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//===- Pass.cpp - LLVM Pass Infrastructure Implementation -----------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// This file implements the LLVM Pass infrastructure. It is primarily
// responsible with ensuring that passes are executed and batched together
// optimally.
//
//===----------------------------------------------------------------------===//
#include "llvm/Pass.h"
#include "llvm/Config/llvm-config.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/IRPrintingPasses.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/LegacyPassNameParser.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/OptBisect.h"
#include "llvm/PassInfo.h"
#include "llvm/PassRegistry.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include <cassert>
#ifdef EXPENSIVE_CHECKS
#include "llvm/IR/StructuralHash.h"
#endif
using namespace llvm;
#define DEBUG_TYPE "ir"
//===----------------------------------------------------------------------===//
// Pass Implementation
//
// Force out-of-line virtual method.
Pass::~Pass() {
delete Resolver;
}
// Force out-of-line virtual method.
ModulePass::~ModulePass() = default;
Pass *ModulePass::createPrinterPass(raw_ostream &OS,
const std::string &Banner) const {
return createPrintModulePass(OS, Banner);
}
PassManagerType ModulePass::getPotentialPassManagerType() const {
return PMT_ModulePassManager;
}
static std::string getDescription(const Module &M) {
return "module (" + M.getName().str() + ")";
}
bool ModulePass::skipModule(Module &M) const {
OptPassGate &Gate = M.getContext().getOptPassGate();
return Gate.isEnabled() &&
!Gate.shouldRunPass(this->getPassName(), getDescription(M));
}
bool Pass::mustPreserveAnalysisID(char &AID) const {
return Resolver->getAnalysisIfAvailable(&AID) != nullptr;
}
// dumpPassStructure - Implement the -debug-pass=Structure option
void Pass::dumpPassStructure(unsigned Offset) {
dbgs().indent(Offset*2) << getPassName() << "\n";
}
/// getPassName - Return a nice clean name for a pass. This usually
/// implemented in terms of the name that is registered by one of the
/// Registration templates, but can be overloaded directly.
StringRef Pass::getPassName() const {
AnalysisID AID = getPassID();
const PassInfo *PI = PassRegistry::getPassRegistry()->getPassInfo(AID);
if (PI)
return PI->getPassName();
return "Unnamed pass: implement Pass::getPassName()";
}
void Pass::preparePassManager(PMStack &) {
// By default, don't do anything.
}
PassManagerType Pass::getPotentialPassManagerType() const {
// Default implementation.
return PMT_Unknown;
}
void Pass::getAnalysisUsage(AnalysisUsage &) const {
// By default, no analysis results are used, all are invalidated.
}
void Pass::releaseMemory() {
// By default, don't do anything.
}
void Pass::verifyAnalysis() const {
// By default, don't do anything.
}
void *Pass::getAdjustedAnalysisPointer(AnalysisID AID) {
return this;
}
ImmutablePass *Pass::getAsImmutablePass() {
return nullptr;
}
PMDataManager *Pass::getAsPMDataManager() {
return nullptr;
}
void Pass::setResolver(AnalysisResolver *AR) {
assert(!Resolver && "Resolver is already set");
Resolver = AR;
}
// print - Print out the internal state of the pass. This is called by Analyze
// to print out the contents of an analysis. Otherwise it is not necessary to
// implement this method.
void Pass::print(raw_ostream &OS, const Module *) const {
OS << "Pass::print not implemented for pass: '" << getPassName() << "'!\n";
}
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
// dump - call print(cerr);
LLVM_DUMP_METHOD void Pass::dump() const {
print(dbgs(), nullptr);
}
#endif
#ifdef EXPENSIVE_CHECKS
uint64_t Pass::structuralHash(Module &M) const { return StructuralHash(M); }
uint64_t Pass::structuralHash(Function &F) const { return StructuralHash(F); }
#endif
//===----------------------------------------------------------------------===//
// ImmutablePass Implementation
//
// Force out-of-line virtual method.
ImmutablePass::~ImmutablePass() = default;
void ImmutablePass::initializePass() {
// By default, don't do anything.
}
//===----------------------------------------------------------------------===//
// FunctionPass Implementation
//
Pass *FunctionPass::createPrinterPass(raw_ostream &OS,
const std::string &Banner) const {
return createPrintFunctionPass(OS, Banner);
}
PassManagerType FunctionPass::getPotentialPassManagerType() const {
return PMT_FunctionPassManager;
}
static std::string getDescription(const Function &F) {
return "function (" + F.getName().str() + ")";
}
bool FunctionPass::skipFunction(const Function &F) const {
OptPassGate &Gate = F.getContext().getOptPassGate();
if (Gate.isEnabled() &&
!Gate.shouldRunPass(this->getPassName(), getDescription(F)))
return true;
if (F.hasOptNone()) {
LLVM_DEBUG(dbgs() << "Skipping pass '" << getPassName() << "' on function "
<< F.getName() << "\n");
return true;
}
return false;
}
const PassInfo *Pass::lookupPassInfo(const void *TI) {
return PassRegistry::getPassRegistry()->getPassInfo(TI);
}
const PassInfo *Pass::lookupPassInfo(StringRef Arg) {
return PassRegistry::getPassRegistry()->getPassInfo(Arg);
}
Pass *Pass::createPass(AnalysisID ID) {
const PassInfo *PI = PassRegistry::getPassRegistry()->getPassInfo(ID);
if (!PI)
return nullptr;
return PI->createPass();
}
//===----------------------------------------------------------------------===//
// Analysis Group Implementation Code
//===----------------------------------------------------------------------===//
// RegisterAGBase implementation
RegisterAGBase::RegisterAGBase(StringRef Name, const void *InterfaceID,
const void *PassID, bool isDefault)
: PassInfo(Name, InterfaceID) {
PassRegistry::getPassRegistry()->registerAnalysisGroup(InterfaceID, PassID,
*this, isDefault);
}
//===----------------------------------------------------------------------===//
// PassRegistrationListener implementation
//
// enumeratePasses - Iterate over the registered passes, calling the
// passEnumerate callback on each PassInfo object.
void PassRegistrationListener::enumeratePasses() {
PassRegistry::getPassRegistry()->enumerateWith(this);
}
PassNameParser::PassNameParser(cl::Option &O)
: cl::parser<const PassInfo *>(O) {
PassRegistry::getPassRegistry()->addRegistrationListener(this);
}
// This only gets called during static destruction, in which case the
// PassRegistry will have already been destroyed by llvm_shutdown(). So
// attempting to remove the registration listener is an error.
PassNameParser::~PassNameParser() = default;
//===----------------------------------------------------------------------===//
// AnalysisUsage Class Implementation
//
namespace {
struct GetCFGOnlyPasses : public PassRegistrationListener {
using VectorType = AnalysisUsage::VectorType;
VectorType &CFGOnlyList;
GetCFGOnlyPasses(VectorType &L) : CFGOnlyList(L) {}
void passEnumerate(const PassInfo *P) override {
if (P->isCFGOnlyPass())
CFGOnlyList.push_back(P->getTypeInfo());
}
};
} // end anonymous namespace
// setPreservesCFG - This function should be called to by the pass, iff they do
// not:
//
// 1. Add or remove basic blocks from the function
// 2. Modify terminator instructions in any way.
//
// This function annotates the AnalysisUsage info object to say that analyses
// that only depend on the CFG are preserved by this pass.
void AnalysisUsage::setPreservesCFG() {
// Since this transformation doesn't modify the CFG, it preserves all analyses
// that only depend on the CFG (like dominators, loop info, etc...)
GetCFGOnlyPasses(Preserved).enumeratePasses();
}
AnalysisUsage &AnalysisUsage::addPreserved(StringRef Arg) {
const PassInfo *PI = Pass::lookupPassInfo(Arg);
// If the pass exists, preserve it. Otherwise silently do nothing.
if (PI)
pushUnique(Preserved, PI->getTypeInfo());
return *this;
}
AnalysisUsage &AnalysisUsage::addRequiredID(const void *ID) {
pushUnique(Required, ID);
return *this;
}
AnalysisUsage &AnalysisUsage::addRequiredID(char &ID) {
pushUnique(Required, &ID);
return *this;
}
AnalysisUsage &AnalysisUsage::addRequiredTransitiveID(char &ID) {
pushUnique(Required, &ID);
pushUnique(RequiredTransitive, &ID);
return *this;
}