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 Name.toVector(NameSV);
161 return GetOrCreateSymbol(NameSV.str());
164 MCSymbol *MCContext::CreateTempSymbol() {
165 SmallString<128> NameSV;
166 raw_svector_ostream(NameSV)
167 << MAI->getPrivateGlobalPrefix() << "tmp" << NextUniqueID++;
168 return CreateSymbol(NameSV);
171 unsigned MCContext::NextInstance(int64_t LocalLabelVal) {
172 MCLabel *&Label = Instances[LocalLabelVal];
174 Label = new (*this) MCLabel(0);
175 return Label->incInstance();
178 unsigned MCContext::GetInstance(int64_t LocalLabelVal) {
179 MCLabel *&Label = Instances[LocalLabelVal];
181 Label = new (*this) MCLabel(0);
182 return Label->getInstance();
185 MCSymbol *MCContext::CreateDirectionalLocalSymbol(int64_t LocalLabelVal) {
186 return GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
187 Twine(LocalLabelVal) +
189 Twine(NextInstance(LocalLabelVal)));
191 MCSymbol *MCContext::GetDirectionalLocalSymbol(int64_t LocalLabelVal,
193 return GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
194 Twine(LocalLabelVal) +
196 Twine(GetInstance(LocalLabelVal) + bORf));
199 MCSymbol *MCContext::LookupSymbol(StringRef Name) const {
200 return Symbols.lookup(Name);
203 MCSymbol *MCContext::LookupSymbol(const Twine &Name) const {
204 SmallString<128> NameSV;
205 Name.toVector(NameSV);
206 return LookupSymbol(NameSV.str());
209 //===----------------------------------------------------------------------===//
210 // Section Management
211 //===----------------------------------------------------------------------===//
213 const MCSectionMachO *MCContext::
214 getMachOSection(StringRef Segment, StringRef Section,
215 unsigned TypeAndAttributes,
216 unsigned Reserved2, SectionKind Kind) {
218 // We unique sections by their segment/section pair. The returned section
219 // may not have the same flags as the requested section, if so this should be
220 // diagnosed by the client as an error.
222 // Create the map if it doesn't already exist.
223 if (MachOUniquingMap == 0)
224 MachOUniquingMap = new MachOUniqueMapTy();
225 MachOUniqueMapTy &Map = *(MachOUniqueMapTy*)MachOUniquingMap;
227 // Form the name to look up.
228 SmallString<64> Name;
233 // Do the lookup, if we have a hit, return it.
234 const MCSectionMachO *&Entry = Map[Name.str()];
235 if (Entry) return Entry;
237 // Otherwise, return a new section.
238 return Entry = new (*this) MCSectionMachO(Segment, Section, TypeAndAttributes,
242 const MCSectionELF *MCContext::
243 getELFSection(StringRef Section, unsigned Type, unsigned Flags,
245 return getELFSection(Section, Type, Flags, Kind, 0, "");
248 const MCSectionELF *MCContext::
249 getELFSection(StringRef Section, unsigned Type, unsigned Flags,
250 SectionKind Kind, unsigned EntrySize, StringRef Group) {
251 if (ELFUniquingMap == 0)
252 ELFUniquingMap = new ELFUniqueMapTy();
253 ELFUniqueMapTy &Map = *(ELFUniqueMapTy*)ELFUniquingMap;
255 // Do the lookup, if we have a hit, return it.
256 std::pair<ELFUniqueMapTy::iterator, bool> Entry = Map.insert(
257 std::make_pair(SectionGroupPair(Section, Group), (MCSectionELF *)0));
258 if (!Entry.second) return Entry.first->second;
260 // Possibly refine the entry size first.
262 EntrySize = MCSectionELF::DetermineEntrySize(Kind);
265 MCSymbol *GroupSym = NULL;
267 GroupSym = GetOrCreateSymbol(Group);
269 MCSectionELF *Result = new (*this) MCSectionELF(
270 Entry.first->first.first, Type, Flags, Kind, EntrySize, GroupSym);
271 Entry.first->second = Result;
275 const MCSectionELF *MCContext::CreateELFGroupSection() {
276 MCSectionELF *Result =
277 new (*this) MCSectionELF(".group", ELF::SHT_GROUP, 0,
278 SectionKind::getReadOnly(), 4, NULL);
282 const MCSectionCOFF *
283 MCContext::getCOFFSection(StringRef Section, unsigned Characteristics,
284 SectionKind Kind, StringRef COMDATSymName,
285 int Selection, const MCSectionCOFF *Assoc) {
286 if (COFFUniquingMap == 0)
287 COFFUniquingMap = new COFFUniqueMapTy();
288 COFFUniqueMapTy &Map = *(COFFUniqueMapTy*)COFFUniquingMap;
290 // Do the lookup, if we have a hit, return it.
292 SectionGroupPair P(Section, COMDATSymName);
293 std::pair<COFFUniqueMapTy::iterator, bool> Entry =
294 Map.insert(std::make_pair(P, (MCSectionCOFF *)0));
295 COFFUniqueMapTy::iterator Iter = Entry.first;
299 const MCSymbol *COMDATSymbol = NULL;
300 if (!COMDATSymName.empty())
301 COMDATSymbol = GetOrCreateSymbol(COMDATSymName);
303 MCSectionCOFF *Result =
304 new (*this) MCSectionCOFF(Iter->first.first, Characteristics,
305 COMDATSymbol, Selection, Assoc, Kind);
307 Iter->second = Result;
311 const MCSectionCOFF *
312 MCContext::getCOFFSection(StringRef Section, unsigned Characteristics,
314 return getCOFFSection(Section, Characteristics, Kind, "", 0);
317 const MCSectionCOFF *MCContext::getCOFFSection(StringRef Section) {
318 if (COFFUniquingMap == 0)
319 COFFUniquingMap = new COFFUniqueMapTy();
320 COFFUniqueMapTy &Map = *(COFFUniqueMapTy*)COFFUniquingMap;
322 SectionGroupPair P(Section, "");
323 COFFUniqueMapTy::iterator Iter = Map.find(P);
324 if (Iter == Map.end())
329 //===----------------------------------------------------------------------===//
331 //===----------------------------------------------------------------------===//
333 /// GetDwarfFile - takes a file name an number to place in the dwarf file and
334 /// directory tables. If the file number has already been allocated it is an
335 /// error and zero is returned and the client reports the error, else the
336 /// allocated file number is returned. The file numbers may be in any order.
337 unsigned MCContext::GetDwarfFile(StringRef Directory, StringRef FileName,
338 unsigned FileNumber, unsigned CUID) {
339 // TODO: a FileNumber of zero says to use the next available file number.
340 // Note: in GenericAsmParser::ParseDirectiveFile() FileNumber was checked
341 // to not be less than one. This needs to be change to be not less than zero.
343 SmallVectorImpl<MCDwarfFile *>& MCDwarfFiles = MCDwarfFilesCUMap[CUID];
344 SmallVectorImpl<StringRef>& MCDwarfDirs = MCDwarfDirsCUMap[CUID];
345 // Make space for this FileNumber in the MCDwarfFiles vector if needed.
346 if (FileNumber >= MCDwarfFiles.size()) {
347 MCDwarfFiles.resize(FileNumber + 1);
349 MCDwarfFile *&ExistingFile = MCDwarfFiles[FileNumber];
351 // It is an error to use see the same number more than once.
355 // Get the new MCDwarfFile slot for this FileNumber.
356 MCDwarfFile *&File = MCDwarfFiles[FileNumber];
358 if (Directory.empty()) {
359 // Separate the directory part from the basename of the FileName.
360 StringRef tFileName = sys::path::filename(FileName);
361 if (!tFileName.empty()) {
362 Directory = sys::path::parent_path(FileName);
363 if (!Directory.empty())
364 FileName = tFileName;
368 // Find or make a entry in the MCDwarfDirs vector for this Directory.
369 // Capture directory name.
371 if (Directory.empty()) {
372 // For FileNames with no directories a DirIndex of 0 is used.
376 for (unsigned End = MCDwarfDirs.size(); DirIndex < End; DirIndex++) {
377 if (Directory == MCDwarfDirs[DirIndex])
380 if (DirIndex >= MCDwarfDirs.size()) {
381 char *Buf = static_cast<char *>(Allocate(Directory.size()));
382 memcpy(Buf, Directory.data(), Directory.size());
383 MCDwarfDirs.push_back(StringRef(Buf, Directory.size()));
385 // The DirIndex is one based, as DirIndex of 0 is used for FileNames with
386 // no directories. MCDwarfDirs[] is unlike MCDwarfFiles[] in that the
387 // directory names are stored at MCDwarfDirs[DirIndex-1] where FileNames
388 // are stored at MCDwarfFiles[FileNumber].Name .
392 // Now make the MCDwarfFile entry and place it in the slot in the MCDwarfFiles
394 char *Buf = static_cast<char *>(Allocate(FileName.size()));
395 memcpy(Buf, FileName.data(), FileName.size());
396 File = new (*this) MCDwarfFile(StringRef(Buf, FileName.size()), DirIndex);
398 // return the allocated FileNumber.
402 /// isValidDwarfFileNumber - takes a dwarf file number and returns true if it
403 /// currently is assigned and false otherwise.
404 bool MCContext::isValidDwarfFileNumber(unsigned FileNumber, unsigned CUID) {
405 SmallVectorImpl<MCDwarfFile *>& MCDwarfFiles = MCDwarfFilesCUMap[CUID];
406 if(FileNumber == 0 || FileNumber >= MCDwarfFiles.size())
409 return MCDwarfFiles[FileNumber] != 0;
412 void MCContext::FatalError(SMLoc Loc, const Twine &Msg) {
413 // If we have a source manager and a location, use it. Otherwise just
414 // use the generic report_fatal_error().
415 if (!SrcMgr || Loc == SMLoc())
416 report_fatal_error(Msg);
418 // Use the source manager to print the message.
419 SrcMgr->PrintMessage(Loc, SourceMgr::DK_Error, Msg);
421 // If we reached here, we are failing ungracefully. Run the interrupt handlers
422 // to make sure any special cleanups get done, in particular that we remove
423 // files registered with RemoveFileOnSignal.
424 sys::RunInterruptHandlers();