M = F->getParent();
PointerType *Int8PtrTy = B.getInt8PtrTy();
IntegerType *IntPtrTy = B.getIntPtrTy(M->getDataLayout());
ArrayType *StatTy = ArrayType::get(Int8PtrTy, 2);
Inits.push_back(ConstantArray::get(
StatTy,
{Constant::getNullValue(Int8PtrTy),
ConstantExpr::getIntToPtr(
ConstantInt::get(IntPtrTy, uint64_t(SK) << (IntPtrTy->getBitWidth() -
kSanitizerStatKindBits)),
Int8PtrTy)}));
FunctionType *StatReportTy =
FunctionType::get(B.getVoidTy(), Int8PtrTy, false);
FunctionCallee StatReport =
M->getOrInsertFunction("__sanitizer_stat_report", StatReportTy);
auto InitAddr = ConstantExpr::getGetElementPtr(
EmptyModuleStatsTy, ModuleStatsGV,
ArrayRef<Constant *>{
ConstantInt::get(IntPtrTy, 0), ConstantInt::get(B.getInt32Ty(), 2),
ConstantInt::get(IntPtrTy, Inits.size() - 1),
});
B.CreateCall(StatReport, ConstantExpr::getBitCast(InitAddr, Int8PtrTy));
}
void SanitizerStatReport::finish() {
if (Inits.empty()) {
ModuleStatsGV->eraseFromParent();
return;
}
PointerType *Int8PtrTy = Type::getInt8PtrTy(M->getContext());
IntegerType *Int32Ty = Type::getInt32Ty(M->getContext());
Type *VoidTy = Type::getVoidTy(M->getContext());
// Create a new ModuleStatsGV to replace the old one. We can't just set the
// old one's initializer because its type is different.
auto NewModuleStatsGV = new GlobalVariable(
*M, makeModuleStatsTy(), false, GlobalValue::InternalLinkage,
ConstantStruct::getAnon(
{Constant::getNullValue(Int8PtrTy),
ConstantInt::get(Int32Ty, Inits.size()),
ConstantArray::get(makeModuleStatsArrayTy(), Inits)}));
ModuleStatsGV->replaceAllUsesWith(
ConstantExpr::getBitCast(NewModuleStatsGV, ModuleStatsGV->getType()));
ModuleStatsGV->eraseFromParent();
// Create a global constructor to register NewModuleStatsGV.
auto F = Function::Create(FunctionType::get(VoidTy, false),
GlobalValue::InternalLinkage, "", M);
auto BB = BasicBlock::Create(M->getContext(), "", F);
IRBuilder<> B(BB);
FunctionType *StatInitTy = FunctionType::get(VoidTy, Int8PtrTy, false);
FunctionCallee StatInit =
M->getOrInsertFunction("__sanitizer_stat_init", StatInitTy);
B.CreateCall(StatInit, ConstantExpr::getBitCast(NewModuleStatsGV, Int8PtrTy));
B.CreateRetVoid();
appendToGlobalCtors(*M, F, 0);
}