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"
30 typedef StringMap<const MCSectionMachO*> MachOUniqueMapTy;
31 typedef StringMap<const MCSectionELF*> ELFUniqueMapTy;
32 typedef StringMap<const MCSectionCOFF*> COFFUniqueMapTy;
35 MCContext::MCContext(const MCAsmInfo *mai, const MCRegisterInfo *mri,
36 const MCObjectFileInfo *mofi, const SourceMgr *mgr,
38 SrcMgr(mgr), MAI(mai), MRI(mri), MOFI(mofi),
39 Allocator(), Symbols(Allocator), UsedNames(Allocator),
41 CurrentDwarfLoc(0,0,0,DWARF2_FLAG_IS_STMT,0,0),
42 DwarfLocSeen(false), GenDwarfForAssembly(false), GenDwarfFileNumber(0),
43 AllowTemporaryLabels(true), DwarfCompileUnitID(0), AutoReset(DoAutoReset) {
45 error_code EC = llvm::sys::fs::current_path(CompilationDir);
46 assert(!EC && "Could not determine the current directory");
53 SecureLogFile = getenv("AS_SECURE_LOG_FILE");
55 SecureLogUsed = false;
57 if (SrcMgr && SrcMgr->getNumBuffers() > 0)
58 MainFileName = SrcMgr->getMemoryBuffer(0)->getBufferIdentifier();
63 MCContext::~MCContext() {
68 // NOTE: The symbols are all allocated out of a bump pointer allocator,
69 // we don't need to free them here.
71 // If the stream for the .secure_log_unique directive was created free it.
72 delete (raw_ostream*)SecureLog;
75 //===----------------------------------------------------------------------===//
76 // Module Lifetime Management
77 //===----------------------------------------------------------------------===//
79 void MCContext::reset() {
84 MCDwarfFilesCUMap.clear();
85 MCDwarfDirsCUMap.clear();
86 MCGenDwarfLabelEntries.clear();
87 DwarfDebugFlags = StringRef();
88 MCLineSections.clear();
89 MCLineSectionOrder.clear();
90 DwarfCompileUnitID = 0;
91 MCLineTableSymbols.clear();
92 CurrentDwarfLoc = MCDwarfLoc(0,0,0,DWARF2_FLAG_IS_STMT,0,0);
94 // If we have the MachO uniquing map, free it.
95 delete (MachOUniqueMapTy*)MachOUniquingMap;
96 delete (ELFUniqueMapTy*)ELFUniquingMap;
97 delete (COFFUniqueMapTy*)COFFUniquingMap;
103 AllowTemporaryLabels = true;
104 DwarfLocSeen = false;
105 GenDwarfForAssembly = false;
106 GenDwarfFileNumber = 0;
109 //===----------------------------------------------------------------------===//
110 // Symbol Manipulation
111 //===----------------------------------------------------------------------===//
113 MCSymbol *MCContext::GetOrCreateSymbol(StringRef Name) {
114 assert(!Name.empty() && "Normal symbols cannot be unnamed!");
116 // Do the lookup and get the entire StringMapEntry. We want access to the
117 // key if we are creating the entry.
118 StringMapEntry<MCSymbol*> &Entry = Symbols.GetOrCreateValue(Name);
119 MCSymbol *Sym = Entry.getValue();
124 Sym = CreateSymbol(Name);
129 MCSymbol *MCContext::CreateSymbol(StringRef Name) {
130 // Determine whether this is an assembler temporary or normal label, if used.
131 bool isTemporary = false;
132 if (AllowTemporaryLabels)
133 isTemporary = Name.startswith(MAI->getPrivateGlobalPrefix());
135 StringMapEntry<bool> *NameEntry = &UsedNames.GetOrCreateValue(Name);
136 if (NameEntry->getValue()) {
137 assert(isTemporary && "Cannot rename non temporary symbols");
138 SmallString<128> NewName = Name;
140 NewName.resize(Name.size());
141 raw_svector_ostream(NewName) << NextUniqueID++;
142 NameEntry = &UsedNames.GetOrCreateValue(NewName);
143 } while (NameEntry->getValue());
145 NameEntry->setValue(true);
147 // Ok, the entry doesn't already exist. Have the MCSymbol object itself refer
148 // to the copy of the string that is embedded in the UsedNames entry.
149 MCSymbol *Result = new (*this) MCSymbol(NameEntry->getKey(), isTemporary);
154 MCSymbol *MCContext::GetOrCreateSymbol(const Twine &Name) {
155 SmallString<128> NameSV;
156 Name.toVector(NameSV);
157 return GetOrCreateSymbol(NameSV.str());
160 MCSymbol *MCContext::CreateTempSymbol() {
161 SmallString<128> NameSV;
162 raw_svector_ostream(NameSV)
163 << MAI->getPrivateGlobalPrefix() << "tmp" << NextUniqueID++;
164 return CreateSymbol(NameSV);
167 unsigned MCContext::NextInstance(int64_t LocalLabelVal) {
168 MCLabel *&Label = Instances[LocalLabelVal];
170 Label = new (*this) MCLabel(0);
171 return Label->incInstance();
174 unsigned MCContext::GetInstance(int64_t LocalLabelVal) {
175 MCLabel *&Label = Instances[LocalLabelVal];
177 Label = new (*this) MCLabel(0);
178 return Label->getInstance();
181 MCSymbol *MCContext::CreateDirectionalLocalSymbol(int64_t LocalLabelVal) {
182 return GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
183 Twine(LocalLabelVal) +
185 Twine(NextInstance(LocalLabelVal)));
187 MCSymbol *MCContext::GetDirectionalLocalSymbol(int64_t LocalLabelVal,
189 return GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
190 Twine(LocalLabelVal) +
192 Twine(GetInstance(LocalLabelVal) + bORf));
195 MCSymbol *MCContext::LookupSymbol(StringRef Name) const {
196 return Symbols.lookup(Name);
199 MCSymbol *MCContext::LookupSymbol(const Twine &Name) const {
200 SmallString<128> NameSV;
201 Name.toVector(NameSV);
202 return LookupSymbol(NameSV.str());
205 //===----------------------------------------------------------------------===//
206 // Section Management
207 //===----------------------------------------------------------------------===//
209 const MCSectionMachO *MCContext::
210 getMachOSection(StringRef Segment, StringRef Section,
211 unsigned TypeAndAttributes,
212 unsigned Reserved2, SectionKind Kind) {
214 // We unique sections by their segment/section pair. The returned section
215 // may not have the same flags as the requested section, if so this should be
216 // diagnosed by the client as an error.
218 // Create the map if it doesn't already exist.
219 if (MachOUniquingMap == 0)
220 MachOUniquingMap = new MachOUniqueMapTy();
221 MachOUniqueMapTy &Map = *(MachOUniqueMapTy*)MachOUniquingMap;
223 // Form the name to look up.
224 SmallString<64> Name;
229 // Do the lookup, if we have a hit, return it.
230 const MCSectionMachO *&Entry = Map[Name.str()];
231 if (Entry) return Entry;
233 // Otherwise, return a new section.
234 return Entry = new (*this) MCSectionMachO(Segment, Section, TypeAndAttributes,
238 const MCSectionELF *MCContext::
239 getELFSection(StringRef Section, unsigned Type, unsigned Flags,
241 return getELFSection(Section, Type, Flags, Kind, 0, "");
244 const MCSectionELF *MCContext::
245 getELFSection(StringRef Section, unsigned Type, unsigned Flags,
246 SectionKind Kind, unsigned EntrySize, StringRef Group) {
247 if (ELFUniquingMap == 0)
248 ELFUniquingMap = new ELFUniqueMapTy();
249 ELFUniqueMapTy &Map = *(ELFUniqueMapTy*)ELFUniquingMap;
251 // Do the lookup, if we have a hit, return it.
252 StringMapEntry<const MCSectionELF*> &Entry = Map.GetOrCreateValue(Section);
253 if (Entry.getValue()) return Entry.getValue();
255 // Possibly refine the entry size first.
257 EntrySize = MCSectionELF::DetermineEntrySize(Kind);
260 MCSymbol *GroupSym = NULL;
262 GroupSym = GetOrCreateSymbol(Group);
264 MCSectionELF *Result = new (*this) MCSectionELF(Entry.getKey(), Type, Flags,
265 Kind, EntrySize, GroupSym);
266 Entry.setValue(Result);
270 const MCSectionELF *MCContext::CreateELFGroupSection() {
271 MCSectionELF *Result =
272 new (*this) MCSectionELF(".group", ELF::SHT_GROUP, 0,
273 SectionKind::getReadOnly(), 4, NULL);
277 const MCSectionCOFF *MCContext::getCOFFSection(StringRef Section,
278 unsigned Characteristics,
279 SectionKind Kind, int Selection,
280 const MCSectionCOFF *Assoc) {
281 if (COFFUniquingMap == 0)
282 COFFUniquingMap = new COFFUniqueMapTy();
283 COFFUniqueMapTy &Map = *(COFFUniqueMapTy*)COFFUniquingMap;
285 // Do the lookup, if we have a hit, return it.
286 StringMapEntry<const MCSectionCOFF*> &Entry = Map.GetOrCreateValue(Section);
287 if (Entry.getValue()) return Entry.getValue();
289 MCSectionCOFF *Result = new (*this) MCSectionCOFF(Entry.getKey(),
291 Selection, Assoc, Kind);
293 Entry.setValue(Result);
297 const MCSectionCOFF *MCContext::getCOFFSection(StringRef Section) {
298 if (COFFUniquingMap == 0)
299 COFFUniquingMap = new COFFUniqueMapTy();
300 COFFUniqueMapTy &Map = *(COFFUniqueMapTy*)COFFUniquingMap;
302 return Map.lookup(Section);
305 //===----------------------------------------------------------------------===//
307 //===----------------------------------------------------------------------===//
309 /// GetDwarfFile - takes a file name an number to place in the dwarf file and
310 /// directory tables. If the file number has already been allocated it is an
311 /// error and zero is returned and the client reports the error, else the
312 /// allocated file number is returned. The file numbers may be in any order.
313 unsigned MCContext::GetDwarfFile(StringRef Directory, StringRef FileName,
314 unsigned FileNumber, unsigned CUID) {
315 // TODO: a FileNumber of zero says to use the next available file number.
316 // Note: in GenericAsmParser::ParseDirectiveFile() FileNumber was checked
317 // to not be less than one. This needs to be change to be not less than zero.
319 SmallVectorImpl<MCDwarfFile *>& MCDwarfFiles = MCDwarfFilesCUMap[CUID];
320 SmallVectorImpl<StringRef>& MCDwarfDirs = MCDwarfDirsCUMap[CUID];
321 // Make space for this FileNumber in the MCDwarfFiles vector if needed.
322 if (FileNumber >= MCDwarfFiles.size()) {
323 MCDwarfFiles.resize(FileNumber + 1);
325 MCDwarfFile *&ExistingFile = MCDwarfFiles[FileNumber];
327 // It is an error to use see the same number more than once.
331 // Get the new MCDwarfFile slot for this FileNumber.
332 MCDwarfFile *&File = MCDwarfFiles[FileNumber];
334 if (Directory.empty()) {
335 // Separate the directory part from the basename of the FileName.
336 StringRef tFileName = sys::path::filename(FileName);
337 if (!tFileName.empty()) {
338 Directory = sys::path::parent_path(FileName);
339 if (!Directory.empty())
340 FileName = tFileName;
344 // Find or make a entry in the MCDwarfDirs vector for this Directory.
345 // Capture directory name.
347 if (Directory.empty()) {
348 // For FileNames with no directories a DirIndex of 0 is used.
352 for (unsigned End = MCDwarfDirs.size(); DirIndex < End; DirIndex++) {
353 if (Directory == MCDwarfDirs[DirIndex])
356 if (DirIndex >= MCDwarfDirs.size()) {
357 char *Buf = static_cast<char *>(Allocate(Directory.size()));
358 memcpy(Buf, Directory.data(), Directory.size());
359 MCDwarfDirs.push_back(StringRef(Buf, Directory.size()));
361 // The DirIndex is one based, as DirIndex of 0 is used for FileNames with
362 // no directories. MCDwarfDirs[] is unlike MCDwarfFiles[] in that the
363 // directory names are stored at MCDwarfDirs[DirIndex-1] where FileNames
364 // are stored at MCDwarfFiles[FileNumber].Name .
368 // Now make the MCDwarfFile entry and place it in the slot in the MCDwarfFiles
370 char *Buf = static_cast<char *>(Allocate(FileName.size()));
371 memcpy(Buf, FileName.data(), FileName.size());
372 File = new (*this) MCDwarfFile(StringRef(Buf, FileName.size()), DirIndex);
374 // return the allocated FileNumber.
378 /// isValidDwarfFileNumber - takes a dwarf file number and returns true if it
379 /// currently is assigned and false otherwise.
380 bool MCContext::isValidDwarfFileNumber(unsigned FileNumber, unsigned CUID) {
381 SmallVectorImpl<MCDwarfFile *>& MCDwarfFiles = MCDwarfFilesCUMap[CUID];
382 if(FileNumber == 0 || FileNumber >= MCDwarfFiles.size())
385 return MCDwarfFiles[FileNumber] != 0;
388 void MCContext::FatalError(SMLoc Loc, const Twine &Msg) {
389 // If we have a source manager and a location, use it. Otherwise just
390 // use the generic report_fatal_error().
391 if (!SrcMgr || Loc == SMLoc())
392 report_fatal_error(Msg);
394 // Use the source manager to print the message.
395 SrcMgr->PrintMessage(Loc, SourceMgr::DK_Error, Msg);
397 // If we reached here, we are failing ungracefully. Run the interrupt handlers
398 // to make sure any special cleanups get done, in particular that we remove
399 // files registered with RemoveFileOnSignal.
400 sys::RunInterruptHandlers();