1 //===-- ArchiveReader.cpp - Read LLVM archive files -------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by Reid Spencer and is distributed under the
6 // University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // Builds up standard unix archive files (.a) containing LLVM bytecode.
12 //===----------------------------------------------------------------------===//
14 #include "ArchiveInternals.h"
15 #include "llvm/Bytecode/Reader.h"
20 /// Read a variable-bit-rate encoded unsigned integer
21 inline unsigned readInteger(const char*&At, const char*End){
28 Result |= (unsigned)((*At++) & 0x7F) << Shift;
30 } while (At[-1] & 0x80);
34 // Completely parse the Archive's symbol table and populate symTab member var.
36 Archive::parseSymbolTable(const void* data, unsigned size, std::string* error) {
37 const char* At = (const char*) data;
38 const char* End = At + size;
40 unsigned offset = readInteger(At, End);
43 *error = "Ran out of data reading vbr_uint for symtab offset!";
46 unsigned length = readInteger(At, End);
49 *error = "Ran out of data reading vbr_uint for symtab length!";
52 if (At + length > End) {
54 *error = "Malformed symbol table: length not consistent with size";
57 // we don't care if it can't be inserted (duplicate entry)
58 symTab.insert(std::make_pair(std::string(At, length), offset));
65 // This member parses an ArchiveMemberHeader that is presumed to be pointed to
66 // by At. The At pointer is updated to the byte just after the header, which
67 // can be variable in size.
69 Archive::parseMemberHeader(const char*& At, const char* End, std::string* error)
71 if (At + sizeof(ArchiveMemberHeader) >= End) {
73 *error = "Unexpected end of file";
77 // Cast archive member header
78 ArchiveMemberHeader* Hdr = (ArchiveMemberHeader*)At;
79 At += sizeof(ArchiveMemberHeader);
81 // Extract the size and determine if the file is
82 // compressed or not (negative length).
84 int MemberSize = atoi(Hdr->size);
86 flags |= ArchiveMember::CompressedFlag;
87 MemberSize = -MemberSize;
90 // Check the size of the member for sanity
91 if (At + MemberSize > End) {
93 *error = "invalid member length in archive file";
97 // Check the member signature
98 if (!Hdr->checkSignature()) {
100 *error = "invalid file member signature";
104 // Convert and check the member name
105 // The empty name ( '/' and 15 blanks) is for a foreign (non-LLVM) symbol
106 // table. The special name "//" and 14 blanks is for a string table, used
107 // for long file names. This library doesn't generate either of those but
108 // it will accept them. If the name starts with #1/ and the remainder is
109 // digits, then those digits specify the length of the name that is
110 // stored immediately following the header. The special name
111 // __LLVM_SYM_TAB__ identifies the symbol table for LLVM bytecode.
112 // Anything else is a regular, short filename that is terminated with
115 std::string pathname;
116 switch (Hdr->name[0]) {
118 if (Hdr->name[1] == '1' && Hdr->name[2] == '/') {
119 if (isdigit(Hdr->name[3])) {
120 unsigned len = atoi(&Hdr->name[3]);
121 pathname.assign(At, len);
124 flags |= ArchiveMember::HasLongFilenameFlag;
127 *error = "invalid long filename";
130 } else if (Hdr->name[1] == '_' &&
131 (0 == memcmp(Hdr->name, ARFILE_LLVM_SYMTAB_NAME, 16))) {
132 // The member is using a long file name (>15 chars) format.
133 // This format is standard for 4.4BSD and Mac OSX operating
134 // systems. LLVM uses it similarly. In this format, the
135 // remainder of the name field (after #1/) specifies the
136 // length of the file name which occupy the first bytes of
137 // the member's data. The pathname already has the #1/ stripped.
138 pathname.assign(ARFILE_LLVM_SYMTAB_NAME);
139 flags |= ArchiveMember::LLVMSymbolTableFlag;
143 if (Hdr->name[1]== '/') {
144 if (0 == memcmp(Hdr->name, ARFILE_STRTAB_NAME, 16)) {
145 pathname.assign(ARFILE_STRTAB_NAME);
146 flags |= ArchiveMember::StringTableFlag;
149 *error = "invalid string table name";
152 } else if (Hdr->name[1] == ' ') {
153 if (0 == memcmp(Hdr->name, ARFILE_SVR4_SYMTAB_NAME, 16)) {
154 pathname.assign(ARFILE_SVR4_SYMTAB_NAME);
155 flags |= ArchiveMember::SVR4SymbolTableFlag;
158 *error = "invalid SVR4 symbol table name";
161 } else if (isdigit(Hdr->name[1])) {
162 unsigned index = atoi(&Hdr->name[1]);
163 if (index < strtab.length()) {
164 const char* namep = strtab.c_str() + index;
165 const char* endp = strtab.c_str() + strtab.length();
166 const char* p = namep;
167 const char* last_p = p;
169 if (*p == '\n' && *last_p == '/') {
170 pathname.assign(namep, last_p - namep);
171 flags |= ArchiveMember::HasLongFilenameFlag;
179 *error = "missing name termiantor in string table";
184 *error = "name index beyond string table";
190 if (Hdr->name[1] == '_' &&
191 (0 == memcmp(Hdr->name, ARFILE_BSD4_SYMTAB_NAME, 16))) {
192 pathname.assign(ARFILE_BSD4_SYMTAB_NAME);
193 flags |= ArchiveMember::BSD4SymbolTableFlag;
199 char* slash = (char*) memchr(Hdr->name, '/', 16);
201 slash = Hdr->name + 16;
202 pathname.assign(Hdr->name, slash - Hdr->name);
206 // Determine if this is a bytecode file
207 switch (sys::IdentifyFileType(At, 4)) {
208 case sys::BytecodeFileType:
209 flags |= ArchiveMember::BytecodeFlag;
211 case sys::CompressedBytecodeFileType:
212 flags |= ArchiveMember::CompressedBytecodeFlag;
213 flags &= ~ArchiveMember::CompressedFlag;
216 flags &= ~(ArchiveMember::BytecodeFlag|
217 ArchiveMember::CompressedBytecodeFlag);
221 // Instantiate the ArchiveMember to be filled
222 ArchiveMember* member = new ArchiveMember(this);
224 // Fill in fields of the ArchiveMember
227 member->parent = this;
228 member->path.set(pathname);
229 member->info.fileSize = MemberSize;
230 member->info.modTime.fromEpochTime(atoi(Hdr->date));
232 sscanf(Hdr->mode, "%o", &mode);
233 member->info.mode = mode;
234 member->info.user = atoi(Hdr->uid);
235 member->info.group = atoi(Hdr->gid);
236 member->flags = flags;
243 Archive::checkSignature(std::string* error) {
244 // Check the magic string at file's header
245 if (mapfile->size() < 8 || memcmp(base, ARFILE_MAGIC, 8)) {
247 *error = "invalid signature for an archive file";
253 // This function loads the entire archive and fully populates its ilist with
254 // the members of the archive file. This is typically used in preparation for
255 // editing the contents of the archive.
257 Archive::loadArchive(std::string* error) {
262 const char *At = base;
263 const char *End = base + mapfile->size();
265 if (!checkSignature(error))
268 At += 8; // Skip the magic string.
270 bool seenSymbolTable = false;
271 bool foundFirstFile = false;
273 // parse the member header
274 const char* Save = At;
275 ArchiveMember* mbr = parseMemberHeader(At, End, error);
279 // check if this is the foreign symbol table
280 if (mbr->isSVR4SymbolTable() || mbr->isBSD4SymbolTable()) {
281 // We just save this but don't do anything special
282 // with it. It doesn't count as the "first file".
284 // What? Multiple foreign symbol tables? Just chuck it
285 // and retain the last one found.
289 At += mbr->getSize();
290 if ((intptr_t(At) & 1) == 1)
292 } else if (mbr->isStringTable()) {
293 // Simply suck the entire string table into a string
294 // variable. This will be used to get the names of the
295 // members that use the "/ddd" format for their names
296 // (SVR4 style long names).
297 strtab.assign(At, mbr->getSize());
298 At += mbr->getSize();
299 if ((intptr_t(At) & 1) == 1)
302 } else if (mbr->isLLVMSymbolTable()) {
303 // This is the LLVM symbol table for the archive. If we've seen it
304 // already, its an error. Otherwise, parse the symbol table and move on.
305 if (seenSymbolTable) {
307 *error = "invalid archive: multiple symbol tables";
310 if (!parseSymbolTable(mbr->getData(), mbr->getSize(), error))
312 seenSymbolTable = true;
313 At += mbr->getSize();
314 if ((intptr_t(At) & 1) == 1)
316 delete mbr; // We don't need this member in the list of members.
318 // This is just a regular file. If its the first one, save its offset.
319 // Otherwise just push it on the list and move on to the next file.
320 if (!foundFirstFile) {
321 firstFileOffset = Save - base;
322 foundFirstFile = true;
324 members.push_back(mbr);
325 At += mbr->getSize();
326 if ((intptr_t(At) & 1) == 1)
333 // Open and completely load the archive file.
335 Archive::OpenAndLoad(const sys::Path& file, std::string* ErrorMessage)
337 std::auto_ptr<Archive> result ( new Archive(file));
338 if (result->mapToMemory(ErrorMessage))
340 if (!result->loadArchive(ErrorMessage))
342 return result.release();
345 // Get all the bytecode modules from the archive
347 Archive::getAllModules(std::vector<Module*>& Modules, std::string* ErrMessage) {
349 for (iterator I=begin(), E=end(); I != E; ++I) {
350 if (I->isBytecode() || I->isCompressedBytecode()) {
351 std::string FullMemberName = archPath.toString() +
352 "(" + I->getPath().toString() + ")";
353 Module* M = ParseBytecodeBuffer((const unsigned char*)I->getData(),
354 I->getSize(), FullMemberName, ErrMessage);
358 Modules.push_back(M);
364 // Load just the symbol table from the archive file
366 Archive::loadSymbolTable(std::string* ErrorMsg) {
371 const char *At = base;
372 const char *End = base + mapfile->size();
374 // Make sure we're dealing with an archive
375 if (!checkSignature(ErrorMsg))
378 At += 8; // Skip signature
380 // Parse the first file member header
381 const char* FirstFile = At;
382 ArchiveMember* mbr = parseMemberHeader(At, End, ErrorMsg);
386 if (mbr->isSVR4SymbolTable() || mbr->isBSD4SymbolTable()) {
387 // Skip the foreign symbol table, we don't do anything with it
388 At += mbr->getSize();
389 if ((intptr_t(At) & 1) == 1)
395 mbr = parseMemberHeader(At, End, ErrorMsg);
402 if (mbr->isStringTable()) {
403 // Process the string table entry
404 strtab.assign((const char*)mbr->getData(), mbr->getSize());
405 At += mbr->getSize();
406 if ((intptr_t(At) & 1) == 1)
411 mbr = parseMemberHeader(At, End, ErrorMsg);
418 // See if its the symbol table
419 if (mbr->isLLVMSymbolTable()) {
420 if (!parseSymbolTable(mbr->getData(), mbr->getSize(), ErrorMsg)) {
425 At += mbr->getSize();
426 if ((intptr_t(At) & 1) == 1)
429 // Can't be any more symtab headers so just advance
432 // There's no symbol table in the file. We have to rebuild it from scratch
433 // because the intent of this method is to get the symbol table loaded so
434 // it can be searched efficiently.
435 // Add the member to the members list
436 members.push_back(mbr);
439 firstFileOffset = FirstFile - base;
443 // Open the archive and load just the symbol tables
445 Archive::OpenAndLoadSymbols(const sys::Path& file, std::string* ErrorMessage) {
446 std::auto_ptr<Archive> result ( new Archive(file) );
447 if (result->mapToMemory(ErrorMessage))
449 if (!result->loadSymbolTable(ErrorMessage))
451 return result.release();
454 // Look up one symbol in the symbol table and return a ModuleProvider for the
455 // module that defines that symbol.
457 Archive::findModuleDefiningSymbol(const std::string& symbol,
458 std::string* ErrMsg) {
459 SymTabType::iterator SI = symTab.find(symbol);
460 if (SI == symTab.end())
463 // The symbol table was previously constructed assuming that the members were
464 // written without the symbol table header. Because VBR encoding is used, the
465 // values could not be adjusted to account for the offset of the symbol table
466 // because that could affect the size of the symbol table due to VBR encoding.
467 // We now have to account for this by adjusting the offset by the size of the
468 // symbol table and its header.
469 unsigned fileOffset =
470 SI->second + // offset in symbol-table-less file
471 firstFileOffset; // add offset to first "real" file in archive
473 // See if the module is already loaded
474 ModuleMap::iterator MI = modules.find(fileOffset);
475 if (MI != modules.end())
476 return MI->second.first;
478 // Module hasn't been loaded yet, we need to load it
479 const char* modptr = base + fileOffset;
480 ArchiveMember* mbr = parseMemberHeader(modptr, base + mapfile->size(),ErrMsg);
484 // Now, load the bytecode module to get the ModuleProvider
485 std::string FullMemberName = archPath.toString() + "(" +
486 mbr->getPath().toString() + ")";
487 ModuleProvider* mp = getBytecodeBufferModuleProvider(
488 (const unsigned char*) mbr->getData(), mbr->getSize(),
489 FullMemberName, ErrMsg, 0);
493 modules.insert(std::make_pair(fileOffset, std::make_pair(mp, mbr)));
498 // Look up multiple symbols in the symbol table and return a set of
499 // ModuleProviders that define those symbols.
501 Archive::findModulesDefiningSymbols(std::set<std::string>& symbols,
502 std::set<ModuleProvider*>& result,
505 if (!mapfile || !base) {
507 *error = "Empty archive invalid for finding modules defining symbols";
511 if (symTab.empty()) {
512 // We don't have a symbol table, so we must build it now but lets also
513 // make sure that we populate the modules table as we do this to ensure
514 // that we don't load them twice when findModuleDefiningSymbol is called
517 // Get a pointer to the first file
518 const char* At = ((const char*)base) + firstFileOffset;
519 const char* End = ((const char*)base) + mapfile->size();
522 // Compute the offset to be put in the symbol table
523 unsigned offset = At - base - firstFileOffset;
525 // Parse the file's header
526 ArchiveMember* mbr = parseMemberHeader(At, End, error);
530 // If it contains symbols
531 if (mbr->isBytecode() || mbr->isCompressedBytecode()) {
533 std::vector<std::string> symbols;
534 std::string FullMemberName = archPath.toString() + "(" +
535 mbr->getPath().toString() + ")";
536 ModuleProvider* MP = GetBytecodeSymbols((const unsigned char*)At,
537 mbr->getSize(), FullMemberName, symbols, error);
540 // Insert the module's symbols into the symbol table
541 for (std::vector<std::string>::iterator I = symbols.begin(),
542 E=symbols.end(); I != E; ++I ) {
543 symTab.insert(std::make_pair(*I, offset));
545 // Insert the ModuleProvider and the ArchiveMember into the table of
547 modules.insert(std::make_pair(offset, std::make_pair(MP, mbr)));
550 *error = "Can't parse bytecode member: " +
551 mbr->getPath().toString() + ": " + *error;
557 // Go to the next file location
558 At += mbr->getSize();
559 if ((intptr_t(At) & 1) == 1)
564 // At this point we have a valid symbol table (one way or another) so we
565 // just use it to quickly find the symbols requested.
567 for (std::set<std::string>::iterator I=symbols.begin(),
568 E=symbols.end(); I != E;) {
569 // See if this symbol exists
570 ModuleProvider* mp = findModuleDefiningSymbol(*I,error);
572 // The symbol exists, insert the ModuleProvider into our result,
573 // duplicates wil be ignored
576 // Remove the symbol now that its been resolved, being careful to
577 // post-increment the iterator.
586 bool Archive::isBytecodeArchive() {
587 // Make sure the symTab has been loaded. In most cases this should have been
588 // done when the archive was constructed, but still, this is just in case.
590 if (!loadSymbolTable(0))
593 // Now that we know it's been loaded, return true
595 if (symTab.size()) return true;
597 //We still can't be sure it isn't a bytecode archive
601 std::vector<Module *> Modules;
602 std::string ErrorMessage;
604 // Scan the archive, trying to load a bytecode member. We only load one to
605 // see if this works.
606 for (iterator I = begin(), E = end(); I != E; ++I) {
607 if (!I->isBytecode() && !I->isCompressedBytecode())
610 std::string FullMemberName =
611 archPath.toString() + "(" + I->getPath().toString() + ")";
612 Module* M = ParseBytecodeBuffer((const unsigned char*)I->getData(),
613 I->getSize(), FullMemberName);
615 return false; // Couldn't parse bytecode, not a bytecode archive.