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 StringMap<const MCSectionCOFF*> COFFUniqueMapTy;
40 MCContext::MCContext(const MCAsmInfo *mai, const MCRegisterInfo *mri,
41 const MCObjectFileInfo *mofi, const SourceMgr *mgr,
43 SrcMgr(mgr), MAI(mai), MRI(mri), MOFI(mofi),
44 Allocator(), Symbols(Allocator), UsedNames(Allocator),
46 CurrentDwarfLoc(0,0,0,DWARF2_FLAG_IS_STMT,0,0),
47 DwarfLocSeen(false), GenDwarfForAssembly(false), GenDwarfFileNumber(0),
48 AllowTemporaryLabels(true), DwarfCompileUnitID(0), AutoReset(DoAutoReset) {
50 error_code EC = llvm::sys::fs::current_path(CompilationDir);
51 assert(!EC && "Could not determine the current directory");
58 SecureLogFile = getenv("AS_SECURE_LOG_FILE");
60 SecureLogUsed = false;
62 if (SrcMgr && SrcMgr->getNumBuffers() > 0)
63 MainFileName = SrcMgr->getMemoryBuffer(0)->getBufferIdentifier();
68 MCContext::~MCContext() {
73 // NOTE: The symbols are all allocated out of a bump pointer allocator,
74 // we don't need to free them here.
76 // If the stream for the .secure_log_unique directive was created free it.
77 delete (raw_ostream*)SecureLog;
80 //===----------------------------------------------------------------------===//
81 // Module Lifetime Management
82 //===----------------------------------------------------------------------===//
84 void MCContext::reset() {
89 MCDwarfFilesCUMap.clear();
90 MCDwarfDirsCUMap.clear();
91 MCGenDwarfLabelEntries.clear();
92 DwarfDebugFlags = StringRef();
93 MCLineSections.clear();
94 MCLineSectionOrder.clear();
95 DwarfCompileUnitID = 0;
96 MCLineTableSymbols.clear();
97 CurrentDwarfLoc = MCDwarfLoc(0,0,0,DWARF2_FLAG_IS_STMT,0,0);
99 // If we have the MachO uniquing map, free it.
100 delete (MachOUniqueMapTy*)MachOUniquingMap;
101 delete (ELFUniqueMapTy*)ELFUniquingMap;
102 delete (COFFUniqueMapTy*)COFFUniquingMap;
103 MachOUniquingMap = 0;
108 AllowTemporaryLabels = true;
109 DwarfLocSeen = false;
110 GenDwarfForAssembly = false;
111 GenDwarfFileNumber = 0;
114 //===----------------------------------------------------------------------===//
115 // Symbol Manipulation
116 //===----------------------------------------------------------------------===//
118 MCSymbol *MCContext::GetOrCreateSymbol(StringRef Name) {
119 assert(!Name.empty() && "Normal symbols cannot be unnamed!");
121 // Do the lookup and get the entire StringMapEntry. We want access to the
122 // key if we are creating the entry.
123 StringMapEntry<MCSymbol*> &Entry = Symbols.GetOrCreateValue(Name);
124 MCSymbol *Sym = Entry.getValue();
129 Sym = CreateSymbol(Name);
134 MCSymbol *MCContext::CreateSymbol(StringRef Name) {
135 // Determine whether this is an assembler temporary or normal label, if used.
136 bool isTemporary = false;
137 if (AllowTemporaryLabels)
138 isTemporary = Name.startswith(MAI->getPrivateGlobalPrefix());
140 StringMapEntry<bool> *NameEntry = &UsedNames.GetOrCreateValue(Name);
141 if (NameEntry->getValue()) {
142 assert(isTemporary && "Cannot rename non temporary symbols");
143 SmallString<128> NewName = Name;
145 NewName.resize(Name.size());
146 raw_svector_ostream(NewName) << NextUniqueID++;
147 NameEntry = &UsedNames.GetOrCreateValue(NewName);
148 } while (NameEntry->getValue());
150 NameEntry->setValue(true);
152 // Ok, the entry doesn't already exist. Have the MCSymbol object itself refer
153 // to the copy of the string that is embedded in the UsedNames entry.
154 MCSymbol *Result = new (*this) MCSymbol(NameEntry->getKey(), isTemporary);
159 MCSymbol *MCContext::GetOrCreateSymbol(const Twine &Name) {
160 SmallString<128> NameSV;
161 Name.toVector(NameSV);
162 return GetOrCreateSymbol(NameSV.str());
165 MCSymbol *MCContext::CreateTempSymbol() {
166 SmallString<128> NameSV;
167 raw_svector_ostream(NameSV)
168 << MAI->getPrivateGlobalPrefix() << "tmp" << NextUniqueID++;
169 return CreateSymbol(NameSV);
172 unsigned MCContext::NextInstance(int64_t LocalLabelVal) {
173 MCLabel *&Label = Instances[LocalLabelVal];
175 Label = new (*this) MCLabel(0);
176 return Label->incInstance();
179 unsigned MCContext::GetInstance(int64_t LocalLabelVal) {
180 MCLabel *&Label = Instances[LocalLabelVal];
182 Label = new (*this) MCLabel(0);
183 return Label->getInstance();
186 MCSymbol *MCContext::CreateDirectionalLocalSymbol(int64_t LocalLabelVal) {
187 return GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
188 Twine(LocalLabelVal) +
190 Twine(NextInstance(LocalLabelVal)));
192 MCSymbol *MCContext::GetDirectionalLocalSymbol(int64_t LocalLabelVal,
194 return GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
195 Twine(LocalLabelVal) +
197 Twine(GetInstance(LocalLabelVal) + bORf));
200 MCSymbol *MCContext::LookupSymbol(StringRef Name) const {
201 return Symbols.lookup(Name);
204 MCSymbol *MCContext::LookupSymbol(const Twine &Name) const {
205 SmallString<128> NameSV;
206 Name.toVector(NameSV);
207 return LookupSymbol(NameSV.str());
210 //===----------------------------------------------------------------------===//
211 // Section Management
212 //===----------------------------------------------------------------------===//
214 const MCSectionMachO *MCContext::
215 getMachOSection(StringRef Segment, StringRef Section,
216 unsigned TypeAndAttributes,
217 unsigned Reserved2, SectionKind Kind) {
219 // We unique sections by their segment/section pair. The returned section
220 // may not have the same flags as the requested section, if so this should be
221 // diagnosed by the client as an error.
223 // Create the map if it doesn't already exist.
224 if (MachOUniquingMap == 0)
225 MachOUniquingMap = new MachOUniqueMapTy();
226 MachOUniqueMapTy &Map = *(MachOUniqueMapTy*)MachOUniquingMap;
228 // Form the name to look up.
229 SmallString<64> Name;
234 // Do the lookup, if we have a hit, return it.
235 const MCSectionMachO *&Entry = Map[Name.str()];
236 if (Entry) return Entry;
238 // Otherwise, return a new section.
239 return Entry = new (*this) MCSectionMachO(Segment, Section, TypeAndAttributes,
243 const MCSectionELF *MCContext::
244 getELFSection(StringRef Section, unsigned Type, unsigned Flags,
246 return getELFSection(Section, Type, Flags, Kind, 0, "");
249 const MCSectionELF *MCContext::
250 getELFSection(StringRef Section, unsigned Type, unsigned Flags,
251 SectionKind Kind, unsigned EntrySize, StringRef Group) {
252 if (ELFUniquingMap == 0)
253 ELFUniquingMap = new ELFUniqueMapTy();
254 ELFUniqueMapTy &Map = *(ELFUniqueMapTy*)ELFUniquingMap;
256 // Do the lookup, if we have a hit, return it.
257 std::pair<ELFUniqueMapTy::iterator, bool> Entry = Map.insert(
258 std::make_pair(SectionGroupPair(Section, Group), (MCSectionELF *)0));
259 if (!Entry.second) return Entry.first->second;
261 // Possibly refine the entry size first.
263 EntrySize = MCSectionELF::DetermineEntrySize(Kind);
266 MCSymbol *GroupSym = NULL;
268 GroupSym = GetOrCreateSymbol(Group);
270 MCSectionELF *Result = new (*this) MCSectionELF(
271 Entry.first->first.first, Type, Flags, Kind, EntrySize, GroupSym);
272 Entry.first->second = Result;
276 const MCSectionELF *MCContext::CreateELFGroupSection() {
277 MCSectionELF *Result =
278 new (*this) MCSectionELF(".group", ELF::SHT_GROUP, 0,
279 SectionKind::getReadOnly(), 4, NULL);
283 const MCSectionCOFF *MCContext::getCOFFSection(StringRef Section,
284 unsigned Characteristics,
285 SectionKind Kind, int Selection,
286 const MCSectionCOFF *Assoc) {
287 if (COFFUniquingMap == 0)
288 COFFUniquingMap = new COFFUniqueMapTy();
289 COFFUniqueMapTy &Map = *(COFFUniqueMapTy*)COFFUniquingMap;
291 // Do the lookup, if we have a hit, return it.
292 StringMapEntry<const MCSectionCOFF*> &Entry = Map.GetOrCreateValue(Section);
293 if (Entry.getValue()) return Entry.getValue();
295 MCSectionCOFF *Result = new (*this) MCSectionCOFF(Entry.getKey(),
297 Selection, Assoc, Kind);
299 Entry.setValue(Result);
303 const MCSectionCOFF *MCContext::getCOFFSection(StringRef Section) {
304 if (COFFUniquingMap == 0)
305 COFFUniquingMap = new COFFUniqueMapTy();
306 COFFUniqueMapTy &Map = *(COFFUniqueMapTy*)COFFUniquingMap;
308 return Map.lookup(Section);
311 //===----------------------------------------------------------------------===//
313 //===----------------------------------------------------------------------===//
315 /// GetDwarfFile - takes a file name an number to place in the dwarf file and
316 /// directory tables. If the file number has already been allocated it is an
317 /// error and zero is returned and the client reports the error, else the
318 /// allocated file number is returned. The file numbers may be in any order.
319 unsigned MCContext::GetDwarfFile(StringRef Directory, StringRef FileName,
320 unsigned FileNumber, unsigned CUID) {
321 // TODO: a FileNumber of zero says to use the next available file number.
322 // Note: in GenericAsmParser::ParseDirectiveFile() FileNumber was checked
323 // to not be less than one. This needs to be change to be not less than zero.
325 SmallVectorImpl<MCDwarfFile *>& MCDwarfFiles = MCDwarfFilesCUMap[CUID];
326 SmallVectorImpl<StringRef>& MCDwarfDirs = MCDwarfDirsCUMap[CUID];
327 // Make space for this FileNumber in the MCDwarfFiles vector if needed.
328 if (FileNumber >= MCDwarfFiles.size()) {
329 MCDwarfFiles.resize(FileNumber + 1);
331 MCDwarfFile *&ExistingFile = MCDwarfFiles[FileNumber];
333 // It is an error to use see the same number more than once.
337 // Get the new MCDwarfFile slot for this FileNumber.
338 MCDwarfFile *&File = MCDwarfFiles[FileNumber];
340 if (Directory.empty()) {
341 // Separate the directory part from the basename of the FileName.
342 StringRef tFileName = sys::path::filename(FileName);
343 if (!tFileName.empty()) {
344 Directory = sys::path::parent_path(FileName);
345 if (!Directory.empty())
346 FileName = tFileName;
350 // Find or make a entry in the MCDwarfDirs vector for this Directory.
351 // Capture directory name.
353 if (Directory.empty()) {
354 // For FileNames with no directories a DirIndex of 0 is used.
358 for (unsigned End = MCDwarfDirs.size(); DirIndex < End; DirIndex++) {
359 if (Directory == MCDwarfDirs[DirIndex])
362 if (DirIndex >= MCDwarfDirs.size()) {
363 char *Buf = static_cast<char *>(Allocate(Directory.size()));
364 memcpy(Buf, Directory.data(), Directory.size());
365 MCDwarfDirs.push_back(StringRef(Buf, Directory.size()));
367 // The DirIndex is one based, as DirIndex of 0 is used for FileNames with
368 // no directories. MCDwarfDirs[] is unlike MCDwarfFiles[] in that the
369 // directory names are stored at MCDwarfDirs[DirIndex-1] where FileNames
370 // are stored at MCDwarfFiles[FileNumber].Name .
374 // Now make the MCDwarfFile entry and place it in the slot in the MCDwarfFiles
376 char *Buf = static_cast<char *>(Allocate(FileName.size()));
377 memcpy(Buf, FileName.data(), FileName.size());
378 File = new (*this) MCDwarfFile(StringRef(Buf, FileName.size()), DirIndex);
380 // return the allocated FileNumber.
384 /// isValidDwarfFileNumber - takes a dwarf file number and returns true if it
385 /// currently is assigned and false otherwise.
386 bool MCContext::isValidDwarfFileNumber(unsigned FileNumber, unsigned CUID) {
387 SmallVectorImpl<MCDwarfFile *>& MCDwarfFiles = MCDwarfFilesCUMap[CUID];
388 if(FileNumber == 0 || FileNumber >= MCDwarfFiles.size())
391 return MCDwarfFiles[FileNumber] != 0;
394 void MCContext::FatalError(SMLoc Loc, const Twine &Msg) {
395 // If we have a source manager and a location, use it. Otherwise just
396 // use the generic report_fatal_error().
397 if (!SrcMgr || Loc == SMLoc())
398 report_fatal_error(Msg);
400 // Use the source manager to print the message.
401 SrcMgr->PrintMessage(Loc, SourceMgr::DK_Error, Msg);
403 // If we reached here, we are failing ungracefully. Run the interrupt handlers
404 // to make sure any special cleanups get done, in particular that we remove
405 // files registered with RemoveFileOnSignal.
406 sys::RunInterruptHandlers();