1 //===- lib/MC/MCContext.cpp - Machine Code Context ------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #include "llvm/MC/MCContext.h"
11 #include "llvm/ADT/SmallString.h"
12 #include "llvm/ADT/Twine.h"
13 #include "llvm/MC/MCAsmInfo.h"
14 #include "llvm/MC/MCDwarf.h"
15 #include "llvm/MC/MCLabel.h"
16 #include "llvm/MC/MCObjectFileInfo.h"
17 #include "llvm/MC/MCRegisterInfo.h"
18 #include "llvm/MC/MCSectionCOFF.h"
19 #include "llvm/MC/MCSectionELF.h"
20 #include "llvm/MC/MCSectionMachO.h"
21 #include "llvm/MC/MCSymbol.h"
22 #include "llvm/Support/ELF.h"
23 #include "llvm/Support/ErrorHandling.h"
24 #include "llvm/Support/FileSystem.h"
25 #include "llvm/Support/MemoryBuffer.h"
26 #include "llvm/Support/Signals.h"
27 #include "llvm/Support/SourceMgr.h"
32 MCContext::MCContext(const MCAsmInfo *mai, const MCRegisterInfo *mri,
33 const MCObjectFileInfo *mofi, const SourceMgr *mgr,
35 : SrcMgr(mgr), MAI(mai), MRI(mri), MOFI(mofi), Allocator(),
36 Symbols(Allocator), UsedNames(Allocator), NextUniqueID(0),
37 CurrentDwarfLoc(0, 0, 0, DWARF2_FLAG_IS_STMT, 0, 0), DwarfLocSeen(false),
38 GenDwarfForAssembly(false), GenDwarfFileNumber(0), DwarfVersion(4),
39 AllowTemporaryLabels(true), DwarfCompileUnitID(0),
40 AutoReset(DoAutoReset) {
42 std::error_code EC = llvm::sys::fs::current_path(CompilationDir);
44 CompilationDir.clear();
46 SecureLogFile = getenv("AS_SECURE_LOG_FILE");
48 SecureLogUsed = false;
50 if (SrcMgr && SrcMgr->getNumBuffers() > 0)
51 MainFileName = SrcMgr->getMemoryBuffer(0)->getBufferIdentifier();
54 MCContext::~MCContext() {
59 // NOTE: The symbols are all allocated out of a bump pointer allocator,
60 // we don't need to free them here.
62 // If the stream for the .secure_log_unique directive was created free it.
63 delete (raw_ostream*)SecureLog;
66 //===----------------------------------------------------------------------===//
67 // Module Lifetime Management
68 //===----------------------------------------------------------------------===//
70 void MCContext::reset() {
75 MCDwarfLineTablesCUMap.clear();
76 MCGenDwarfLabelEntries.clear();
77 DwarfDebugFlags = StringRef();
78 DwarfCompileUnitID = 0;
79 CurrentDwarfLoc = MCDwarfLoc(0,0,0,DWARF2_FLAG_IS_STMT,0,0);
81 MachOUniquingMap.clear();
82 ELFUniquingMap.clear();
83 COFFUniquingMap.clear();
86 AllowTemporaryLabels = true;
88 GenDwarfForAssembly = false;
89 GenDwarfFileNumber = 0;
92 //===----------------------------------------------------------------------===//
93 // Symbol Manipulation
94 //===----------------------------------------------------------------------===//
96 MCSymbol *MCContext::GetOrCreateSymbol(StringRef Name) {
97 assert(!Name.empty() && "Normal symbols cannot be unnamed!");
99 // Do the lookup and get the entire StringMapEntry. We want access to the
100 // key if we are creating the entry.
101 StringMapEntry<MCSymbol*> &Entry = Symbols.GetOrCreateValue(Name);
102 MCSymbol *Sym = Entry.getValue();
107 Sym = CreateSymbol(Name);
112 MCSymbol *MCContext::CreateSymbol(StringRef Name) {
113 // Determine whether this is an assembler temporary or normal label, if used.
114 bool isTemporary = false;
115 if (AllowTemporaryLabels)
116 isTemporary = Name.startswith(MAI->getPrivateGlobalPrefix());
118 StringMapEntry<bool> *NameEntry = &UsedNames.GetOrCreateValue(Name);
119 if (NameEntry->getValue()) {
120 assert(isTemporary && "Cannot rename non-temporary symbols");
121 SmallString<128> NewName = Name;
123 NewName.resize(Name.size());
124 raw_svector_ostream(NewName) << NextUniqueID++;
125 NameEntry = &UsedNames.GetOrCreateValue(NewName);
126 } while (NameEntry->getValue());
128 NameEntry->setValue(true);
130 // Ok, the entry doesn't already exist. Have the MCSymbol object itself refer
131 // to the copy of the string that is embedded in the UsedNames entry.
132 MCSymbol *Result = new (*this) MCSymbol(NameEntry->getKey(), isTemporary);
137 MCSymbol *MCContext::GetOrCreateSymbol(const Twine &Name) {
138 SmallString<128> NameSV;
139 return GetOrCreateSymbol(Name.toStringRef(NameSV));
142 MCSymbol *MCContext::CreateLinkerPrivateTempSymbol() {
143 SmallString<128> NameSV;
144 raw_svector_ostream(NameSV)
145 << MAI->getLinkerPrivateGlobalPrefix() << "tmp" << NextUniqueID++;
146 return CreateSymbol(NameSV);
149 MCSymbol *MCContext::CreateTempSymbol() {
150 SmallString<128> NameSV;
151 raw_svector_ostream(NameSV)
152 << MAI->getPrivateGlobalPrefix() << "tmp" << NextUniqueID++;
153 return CreateSymbol(NameSV);
156 unsigned MCContext::NextInstance(unsigned LocalLabelVal) {
157 MCLabel *&Label = Instances[LocalLabelVal];
159 Label = new (*this) MCLabel(0);
160 return Label->incInstance();
163 unsigned MCContext::GetInstance(unsigned LocalLabelVal) {
164 MCLabel *&Label = Instances[LocalLabelVal];
166 Label = new (*this) MCLabel(0);
167 return Label->getInstance();
170 MCSymbol *MCContext::getOrCreateDirectionalLocalSymbol(unsigned LocalLabelVal,
172 MCSymbol *&Sym = LocalSymbols[std::make_pair(LocalLabelVal, Instance)];
174 Sym = CreateTempSymbol();
178 MCSymbol *MCContext::CreateDirectionalLocalSymbol(unsigned LocalLabelVal) {
179 unsigned Instance = NextInstance(LocalLabelVal);
180 return getOrCreateDirectionalLocalSymbol(LocalLabelVal, Instance);
183 MCSymbol *MCContext::GetDirectionalLocalSymbol(unsigned LocalLabelVal,
185 unsigned Instance = GetInstance(LocalLabelVal);
188 return getOrCreateDirectionalLocalSymbol(LocalLabelVal, Instance);
191 MCSymbol *MCContext::LookupSymbol(StringRef Name) const {
192 return Symbols.lookup(Name);
195 MCSymbol *MCContext::LookupSymbol(const Twine &Name) const {
196 SmallString<128> NameSV;
197 Name.toVector(NameSV);
198 return LookupSymbol(NameSV.str());
201 //===----------------------------------------------------------------------===//
202 // Section Management
203 //===----------------------------------------------------------------------===//
205 const MCSectionMachO *MCContext::
206 getMachOSection(StringRef Segment, StringRef Section,
207 unsigned TypeAndAttributes,
208 unsigned Reserved2, SectionKind Kind) {
210 // We unique sections by their segment/section pair. The returned section
211 // may not have the same flags as the requested section, if so this should be
212 // diagnosed by the client as an error.
214 // Form the name to look up.
215 SmallString<64> Name;
220 // Do the lookup, if we have a hit, return it.
221 const MCSectionMachO *&Entry = MachOUniquingMap[Name.str()];
222 if (Entry) return Entry;
224 // Otherwise, return a new section.
225 return Entry = new (*this) MCSectionMachO(Segment, Section, TypeAndAttributes,
229 const MCSectionELF *MCContext::
230 getELFSection(StringRef Section, unsigned Type, unsigned Flags,
232 return getELFSection(Section, Type, Flags, Kind, 0, "");
235 void MCContext::renameELFSection(const MCSectionELF *Section, StringRef Name) {
237 if (const MCSymbol *Group = Section->getGroup())
238 GroupName = Group->getName();
240 ELFUniquingMap.erase(SectionGroupPair(Section->getSectionName(), GroupName));
242 ELFUniquingMap.insert(std::make_pair(SectionGroupPair(Name, GroupName),
244 StringRef CachedName = I->first.first;
245 const_cast<MCSectionELF*>(Section)->setSectionName(CachedName);
248 const MCSectionELF *MCContext::
249 getELFSection(StringRef Section, unsigned Type, unsigned Flags,
250 SectionKind Kind, unsigned EntrySize, StringRef Group) {
251 // Do the lookup, if we have a hit, return it.
252 auto IterBool = ELFUniquingMap.insert(
253 std::make_pair(SectionGroupPair(Section, Group), nullptr));
254 auto &Entry = *IterBool.first;
255 if (!IterBool.second) return Entry.second;
257 // Possibly refine the entry size first.
259 EntrySize = MCSectionELF::DetermineEntrySize(Kind);
262 MCSymbol *GroupSym = nullptr;
264 GroupSym = GetOrCreateSymbol(Group);
266 StringRef CachedName = Entry.first.first;
267 MCSectionELF *Result = new (*this)
268 MCSectionELF(CachedName, Type, Flags, Kind, EntrySize, GroupSym);
269 Entry.second = Result;
273 const MCSectionELF *MCContext::CreateELFGroupSection() {
274 MCSectionELF *Result =
275 new (*this) MCSectionELF(".group", ELF::SHT_GROUP, 0,
276 SectionKind::getReadOnly(), 4, nullptr);
280 const MCSectionCOFF *MCContext::getCOFFSection(StringRef Section,
281 unsigned Characteristics,
283 StringRef COMDATSymName,
285 // Do the lookup, if we have a hit, return it.
287 SectionGroupPair P(Section, COMDATSymName);
288 auto IterBool = COFFUniquingMap.insert(std::make_pair(P, nullptr));
289 auto Iter = IterBool.first;
290 if (!IterBool.second)
293 const MCSymbol *COMDATSymbol = nullptr;
294 if (!COMDATSymName.empty())
295 COMDATSymbol = GetOrCreateSymbol(COMDATSymName);
297 StringRef CachedName = Iter->first.first;
298 MCSectionCOFF *Result = new (*this)
299 MCSectionCOFF(CachedName, Characteristics, COMDATSymbol, Selection, Kind);
301 Iter->second = Result;
305 const MCSectionCOFF *
306 MCContext::getCOFFSection(StringRef Section, unsigned Characteristics,
308 return getCOFFSection(Section, Characteristics, Kind, "", 0);
311 const MCSectionCOFF *MCContext::getCOFFSection(StringRef Section) {
312 SectionGroupPair P(Section, "");
313 auto Iter = COFFUniquingMap.find(P);
314 if (Iter == COFFUniquingMap.end())
319 //===----------------------------------------------------------------------===//
321 //===----------------------------------------------------------------------===//
323 /// GetDwarfFile - takes a file name an number to place in the dwarf file and
324 /// directory tables. If the file number has already been allocated it is an
325 /// error and zero is returned and the client reports the error, else the
326 /// allocated file number is returned. The file numbers may be in any order.
327 unsigned MCContext::GetDwarfFile(StringRef Directory, StringRef FileName,
328 unsigned FileNumber, unsigned CUID) {
329 MCDwarfLineTable &Table = MCDwarfLineTablesCUMap[CUID];
330 return Table.getFile(Directory, FileName, FileNumber);
333 /// isValidDwarfFileNumber - takes a dwarf file number and returns true if it
334 /// currently is assigned and false otherwise.
335 bool MCContext::isValidDwarfFileNumber(unsigned FileNumber, unsigned CUID) {
336 const SmallVectorImpl<MCDwarfFile>& MCDwarfFiles = getMCDwarfFiles(CUID);
337 if(FileNumber == 0 || FileNumber >= MCDwarfFiles.size())
340 return !MCDwarfFiles[FileNumber].Name.empty();
343 void MCContext::FatalError(SMLoc Loc, const Twine &Msg) const {
344 // If we have a source manager and a location, use it. Otherwise just
345 // use the generic report_fatal_error().
346 if (!SrcMgr || Loc == SMLoc())
347 report_fatal_error(Msg, false);
349 // Use the source manager to print the message.
350 SrcMgr->PrintMessage(Loc, SourceMgr::DK_Error, Msg);
352 // If we reached here, we are failing ungracefully. Run the interrupt handlers
353 // to make sure any special cleanups get done, in particular that we remove
354 // files registered with RemoveFileOnSignal.
355 sys::RunInterruptHandlers();