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//===-- llvm/CodeGen/MachineModuleInfo.cpp ----------------------*- C++ -*-===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/PostOrderIterator.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/TinyPtrVector.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Value.h"
#include "llvm/IR/ValueHandle.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Pass.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Target/TargetLoweringObjectFile.h"
#include "llvm/Target/TargetMachine.h"
#include <algorithm>
#include <cassert>
#include <memory>
#include <utility>
#include <vector>
using namespace llvm;
using namespace llvm::dwarf;
// Handle the Pass registration stuff necessary to use DataLayout's.
INITIALIZE_PASS(MachineModuleInfo, "machinemoduleinfo",
"Machine Module Information", false, false)
char MachineModuleInfo::ID = 0;
// Out of line virtual method.
MachineModuleInfoImpl::~MachineModuleInfoImpl() = default;
namespace llvm {
class MMIAddrLabelMapCallbackPtr final : CallbackVH {
MMIAddrLabelMap *Map = nullptr;
MMIAddrLabelMapCallbackPtr() = default;
MMIAddrLabelMapCallbackPtr(Value *V) : CallbackVH(V) {}
void setPtr(BasicBlock *BB) {
void setMap(MMIAddrLabelMap *map) { Map = map; }
void deleted() override;
void allUsesReplacedWith(Value *V2) override;
class MMIAddrLabelMap {
MCContext &Context;
struct AddrLabelSymEntry {
/// The symbols for the label.
TinyPtrVector<MCSymbol *> Symbols;
Function *Fn; // The containing function of the BasicBlock.
unsigned Index; // The index in BBCallbacks for the BasicBlock.
DenseMap<AssertingVH<BasicBlock>, AddrLabelSymEntry> AddrLabelSymbols;
/// Callbacks for the BasicBlock's that we have entries for. We use this so
/// we get notified if a block is deleted or RAUWd.
std::vector<MMIAddrLabelMapCallbackPtr> BBCallbacks;
/// This is a per-function list of symbols whose corresponding BasicBlock got
/// deleted. These symbols need to be emitted at some point in the file, so
/// AsmPrinter emits them after the function body.
DenseMap<AssertingVH<Function>, std::vector<MCSymbol*>>
MMIAddrLabelMap(MCContext &context) : Context(context) {}
~MMIAddrLabelMap() {
assert(DeletedAddrLabelsNeedingEmission.empty() &&
"Some labels for deleted blocks never got emitted");
ArrayRef<MCSymbol *> getAddrLabelSymbolToEmit(BasicBlock *BB);
void takeDeletedSymbolsForFunction(Function *F,
std::vector<MCSymbol*> &Result);
void UpdateForDeletedBlock(BasicBlock *BB);
void UpdateForRAUWBlock(BasicBlock *Old, BasicBlock *New);
} // end namespace llvm
ArrayRef<MCSymbol *> MMIAddrLabelMap::getAddrLabelSymbolToEmit(BasicBlock *BB) {
assert(BB->hasAddressTaken() &&
"Shouldn't get label for block without address taken");
AddrLabelSymEntry &Entry = AddrLabelSymbols[BB];
// If we already had an entry for this block, just return it.
if (!Entry.Symbols.empty()) {
assert(BB->getParent() == Entry.Fn && "Parent changed");
return Entry.Symbols;
// Otherwise, this is a new entry, create a new symbol for it and add an
// entry to BBCallbacks so we can be notified if the BB is deleted or RAUWd.
Entry.Index = BBCallbacks.size() - 1;
Entry.Fn = BB->getParent();
return Entry.Symbols;
/// If we have any deleted symbols for F, return them.
void MMIAddrLabelMap::
takeDeletedSymbolsForFunction(Function *F, std::vector<MCSymbol*> &Result) {
DenseMap<AssertingVH<Function>, std::vector<MCSymbol*>>::iterator I =
// If there are no entries for the function, just return.
if (I == DeletedAddrLabelsNeedingEmission.end()) return;
// Otherwise, take the list.
std::swap(Result, I->second);
void MMIAddrLabelMap::UpdateForDeletedBlock(BasicBlock *BB) {
// If the block got deleted, there is no need for the symbol. If the symbol
// was already emitted, we can just forget about it, otherwise we need to
// queue it up for later emission when the function is output.
AddrLabelSymEntry Entry = std::move(AddrLabelSymbols[BB]);
assert(!Entry.Symbols.empty() && "Didn't have a symbol, why a callback?");
BBCallbacks[Entry.Index] = nullptr; // Clear the callback.
assert((BB->getParent() == nullptr || BB->getParent() == Entry.Fn) &&
"Block/parent mismatch");
for (MCSymbol *Sym : Entry.Symbols) {
if (Sym->isDefined())
// If the block is not yet defined, we need to emit it at the end of the
// function. Add the symbol to the DeletedAddrLabelsNeedingEmission list
// for the containing Function. Since the block is being deleted, its
// parent may already be removed, we have to get the function from 'Entry'.
void MMIAddrLabelMap::UpdateForRAUWBlock(BasicBlock *Old, BasicBlock *New) {
// Get the entry for the RAUW'd block and remove it from our map.
AddrLabelSymEntry OldEntry = std::move(AddrLabelSymbols[Old]);
assert(!OldEntry.Symbols.empty() && "Didn't have a symbol, why a callback?");
AddrLabelSymEntry &NewEntry = AddrLabelSymbols[New];
// If New is not address taken, just move our symbol over to it.
if (NewEntry.Symbols.empty()) {
BBCallbacks[OldEntry.Index].setPtr(New); // Update the callback.
NewEntry = std::move(OldEntry); // Set New's entry.
BBCallbacks[OldEntry.Index] = nullptr; // Update the callback.
// Otherwise, we need to add the old symbols to the new block's set.
NewEntry.Symbols.insert(NewEntry.Symbols.end(), OldEntry.Symbols.begin(),
void MMIAddrLabelMapCallbackPtr::deleted() {
void MMIAddrLabelMapCallbackPtr::allUsesReplacedWith(Value *V2) {
Map->UpdateForRAUWBlock(cast<BasicBlock>(getValPtr()), cast<BasicBlock>(V2));
MachineModuleInfo::MachineModuleInfo(const LLVMTargetMachine *TM)
: ImmutablePass(ID), TM(*TM),
Context(TM->getMCAsmInfo(), TM->getMCRegisterInfo(),
TM->getObjFileLowering(), nullptr, false) {
MachineModuleInfo::~MachineModuleInfo() = default;
bool MachineModuleInfo::doInitialization(Module &M) {
ObjFileMMI = nullptr;
CurCallSite = 0;
UsesMSVCFloatingPoint = UsesMorestackAddr = false;
HasSplitStack = HasNosplitStack = false;
AddrLabelSymbols = nullptr;
TheModule = &M;
DbgInfoAvailable = !empty(M.debug_compile_units());
return false;
bool MachineModuleInfo::doFinalization(Module &M) {
delete AddrLabelSymbols;
AddrLabelSymbols = nullptr;
delete ObjFileMMI;
ObjFileMMI = nullptr;
return false;
//===- Address of Block Management ----------------------------------------===//
ArrayRef<MCSymbol *>
MachineModuleInfo::getAddrLabelSymbolToEmit(const BasicBlock *BB) {
// Lazily create AddrLabelSymbols.
if (!AddrLabelSymbols)
AddrLabelSymbols = new MMIAddrLabelMap(Context);
return AddrLabelSymbols->getAddrLabelSymbolToEmit(const_cast<BasicBlock*>(BB));
void MachineModuleInfo::
takeDeletedSymbolsForFunction(const Function *F,
std::vector<MCSymbol*> &Result) {
// If no blocks have had their addresses taken, we're done.
if (!AddrLabelSymbols) return;
return AddrLabelSymbols->
takeDeletedSymbolsForFunction(const_cast<Function*>(F), Result);
/// \name Exception Handling
/// \{
void MachineModuleInfo::addPersonality(const Function *Personality) {
for (unsigned i = 0; i < Personalities.size(); ++i)
if (Personalities[i] == Personality)
/// \}
MachineFunction *
MachineModuleInfo::getMachineFunction(const Function &F) const {
auto I = MachineFunctions.find(&F);
return I != MachineFunctions.end() ? I->second.get() : nullptr;
MachineFunction &
MachineModuleInfo::getOrCreateMachineFunction(const Function &F) {
// Shortcut for the common case where a sequence of MachineFunctionPasses
// all query for the same Function.
if (LastRequest == &F)
return *LastResult;
auto I = MachineFunctions.insert(
std::make_pair(&F, std::unique_ptr<MachineFunction>()));
MachineFunction *MF;
if (I.second) {
// No pre-existing machine function, create a new one.
const TargetSubtargetInfo &STI = *TM.getSubtargetImpl(F);
MF = new MachineFunction(F, TM, STI, NextFnNum++, *this);
// Update the set entry.
} else {
MF = I.first->second.get();
LastRequest = &F;
LastResult = MF;
return *MF;
void MachineModuleInfo::deleteMachineFunctionFor(Function &F) {
LastRequest = nullptr;
LastResult = nullptr;
namespace {
/// This pass frees the MachineFunction object associated with a Function.
class FreeMachineFunction : public FunctionPass {
static char ID;
FreeMachineFunction() : FunctionPass(ID) {}
void getAnalysisUsage(AnalysisUsage &AU) const override {
bool runOnFunction(Function &F) override {
MachineModuleInfo &MMI = getAnalysis<MachineModuleInfo>();
return true;
StringRef getPassName() const override {
return "Free MachineFunction";
} // end anonymous namespace
char FreeMachineFunction::ID;
FunctionPass *llvm::createFreeMachineFunctionPass() {
return new FreeMachineFunction();