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1 | //===- lib/MC/MCContext.cpp - Machine Code Context ------------------------===// |
2 | // | |
3 | // The LLVM Compiler Infrastructure | |
4 | // | |
5 | // This file is distributed under the University of Illinois Open Source | |
6 | // License. See LICENSE.TXT for details. | |
7 | // | |
8 | //===----------------------------------------------------------------------===// | |
9 | ||
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/ADT/SmallString.h" | |
21 | #include "llvm/ADT/Twine.h" | |
22 | #include "llvm/Support/ELF.h" | |
23 | #include "llvm/Support/ErrorHandling.h" | |
24 | #include "llvm/Support/SourceMgr.h" | |
25 | #include "llvm/Support/Signals.h" | |
26 | using namespace llvm; | |
27 | ||
28 | typedef StringMap<const MCSectionMachO*> MachOUniqueMapTy; | |
29 | typedef StringMap<const MCSectionELF*> ELFUniqueMapTy; | |
30 | typedef StringMap<const MCSectionCOFF*> COFFUniqueMapTy; | |
31 | ||
32 | ||
33 | MCContext::MCContext(const MCAsmInfo &mai, const MCRegisterInfo &mri, | |
34 | const MCObjectFileInfo *mofi, const SourceMgr *mgr) : | |
35 | SrcMgr(mgr), MAI(mai), MRI(mri), MOFI(mofi), | |
36 | Allocator(), Symbols(Allocator), UsedNames(Allocator), | |
37 | NextUniqueID(0), | |
38 | CurrentDwarfLoc(0,0,0,DWARF2_FLAG_IS_STMT,0,0), | |
39 | AllowTemporaryLabels(true) { | |
40 | MachOUniquingMap = 0; | |
41 | ELFUniquingMap = 0; | |
42 | COFFUniquingMap = 0; | |
43 | ||
44 | SecureLogFile = getenv("AS_SECURE_LOG_FILE"); | |
45 | SecureLog = 0; | |
46 | SecureLogUsed = false; | |
47 | ||
48 | DwarfLocSeen = false; | |
49 | GenDwarfForAssembly = false; | |
50 | GenDwarfFileNumber = 0; | |
51 | } | |
52 | ||
53 | MCContext::~MCContext() { | |
54 | // NOTE: The symbols are all allocated out of a bump pointer allocator, | |
55 | // we don't need to free them here. | |
56 | ||
57 | // If we have the MachO uniquing map, free it. | |
58 | delete (MachOUniqueMapTy*)MachOUniquingMap; | |
59 | delete (ELFUniqueMapTy*)ELFUniquingMap; | |
60 | delete (COFFUniqueMapTy*)COFFUniquingMap; | |
61 | ||
62 | // If the stream for the .secure_log_unique directive was created free it. | |
63 | delete (raw_ostream*)SecureLog; | |
64 | } | |
65 | ||
66 | //===----------------------------------------------------------------------===// | |
67 | // Symbol Manipulation | |
68 | //===----------------------------------------------------------------------===// | |
69 | ||
70 | MCSymbol *MCContext::GetOrCreateSymbol(StringRef Name) { | |
71 | assert(!Name.empty() && "Normal symbols cannot be unnamed!"); | |
72 | ||
73 | // Do the lookup and get the entire StringMapEntry. We want access to the | |
74 | // key if we are creating the entry. | |
75 | StringMapEntry<MCSymbol*> &Entry = Symbols.GetOrCreateValue(Name); | |
76 | MCSymbol *Sym = Entry.getValue(); | |
77 | ||
78 | if (Sym) | |
79 | return Sym; | |
80 | ||
81 | Sym = CreateSymbol(Name); | |
82 | Entry.setValue(Sym); | |
83 | return Sym; | |
84 | } | |
85 | ||
86 | MCSymbol *MCContext::CreateSymbol(StringRef Name) { | |
87 | // Determine whether this is an assembler temporary or normal label, if used. | |
88 | bool isTemporary = false; | |
89 | if (AllowTemporaryLabels) | |
90 | isTemporary = Name.startswith(MAI.getPrivateGlobalPrefix()); | |
91 | ||
92 | StringMapEntry<bool> *NameEntry = &UsedNames.GetOrCreateValue(Name); | |
93 | if (NameEntry->getValue()) { | |
94 | assert(isTemporary && "Cannot rename non temporary symbols"); | |
95 | SmallString<128> NewName = Name; | |
96 | do { | |
97 | NewName.resize(Name.size()); | |
98 | raw_svector_ostream(NewName) << NextUniqueID++; | |
99 | NameEntry = &UsedNames.GetOrCreateValue(NewName); | |
100 | } while (NameEntry->getValue()); | |
101 | } | |
102 | NameEntry->setValue(true); | |
103 | ||
104 | // Ok, the entry doesn't already exist. Have the MCSymbol object itself refer | |
105 | // to the copy of the string that is embedded in the UsedNames entry. | |
106 | MCSymbol *Result = new (*this) MCSymbol(NameEntry->getKey(), isTemporary); | |
107 | ||
108 | return Result; | |
109 | } | |
110 | ||
111 | MCSymbol *MCContext::GetOrCreateSymbol(const Twine &Name) { | |
112 | SmallString<128> NameSV; | |
113 | Name.toVector(NameSV); | |
114 | return GetOrCreateSymbol(NameSV.str()); | |
115 | } | |
116 | ||
117 | MCSymbol *MCContext::CreateTempSymbol() { | |
118 | SmallString<128> NameSV; | |
119 | raw_svector_ostream(NameSV) | |
120 | << MAI.getPrivateGlobalPrefix() << "tmp" << NextUniqueID++; | |
121 | return CreateSymbol(NameSV); | |
122 | } | |
123 | ||
124 | unsigned MCContext::NextInstance(int64_t LocalLabelVal) { | |
125 | MCLabel *&Label = Instances[LocalLabelVal]; | |
126 | if (!Label) | |
127 | Label = new (*this) MCLabel(0); | |
128 | return Label->incInstance(); | |
129 | } | |
130 | ||
131 | unsigned MCContext::GetInstance(int64_t LocalLabelVal) { | |
132 | MCLabel *&Label = Instances[LocalLabelVal]; | |
133 | if (!Label) | |
134 | Label = new (*this) MCLabel(0); | |
135 | return Label->getInstance(); | |
136 | } | |
137 | ||
138 | MCSymbol *MCContext::CreateDirectionalLocalSymbol(int64_t LocalLabelVal) { | |
139 | return GetOrCreateSymbol(Twine(MAI.getPrivateGlobalPrefix()) + | |
140 | Twine(LocalLabelVal) + | |
141 | "\2" + | |
142 | Twine(NextInstance(LocalLabelVal))); | |
143 | } | |
144 | MCSymbol *MCContext::GetDirectionalLocalSymbol(int64_t LocalLabelVal, | |
145 | int bORf) { | |
146 | return GetOrCreateSymbol(Twine(MAI.getPrivateGlobalPrefix()) + | |
147 | Twine(LocalLabelVal) + | |
148 | "\2" + | |
149 | Twine(GetInstance(LocalLabelVal) + bORf)); | |
150 | } | |
151 | ||
152 | MCSymbol *MCContext::LookupSymbol(StringRef Name) const { | |
153 | return Symbols.lookup(Name); | |
154 | } | |
155 | ||
156 | MCSymbol *MCContext::LookupSymbol(const Twine &Name) const { | |
157 | SmallString<128> NameSV; | |
158 | Name.toVector(NameSV); | |
159 | return LookupSymbol(NameSV.str()); | |
160 | } | |
161 | ||
162 | //===----------------------------------------------------------------------===// | |
163 | // Section Management | |
164 | //===----------------------------------------------------------------------===// | |
165 | ||
166 | const MCSectionMachO *MCContext:: | |
167 | getMachOSection(StringRef Segment, StringRef Section, | |
168 | unsigned TypeAndAttributes, | |
169 | unsigned Reserved2, SectionKind Kind) { | |
170 | ||
171 | // We unique sections by their segment/section pair. The returned section | |
172 | // may not have the same flags as the requested section, if so this should be | |
173 | // diagnosed by the client as an error. | |
174 | ||
175 | // Create the map if it doesn't already exist. | |
176 | if (MachOUniquingMap == 0) | |
177 | MachOUniquingMap = new MachOUniqueMapTy(); | |
178 | MachOUniqueMapTy &Map = *(MachOUniqueMapTy*)MachOUniquingMap; | |
179 | ||
180 | // Form the name to look up. | |
181 | SmallString<64> Name; | |
182 | Name += Segment; | |
183 | Name.push_back(','); | |
184 | Name += Section; | |
185 | ||
186 | // Do the lookup, if we have a hit, return it. | |
187 | const MCSectionMachO *&Entry = Map[Name.str()]; | |
188 | if (Entry) return Entry; | |
189 | ||
190 | // Otherwise, return a new section. | |
191 | return Entry = new (*this) MCSectionMachO(Segment, Section, TypeAndAttributes, | |
192 | Reserved2, Kind); | |
193 | } | |
194 | ||
195 | const MCSectionELF *MCContext:: | |
196 | getELFSection(StringRef Section, unsigned Type, unsigned Flags, | |
197 | SectionKind Kind) { | |
198 | return getELFSection(Section, Type, Flags, Kind, 0, ""); | |
199 | } | |
200 | ||
201 | const MCSectionELF *MCContext:: | |
202 | getELFSection(StringRef Section, unsigned Type, unsigned Flags, | |
203 | SectionKind Kind, unsigned EntrySize, StringRef Group) { | |
204 | if (ELFUniquingMap == 0) | |
205 | ELFUniquingMap = new ELFUniqueMapTy(); | |
206 | ELFUniqueMapTy &Map = *(ELFUniqueMapTy*)ELFUniquingMap; | |
207 | ||
208 | // Do the lookup, if we have a hit, return it. | |
209 | StringMapEntry<const MCSectionELF*> &Entry = Map.GetOrCreateValue(Section); | |
210 | if (Entry.getValue()) return Entry.getValue(); | |
211 | ||
212 | // Possibly refine the entry size first. | |
213 | if (!EntrySize) { | |
214 | EntrySize = MCSectionELF::DetermineEntrySize(Kind); | |
215 | } | |
216 | ||
217 | MCSymbol *GroupSym = NULL; | |
218 | if (!Group.empty()) | |
219 | GroupSym = GetOrCreateSymbol(Group); | |
220 | ||
221 | MCSectionELF *Result = new (*this) MCSectionELF(Entry.getKey(), Type, Flags, | |
222 | Kind, EntrySize, GroupSym); | |
223 | Entry.setValue(Result); | |
224 | return Result; | |
225 | } | |
226 | ||
227 | const MCSectionELF *MCContext::CreateELFGroupSection() { | |
228 | MCSectionELF *Result = | |
229 | new (*this) MCSectionELF(".group", ELF::SHT_GROUP, 0, | |
230 | SectionKind::getReadOnly(), 4, NULL); | |
231 | return Result; | |
232 | } | |
233 | ||
234 | const MCSection *MCContext::getCOFFSection(StringRef Section, | |
235 | unsigned Characteristics, | |
236 | int Selection, | |
237 | SectionKind Kind) { | |
238 | if (COFFUniquingMap == 0) | |
239 | COFFUniquingMap = new COFFUniqueMapTy(); | |
240 | COFFUniqueMapTy &Map = *(COFFUniqueMapTy*)COFFUniquingMap; | |
241 | ||
242 | // Do the lookup, if we have a hit, return it. | |
243 | StringMapEntry<const MCSectionCOFF*> &Entry = Map.GetOrCreateValue(Section); | |
244 | if (Entry.getValue()) return Entry.getValue(); | |
245 | ||
246 | MCSectionCOFF *Result = new (*this) MCSectionCOFF(Entry.getKey(), | |
247 | Characteristics, | |
248 | Selection, Kind); | |
249 | ||
250 | Entry.setValue(Result); | |
251 | return Result; | |
252 | } | |
253 | ||
254 | //===----------------------------------------------------------------------===// | |
255 | // Dwarf Management | |
256 | //===----------------------------------------------------------------------===// | |
257 | ||
258 | /// GetDwarfFile - takes a file name an number to place in the dwarf file and | |
259 | /// directory tables. If the file number has already been allocated it is an | |
260 | /// error and zero is returned and the client reports the error, else the | |
261 | /// allocated file number is returned. The file numbers may be in any order. | |
262 | unsigned MCContext::GetDwarfFile(StringRef Directory, StringRef FileName, | |
263 | unsigned FileNumber) { | |
264 | // TODO: a FileNumber of zero says to use the next available file number. | |
265 | // Note: in GenericAsmParser::ParseDirectiveFile() FileNumber was checked | |
266 | // to not be less than one. This needs to be change to be not less than zero. | |
267 | ||
268 | // Make space for this FileNumber in the MCDwarfFiles vector if needed. | |
269 | if (FileNumber >= MCDwarfFiles.size()) { | |
270 | MCDwarfFiles.resize(FileNumber + 1); | |
271 | } else { | |
272 | MCDwarfFile *&ExistingFile = MCDwarfFiles[FileNumber]; | |
273 | if (ExistingFile) | |
274 | // It is an error to use see the same number more than once. | |
275 | return 0; | |
276 | } | |
277 | ||
278 | // Get the new MCDwarfFile slot for this FileNumber. | |
279 | MCDwarfFile *&File = MCDwarfFiles[FileNumber]; | |
280 | ||
281 | if (Directory.empty()) { | |
282 | // Separate the directory part from the basename of the FileName. | |
283 | StringRef tFileName = sys::path::filename(FileName); | |
284 | if (!tFileName.empty()) { | |
285 | Directory = sys::path::parent_path(FileName); | |
286 | if (!Directory.empty()) | |
287 | FileName = tFileName; | |
288 | } | |
289 | } | |
290 | ||
291 | // Find or make a entry in the MCDwarfDirs vector for this Directory. | |
292 | // Capture directory name. | |
293 | unsigned DirIndex; | |
294 | if (Directory.empty()) { | |
295 | // For FileNames with no directories a DirIndex of 0 is used. | |
296 | DirIndex = 0; | |
297 | } else { | |
298 | DirIndex = 0; | |
299 | for (unsigned End = MCDwarfDirs.size(); DirIndex < End; DirIndex++) { | |
300 | if (Directory == MCDwarfDirs[DirIndex]) | |
301 | break; | |
302 | } | |
303 | if (DirIndex >= MCDwarfDirs.size()) { | |
304 | char *Buf = static_cast<char *>(Allocate(Directory.size())); | |
305 | memcpy(Buf, Directory.data(), Directory.size()); | |
306 | MCDwarfDirs.push_back(StringRef(Buf, Directory.size())); | |
307 | } | |
308 | // The DirIndex is one based, as DirIndex of 0 is used for FileNames with | |
309 | // no directories. MCDwarfDirs[] is unlike MCDwarfFiles[] in that the | |
310 | // directory names are stored at MCDwarfDirs[DirIndex-1] where FileNames | |
311 | // are stored at MCDwarfFiles[FileNumber].Name . | |
312 | DirIndex++; | |
313 | } | |
314 | ||
315 | // Now make the MCDwarfFile entry and place it in the slot in the MCDwarfFiles | |
316 | // vector. | |
317 | char *Buf = static_cast<char *>(Allocate(FileName.size())); | |
318 | memcpy(Buf, FileName.data(), FileName.size()); | |
319 | File = new (*this) MCDwarfFile(StringRef(Buf, FileName.size()), DirIndex); | |
320 | ||
321 | // return the allocated FileNumber. | |
322 | return FileNumber; | |
323 | } | |
324 | ||
325 | /// isValidDwarfFileNumber - takes a dwarf file number and returns true if it | |
326 | /// currently is assigned and false otherwise. | |
327 | bool MCContext::isValidDwarfFileNumber(unsigned FileNumber) { | |
328 | if(FileNumber == 0 || FileNumber >= MCDwarfFiles.size()) | |
329 | return false; | |
330 | ||
331 | return MCDwarfFiles[FileNumber] != 0; | |
332 | } | |
333 | ||
334 | void MCContext::FatalError(SMLoc Loc, const Twine &Msg) { | |
335 | // If we have a source manager and a location, use it. Otherwise just | |
336 | // use the generic report_fatal_error(). | |
337 | if (!SrcMgr || Loc == SMLoc()) | |
338 | report_fatal_error(Msg); | |
339 | ||
340 | // Use the source manager to print the message. | |
341 | SrcMgr->PrintMessage(Loc, SourceMgr::DK_Error, Msg); | |
342 | ||
343 | // If we reached here, we are failing ungracefully. Run the interrupt handlers | |
344 | // to make sure any special cleanups get done, in particular that we remove | |
345 | // files registered with RemoveFileOnSignal. | |
346 | sys::RunInterruptHandlers(); | |
347 | exit(1); | |
348 | } |