llvm-6502/lib/MC/MCContext.cpp
David Blaikie 42382d3e37 Remove lazy-initialization of section caches in MCContext
This seems to have been a cargo-culted habit from the very first such
cache which didn't have any specific justification (but might've been a
layering constraint at the time).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206003 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-10 23:55:11 +00:00

355 lines
12 KiB
C++

//===- lib/MC/MCContext.cpp - Machine Code Context ------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/MC/MCContext.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/Twine.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCDwarf.h"
#include "llvm/MC/MCLabel.h"
#include "llvm/MC/MCObjectFileInfo.h"
#include "llvm/MC/MCRegisterInfo.h"
#include "llvm/MC/MCSectionCOFF.h"
#include "llvm/MC/MCSectionELF.h"
#include "llvm/MC/MCSectionMachO.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Support/ELF.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Signals.h"
#include "llvm/Support/SourceMgr.h"
#include <map>
using namespace llvm;
MCContext::MCContext(const MCAsmInfo *mai, const MCRegisterInfo *mri,
const MCObjectFileInfo *mofi, const SourceMgr *mgr,
bool DoAutoReset)
: SrcMgr(mgr), MAI(mai), MRI(mri), MOFI(mofi), Allocator(),
Symbols(Allocator), UsedNames(Allocator), NextUniqueID(0),
CurrentDwarfLoc(0, 0, 0, DWARF2_FLAG_IS_STMT, 0, 0), DwarfLocSeen(false),
GenDwarfForAssembly(false), GenDwarfFileNumber(0),
AllowTemporaryLabels(true), DwarfCompileUnitID(0),
AutoReset(DoAutoReset) {
error_code EC = llvm::sys::fs::current_path(CompilationDir);
if (EC)
CompilationDir.clear();
SecureLogFile = getenv("AS_SECURE_LOG_FILE");
SecureLog = 0;
SecureLogUsed = false;
if (SrcMgr && SrcMgr->getNumBuffers() > 0)
MainFileName = SrcMgr->getMemoryBuffer(0)->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.
// If the stream for the .secure_log_unique directive was created free it.
delete (raw_ostream*)SecureLog;
}
//===----------------------------------------------------------------------===//
// Module Lifetime Management
//===----------------------------------------------------------------------===//
void MCContext::reset() {
UsedNames.clear();
Symbols.clear();
Allocator.Reset();
Instances.clear();
MCDwarfLineTablesCUMap.clear();
MCGenDwarfLabelEntries.clear();
DwarfDebugFlags = StringRef();
DwarfCompileUnitID = 0;
CurrentDwarfLoc = MCDwarfLoc(0,0,0,DWARF2_FLAG_IS_STMT,0,0);
MachOUniquingMap.clear();
ELFUniquingMap.clear();
COFFUniquingMap.clear();
NextUniqueID = 0;
AllowTemporaryLabels = true;
DwarfLocSeen = false;
GenDwarfForAssembly = false;
GenDwarfFileNumber = 0;
}
//===----------------------------------------------------------------------===//
// Symbol Manipulation
//===----------------------------------------------------------------------===//
MCSymbol *MCContext::GetOrCreateSymbol(StringRef Name) {
assert(!Name.empty() && "Normal symbols cannot be unnamed!");
// Do the lookup and get the entire StringMapEntry. We want access to the
// key if we are creating the entry.
StringMapEntry<MCSymbol*> &Entry = Symbols.GetOrCreateValue(Name);
MCSymbol *Sym = Entry.getValue();
if (Sym)
return Sym;
Sym = CreateSymbol(Name);
Entry.setValue(Sym);
return Sym;
}
MCSymbol *MCContext::CreateSymbol(StringRef Name) {
// Determine whether this is an assembler temporary or normal label, if used.
bool isTemporary = false;
if (AllowTemporaryLabels)
isTemporary = Name.startswith(MAI->getPrivateGlobalPrefix());
StringMapEntry<bool> *NameEntry = &UsedNames.GetOrCreateValue(Name);
if (NameEntry->getValue()) {
assert(isTemporary && "Cannot rename non-temporary symbols");
SmallString<128> NewName = Name;
do {
NewName.resize(Name.size());
raw_svector_ostream(NewName) << NextUniqueID++;
NameEntry = &UsedNames.GetOrCreateValue(NewName);
} while (NameEntry->getValue());
}
NameEntry->setValue(true);
// Ok, the entry doesn't already exist. Have the MCSymbol object itself refer
// to the copy of the string that is embedded in the UsedNames entry.
MCSymbol *Result = new (*this) MCSymbol(NameEntry->getKey(), isTemporary);
return Result;
}
MCSymbol *MCContext::GetOrCreateSymbol(const Twine &Name) {
SmallString<128> NameSV;
return GetOrCreateSymbol(Name.toStringRef(NameSV));
}
MCSymbol *MCContext::CreateLinkerPrivateTempSymbol() {
SmallString<128> NameSV;
raw_svector_ostream(NameSV)
<< MAI->getLinkerPrivateGlobalPrefix() << "tmp" << NextUniqueID++;
return CreateSymbol(NameSV);
}
MCSymbol *MCContext::CreateTempSymbol() {
SmallString<128> NameSV;
raw_svector_ostream(NameSV)
<< MAI->getPrivateGlobalPrefix() << "tmp" << NextUniqueID++;
return CreateSymbol(NameSV);
}
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 = CreateTempSymbol();
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(StringRef Name) const {
return Symbols.lookup(Name);
}
MCSymbol *MCContext::LookupSymbol(const Twine &Name) const {
SmallString<128> NameSV;
Name.toVector(NameSV);
return LookupSymbol(NameSV.str());
}
//===----------------------------------------------------------------------===//
// Section Management
//===----------------------------------------------------------------------===//
const MCSectionMachO *MCContext::
getMachOSection(StringRef Segment, StringRef Section,
unsigned TypeAndAttributes,
unsigned Reserved2, SectionKind Kind) {
// 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.
SmallString<64> Name;
Name += Segment;
Name.push_back(',');
Name += Section;
// Do the lookup, if we have a hit, return it.
const MCSectionMachO *&Entry = MachOUniquingMap[Name.str()];
if (Entry) return Entry;
// Otherwise, return a new section.
return Entry = new (*this) MCSectionMachO(Segment, Section, TypeAndAttributes,
Reserved2, Kind);
}
const MCSectionELF *MCContext::
getELFSection(StringRef Section, unsigned Type, unsigned Flags,
SectionKind Kind) {
return getELFSection(Section, Type, Flags, Kind, 0, "");
}
void MCContext::renameELFSection(const MCSectionELF *Section, StringRef Name) {
StringRef GroupName;
if (const MCSymbol *Group = Section->getGroup())
GroupName = Group->getName();
ELFUniquingMap.erase(SectionGroupPair(Section->getSectionName(), GroupName));
auto I =
ELFUniquingMap.insert(std::make_pair(SectionGroupPair(Name, GroupName),
Section)).first;
const_cast<MCSectionELF*>(Section)->setSectionName(I->first.first);
}
const MCSectionELF *MCContext::
getELFSection(StringRef Section, unsigned Type, unsigned Flags,
SectionKind Kind, unsigned EntrySize, StringRef Group) {
// Do the lookup, if we have a hit, return it.
auto IterBool = ELFUniquingMap.insert(
std::make_pair(SectionGroupPair(Section, Group), (MCSectionELF *)0));
auto &Entry = *IterBool.first;
if (!IterBool.second) return Entry.second;
// Possibly refine the entry size first.
if (!EntrySize) {
EntrySize = MCSectionELF::DetermineEntrySize(Kind);
}
MCSymbol *GroupSym = NULL;
if (!Group.empty())
GroupSym = GetOrCreateSymbol(Group);
MCSectionELF *Result = new (*this) MCSectionELF(
Entry.first.first, Type, Flags, Kind, EntrySize, GroupSym);
Entry.second = Result;
return Result;
}
const MCSectionELF *MCContext::CreateELFGroupSection() {
MCSectionELF *Result =
new (*this) MCSectionELF(".group", ELF::SHT_GROUP, 0,
SectionKind::getReadOnly(), 4, NULL);
return Result;
}
const MCSectionCOFF *
MCContext::getCOFFSection(StringRef Section, unsigned Characteristics,
SectionKind Kind, StringRef COMDATSymName,
int Selection, const MCSectionCOFF *Assoc) {
// Do the lookup, if we have a hit, return it.
SectionGroupPair P(Section, COMDATSymName);
auto IterBool = COFFUniquingMap.insert(std::make_pair(P, (MCSectionCOFF *)0));
auto Iter = IterBool.first;
if (!IterBool.second)
return Iter->second;
const MCSymbol *COMDATSymbol = NULL;
if (!COMDATSymName.empty())
COMDATSymbol = GetOrCreateSymbol(COMDATSymName);
MCSectionCOFF *Result =
new (*this) MCSectionCOFF(Iter->first.first, Characteristics,
COMDATSymbol, Selection, Assoc, Kind);
Iter->second = Result;
return Result;
}
const MCSectionCOFF *
MCContext::getCOFFSection(StringRef Section, unsigned Characteristics,
SectionKind Kind) {
return getCOFFSection(Section, Characteristics, Kind, "", 0);
}
const MCSectionCOFF *MCContext::getCOFFSection(StringRef Section) {
SectionGroupPair P(Section, "");
auto Iter = COFFUniquingMap.find(P);
if (Iter == COFFUniquingMap.end())
return 0;
return Iter->second;
}
//===----------------------------------------------------------------------===//
// Dwarf Management
//===----------------------------------------------------------------------===//
/// GetDwarfFile - takes a file name an 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.
unsigned MCContext::GetDwarfFile(StringRef Directory, StringRef FileName,
unsigned FileNumber, unsigned CUID) {
MCDwarfLineTable &Table = MCDwarfLineTablesCUMap[CUID];
return Table.getFile(Directory, FileName, 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 SmallVectorImpl<MCDwarfFile>& MCDwarfFiles = getMCDwarfFiles(CUID);
if(FileNumber == 0 || FileNumber >= MCDwarfFiles.size())
return false;
return !MCDwarfFiles[FileNumber].Name.empty();
}
void MCContext::FatalError(SMLoc Loc, const Twine &Msg) {
// If we have a source manager and a location, use it. Otherwise just
// use the generic report_fatal_error().
if (!SrcMgr || Loc == SMLoc())
report_fatal_error(Msg, false);
// Use the source manager to print the message.
SrcMgr->PrintMessage(Loc, SourceMgr::DK_Error, 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);
}