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"
33 typedef std::pair<std::string, std::string> SectionGroupPair;
35 typedef StringMap<const MCSectionMachO*> MachOUniqueMapTy;
36 typedef std::map<SectionGroupPair, const MCSectionELF *> ELFUniqueMapTy;
37 typedef std::map<SectionGroupPair, const MCSectionCOFF *> COFFUniqueMapTy;
39 MCContext::MCContext(const MCAsmInfo *mai, const MCRegisterInfo *mri,
40 const MCObjectFileInfo *mofi, const SourceMgr *mgr,
42 SrcMgr(mgr), MAI(mai), MRI(mri), MOFI(mofi),
43 Allocator(), Symbols(Allocator), UsedNames(Allocator),
45 CurrentDwarfLoc(0,0,0,DWARF2_FLAG_IS_STMT,0,0),
46 DwarfLocSeen(false), GenDwarfForAssembly(false), GenDwarfFileNumber(0),
47 AllowTemporaryLabels(true), DwarfCompileUnitID(0), AutoReset(DoAutoReset) {
49 error_code EC = llvm::sys::fs::current_path(CompilationDir);
50 assert(!EC && "Could not determine the current directory");
57 SecureLogFile = getenv("AS_SECURE_LOG_FILE");
59 SecureLogUsed = false;
61 if (SrcMgr && SrcMgr->getNumBuffers() > 0)
62 MainFileName = SrcMgr->getMemoryBuffer(0)->getBufferIdentifier();
67 MCContext::~MCContext() {
72 // NOTE: The symbols are all allocated out of a bump pointer allocator,
73 // we don't need to free them here.
75 // If the stream for the .secure_log_unique directive was created free it.
76 delete (raw_ostream*)SecureLog;
79 //===----------------------------------------------------------------------===//
80 // Module Lifetime Management
81 //===----------------------------------------------------------------------===//
83 void MCContext::reset() {
88 MCDwarfFilesCUMap.clear();
89 MCDwarfDirsCUMap.clear();
90 MCGenDwarfLabelEntries.clear();
91 DwarfDebugFlags = StringRef();
92 MCLineSections.clear();
93 MCLineSectionOrder.clear();
94 DwarfCompileUnitID = 0;
95 MCLineTableSymbols.clear();
96 CurrentDwarfLoc = MCDwarfLoc(0,0,0,DWARF2_FLAG_IS_STMT,0,0);
98 // If we have the MachO uniquing map, free it.
99 delete (MachOUniqueMapTy*)MachOUniquingMap;
100 delete (ELFUniqueMapTy*)ELFUniquingMap;
101 delete (COFFUniqueMapTy*)COFFUniquingMap;
102 MachOUniquingMap = 0;
107 AllowTemporaryLabels = true;
108 DwarfLocSeen = false;
109 GenDwarfForAssembly = false;
110 GenDwarfFileNumber = 0;
113 //===----------------------------------------------------------------------===//
114 // Symbol Manipulation
115 //===----------------------------------------------------------------------===//
117 MCSymbol *MCContext::GetOrCreateSymbol(StringRef Name) {
118 assert(!Name.empty() && "Normal symbols cannot be unnamed!");
120 // Do the lookup and get the entire StringMapEntry. We want access to the
121 // key if we are creating the entry.
122 StringMapEntry<MCSymbol*> &Entry = Symbols.GetOrCreateValue(Name);
123 MCSymbol *Sym = Entry.getValue();
128 Sym = CreateSymbol(Name);
133 MCSymbol *MCContext::CreateSymbol(StringRef Name) {
134 // Determine whether this is an assembler temporary or normal label, if used.
135 bool isTemporary = false;
136 if (AllowTemporaryLabels)
137 isTemporary = Name.startswith(MAI->getPrivateGlobalPrefix());
139 StringMapEntry<bool> *NameEntry = &UsedNames.GetOrCreateValue(Name);
140 if (NameEntry->getValue()) {
141 assert(isTemporary && "Cannot rename non-temporary symbols");
142 SmallString<128> NewName = Name;
144 NewName.resize(Name.size());
145 raw_svector_ostream(NewName) << NextUniqueID++;
146 NameEntry = &UsedNames.GetOrCreateValue(NewName);
147 } while (NameEntry->getValue());
149 NameEntry->setValue(true);
151 // Ok, the entry doesn't already exist. Have the MCSymbol object itself refer
152 // to the copy of the string that is embedded in the UsedNames entry.
153 MCSymbol *Result = new (*this) MCSymbol(NameEntry->getKey(), isTemporary);
158 MCSymbol *MCContext::GetOrCreateSymbol(const Twine &Name) {
159 SmallString<128> NameSV;
160 return GetOrCreateSymbol(Name.toStringRef(NameSV));
163 MCSymbol *MCContext::CreateTempSymbol() {
164 SmallString<128> NameSV;
165 raw_svector_ostream(NameSV)
166 << MAI->getPrivateGlobalPrefix() << "tmp" << NextUniqueID++;
167 return CreateSymbol(NameSV);
170 unsigned MCContext::NextInstance(int64_t LocalLabelVal) {
171 MCLabel *&Label = Instances[LocalLabelVal];
173 Label = new (*this) MCLabel(0);
174 return Label->incInstance();
177 unsigned MCContext::GetInstance(int64_t LocalLabelVal) {
178 MCLabel *&Label = Instances[LocalLabelVal];
180 Label = new (*this) MCLabel(0);
181 return Label->getInstance();
184 MCSymbol *MCContext::CreateDirectionalLocalSymbol(int64_t LocalLabelVal) {
185 return GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
186 Twine(LocalLabelVal) +
188 Twine(NextInstance(LocalLabelVal)));
190 MCSymbol *MCContext::GetDirectionalLocalSymbol(int64_t LocalLabelVal,
192 return GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
193 Twine(LocalLabelVal) +
195 Twine(GetInstance(LocalLabelVal) + bORf));
198 MCSymbol *MCContext::LookupSymbol(StringRef Name) const {
199 return Symbols.lookup(Name);
202 MCSymbol *MCContext::LookupSymbol(const Twine &Name) const {
203 SmallString<128> NameSV;
204 Name.toVector(NameSV);
205 return LookupSymbol(NameSV.str());
208 //===----------------------------------------------------------------------===//
209 // Section Management
210 //===----------------------------------------------------------------------===//
212 const MCSectionMachO *MCContext::
213 getMachOSection(StringRef Segment, StringRef Section,
214 unsigned TypeAndAttributes,
215 unsigned Reserved2, SectionKind Kind) {
217 // We unique sections by their segment/section pair. The returned section
218 // may not have the same flags as the requested section, if so this should be
219 // diagnosed by the client as an error.
221 // Create the map if it doesn't already exist.
222 if (MachOUniquingMap == 0)
223 MachOUniquingMap = new MachOUniqueMapTy();
224 MachOUniqueMapTy &Map = *(MachOUniqueMapTy*)MachOUniquingMap;
226 // Form the name to look up.
227 SmallString<64> Name;
232 // Do the lookup, if we have a hit, return it.
233 const MCSectionMachO *&Entry = Map[Name.str()];
234 if (Entry) return Entry;
236 // Otherwise, return a new section.
237 return Entry = new (*this) MCSectionMachO(Segment, Section, TypeAndAttributes,
241 const MCSectionELF *MCContext::
242 getELFSection(StringRef Section, unsigned Type, unsigned Flags,
244 return getELFSection(Section, Type, Flags, Kind, 0, "");
247 const MCSectionELF *MCContext::
248 getELFSection(StringRef Section, unsigned Type, unsigned Flags,
249 SectionKind Kind, unsigned EntrySize, StringRef Group) {
250 if (ELFUniquingMap == 0)
251 ELFUniquingMap = new ELFUniqueMapTy();
252 ELFUniqueMapTy &Map = *(ELFUniqueMapTy*)ELFUniquingMap;
254 // Do the lookup, if we have a hit, return it.
255 std::pair<ELFUniqueMapTy::iterator, bool> Entry = Map.insert(
256 std::make_pair(SectionGroupPair(Section, Group), (MCSectionELF *)0));
257 if (!Entry.second) return Entry.first->second;
259 // Possibly refine the entry size first.
261 EntrySize = MCSectionELF::DetermineEntrySize(Kind);
264 MCSymbol *GroupSym = NULL;
266 GroupSym = GetOrCreateSymbol(Group);
268 MCSectionELF *Result = new (*this) MCSectionELF(
269 Entry.first->first.first, Type, Flags, Kind, EntrySize, GroupSym);
270 Entry.first->second = Result;
274 const MCSectionELF *MCContext::CreateELFGroupSection() {
275 MCSectionELF *Result =
276 new (*this) MCSectionELF(".group", ELF::SHT_GROUP, 0,
277 SectionKind::getReadOnly(), 4, NULL);
281 const MCSectionCOFF *
282 MCContext::getCOFFSection(StringRef Section, unsigned Characteristics,
283 SectionKind Kind, StringRef COMDATSymName,
284 int Selection, const MCSectionCOFF *Assoc) {
285 if (COFFUniquingMap == 0)
286 COFFUniquingMap = new COFFUniqueMapTy();
287 COFFUniqueMapTy &Map = *(COFFUniqueMapTy*)COFFUniquingMap;
289 // Do the lookup, if we have a hit, return it.
291 SectionGroupPair P(Section, COMDATSymName);
292 std::pair<COFFUniqueMapTy::iterator, bool> Entry =
293 Map.insert(std::make_pair(P, (MCSectionCOFF *)0));
294 COFFUniqueMapTy::iterator Iter = Entry.first;
298 const MCSymbol *COMDATSymbol = NULL;
299 if (!COMDATSymName.empty())
300 COMDATSymbol = GetOrCreateSymbol(COMDATSymName);
302 MCSectionCOFF *Result =
303 new (*this) MCSectionCOFF(Iter->first.first, Characteristics,
304 COMDATSymbol, Selection, Assoc, Kind);
306 Iter->second = Result;
310 const MCSectionCOFF *
311 MCContext::getCOFFSection(StringRef Section, unsigned Characteristics,
313 return getCOFFSection(Section, Characteristics, Kind, "", 0);
316 const MCSectionCOFF *MCContext::getCOFFSection(StringRef Section) {
317 if (COFFUniquingMap == 0)
318 COFFUniquingMap = new COFFUniqueMapTy();
319 COFFUniqueMapTy &Map = *(COFFUniqueMapTy*)COFFUniquingMap;
321 SectionGroupPair P(Section, "");
322 COFFUniqueMapTy::iterator Iter = Map.find(P);
323 if (Iter == Map.end())
328 //===----------------------------------------------------------------------===//
330 //===----------------------------------------------------------------------===//
332 /// GetDwarfFile - takes a file name an number to place in the dwarf file and
333 /// directory tables. If the file number has already been allocated it is an
334 /// error and zero is returned and the client reports the error, else the
335 /// allocated file number is returned. The file numbers may be in any order.
336 unsigned MCContext::GetDwarfFile(StringRef Directory, StringRef FileName,
337 unsigned FileNumber, unsigned CUID) {
338 // TODO: a FileNumber of zero says to use the next available file number.
339 // Note: in GenericAsmParser::ParseDirectiveFile() FileNumber was checked
340 // to not be less than one. This needs to be change to be not less than zero.
342 SmallVectorImpl<MCDwarfFile *>& MCDwarfFiles = MCDwarfFilesCUMap[CUID];
343 SmallVectorImpl<StringRef>& MCDwarfDirs = MCDwarfDirsCUMap[CUID];
344 // Make space for this FileNumber in the MCDwarfFiles vector if needed.
345 if (FileNumber >= MCDwarfFiles.size()) {
346 MCDwarfFiles.resize(FileNumber + 1);
348 MCDwarfFile *&ExistingFile = MCDwarfFiles[FileNumber];
350 // It is an error to use see the same number more than once.
354 // Get the new MCDwarfFile slot for this FileNumber.
355 MCDwarfFile *&File = MCDwarfFiles[FileNumber];
357 if (Directory.empty()) {
358 // Separate the directory part from the basename of the FileName.
359 StringRef tFileName = sys::path::filename(FileName);
360 if (!tFileName.empty()) {
361 Directory = sys::path::parent_path(FileName);
362 if (!Directory.empty())
363 FileName = tFileName;
367 // Find or make a entry in the MCDwarfDirs vector for this Directory.
368 // Capture directory name.
370 if (Directory.empty()) {
371 // For FileNames with no directories a DirIndex of 0 is used.
375 for (unsigned End = MCDwarfDirs.size(); DirIndex < End; DirIndex++) {
376 if (Directory == MCDwarfDirs[DirIndex])
379 if (DirIndex >= MCDwarfDirs.size()) {
380 char *Buf = static_cast<char *>(Allocate(Directory.size()));
381 memcpy(Buf, Directory.data(), Directory.size());
382 MCDwarfDirs.push_back(StringRef(Buf, Directory.size()));
384 // The DirIndex is one based, as DirIndex of 0 is used for FileNames with
385 // no directories. MCDwarfDirs[] is unlike MCDwarfFiles[] in that the
386 // directory names are stored at MCDwarfDirs[DirIndex-1] where FileNames
387 // are stored at MCDwarfFiles[FileNumber].Name .
391 // Now make the MCDwarfFile entry and place it in the slot in the MCDwarfFiles
393 char *Buf = static_cast<char *>(Allocate(FileName.size()));
394 memcpy(Buf, FileName.data(), FileName.size());
395 File = new (*this) MCDwarfFile(StringRef(Buf, FileName.size()), DirIndex);
397 // return the allocated FileNumber.
401 /// isValidDwarfFileNumber - takes a dwarf file number and returns true if it
402 /// currently is assigned and false otherwise.
403 bool MCContext::isValidDwarfFileNumber(unsigned FileNumber, unsigned CUID) {
404 SmallVectorImpl<MCDwarfFile *>& MCDwarfFiles = MCDwarfFilesCUMap[CUID];
405 if(FileNumber == 0 || FileNumber >= MCDwarfFiles.size())
408 return MCDwarfFiles[FileNumber] != 0;
411 void MCContext::FatalError(SMLoc Loc, const Twine &Msg) {
412 // If we have a source manager and a location, use it. Otherwise just
413 // use the generic report_fatal_error().
414 if (!SrcMgr || Loc == SMLoc())
415 report_fatal_error(Msg);
417 // Use the source manager to print the message.
418 SrcMgr->PrintMessage(Loc, SourceMgr::DK_Error, Msg);
420 // If we reached here, we are failing ungracefully. Run the interrupt handlers
421 // to make sure any special cleanups get done, in particular that we remove
422 // files registered with RemoveFileOnSignal.
423 sys::RunInterruptHandlers();