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/MC/MCAsmInfo.h"
12 #include "llvm/MC/MCObjectFileInfo.h"
13 #include "llvm/MC/MCRegisterInfo.h"
14 #include "llvm/MC/MCSectionMachO.h"
15 #include "llvm/MC/MCSectionELF.h"
16 #include "llvm/MC/MCSectionCOFF.h"
17 #include "llvm/MC/MCSymbol.h"
18 #include "llvm/MC/MCLabel.h"
19 #include "llvm/MC/MCDwarf.h"
20 #include "llvm/Target/TargetAsmInfo.h"
21 #include "llvm/ADT/SmallString.h"
22 #include "llvm/ADT/Twine.h"
23 #include "llvm/Support/ELF.h"
26 typedef StringMap<const MCSectionMachO*> MachOUniqueMapTy;
27 typedef StringMap<const MCSectionELF*> ELFUniqueMapTy;
28 typedef StringMap<const MCSectionCOFF*> COFFUniqueMapTy;
31 MCContext::MCContext(const MCAsmInfo &mai, const MCRegisterInfo &mri,
32 const MCObjectFileInfo *mofi, const TargetAsmInfo *tai) :
33 MAI(mai), MRI(mri), MOFI(mofi), TAI(tai),
34 Allocator(), Symbols(Allocator), UsedNames(Allocator),
36 CurrentDwarfLoc(0,0,0,DWARF2_FLAG_IS_STMT,0,0),
37 AllowTemporaryLabels(true) {
42 SecureLogFile = getenv("AS_SECURE_LOG_FILE");
44 SecureLogUsed = false;
49 MCContext::~MCContext() {
50 // NOTE: The symbols are all allocated out of a bump pointer allocator,
51 // we don't need to free them here.
53 // If we have the MachO uniquing map, free it.
54 delete (MachOUniqueMapTy*)MachOUniquingMap;
55 delete (ELFUniqueMapTy*)ELFUniquingMap;
56 delete (COFFUniqueMapTy*)COFFUniquingMap;
58 // If the stream for the .secure_log_unique directive was created free it.
59 delete (raw_ostream*)SecureLog;
64 //===----------------------------------------------------------------------===//
65 // Symbol Manipulation
66 //===----------------------------------------------------------------------===//
68 MCSymbol *MCContext::GetOrCreateSymbol(StringRef Name) {
69 assert(!Name.empty() && "Normal symbols cannot be unnamed!");
71 // Do the lookup and get the entire StringMapEntry. We want access to the
72 // key if we are creating the entry.
73 StringMapEntry<MCSymbol*> &Entry = Symbols.GetOrCreateValue(Name);
74 MCSymbol *Sym = Entry.getValue();
79 Sym = CreateSymbol(Name);
84 MCSymbol *MCContext::CreateSymbol(StringRef Name) {
85 // Determine whether this is an assembler temporary or normal label, if used.
86 bool isTemporary = false;
87 if (AllowTemporaryLabels)
88 isTemporary = Name.startswith(MAI.getPrivateGlobalPrefix());
90 StringMapEntry<bool> *NameEntry = &UsedNames.GetOrCreateValue(Name);
91 if (NameEntry->getValue()) {
92 assert(isTemporary && "Cannot rename non temporary symbols");
93 SmallString<128> NewName = Name;
95 NewName.resize(Name.size());
96 raw_svector_ostream(NewName) << NextUniqueID++;
97 NameEntry = &UsedNames.GetOrCreateValue(NewName);
98 } while (NameEntry->getValue());
100 NameEntry->setValue(true);
102 // Ok, the entry doesn't already exist. Have the MCSymbol object itself refer
103 // to the copy of the string that is embedded in the UsedNames entry.
104 MCSymbol *Result = new (*this) MCSymbol(NameEntry->getKey(), isTemporary);
109 MCSymbol *MCContext::GetOrCreateSymbol(const Twine &Name) {
110 SmallString<128> NameSV;
111 Name.toVector(NameSV);
112 return GetOrCreateSymbol(NameSV.str());
115 MCSymbol *MCContext::CreateTempSymbol() {
116 SmallString<128> NameSV;
117 raw_svector_ostream(NameSV)
118 << MAI.getPrivateGlobalPrefix() << "tmp" << NextUniqueID++;
119 return CreateSymbol(NameSV);
122 unsigned MCContext::NextInstance(int64_t LocalLabelVal) {
123 MCLabel *&Label = Instances[LocalLabelVal];
125 Label = new (*this) MCLabel(0);
126 return Label->incInstance();
129 unsigned MCContext::GetInstance(int64_t LocalLabelVal) {
130 MCLabel *&Label = Instances[LocalLabelVal];
132 Label = new (*this) MCLabel(0);
133 return Label->getInstance();
136 MCSymbol *MCContext::CreateDirectionalLocalSymbol(int64_t LocalLabelVal) {
137 return GetOrCreateSymbol(Twine(MAI.getPrivateGlobalPrefix()) +
138 Twine(LocalLabelVal) +
140 Twine(NextInstance(LocalLabelVal)));
142 MCSymbol *MCContext::GetDirectionalLocalSymbol(int64_t LocalLabelVal,
144 return GetOrCreateSymbol(Twine(MAI.getPrivateGlobalPrefix()) +
145 Twine(LocalLabelVal) +
147 Twine(GetInstance(LocalLabelVal) + bORf));
150 MCSymbol *MCContext::LookupSymbol(StringRef Name) const {
151 return Symbols.lookup(Name);
154 //===----------------------------------------------------------------------===//
155 // Section Management
156 //===----------------------------------------------------------------------===//
158 const MCSectionMachO *MCContext::
159 getMachOSection(StringRef Segment, StringRef Section,
160 unsigned TypeAndAttributes,
161 unsigned Reserved2, SectionKind Kind) {
163 // We unique sections by their segment/section pair. The returned section
164 // may not have the same flags as the requested section, if so this should be
165 // diagnosed by the client as an error.
167 // Create the map if it doesn't already exist.
168 if (MachOUniquingMap == 0)
169 MachOUniquingMap = new MachOUniqueMapTy();
170 MachOUniqueMapTy &Map = *(MachOUniqueMapTy*)MachOUniquingMap;
172 // Form the name to look up.
173 SmallString<64> Name;
178 // Do the lookup, if we have a hit, return it.
179 const MCSectionMachO *&Entry = Map[Name.str()];
180 if (Entry) return Entry;
182 // Otherwise, return a new section.
183 return Entry = new (*this) MCSectionMachO(Segment, Section, TypeAndAttributes,
187 const MCSectionELF *MCContext::
188 getELFSection(StringRef Section, unsigned Type, unsigned Flags,
190 return getELFSection(Section, Type, Flags, Kind, 0, "");
193 const MCSectionELF *MCContext::
194 getELFSection(StringRef Section, unsigned Type, unsigned Flags,
195 SectionKind Kind, unsigned EntrySize, StringRef Group) {
196 if (ELFUniquingMap == 0)
197 ELFUniquingMap = new ELFUniqueMapTy();
198 ELFUniqueMapTy &Map = *(ELFUniqueMapTy*)ELFUniquingMap;
200 // Do the lookup, if we have a hit, return it.
201 StringMapEntry<const MCSectionELF*> &Entry = Map.GetOrCreateValue(Section);
202 if (Entry.getValue()) return Entry.getValue();
204 // Possibly refine the entry size first.
206 EntrySize = MCSectionELF::DetermineEntrySize(Kind);
209 MCSymbol *GroupSym = NULL;
211 GroupSym = GetOrCreateSymbol(Group);
213 MCSectionELF *Result = new (*this) MCSectionELF(Entry.getKey(), Type, Flags,
214 Kind, EntrySize, GroupSym);
215 Entry.setValue(Result);
219 const MCSectionELF *MCContext::CreateELFGroupSection() {
220 MCSectionELF *Result =
221 new (*this) MCSectionELF(".group", ELF::SHT_GROUP, 0,
222 SectionKind::getReadOnly(), 4, NULL);
226 const MCSection *MCContext::getCOFFSection(StringRef Section,
227 unsigned Characteristics,
230 if (COFFUniquingMap == 0)
231 COFFUniquingMap = new COFFUniqueMapTy();
232 COFFUniqueMapTy &Map = *(COFFUniqueMapTy*)COFFUniquingMap;
234 // Do the lookup, if we have a hit, return it.
235 StringMapEntry<const MCSectionCOFF*> &Entry = Map.GetOrCreateValue(Section);
236 if (Entry.getValue()) return Entry.getValue();
238 MCSectionCOFF *Result = new (*this) MCSectionCOFF(Entry.getKey(),
242 Entry.setValue(Result);
246 //===----------------------------------------------------------------------===//
248 //===----------------------------------------------------------------------===//
250 /// GetDwarfFile - takes a file name an number to place in the dwarf file and
251 /// directory tables. If the file number has already been allocated it is an
252 /// error and zero is returned and the client reports the error, else the
253 /// allocated file number is returned. The file numbers may be in any order.
254 unsigned MCContext::GetDwarfFile(StringRef FileName, unsigned FileNumber) {
255 // TODO: a FileNumber of zero says to use the next available file number.
256 // Note: in GenericAsmParser::ParseDirectiveFile() FileNumber was checked
257 // to not be less than one. This needs to be change to be not less than zero.
259 // Make space for this FileNumber in the MCDwarfFiles vector if needed.
260 if (FileNumber >= MCDwarfFiles.size()) {
261 MCDwarfFiles.resize(FileNumber + 1);
263 MCDwarfFile *&ExistingFile = MCDwarfFiles[FileNumber];
265 // It is an error to use see the same number more than once.
269 // Get the new MCDwarfFile slot for this FileNumber.
270 MCDwarfFile *&File = MCDwarfFiles[FileNumber];
272 // Separate the directory part from the basename of the FileName.
273 std::pair<StringRef, StringRef> Slash = FileName.rsplit('/');
275 // Find or make a entry in the MCDwarfDirs vector for this Directory.
278 // Capture directory name.
279 if (Slash.second.empty()) {
281 DirIndex = 0; // For FileNames with no directories a DirIndex of 0 is used.
283 StringRef Directory = Slash.first;
285 for (DirIndex = 0; DirIndex < MCDwarfDirs.size(); DirIndex++) {
286 if (Directory == MCDwarfDirs[DirIndex])
289 if (DirIndex >= MCDwarfDirs.size()) {
290 char *Buf = static_cast<char *>(Allocate(Directory.size()));
291 memcpy(Buf, Directory.data(), Directory.size());
292 MCDwarfDirs.push_back(StringRef(Buf, Directory.size()));
294 // The DirIndex is one based, as DirIndex of 0 is used for FileNames with
295 // no directories. MCDwarfDirs[] is unlike MCDwarfFiles[] in that the
296 // directory names are stored at MCDwarfDirs[DirIndex-1] where FileNames are
297 // stored at MCDwarfFiles[FileNumber].Name .
301 // Now make the MCDwarfFile entry and place it in the slot in the MCDwarfFiles
303 char *Buf = static_cast<char *>(Allocate(Name.size()));
304 memcpy(Buf, Name.data(), Name.size());
305 File = new (*this) MCDwarfFile(StringRef(Buf, Name.size()), DirIndex);
307 // return the allocated FileNumber.
311 /// isValidDwarfFileNumber - takes a dwarf file number and returns true if it
312 /// currently is assigned and false otherwise.
313 bool MCContext::isValidDwarfFileNumber(unsigned FileNumber) {
314 if(FileNumber == 0 || FileNumber >= MCDwarfFiles.size())
317 return MCDwarfFiles[FileNumber] != 0;