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 typedef std::pair<std::string, std::string> SectionGroupPair;
34 typedef StringMap<const MCSectionMachO*> MachOUniqueMapTy;
35 typedef std::map<SectionGroupPair, const MCSectionELF *> ELFUniqueMapTy;
36 typedef std::map<SectionGroupPair, const MCSectionCOFF *> COFFUniqueMapTy;
38 MCContext::MCContext(const MCAsmInfo *mai, const MCRegisterInfo *mri,
39 const MCObjectFileInfo *mofi, const SourceMgr *mgr,
41 SrcMgr(mgr), MAI(mai), MRI(mri), MOFI(mofi),
42 Allocator(), Symbols(Allocator), UsedNames(Allocator),
44 CurrentDwarfLoc(0,0,0,DWARF2_FLAG_IS_STMT,0,0),
45 DwarfLocSeen(false), GenDwarfForAssembly(false), GenDwarfFileNumber(0),
46 AllowTemporaryLabels(true), DwarfCompileUnitID(0), AutoReset(DoAutoReset) {
48 error_code EC = llvm::sys::fs::current_path(CompilationDir);
50 CompilationDir.clear();
56 SecureLogFile = getenv("AS_SECURE_LOG_FILE");
58 SecureLogUsed = false;
60 if (SrcMgr && SrcMgr->getNumBuffers() > 0)
61 MainFileName = SrcMgr->getMemoryBuffer(0)->getBufferIdentifier();
66 MCContext::~MCContext() {
71 // NOTE: The symbols are all allocated out of a bump pointer allocator,
72 // we don't need to free them here.
74 // If the stream for the .secure_log_unique directive was created free it.
75 delete (raw_ostream*)SecureLog;
78 //===----------------------------------------------------------------------===//
79 // Module Lifetime Management
80 //===----------------------------------------------------------------------===//
82 void MCContext::reset() {
87 MCDwarfFileTablesCUMap.clear();
88 MCGenDwarfLabelEntries.clear();
89 DwarfDebugFlags = StringRef();
90 DwarfCompileUnitID = 0;
91 CurrentDwarfLoc = MCDwarfLoc(0,0,0,DWARF2_FLAG_IS_STMT,0,0);
93 // If we have the MachO uniquing map, free it.
94 delete (MachOUniqueMapTy*)MachOUniquingMap;
95 delete (ELFUniqueMapTy*)ELFUniquingMap;
96 delete (COFFUniqueMapTy*)COFFUniquingMap;
102 AllowTemporaryLabels = true;
103 DwarfLocSeen = false;
104 GenDwarfForAssembly = false;
105 GenDwarfFileNumber = 0;
108 //===----------------------------------------------------------------------===//
109 // Symbol Manipulation
110 //===----------------------------------------------------------------------===//
112 MCSymbol *MCContext::GetOrCreateSymbol(StringRef Name) {
113 assert(!Name.empty() && "Normal symbols cannot be unnamed!");
115 // Do the lookup and get the entire StringMapEntry. We want access to the
116 // key if we are creating the entry.
117 StringMapEntry<MCSymbol*> &Entry = Symbols.GetOrCreateValue(Name);
118 MCSymbol *Sym = Entry.getValue();
123 Sym = CreateSymbol(Name);
128 MCSymbol *MCContext::CreateSymbol(StringRef Name) {
129 // Determine whether this is an assembler temporary or normal label, if used.
130 bool isTemporary = false;
131 if (AllowTemporaryLabels)
132 isTemporary = Name.startswith(MAI->getPrivateGlobalPrefix());
134 StringMapEntry<bool> *NameEntry = &UsedNames.GetOrCreateValue(Name);
135 if (NameEntry->getValue()) {
136 assert(isTemporary && "Cannot rename non-temporary symbols");
137 SmallString<128> NewName = Name;
139 NewName.resize(Name.size());
140 raw_svector_ostream(NewName) << NextUniqueID++;
141 NameEntry = &UsedNames.GetOrCreateValue(NewName);
142 } while (NameEntry->getValue());
144 NameEntry->setValue(true);
146 // Ok, the entry doesn't already exist. Have the MCSymbol object itself refer
147 // to the copy of the string that is embedded in the UsedNames entry.
148 MCSymbol *Result = new (*this) MCSymbol(NameEntry->getKey(), isTemporary);
153 MCSymbol *MCContext::GetOrCreateSymbol(const Twine &Name) {
154 SmallString<128> NameSV;
155 return GetOrCreateSymbol(Name.toStringRef(NameSV));
158 MCSymbol *MCContext::CreateTempSymbol() {
159 SmallString<128> NameSV;
160 raw_svector_ostream(NameSV)
161 << MAI->getPrivateGlobalPrefix() << "tmp" << NextUniqueID++;
162 return CreateSymbol(NameSV);
165 unsigned MCContext::NextInstance(int64_t LocalLabelVal) {
166 MCLabel *&Label = Instances[LocalLabelVal];
168 Label = new (*this) MCLabel(0);
169 return Label->incInstance();
172 unsigned MCContext::GetInstance(int64_t LocalLabelVal) {
173 MCLabel *&Label = Instances[LocalLabelVal];
175 Label = new (*this) MCLabel(0);
176 return Label->getInstance();
179 MCSymbol *MCContext::CreateDirectionalLocalSymbol(int64_t LocalLabelVal) {
180 return GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
181 Twine(LocalLabelVal) +
183 Twine(NextInstance(LocalLabelVal)));
185 MCSymbol *MCContext::GetDirectionalLocalSymbol(int64_t LocalLabelVal,
187 return GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
188 Twine(LocalLabelVal) +
190 Twine(GetInstance(LocalLabelVal) + bORf));
193 MCSymbol *MCContext::LookupSymbol(StringRef Name) const {
194 return Symbols.lookup(Name);
197 MCSymbol *MCContext::LookupSymbol(const Twine &Name) const {
198 SmallString<128> NameSV;
199 Name.toVector(NameSV);
200 return LookupSymbol(NameSV.str());
203 //===----------------------------------------------------------------------===//
204 // Section Management
205 //===----------------------------------------------------------------------===//
207 const MCSectionMachO *MCContext::
208 getMachOSection(StringRef Segment, StringRef Section,
209 unsigned TypeAndAttributes,
210 unsigned Reserved2, SectionKind Kind) {
212 // We unique sections by their segment/section pair. The returned section
213 // may not have the same flags as the requested section, if so this should be
214 // diagnosed by the client as an error.
216 // Create the map if it doesn't already exist.
217 if (MachOUniquingMap == 0)
218 MachOUniquingMap = new MachOUniqueMapTy();
219 MachOUniqueMapTy &Map = *(MachOUniqueMapTy*)MachOUniquingMap;
221 // Form the name to look up.
222 SmallString<64> Name;
227 // Do the lookup, if we have a hit, return it.
228 const MCSectionMachO *&Entry = Map[Name.str()];
229 if (Entry) return Entry;
231 // Otherwise, return a new section.
232 return Entry = new (*this) MCSectionMachO(Segment, Section, TypeAndAttributes,
236 const MCSectionELF *MCContext::
237 getELFSection(StringRef Section, unsigned Type, unsigned Flags,
239 return getELFSection(Section, Type, Flags, Kind, 0, "");
242 const MCSectionELF *MCContext::
243 getELFSection(StringRef Section, unsigned Type, unsigned Flags,
244 SectionKind Kind, unsigned EntrySize, StringRef Group) {
245 if (ELFUniquingMap == 0)
246 ELFUniquingMap = new ELFUniqueMapTy();
247 ELFUniqueMapTy &Map = *(ELFUniqueMapTy*)ELFUniquingMap;
249 // Do the lookup, if we have a hit, return it.
250 std::pair<ELFUniqueMapTy::iterator, bool> Entry = Map.insert(
251 std::make_pair(SectionGroupPair(Section, Group), (MCSectionELF *)0));
252 if (!Entry.second) return Entry.first->second;
254 // Possibly refine the entry size first.
256 EntrySize = MCSectionELF::DetermineEntrySize(Kind);
259 MCSymbol *GroupSym = NULL;
261 GroupSym = GetOrCreateSymbol(Group);
263 MCSectionELF *Result = new (*this) MCSectionELF(
264 Entry.first->first.first, Type, Flags, Kind, EntrySize, GroupSym);
265 Entry.first->second = Result;
269 const MCSectionELF *MCContext::CreateELFGroupSection() {
270 MCSectionELF *Result =
271 new (*this) MCSectionELF(".group", ELF::SHT_GROUP, 0,
272 SectionKind::getReadOnly(), 4, NULL);
276 const MCSectionCOFF *
277 MCContext::getCOFFSection(StringRef Section, unsigned Characteristics,
278 SectionKind Kind, StringRef COMDATSymName,
279 int Selection, const MCSectionCOFF *Assoc) {
280 if (COFFUniquingMap == 0)
281 COFFUniquingMap = new COFFUniqueMapTy();
282 COFFUniqueMapTy &Map = *(COFFUniqueMapTy*)COFFUniquingMap;
284 // Do the lookup, if we have a hit, return it.
286 SectionGroupPair P(Section, COMDATSymName);
287 std::pair<COFFUniqueMapTy::iterator, bool> Entry =
288 Map.insert(std::make_pair(P, (MCSectionCOFF *)0));
289 COFFUniqueMapTy::iterator Iter = Entry.first;
293 const MCSymbol *COMDATSymbol = NULL;
294 if (!COMDATSymName.empty())
295 COMDATSymbol = GetOrCreateSymbol(COMDATSymName);
297 MCSectionCOFF *Result =
298 new (*this) MCSectionCOFF(Iter->first.first, Characteristics,
299 COMDATSymbol, Selection, Assoc, 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 if (COFFUniquingMap == 0)
313 COFFUniquingMap = new COFFUniqueMapTy();
314 COFFUniqueMapTy &Map = *(COFFUniqueMapTy*)COFFUniquingMap;
316 SectionGroupPair P(Section, "");
317 COFFUniqueMapTy::iterator Iter = Map.find(P);
318 if (Iter == Map.end())
323 //===----------------------------------------------------------------------===//
325 //===----------------------------------------------------------------------===//
327 /// GetDwarfFile - takes a file name an number to place in the dwarf file and
328 /// directory tables. If the file number has already been allocated it is an
329 /// error and zero is returned and the client reports the error, else the
330 /// allocated file number is returned. The file numbers may be in any order.
331 unsigned MCContext::GetDwarfFile(StringRef Directory, StringRef FileName,
332 unsigned FileNumber, unsigned CUID) {
333 // TODO: a FileNumber of zero says to use the next available file number.
334 // Note: in GenericAsmParser::ParseDirectiveFile() FileNumber was checked
335 // to not be less than one. This needs to be change to be not less than zero.
337 MCDwarfFileTable &Table = MCDwarfFileTablesCUMap[CUID];
338 SmallVectorImpl<MCDwarfFile *>& MCDwarfFiles = Table.getMCDwarfFiles();
339 SmallVectorImpl<StringRef>& MCDwarfDirs = Table.getMCDwarfDirs();
340 // Make space for this FileNumber in the MCDwarfFiles vector if needed.
341 if (FileNumber >= MCDwarfFiles.size()) {
342 MCDwarfFiles.resize(FileNumber + 1);
344 MCDwarfFile *&ExistingFile = MCDwarfFiles[FileNumber];
346 // It is an error to use see the same number more than once.
350 // Get the new MCDwarfFile slot for this FileNumber.
351 MCDwarfFile *&File = MCDwarfFiles[FileNumber];
353 if (Directory.empty()) {
354 // Separate the directory part from the basename of the FileName.
355 StringRef tFileName = sys::path::filename(FileName);
356 if (!tFileName.empty()) {
357 Directory = sys::path::parent_path(FileName);
358 if (!Directory.empty())
359 FileName = tFileName;
363 // Find or make an entry in the MCDwarfDirs vector for this Directory.
364 // Capture directory name.
366 if (Directory.empty()) {
367 // For FileNames with no directories a DirIndex of 0 is used.
371 for (unsigned End = MCDwarfDirs.size(); DirIndex < End; DirIndex++) {
372 if (Directory == MCDwarfDirs[DirIndex])
375 if (DirIndex >= MCDwarfDirs.size()) {
376 char *Buf = static_cast<char *>(Allocate(Directory.size()));
377 memcpy(Buf, Directory.data(), Directory.size());
378 MCDwarfDirs.push_back(StringRef(Buf, Directory.size()));
380 // The DirIndex is one based, as DirIndex of 0 is used for FileNames with
381 // no directories. MCDwarfDirs[] is unlike MCDwarfFiles[] in that the
382 // directory names are stored at MCDwarfDirs[DirIndex-1] where FileNames
383 // are stored at MCDwarfFiles[FileNumber].Name .
387 // Now make the MCDwarfFile entry and place it in the slot in the MCDwarfFiles
389 char *Buf = static_cast<char *>(Allocate(FileName.size()));
390 memcpy(Buf, FileName.data(), FileName.size());
391 File = new (*this) MCDwarfFile(StringRef(Buf, FileName.size()), DirIndex);
393 // return the allocated FileNumber.
397 /// isValidDwarfFileNumber - takes a dwarf file number and returns true if it
398 /// currently is assigned and false otherwise.
399 bool MCContext::isValidDwarfFileNumber(unsigned FileNumber, unsigned CUID) {
400 const SmallVectorImpl<MCDwarfFile *>& MCDwarfFiles = getMCDwarfFiles(CUID);
401 if(FileNumber == 0 || FileNumber >= MCDwarfFiles.size())
404 return MCDwarfFiles[FileNumber] != 0;
407 void MCContext::FatalError(SMLoc Loc, const Twine &Msg) {
408 // If we have a source manager and a location, use it. Otherwise just
409 // use the generic report_fatal_error().
410 if (!SrcMgr || Loc == SMLoc())
411 report_fatal_error(Msg);
413 // Use the source manager to print the message.
414 SrcMgr->PrintMessage(Loc, SourceMgr::DK_Error, Msg);
416 // If we reached here, we are failing ungracefully. Run the interrupt handlers
417 // to make sure any special cleanups get done, in particular that we remove
418 // files registered with RemoveFileOnSignal.
419 sys::RunInterruptHandlers();