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mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-23 19:23:23 +01:00
llvm-mirror/lib/MC/MCContext.cpp
Wouter van Oortmerssen c0b486e8f3 [WebAssembly] Fix assert in lookup of section symbols
Fixes assert in: https://bugs.llvm.org/show_bug.cgi?id=49036

getWasmSection creates sections if they don't exist, but doesn't add them to the Symbols table. This may cause problems in subsequent calls to getOrCreateSymbol which checks this table, the calls createSymbol assuming it doesn't exist, which then checks UsedNames and finds out it does exist, causing an assert on trying to rename a non-temp symbol.

I tried also fixing the somewhat unintuitive forced suffixing (adding `0`), but it turns out that WasmObjectWriter currently assumes these section symbols are unique, so that may have to be a separate fix: https://bugs.llvm.org/show_bug.cgi?id=49252

Also worth noting is that getWasmSection calling createSymbol may not be correct to start with, given that createSymbol seems to assume it is creating non-section symbols. But again, for a future fix.

Related: where some of this was introduced: 8d396acac3

Differential Revision: https://reviews.llvm.org/D96473
2021-02-18 11:50:14 -08:00

876 lines
33 KiB
C++

//===- lib/MC/MCContext.cpp - Machine Code Context ------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
#include "llvm/MC/MCContext.h"
#include "llvm/ADT/Optional.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Twine.h"
#include "llvm/BinaryFormat/COFF.h"
#include "llvm/BinaryFormat/ELF.h"
#include "llvm/BinaryFormat/XCOFF.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCCodeView.h"
#include "llvm/MC/MCDwarf.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCFragment.h"
#include "llvm/MC/MCLabel.h"
#include "llvm/MC/MCObjectFileInfo.h"
#include "llvm/MC/MCSectionCOFF.h"
#include "llvm/MC/MCSectionELF.h"
#include "llvm/MC/MCSectionMachO.h"
#include "llvm/MC/MCSectionWasm.h"
#include "llvm/MC/MCSectionXCOFF.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MCSymbolCOFF.h"
#include "llvm/MC/MCSymbolELF.h"
#include "llvm/MC/MCSymbolMachO.h"
#include "llvm/MC/MCSymbolWasm.h"
#include "llvm/MC/MCSymbolXCOFF.h"
#include "llvm/MC/SectionKind.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/Signals.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Support/raw_ostream.h"
#include <cassert>
#include <cstdlib>
#include <tuple>
#include <utility>
using namespace llvm;
static cl::opt<char*>
AsSecureLogFileName("as-secure-log-file-name",
cl::desc("As secure log file name (initialized from "
"AS_SECURE_LOG_FILE env variable)"),
cl::init(getenv("AS_SECURE_LOG_FILE")), cl::Hidden);
MCContext::MCContext(const MCAsmInfo *mai, const MCRegisterInfo *mri,
const MCObjectFileInfo *mofi, const SourceMgr *mgr,
MCTargetOptions const *TargetOpts, bool DoAutoReset)
: SrcMgr(mgr), InlineSrcMgr(nullptr), MAI(mai), MRI(mri), MOFI(mofi),
Symbols(Allocator), UsedNames(Allocator),
InlineAsmUsedLabelNames(Allocator),
CurrentDwarfLoc(0, 0, 0, DWARF2_FLAG_IS_STMT, 0, 0),
AutoReset(DoAutoReset), TargetOptions(TargetOpts) {
SecureLogFile = AsSecureLogFileName;
if (SrcMgr && SrcMgr->getNumBuffers())
MainFileName = std::string(SrcMgr->getMemoryBuffer(SrcMgr->getMainFileID())
->getBufferIdentifier());
}
MCContext::~MCContext() {
if (AutoReset)
reset();
// NOTE: The symbols are all allocated out of a bump pointer allocator,
// we don't need to free them here.
}
//===----------------------------------------------------------------------===//
// Module Lifetime Management
//===----------------------------------------------------------------------===//
void MCContext::reset() {
// Call the destructors so the fragments are freed
COFFAllocator.DestroyAll();
ELFAllocator.DestroyAll();
MachOAllocator.DestroyAll();
XCOFFAllocator.DestroyAll();
MCInstAllocator.DestroyAll();
MCSubtargetAllocator.DestroyAll();
InlineAsmUsedLabelNames.clear();
UsedNames.clear();
Symbols.clear();
Allocator.Reset();
Instances.clear();
CompilationDir.clear();
MainFileName.clear();
MCDwarfLineTablesCUMap.clear();
SectionsForRanges.clear();
MCGenDwarfLabelEntries.clear();
DwarfDebugFlags = StringRef();
DwarfCompileUnitID = 0;
CurrentDwarfLoc = MCDwarfLoc(0, 0, 0, DWARF2_FLAG_IS_STMT, 0, 0);
CVContext.reset();
MachOUniquingMap.clear();
ELFUniquingMap.clear();
COFFUniquingMap.clear();
WasmUniquingMap.clear();
XCOFFUniquingMap.clear();
ELFEntrySizeMap.clear();
ELFSeenGenericMergeableSections.clear();
NextID.clear();
AllowTemporaryLabels = true;
DwarfLocSeen = false;
GenDwarfForAssembly = false;
GenDwarfFileNumber = 0;
HadError = false;
}
//===----------------------------------------------------------------------===//
// MCInst Management
//===----------------------------------------------------------------------===//
MCInst *MCContext::createMCInst() {
return new (MCInstAllocator.Allocate()) MCInst;
}
//===----------------------------------------------------------------------===//
// Symbol Manipulation
//===----------------------------------------------------------------------===//
MCSymbol *MCContext::getOrCreateSymbol(const Twine &Name) {
SmallString<128> NameSV;
StringRef NameRef = Name.toStringRef(NameSV);
assert(!NameRef.empty() && "Normal symbols cannot be unnamed!");
MCSymbol *&Sym = Symbols[NameRef];
if (!Sym)
Sym = createSymbol(NameRef, false, false);
return Sym;
}
MCSymbol *MCContext::getOrCreateFrameAllocSymbol(StringRef FuncName,
unsigned Idx) {
return getOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) + FuncName +
"$frame_escape_" + Twine(Idx));
}
MCSymbol *MCContext::getOrCreateParentFrameOffsetSymbol(StringRef FuncName) {
return getOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) + FuncName +
"$parent_frame_offset");
}
MCSymbol *MCContext::getOrCreateLSDASymbol(StringRef FuncName) {
return getOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) + "__ehtable$" +
FuncName);
}
MCSymbol *MCContext::createSymbolImpl(const StringMapEntry<bool> *Name,
bool IsTemporary) {
static_assert(std::is_trivially_destructible<MCSymbolCOFF>(),
"MCSymbol classes must be trivially destructible");
static_assert(std::is_trivially_destructible<MCSymbolELF>(),
"MCSymbol classes must be trivially destructible");
static_assert(std::is_trivially_destructible<MCSymbolMachO>(),
"MCSymbol classes must be trivially destructible");
static_assert(std::is_trivially_destructible<MCSymbolWasm>(),
"MCSymbol classes must be trivially destructible");
static_assert(std::is_trivially_destructible<MCSymbolXCOFF>(),
"MCSymbol classes must be trivially destructible");
if (MOFI) {
switch (MOFI->getObjectFileType()) {
case MCObjectFileInfo::IsCOFF:
return new (Name, *this) MCSymbolCOFF(Name, IsTemporary);
case MCObjectFileInfo::IsELF:
return new (Name, *this) MCSymbolELF(Name, IsTemporary);
case MCObjectFileInfo::IsMachO:
return new (Name, *this) MCSymbolMachO(Name, IsTemporary);
case MCObjectFileInfo::IsWasm:
return new (Name, *this) MCSymbolWasm(Name, IsTemporary);
case MCObjectFileInfo::IsXCOFF:
return createXCOFFSymbolImpl(Name, IsTemporary);
}
}
return new (Name, *this) MCSymbol(MCSymbol::SymbolKindUnset, Name,
IsTemporary);
}
MCSymbol *MCContext::createSymbol(StringRef Name, bool AlwaysAddSuffix,
bool CanBeUnnamed) {
if (CanBeUnnamed && !UseNamesOnTempLabels)
return createSymbolImpl(nullptr, true);
// Determine whether this is a user written assembler temporary or normal
// label, if used.
bool IsTemporary = CanBeUnnamed;
if (AllowTemporaryLabels && !IsTemporary)
IsTemporary = Name.startswith(MAI->getPrivateGlobalPrefix());
SmallString<128> NewName = Name;
bool AddSuffix = AlwaysAddSuffix;
unsigned &NextUniqueID = NextID[Name];
while (true) {
if (AddSuffix) {
NewName.resize(Name.size());
raw_svector_ostream(NewName) << NextUniqueID++;
}
auto NameEntry = UsedNames.insert(std::make_pair(NewName, true));
if (NameEntry.second || !NameEntry.first->second) {
// Ok, we found a name.
// Mark it as used for a non-section symbol.
NameEntry.first->second = true;
// Have the MCSymbol object itself refer to the copy of the string that is
// embedded in the UsedNames entry.
return createSymbolImpl(&*NameEntry.first, IsTemporary);
}
assert(IsTemporary && "Cannot rename non-temporary symbols");
AddSuffix = true;
}
llvm_unreachable("Infinite loop");
}
MCSymbol *MCContext::createTempSymbol(const Twine &Name, bool AlwaysAddSuffix) {
SmallString<128> NameSV;
raw_svector_ostream(NameSV) << MAI->getPrivateGlobalPrefix() << Name;
return createSymbol(NameSV, AlwaysAddSuffix, true);
}
MCSymbol *MCContext::createNamedTempSymbol(const Twine &Name) {
SmallString<128> NameSV;
raw_svector_ostream(NameSV) << MAI->getPrivateGlobalPrefix() << Name;
return createSymbol(NameSV, true, false);
}
MCSymbol *MCContext::createLinkerPrivateTempSymbol() {
SmallString<128> NameSV;
raw_svector_ostream(NameSV) << MAI->getLinkerPrivateGlobalPrefix() << "tmp";
return createSymbol(NameSV, true, false);
}
MCSymbol *MCContext::createTempSymbol() { return createTempSymbol("tmp"); }
MCSymbol *MCContext::createNamedTempSymbol() {
return createNamedTempSymbol("tmp");
}
unsigned MCContext::NextInstance(unsigned LocalLabelVal) {
MCLabel *&Label = Instances[LocalLabelVal];
if (!Label)
Label = new (*this) MCLabel(0);
return Label->incInstance();
}
unsigned MCContext::GetInstance(unsigned LocalLabelVal) {
MCLabel *&Label = Instances[LocalLabelVal];
if (!Label)
Label = new (*this) MCLabel(0);
return Label->getInstance();
}
MCSymbol *MCContext::getOrCreateDirectionalLocalSymbol(unsigned LocalLabelVal,
unsigned Instance) {
MCSymbol *&Sym = LocalSymbols[std::make_pair(LocalLabelVal, Instance)];
if (!Sym)
Sym = createNamedTempSymbol();
return Sym;
}
MCSymbol *MCContext::createDirectionalLocalSymbol(unsigned LocalLabelVal) {
unsigned Instance = NextInstance(LocalLabelVal);
return getOrCreateDirectionalLocalSymbol(LocalLabelVal, Instance);
}
MCSymbol *MCContext::getDirectionalLocalSymbol(unsigned LocalLabelVal,
bool Before) {
unsigned Instance = GetInstance(LocalLabelVal);
if (!Before)
++Instance;
return getOrCreateDirectionalLocalSymbol(LocalLabelVal, Instance);
}
MCSymbol *MCContext::lookupSymbol(const Twine &Name) const {
SmallString<128> NameSV;
StringRef NameRef = Name.toStringRef(NameSV);
return Symbols.lookup(NameRef);
}
void MCContext::setSymbolValue(MCStreamer &Streamer,
StringRef Sym,
uint64_t Val) {
auto Symbol = getOrCreateSymbol(Sym);
Streamer.emitAssignment(Symbol, MCConstantExpr::create(Val, *this));
}
void MCContext::registerInlineAsmLabel(MCSymbol *Sym) {
InlineAsmUsedLabelNames[Sym->getName()] = Sym;
}
MCSymbolXCOFF *
MCContext::createXCOFFSymbolImpl(const StringMapEntry<bool> *Name,
bool IsTemporary) {
if (!Name)
return new (nullptr, *this) MCSymbolXCOFF(nullptr, IsTemporary);
StringRef OriginalName = Name->first();
if (OriginalName.startswith("._Renamed..") ||
OriginalName.startswith("_Renamed.."))
reportError(SMLoc(), "invalid symbol name from source");
if (MAI->isValidUnquotedName(OriginalName))
return new (Name, *this) MCSymbolXCOFF(Name, IsTemporary);
// Now we have a name that contains invalid character(s) for XCOFF symbol.
// Let's replace with something valid, but save the original name so that
// we could still use the original name in the symbol table.
SmallString<128> InvalidName(OriginalName);
// If it's an entry point symbol, we will keep the '.'
// in front for the convention purpose. Otherwise, add "_Renamed.."
// as prefix to signal this is an renamed symbol.
const bool IsEntryPoint = !InvalidName.empty() && InvalidName[0] == '.';
SmallString<128> ValidName =
StringRef(IsEntryPoint ? "._Renamed.." : "_Renamed..");
// Append the hex values of '_' and invalid characters with "_Renamed..";
// at the same time replace invalid characters with '_'.
for (size_t I = 0; I < InvalidName.size(); ++I) {
if (!MAI->isAcceptableChar(InvalidName[I]) || InvalidName[I] == '_') {
raw_svector_ostream(ValidName).write_hex(InvalidName[I]);
InvalidName[I] = '_';
}
}
// Skip entry point symbol's '.' as we already have a '.' in front of
// "_Renamed".
if (IsEntryPoint)
ValidName.append(InvalidName.substr(1, InvalidName.size() - 1));
else
ValidName.append(InvalidName);
auto NameEntry = UsedNames.insert(std::make_pair(ValidName, true));
assert((NameEntry.second || !NameEntry.first->second) &&
"This name is used somewhere else.");
// Mark the name as used for a non-section symbol.
NameEntry.first->second = true;
// Have the MCSymbol object itself refer to the copy of the string
// that is embedded in the UsedNames entry.
MCSymbolXCOFF *XSym = new (&*NameEntry.first, *this)
MCSymbolXCOFF(&*NameEntry.first, IsTemporary);
XSym->setSymbolTableName(MCSymbolXCOFF::getUnqualifiedName(OriginalName));
return XSym;
}
//===----------------------------------------------------------------------===//
// Section Management
//===----------------------------------------------------------------------===//
MCSectionMachO *MCContext::getMachOSection(StringRef Segment, StringRef Section,
unsigned TypeAndAttributes,
unsigned Reserved2, SectionKind Kind,
const char *BeginSymName) {
// We unique sections by their segment/section pair. The returned section
// may not have the same flags as the requested section, if so this should be
// diagnosed by the client as an error.
// Form the name to look up.
assert(Section.size() <= 16 && "section name is too long");
assert(!memchr(Section.data(), '\0', Section.size()) &&
"section name cannot contain NUL");
// Do the lookup, if we have a hit, return it.
auto R = MachOUniquingMap.try_emplace((Segment + Twine(',') + Section).str());
if (!R.second)
return R.first->second;
MCSymbol *Begin = nullptr;
if (BeginSymName)
Begin = createTempSymbol(BeginSymName, false);
// Otherwise, return a new section.
StringRef Name = R.first->first();
R.first->second = new (MachOAllocator.Allocate())
MCSectionMachO(Segment, Name.substr(Name.size() - Section.size()),
TypeAndAttributes, Reserved2, Kind, Begin);
return R.first->second;
}
void MCContext::renameELFSection(MCSectionELF *Section, StringRef Name) {
StringRef GroupName;
if (const MCSymbol *Group = Section->getGroup())
GroupName = Group->getName();
// This function is only used by .debug*, which should not have the
// SHF_LINK_ORDER flag.
unsigned UniqueID = Section->getUniqueID();
ELFUniquingMap.erase(
ELFSectionKey{Section->getName(), GroupName, "", UniqueID});
auto I = ELFUniquingMap
.insert(std::make_pair(
ELFSectionKey{Name, GroupName, "", UniqueID}, Section))
.first;
StringRef CachedName = I->first.SectionName;
const_cast<MCSectionELF *>(Section)->setSectionName(CachedName);
}
MCSectionELF *MCContext::createELFSectionImpl(StringRef Section, unsigned Type,
unsigned Flags, SectionKind K,
unsigned EntrySize,
const MCSymbolELF *Group,
bool Comdat, unsigned UniqueID,
const MCSymbolELF *LinkedToSym) {
MCSymbolELF *R;
MCSymbol *&Sym = Symbols[Section];
// A section symbol can not redefine regular symbols. There may be multiple
// sections with the same name, in which case the first such section wins.
if (Sym && Sym->isDefined() &&
(!Sym->isInSection() || Sym->getSection().getBeginSymbol() != Sym))
reportError(SMLoc(), "invalid symbol redefinition");
if (Sym && Sym->isUndefined()) {
R = cast<MCSymbolELF>(Sym);
} else {
auto NameIter = UsedNames.insert(std::make_pair(Section, false)).first;
R = new (&*NameIter, *this) MCSymbolELF(&*NameIter, /*isTemporary*/ false);
if (!Sym)
Sym = R;
}
R->setBinding(ELF::STB_LOCAL);
R->setType(ELF::STT_SECTION);
auto *Ret = new (ELFAllocator.Allocate())
MCSectionELF(Section, Type, Flags, K, EntrySize, Group, Comdat, UniqueID,
R, LinkedToSym);
auto *F = new MCDataFragment();
Ret->getFragmentList().insert(Ret->begin(), F);
F->setParent(Ret);
R->setFragment(F);
return Ret;
}
MCSectionELF *MCContext::createELFRelSection(const Twine &Name, unsigned Type,
unsigned Flags, unsigned EntrySize,
const MCSymbolELF *Group,
const MCSectionELF *RelInfoSection) {
StringMap<bool>::iterator I;
bool Inserted;
std::tie(I, Inserted) =
RelSecNames.insert(std::make_pair(Name.str(), true));
return createELFSectionImpl(
I->getKey(), Type, Flags, SectionKind::getReadOnly(), EntrySize, Group,
true, true, cast<MCSymbolELF>(RelInfoSection->getBeginSymbol()));
}
MCSectionELF *MCContext::getELFNamedSection(const Twine &Prefix,
const Twine &Suffix, unsigned Type,
unsigned Flags,
unsigned EntrySize) {
return getELFSection(Prefix + "." + Suffix, Type, Flags, EntrySize, Suffix,
/*IsComdat=*/true);
}
MCSectionELF *MCContext::getELFSection(const Twine &Section, unsigned Type,
unsigned Flags, unsigned EntrySize,
const Twine &Group, bool IsComdat,
unsigned UniqueID,
const MCSymbolELF *LinkedToSym) {
MCSymbolELF *GroupSym = nullptr;
if (!Group.isTriviallyEmpty() && !Group.str().empty())
GroupSym = cast<MCSymbolELF>(getOrCreateSymbol(Group));
return getELFSection(Section, Type, Flags, EntrySize, GroupSym, IsComdat,
UniqueID, LinkedToSym);
}
MCSectionELF *MCContext::getELFSection(const Twine &Section, unsigned Type,
unsigned Flags, unsigned EntrySize,
const MCSymbolELF *GroupSym,
bool IsComdat, unsigned UniqueID,
const MCSymbolELF *LinkedToSym) {
StringRef Group = "";
if (GroupSym)
Group = GroupSym->getName();
assert(!(LinkedToSym && LinkedToSym->getName().empty()));
// Do the lookup, if we have a hit, return it.
auto IterBool = ELFUniquingMap.insert(std::make_pair(
ELFSectionKey{Section.str(), Group,
LinkedToSym ? LinkedToSym->getName() : "", UniqueID},
nullptr));
auto &Entry = *IterBool.first;
if (!IterBool.second)
return Entry.second;
StringRef CachedName = Entry.first.SectionName;
SectionKind Kind;
if (Flags & ELF::SHF_ARM_PURECODE)
Kind = SectionKind::getExecuteOnly();
else if (Flags & ELF::SHF_EXECINSTR)
Kind = SectionKind::getText();
else
Kind = SectionKind::getReadOnly();
MCSectionELF *Result =
createELFSectionImpl(CachedName, Type, Flags, Kind, EntrySize, GroupSym,
IsComdat, UniqueID, LinkedToSym);
Entry.second = Result;
recordELFMergeableSectionInfo(Result->getName(), Result->getFlags(),
Result->getUniqueID(), Result->getEntrySize());
return Result;
}
MCSectionELF *MCContext::createELFGroupSection(const MCSymbolELF *Group,
bool IsComdat) {
return createELFSectionImpl(".group", ELF::SHT_GROUP, 0,
SectionKind::getReadOnly(), 4, Group, IsComdat,
MCSection::NonUniqueID, nullptr);
}
void MCContext::recordELFMergeableSectionInfo(StringRef SectionName,
unsigned Flags, unsigned UniqueID,
unsigned EntrySize) {
bool IsMergeable = Flags & ELF::SHF_MERGE;
if (IsMergeable && (UniqueID == GenericSectionID))
ELFSeenGenericMergeableSections.insert(SectionName);
// For mergeable sections or non-mergeable sections with a generic mergeable
// section name we enter their Unique ID into the ELFEntrySizeMap so that
// compatible globals can be assigned to the same section.
if (IsMergeable || isELFGenericMergeableSection(SectionName)) {
ELFEntrySizeMap.insert(std::make_pair(
ELFEntrySizeKey{SectionName, Flags, EntrySize}, UniqueID));
}
}
bool MCContext::isELFImplicitMergeableSectionNamePrefix(StringRef SectionName) {
return SectionName.startswith(".rodata.str") ||
SectionName.startswith(".rodata.cst");
}
bool MCContext::isELFGenericMergeableSection(StringRef SectionName) {
return isELFImplicitMergeableSectionNamePrefix(SectionName) ||
ELFSeenGenericMergeableSections.count(SectionName);
}
Optional<unsigned> MCContext::getELFUniqueIDForEntsize(StringRef SectionName,
unsigned Flags,
unsigned EntrySize) {
auto I = ELFEntrySizeMap.find(
MCContext::ELFEntrySizeKey{SectionName, Flags, EntrySize});
return (I != ELFEntrySizeMap.end()) ? Optional<unsigned>(I->second) : None;
}
MCSectionCOFF *MCContext::getCOFFSection(StringRef Section,
unsigned Characteristics,
SectionKind Kind,
StringRef COMDATSymName, int Selection,
unsigned UniqueID,
const char *BeginSymName) {
MCSymbol *COMDATSymbol = nullptr;
if (!COMDATSymName.empty()) {
COMDATSymbol = getOrCreateSymbol(COMDATSymName);
COMDATSymName = COMDATSymbol->getName();
}
// Do the lookup, if we have a hit, return it.
COFFSectionKey T{Section, COMDATSymName, Selection, UniqueID};
auto IterBool = COFFUniquingMap.insert(std::make_pair(T, nullptr));
auto Iter = IterBool.first;
if (!IterBool.second)
return Iter->second;
MCSymbol *Begin = nullptr;
if (BeginSymName)
Begin = createTempSymbol(BeginSymName, false);
StringRef CachedName = Iter->first.SectionName;
MCSectionCOFF *Result = new (COFFAllocator.Allocate()) MCSectionCOFF(
CachedName, Characteristics, COMDATSymbol, Selection, Kind, Begin);
Iter->second = Result;
return Result;
}
MCSectionCOFF *MCContext::getCOFFSection(StringRef Section,
unsigned Characteristics,
SectionKind Kind,
const char *BeginSymName) {
return getCOFFSection(Section, Characteristics, Kind, "", 0, GenericSectionID,
BeginSymName);
}
MCSectionCOFF *MCContext::getAssociativeCOFFSection(MCSectionCOFF *Sec,
const MCSymbol *KeySym,
unsigned UniqueID) {
// Return the normal section if we don't have to be associative or unique.
if (!KeySym && UniqueID == GenericSectionID)
return Sec;
// If we have a key symbol, make an associative section with the same name and
// kind as the normal section.
unsigned Characteristics = Sec->getCharacteristics();
if (KeySym) {
Characteristics |= COFF::IMAGE_SCN_LNK_COMDAT;
return getCOFFSection(Sec->getName(), Characteristics, Sec->getKind(),
KeySym->getName(),
COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE, UniqueID);
}
return getCOFFSection(Sec->getName(), Characteristics, Sec->getKind(), "", 0,
UniqueID);
}
MCSectionWasm *MCContext::getWasmSection(const Twine &Section, SectionKind K,
const Twine &Group, unsigned UniqueID,
const char *BeginSymName) {
MCSymbolWasm *GroupSym = nullptr;
if (!Group.isTriviallyEmpty() && !Group.str().empty()) {
GroupSym = cast<MCSymbolWasm>(getOrCreateSymbol(Group));
GroupSym->setComdat(true);
}
return getWasmSection(Section, K, GroupSym, UniqueID, BeginSymName);
}
MCSectionWasm *MCContext::getWasmSection(const Twine &Section, SectionKind Kind,
const MCSymbolWasm *GroupSym,
unsigned UniqueID,
const char *BeginSymName) {
StringRef Group = "";
if (GroupSym)
Group = GroupSym->getName();
// Do the lookup, if we have a hit, return it.
auto IterBool = WasmUniquingMap.insert(
std::make_pair(WasmSectionKey{Section.str(), Group, UniqueID}, nullptr));
auto &Entry = *IterBool.first;
if (!IterBool.second)
return Entry.second;
StringRef CachedName = Entry.first.SectionName;
MCSymbol *Begin = createSymbol(CachedName, true, false);
Symbols[Begin->getName()] = Begin;
cast<MCSymbolWasm>(Begin)->setType(wasm::WASM_SYMBOL_TYPE_SECTION);
MCSectionWasm *Result = new (WasmAllocator.Allocate())
MCSectionWasm(CachedName, Kind, GroupSym, UniqueID, Begin);
Entry.second = Result;
auto *F = new MCDataFragment();
Result->getFragmentList().insert(Result->begin(), F);
F->setParent(Result);
Begin->setFragment(F);
return Result;
}
MCSectionXCOFF *
MCContext::getXCOFFSection(StringRef Section, SectionKind Kind,
Optional<XCOFF::CsectProperties> CsectProp,
bool MultiSymbolsAllowed, const char *BeginSymName) {
// Do the lookup. If we have a hit, return it.
// FIXME: handle the case for non-csect sections. Non-csect section has None
// CsectProp.
auto IterBool = XCOFFUniquingMap.insert(std::make_pair(
XCOFFSectionKey{Section.str(), CsectProp->MappingClass}, nullptr));
auto &Entry = *IterBool.first;
if (!IterBool.second) {
MCSectionXCOFF *ExistedEntry = Entry.second;
if (ExistedEntry->isMultiSymbolsAllowed() != MultiSymbolsAllowed)
report_fatal_error("section's multiply symbols policy does not match");
return ExistedEntry;
}
// Otherwise, return a new section.
StringRef CachedName = Entry.first.SectionName;
MCSymbolXCOFF *QualName = cast<MCSymbolXCOFF>(getOrCreateSymbol(
CachedName + "[" + XCOFF::getMappingClassString(CsectProp->MappingClass) +
"]"));
MCSymbol *Begin = nullptr;
if (BeginSymName)
Begin = createTempSymbol(BeginSymName, false);
// QualName->getUnqualifiedName() and CachedName are the same except when
// CachedName contains invalid character(s) such as '$' for an XCOFF symbol.
MCSectionXCOFF *Result = new (XCOFFAllocator.Allocate()) MCSectionXCOFF(
QualName->getUnqualifiedName(), CsectProp->MappingClass, CsectProp->Type,
Kind, QualName, Begin, CachedName, MultiSymbolsAllowed);
Entry.second = Result;
auto *F = new MCDataFragment();
Result->getFragmentList().insert(Result->begin(), F);
F->setParent(Result);
if (Begin)
Begin->setFragment(F);
return Result;
}
MCSubtargetInfo &MCContext::getSubtargetCopy(const MCSubtargetInfo &STI) {
return *new (MCSubtargetAllocator.Allocate()) MCSubtargetInfo(STI);
}
void MCContext::addDebugPrefixMapEntry(const std::string &From,
const std::string &To) {
DebugPrefixMap.insert(std::make_pair(From, To));
}
void MCContext::RemapDebugPaths() {
const auto &DebugPrefixMap = this->DebugPrefixMap;
if (DebugPrefixMap.empty())
return;
const auto RemapDebugPath = [&DebugPrefixMap](std::string &Path) {
SmallString<256> P(Path);
for (const auto &Entry : DebugPrefixMap) {
if (llvm::sys::path::replace_path_prefix(P, Entry.first, Entry.second)) {
Path = P.str().str();
break;
}
}
};
// Remap compilation directory.
std::string CompDir = std::string(CompilationDir.str());
RemapDebugPath(CompDir);
CompilationDir = CompDir;
// Remap MCDwarfDirs in all compilation units.
for (auto &CUIDTablePair : MCDwarfLineTablesCUMap)
for (auto &Dir : CUIDTablePair.second.getMCDwarfDirs())
RemapDebugPath(Dir);
}
//===----------------------------------------------------------------------===//
// Dwarf Management
//===----------------------------------------------------------------------===//
void MCContext::setGenDwarfRootFile(StringRef InputFileName, StringRef Buffer) {
// MCDwarf needs the root file as well as the compilation directory.
// If we find a '.file 0' directive that will supersede these values.
Optional<MD5::MD5Result> Cksum;
if (getDwarfVersion() >= 5) {
MD5 Hash;
MD5::MD5Result Sum;
Hash.update(Buffer);
Hash.final(Sum);
Cksum = Sum;
}
// Canonicalize the root filename. It cannot be empty, and should not
// repeat the compilation dir.
// The MCContext ctor initializes MainFileName to the name associated with
// the SrcMgr's main file ID, which might be the same as InputFileName (and
// possibly include directory components).
// Or, MainFileName might have been overridden by a -main-file-name option,
// which is supposed to be just a base filename with no directory component.
// So, if the InputFileName and MainFileName are not equal, assume
// MainFileName is a substitute basename and replace the last component.
SmallString<1024> FileNameBuf = InputFileName;
if (FileNameBuf.empty() || FileNameBuf == "-")
FileNameBuf = "<stdin>";
if (!getMainFileName().empty() && FileNameBuf != getMainFileName()) {
llvm::sys::path::remove_filename(FileNameBuf);
llvm::sys::path::append(FileNameBuf, getMainFileName());
}
StringRef FileName = FileNameBuf;
if (FileName.consume_front(getCompilationDir()))
if (llvm::sys::path::is_separator(FileName.front()))
FileName = FileName.drop_front();
assert(!FileName.empty());
setMCLineTableRootFile(
/*CUID=*/0, getCompilationDir(), FileName, Cksum, None);
}
/// getDwarfFile - takes a file name and number to place in the dwarf file and
/// directory tables. If the file number has already been allocated it is an
/// error and zero is returned and the client reports the error, else the
/// allocated file number is returned. The file numbers may be in any order.
Expected<unsigned> MCContext::getDwarfFile(StringRef Directory,
StringRef FileName,
unsigned FileNumber,
Optional<MD5::MD5Result> Checksum,
Optional<StringRef> Source,
unsigned CUID) {
MCDwarfLineTable &Table = MCDwarfLineTablesCUMap[CUID];
return Table.tryGetFile(Directory, FileName, Checksum, Source, DwarfVersion,
FileNumber);
}
/// isValidDwarfFileNumber - takes a dwarf file number and returns true if it
/// currently is assigned and false otherwise.
bool MCContext::isValidDwarfFileNumber(unsigned FileNumber, unsigned CUID) {
const MCDwarfLineTable &LineTable = getMCDwarfLineTable(CUID);
if (FileNumber == 0)
return getDwarfVersion() >= 5;
if (FileNumber >= LineTable.getMCDwarfFiles().size())
return false;
return !LineTable.getMCDwarfFiles()[FileNumber].Name.empty();
}
/// Remove empty sections from SectionsForRanges, to avoid generating
/// useless debug info for them.
void MCContext::finalizeDwarfSections(MCStreamer &MCOS) {
SectionsForRanges.remove_if(
[&](MCSection *Sec) { return !MCOS.mayHaveInstructions(*Sec); });
}
CodeViewContext &MCContext::getCVContext() {
if (!CVContext.get())
CVContext.reset(new CodeViewContext);
return *CVContext.get();
}
//===----------------------------------------------------------------------===//
// Error Reporting
//===----------------------------------------------------------------------===//
void MCContext::reportError(SMLoc Loc, const Twine &Msg) {
HadError = true;
// If we have a source manager use it. Otherwise, try using the inline source
// manager.
// If that fails, construct a temporary SourceMgr.
if (SrcMgr)
SrcMgr->PrintMessage(Loc, SourceMgr::DK_Error, Msg);
else if (InlineSrcMgr)
InlineSrcMgr->PrintMessage(Loc, SourceMgr::DK_Error, Msg);
else
SourceMgr().PrintMessage(Loc, SourceMgr::DK_Error, Msg);
}
void MCContext::reportWarning(SMLoc Loc, const Twine &Msg) {
if (TargetOptions && TargetOptions->MCNoWarn)
return;
if (TargetOptions && TargetOptions->MCFatalWarnings)
reportError(Loc, Msg);
else {
// If we have a source manager use it. Otherwise, try using the inline
// source manager.
if (SrcMgr)
SrcMgr->PrintMessage(Loc, SourceMgr::DK_Warning, Msg);
else if (InlineSrcMgr)
InlineSrcMgr->PrintMessage(Loc, SourceMgr::DK_Warning, Msg);
}
}
void MCContext::reportFatalError(SMLoc Loc, const Twine &Msg) {
reportError(Loc, Msg);
// If we reached here, we are failing ungracefully. Run the interrupt handlers
// to make sure any special cleanups get done, in particular that we remove
// files registered with RemoveFileOnSignal.
sys::RunInterruptHandlers();
exit(1);
}