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llvm-project/llvm/lib/CodeGen/MachineModuleInfo.cpp

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//===-- llvm/CodeGen/MachineModuleInfo.cpp ----------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/ADT/PointerUnion.h"
#include "llvm/Analysis/LibCallSemantics.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/CodeGen/WinEHFuncInfo.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/Module.h"
#include "llvm/MC/MCObjectFileInfo.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Support/Dwarf.h"
#include "llvm/Support/ErrorHandling.h"
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() {}
namespace llvm {
class MMIAddrLabelMapCallbackPtr : CallbackVH {
MMIAddrLabelMap *Map;
public:
MMIAddrLabelMapCallbackPtr() : Map(nullptr) {}
MMIAddrLabelMapCallbackPtr(Value *V) : CallbackVH(V), Map(nullptr) {}
void setPtr(BasicBlock *BB) {
ValueHandleBase::operator=(BB);
}
void setMap(MMIAddrLabelMap *map) { Map = map; }
void deleted() override;
void allUsesReplacedWith(Value *V2) override;
};
class MMIAddrLabelMap {
MCContext &Context;
struct AddrLabelSymEntry {
/// Symbols - The symbols for the label. This is a pointer union that is
/// either one symbol (the common case) or a list of symbols.
PointerUnion<MCSymbol *, std::vector<MCSymbol*>*> Symbols;
Function *Fn; // The containing function of the BasicBlock.
unsigned Index; // The index in BBCallbacks for the BasicBlock.
};
DenseMap<AssertingVH<BasicBlock>, AddrLabelSymEntry> AddrLabelSymbols;
/// BBCallbacks - 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;
/// DeletedAddrLabelsNeedingEmission - 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*> >
DeletedAddrLabelsNeedingEmission;
public:
MMIAddrLabelMap(MCContext &context) : Context(context) {}
~MMIAddrLabelMap() {
assert(DeletedAddrLabelsNeedingEmission.empty() &&
"Some labels for deleted blocks never got emitted");
// Deallocate any of the 'list of symbols' case.
for (DenseMap<AssertingVH<BasicBlock>, AddrLabelSymEntry>::iterator
I = AddrLabelSymbols.begin(), E = AddrLabelSymbols.end(); I != E; ++I)
if (I->second.Symbols.is<std::vector<MCSymbol*>*>())
delete I->second.Symbols.get<std::vector<MCSymbol*>*>();
}
MCSymbol *getAddrLabelSymbol(BasicBlock *BB);
std::vector<MCSymbol*> getAddrLabelSymbolToEmit(BasicBlock *BB);
void takeDeletedSymbolsForFunction(Function *F,
std::vector<MCSymbol*> &Result);
void UpdateForDeletedBlock(BasicBlock *BB);
void UpdateForRAUWBlock(BasicBlock *Old, BasicBlock *New);
};
}
MCSymbol *MMIAddrLabelMap::getAddrLabelSymbol(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.isNull()) {
assert(BB->getParent() == Entry.Fn && "Parent changed");
if (Entry.Symbols.is<MCSymbol*>())
return Entry.Symbols.get<MCSymbol*>();
return (*Entry.Symbols.get<std::vector<MCSymbol*>*>())[0];
}
// 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.
BBCallbacks.push_back(BB);
BBCallbacks.back().setMap(this);
Entry.Index = BBCallbacks.size()-1;
Entry.Fn = BB->getParent();
MCSymbol *Result = Context.CreateTempSymbol();
Entry.Symbols = Result;
return Result;
}
std::vector<MCSymbol*>
MMIAddrLabelMap::getAddrLabelSymbolToEmit(BasicBlock *BB) {
assert(BB->hasAddressTaken() &&
"Shouldn't get label for block without address taken");
AddrLabelSymEntry &Entry = AddrLabelSymbols[BB];
std::vector<MCSymbol*> Result;
// If we already had an entry for this block, just return it.
if (Entry.Symbols.isNull())
Result.push_back(getAddrLabelSymbol(BB));
else if (MCSymbol *Sym = Entry.Symbols.dyn_cast<MCSymbol*>())
Result.push_back(Sym);
else
Result = *Entry.Symbols.get<std::vector<MCSymbol*>*>();
return Result;
}
/// takeDeletedSymbolsForFunction - 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 =
DeletedAddrLabelsNeedingEmission.find(F);
// If there are no entries for the function, just return.
if (I == DeletedAddrLabelsNeedingEmission.end()) return;
// Otherwise, take the list.
std::swap(Result, I->second);
DeletedAddrLabelsNeedingEmission.erase(I);
}
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 = AddrLabelSymbols[BB];
AddrLabelSymbols.erase(BB);
assert(!Entry.Symbols.isNull() && "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");
// Handle both the single and the multiple symbols cases.
if (MCSymbol *Sym = Entry.Symbols.dyn_cast<MCSymbol*>()) {
if (Sym->isDefined())
return;
// 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'.
DeletedAddrLabelsNeedingEmission[Entry.Fn].push_back(Sym);
} else {
std::vector<MCSymbol*> *Syms = Entry.Symbols.get<std::vector<MCSymbol*>*>();
for (unsigned i = 0, e = Syms->size(); i != e; ++i) {
MCSymbol *Sym = (*Syms)[i];
if (Sym->isDefined()) continue; // Ignore already emitted labels.
// 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'.
DeletedAddrLabelsNeedingEmission[Entry.Fn].push_back(Sym);
}
// The entry is deleted, free the memory associated with the symbol list.
delete Syms;
}
}
void MMIAddrLabelMap::UpdateForRAUWBlock(BasicBlock *Old, BasicBlock *New) {
// Get the entry for the RAUW'd block and remove it from our map.
AddrLabelSymEntry OldEntry = AddrLabelSymbols[Old];
AddrLabelSymbols.erase(Old);
assert(!OldEntry.Symbols.isNull() && "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.isNull()) {
BBCallbacks[OldEntry.Index].setPtr(New); // Update the callback.
NewEntry = OldEntry; // Set New's entry.
return;
}
BBCallbacks[OldEntry.Index] = nullptr; // Update the callback.
// Otherwise, we need to add the old symbol to the new block's set. If it is
// just a single entry, upgrade it to a symbol list.
if (MCSymbol *PrevSym = NewEntry.Symbols.dyn_cast<MCSymbol*>()) {
std::vector<MCSymbol*> *SymList = new std::vector<MCSymbol*>();
SymList->push_back(PrevSym);
NewEntry.Symbols = SymList;
}
std::vector<MCSymbol*> *SymList =
NewEntry.Symbols.get<std::vector<MCSymbol*>*>();
// If the old entry was a single symbol, add it.
if (MCSymbol *Sym = OldEntry.Symbols.dyn_cast<MCSymbol*>()) {
SymList->push_back(Sym);
return;
}
// Otherwise, concatenate the list.
std::vector<MCSymbol*> *Syms =OldEntry.Symbols.get<std::vector<MCSymbol*>*>();
SymList->insert(SymList->end(), Syms->begin(), Syms->end());
delete Syms;
}
void MMIAddrLabelMapCallbackPtr::deleted() {
Map->UpdateForDeletedBlock(cast<BasicBlock>(getValPtr()));
}
void MMIAddrLabelMapCallbackPtr::allUsesReplacedWith(Value *V2) {
Map->UpdateForRAUWBlock(cast<BasicBlock>(getValPtr()), cast<BasicBlock>(V2));
}
//===----------------------------------------------------------------------===//
MachineModuleInfo::MachineModuleInfo(const MCAsmInfo &MAI,
const MCRegisterInfo &MRI,
const MCObjectFileInfo *MOFI)
: ImmutablePass(ID), Context(&MAI, &MRI, MOFI, nullptr, false) {
initializeMachineModuleInfoPass(*PassRegistry::getPassRegistry());
}
MachineModuleInfo::MachineModuleInfo()
: ImmutablePass(ID), Context(nullptr, nullptr, nullptr) {
llvm_unreachable("This MachineModuleInfo constructor should never be called, "
"MMI should always be explicitly constructed by "
"LLVMTargetMachine");
}
MachineModuleInfo::~MachineModuleInfo() {
}
bool MachineModuleInfo::doInitialization(Module &M) {
ObjFileMMI = nullptr;
CurCallSite = 0;
CallsEHReturn = 0;
CallsUnwindInit = 0;
DbgInfoAvailable = UsesVAFloatArgument = UsesMorestackAddr = false;
// Always emit some info, by default "no personality" info.
Personalities.push_back(nullptr);
PersonalityTypeCache = EHPersonality::Unknown;
AddrLabelSymbols = nullptr;
TheModule = nullptr;
return false;
}
bool MachineModuleInfo::doFinalization(Module &M) {
Personalities.clear();
delete AddrLabelSymbols;
AddrLabelSymbols = nullptr;
Context.reset();
delete ObjFileMMI;
ObjFileMMI = nullptr;
return false;
}
/// EndFunction - Discard function meta information.
///
void MachineModuleInfo::EndFunction() {
// Clean up frame info.
FrameInstructions.clear();
// Clean up exception info.
LandingPads.clear();
CallSiteMap.clear();
TypeInfos.clear();
FilterIds.clear();
FilterEnds.clear();
CallsEHReturn = 0;
CallsUnwindInit = 0;
VariableDbgInfos.clear();
}
/// AnalyzeModule - Scan the module for global debug information.
///
void MachineModuleInfo::AnalyzeModule(const Module &M) {
// Insert functions in the llvm.used array (but not llvm.compiler.used) into
// UsedFunctions.
const GlobalVariable *GV = M.getGlobalVariable("llvm.used");
if (!GV || !GV->hasInitializer()) return;
// Should be an array of 'i8*'.
const ConstantArray *InitList = cast<ConstantArray>(GV->getInitializer());
for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
if (const Function *F =
dyn_cast<Function>(InitList->getOperand(i)->stripPointerCasts()))
UsedFunctions.insert(F);
}
//===- Address of Block Management ----------------------------------------===//
/// getAddrLabelSymbol - Return the symbol to be used for the specified basic
/// block when its address is taken. This cannot be its normal LBB label
/// because the block may be accessed outside its containing function.
MCSymbol *MachineModuleInfo::getAddrLabelSymbol(const BasicBlock *BB) {
// Lazily create AddrLabelSymbols.
if (!AddrLabelSymbols)
AddrLabelSymbols = new MMIAddrLabelMap(Context);
return AddrLabelSymbols->getAddrLabelSymbol(const_cast<BasicBlock*>(BB));
}
/// getAddrLabelSymbolToEmit - Return the symbol to be used for the specified
/// basic block when its address is taken. If other blocks were RAUW'd to
/// this one, we may have to emit them as well, return the whole set.
std::vector<MCSymbol*> MachineModuleInfo::
getAddrLabelSymbolToEmit(const BasicBlock *BB) {
// Lazily create AddrLabelSymbols.
if (!AddrLabelSymbols)
AddrLabelSymbols = new MMIAddrLabelMap(Context);
return AddrLabelSymbols->getAddrLabelSymbolToEmit(const_cast<BasicBlock*>(BB));
}
/// takeDeletedSymbolsForFunction - If the specified function has had any
/// references to address-taken blocks generated, but the block got deleted,
/// return the symbol now so we can emit it. This prevents emitting a
/// reference to a symbol that has no definition.
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);
}
//===- EH -----------------------------------------------------------------===//
/// getOrCreateLandingPadInfo - Find or create an LandingPadInfo for the
/// specified MachineBasicBlock.
LandingPadInfo &MachineModuleInfo::getOrCreateLandingPadInfo
(MachineBasicBlock *LandingPad) {
unsigned N = LandingPads.size();
for (unsigned i = 0; i < N; ++i) {
LandingPadInfo &LP = LandingPads[i];
if (LP.LandingPadBlock == LandingPad)
return LP;
}
LandingPads.push_back(LandingPadInfo(LandingPad));
return LandingPads[N];
}
/// addInvoke - Provide the begin and end labels of an invoke style call and
/// associate it with a try landing pad block.
void MachineModuleInfo::addInvoke(MachineBasicBlock *LandingPad,
MCSymbol *BeginLabel, MCSymbol *EndLabel) {
LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
LP.BeginLabels.push_back(BeginLabel);
LP.EndLabels.push_back(EndLabel);
}
/// addLandingPad - Provide the label of a try LandingPad block.
///
MCSymbol *MachineModuleInfo::addLandingPad(MachineBasicBlock *LandingPad) {
MCSymbol *LandingPadLabel = Context.CreateTempSymbol();
LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
LP.LandingPadLabel = LandingPadLabel;
return LandingPadLabel;
}
/// addPersonality - Provide the personality function for the exception
/// information.
void MachineModuleInfo::addPersonality(MachineBasicBlock *LandingPad,
const Function *Personality) {
LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
LP.Personality = Personality;
for (unsigned i = 0; i < Personalities.size(); ++i)
if (Personalities[i] == Personality)
return;
// If this is the first personality we're adding go
// ahead and add it at the beginning.
if (!Personalities[0])
Personalities[0] = Personality;
else
Personalities.push_back(Personality);
}
void MachineModuleInfo::addWinEHState(MachineBasicBlock *LandingPad,
int State) {
LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
LP.WinEHState = State;
}
/// addCatchTypeInfo - Provide the catch typeinfo for a landing pad.
///
void MachineModuleInfo::
addCatchTypeInfo(MachineBasicBlock *LandingPad,
ArrayRef<const GlobalValue *> TyInfo) {
LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
for (unsigned N = TyInfo.size(); N; --N)
LP.TypeIds.push_back(getTypeIDFor(TyInfo[N - 1]));
}
/// addFilterTypeInfo - Provide the filter typeinfo for a landing pad.
///
void MachineModuleInfo::
addFilterTypeInfo(MachineBasicBlock *LandingPad,
ArrayRef<const GlobalValue *> TyInfo) {
LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
std::vector<unsigned> IdsInFilter(TyInfo.size());
for (unsigned I = 0, E = TyInfo.size(); I != E; ++I)
IdsInFilter[I] = getTypeIDFor(TyInfo[I]);
LP.TypeIds.push_back(getFilterIDFor(IdsInFilter));
}
/// addCleanup - Add a cleanup action for a landing pad.
///
void MachineModuleInfo::addCleanup(MachineBasicBlock *LandingPad) {
LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
LP.TypeIds.push_back(0);
}
MCSymbol *
MachineModuleInfo::addClauseForLandingPad(MachineBasicBlock *LandingPad) {
MCSymbol *ClauseLabel = Context.CreateTempSymbol();
LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
LP.ClauseLabels.push_back(ClauseLabel);
return ClauseLabel;
}
/// TidyLandingPads - Remap landing pad labels and remove any deleted landing
/// pads.
void MachineModuleInfo::TidyLandingPads(DenseMap<MCSymbol*, uintptr_t> *LPMap) {
for (unsigned i = 0; i != LandingPads.size(); ) {
LandingPadInfo &LandingPad = LandingPads[i];
if (LandingPad.LandingPadLabel &&
!LandingPad.LandingPadLabel->isDefined() &&
(!LPMap || (*LPMap)[LandingPad.LandingPadLabel] == 0))
LandingPad.LandingPadLabel = nullptr;
// Special case: we *should* emit LPs with null LP MBB. This indicates
// "nounwind" case.
if (!LandingPad.LandingPadLabel && LandingPad.LandingPadBlock) {
LandingPads.erase(LandingPads.begin() + i);
continue;
}
for (unsigned j = 0, e = LandingPads[i].BeginLabels.size(); j != e; ++j) {
MCSymbol *BeginLabel = LandingPad.BeginLabels[j];
MCSymbol *EndLabel = LandingPad.EndLabels[j];
if ((BeginLabel->isDefined() ||
(LPMap && (*LPMap)[BeginLabel] != 0)) &&
(EndLabel->isDefined() ||
(LPMap && (*LPMap)[EndLabel] != 0))) continue;
LandingPad.BeginLabels.erase(LandingPad.BeginLabels.begin() + j);
LandingPad.EndLabels.erase(LandingPad.EndLabels.begin() + j);
--j, --e;
}
// Remove landing pads with no try-ranges.
if (LandingPads[i].BeginLabels.empty()) {
LandingPads.erase(LandingPads.begin() + i);
continue;
}
// If there is no landing pad, ensure that the list of typeids is empty.
// If the only typeid is a cleanup, this is the same as having no typeids.
if (!LandingPad.LandingPadBlock ||
(LandingPad.TypeIds.size() == 1 && !LandingPad.TypeIds[0]))
LandingPad.TypeIds.clear();
++i;
}
}
/// setCallSiteLandingPad - Map the landing pad's EH symbol to the call site
/// indexes.
void MachineModuleInfo::setCallSiteLandingPad(MCSymbol *Sym,
ArrayRef<unsigned> Sites) {
LPadToCallSiteMap[Sym].append(Sites.begin(), Sites.end());
}
/// getTypeIDFor - Return the type id for the specified typeinfo. This is
/// function wide.
unsigned MachineModuleInfo::getTypeIDFor(const GlobalValue *TI) {
for (unsigned i = 0, N = TypeInfos.size(); i != N; ++i)
if (TypeInfos[i] == TI) return i + 1;
TypeInfos.push_back(TI);
return TypeInfos.size();
}
/// getFilterIDFor - Return the filter id for the specified typeinfos. This is
/// function wide.
int MachineModuleInfo::getFilterIDFor(std::vector<unsigned> &TyIds) {
// If the new filter coincides with the tail of an existing filter, then
// re-use the existing filter. Folding filters more than this requires
// re-ordering filters and/or their elements - probably not worth it.
for (std::vector<unsigned>::iterator I = FilterEnds.begin(),
E = FilterEnds.end(); I != E; ++I) {
unsigned i = *I, j = TyIds.size();
while (i && j)
if (FilterIds[--i] != TyIds[--j])
goto try_next;
if (!j)
// The new filter coincides with range [i, end) of the existing filter.
return -(1 + i);
try_next:;
}
// Add the new filter.
int FilterID = -(1 + FilterIds.size());
FilterIds.reserve(FilterIds.size() + TyIds.size() + 1);
FilterIds.insert(FilterIds.end(), TyIds.begin(), TyIds.end());
FilterEnds.push_back(FilterIds.size());
FilterIds.push_back(0); // terminator
return FilterID;
}
/// getPersonality - Return the personality function for the current function.
const Function *MachineModuleInfo::getPersonality() const {
for (const LandingPadInfo &LPI : LandingPads)
if (LPI.Personality)
return LPI.Personality;
return nullptr;
}
EHPersonality MachineModuleInfo::getPersonalityType() {
if (PersonalityTypeCache == EHPersonality::Unknown) {
if (const Function *F = getPersonality())
PersonalityTypeCache = classifyEHPersonality(F);
}
return PersonalityTypeCache;
}
/// getPersonalityIndex - Return unique index for current personality
/// function. NULL/first personality function should always get zero index.
unsigned MachineModuleInfo::getPersonalityIndex() const {
const Function* Personality = nullptr;
// Scan landing pads. If there is at least one non-NULL personality - use it.
for (unsigned i = 0, e = LandingPads.size(); i != e; ++i)
if (LandingPads[i].Personality) {
Personality = LandingPads[i].Personality;
break;
}
for (unsigned i = 0, e = Personalities.size(); i < e; ++i) {
if (Personalities[i] == Personality)
return i;
}
// This will happen if the current personality function is
// in the zero index.
return 0;
}
const Function *MachineModuleInfo::getWinEHParent(const Function *F) const {
StringRef WinEHParentName =
F->getFnAttribute("wineh-parent").getValueAsString();
if (WinEHParentName.empty() || WinEHParentName == F->getName())
return F;
return F->getParent()->getFunction(WinEHParentName);
}
WinEHFuncInfo &MachineModuleInfo::getWinEHFuncInfo(const Function *F) {
auto &Ptr = FuncInfoMap[getWinEHParent(F)];
if (!Ptr)
Ptr.reset(new WinEHFuncInfo);
return *Ptr;
}
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