| //===-- ArchiveReader.cpp - Read LLVM archive files -------------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // Builds up standard unix archive files (.a) containing LLVM bitcode. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "ArchiveInternals.h" |
| #include "llvm/ADT/SmallPtrSet.h" |
| #include "llvm/Bitcode/ReaderWriter.h" |
| #include "llvm/Support/MemoryBuffer.h" |
| #include "llvm/Module.h" |
| #include <cstdio> |
| #include <cstdlib> |
| #include <memory> |
| using namespace llvm; |
| |
| /// Read a variable-bit-rate encoded unsigned integer |
| static inline unsigned readInteger(const char*&At, const char*End) { |
| unsigned Shift = 0; |
| unsigned Result = 0; |
| |
| do { |
| if (At == End) |
| return Result; |
| Result |= (unsigned)((*At++) & 0x7F) << Shift; |
| Shift += 7; |
| } while (At[-1] & 0x80); |
| return Result; |
| } |
| |
| // Completely parse the Archive's symbol table and populate symTab member var. |
| bool |
| Archive::parseSymbolTable(const void* data, unsigned size, std::string* error) { |
| const char* At = (const char*) data; |
| const char* End = At + size; |
| while (At < End) { |
| unsigned offset = readInteger(At, End); |
| if (At == End) { |
| if (error) |
| *error = "Ran out of data reading vbr_uint for symtab offset!"; |
| return false; |
| } |
| unsigned length = readInteger(At, End); |
| if (At == End) { |
| if (error) |
| *error = "Ran out of data reading vbr_uint for symtab length!"; |
| return false; |
| } |
| if (At + length > End) { |
| if (error) |
| *error = "Malformed symbol table: length not consistent with size"; |
| return false; |
| } |
| // we don't care if it can't be inserted (duplicate entry) |
| symTab.insert(std::make_pair(std::string(At, length), offset)); |
| At += length; |
| } |
| symTabSize = size; |
| return true; |
| } |
| |
| // This member parses an ArchiveMemberHeader that is presumed to be pointed to |
| // by At. The At pointer is updated to the byte just after the header, which |
| // can be variable in size. |
| ArchiveMember* |
| Archive::parseMemberHeader(const char*& At, const char* End, std::string* error) |
| { |
| if (At + sizeof(ArchiveMemberHeader) >= End) { |
| if (error) |
| *error = "Unexpected end of file"; |
| return 0; |
| } |
| |
| // Cast archive member header |
| ArchiveMemberHeader* Hdr = (ArchiveMemberHeader*)At; |
| At += sizeof(ArchiveMemberHeader); |
| |
| // Extract the size and determine if the file is |
| // compressed or not (negative length). |
| int flags = 0; |
| int MemberSize = atoi(Hdr->size); |
| if (MemberSize < 0) { |
| flags |= ArchiveMember::CompressedFlag; |
| MemberSize = -MemberSize; |
| } |
| |
| // Check the size of the member for sanity |
| if (At + MemberSize > End) { |
| if (error) |
| *error = "invalid member length in archive file"; |
| return 0; |
| } |
| |
| // Check the member signature |
| if (!Hdr->checkSignature()) { |
| if (error) |
| *error = "invalid file member signature"; |
| return 0; |
| } |
| |
| // Convert and check the member name |
| // The empty name ( '/' and 15 blanks) is for a foreign (non-LLVM) symbol |
| // table. The special name "//" and 14 blanks is for a string table, used |
| // for long file names. This library doesn't generate either of those but |
| // it will accept them. If the name starts with #1/ and the remainder is |
| // digits, then those digits specify the length of the name that is |
| // stored immediately following the header. The special name |
| // __LLVM_SYM_TAB__ identifies the symbol table for LLVM bitcode. |
| // Anything else is a regular, short filename that is terminated with |
| // a '/' and blanks. |
| |
| std::string pathname; |
| switch (Hdr->name[0]) { |
| case '#': |
| if (Hdr->name[1] == '1' && Hdr->name[2] == '/') { |
| if (isdigit(Hdr->name[3])) { |
| unsigned len = atoi(&Hdr->name[3]); |
| const char *nulp = (const char *)memchr(At, '\0', len); |
| pathname.assign(At, nulp != 0 ? (uintptr_t)(nulp - At) : len); |
| At += len; |
| MemberSize -= len; |
| flags |= ArchiveMember::HasLongFilenameFlag; |
| } else { |
| if (error) |
| *error = "invalid long filename"; |
| return 0; |
| } |
| } else if (Hdr->name[1] == '_' && |
| (0 == memcmp(Hdr->name, ARFILE_LLVM_SYMTAB_NAME, 16))) { |
| // The member is using a long file name (>15 chars) format. |
| // This format is standard for 4.4BSD and Mac OSX operating |
| // systems. LLVM uses it similarly. In this format, the |
| // remainder of the name field (after #1/) specifies the |
| // length of the file name which occupy the first bytes of |
| // the member's data. The pathname already has the #1/ stripped. |
| pathname.assign(ARFILE_LLVM_SYMTAB_NAME); |
| flags |= ArchiveMember::LLVMSymbolTableFlag; |
| } |
| break; |
| case '/': |
| if (Hdr->name[1]== '/') { |
| if (0 == memcmp(Hdr->name, ARFILE_STRTAB_NAME, 16)) { |
| pathname.assign(ARFILE_STRTAB_NAME); |
| flags |= ArchiveMember::StringTableFlag; |
| } else { |
| if (error) |
| *error = "invalid string table name"; |
| return 0; |
| } |
| } else if (Hdr->name[1] == ' ') { |
| if (0 == memcmp(Hdr->name, ARFILE_SVR4_SYMTAB_NAME, 16)) { |
| pathname.assign(ARFILE_SVR4_SYMTAB_NAME); |
| flags |= ArchiveMember::SVR4SymbolTableFlag; |
| } else { |
| if (error) |
| *error = "invalid SVR4 symbol table name"; |
| return 0; |
| } |
| } else if (isdigit(Hdr->name[1])) { |
| unsigned index = atoi(&Hdr->name[1]); |
| if (index < strtab.length()) { |
| const char* namep = strtab.c_str() + index; |
| const char* endp = strtab.c_str() + strtab.length(); |
| const char* p = namep; |
| const char* last_p = p; |
| while (p < endp) { |
| if (*p == '\n' && *last_p == '/') { |
| pathname.assign(namep, last_p - namep); |
| flags |= ArchiveMember::HasLongFilenameFlag; |
| break; |
| } |
| last_p = p; |
| p++; |
| } |
| if (p >= endp) { |
| if (error) |
| *error = "missing name termiantor in string table"; |
| return 0; |
| } |
| } else { |
| if (error) |
| *error = "name index beyond string table"; |
| return 0; |
| } |
| } |
| break; |
| case '_': |
| if (Hdr->name[1] == '_' && |
| (0 == memcmp(Hdr->name, ARFILE_BSD4_SYMTAB_NAME, 16))) { |
| pathname.assign(ARFILE_BSD4_SYMTAB_NAME); |
| flags |= ArchiveMember::BSD4SymbolTableFlag; |
| break; |
| } |
| /* FALL THROUGH */ |
| |
| default: |
| char* slash = (char*) memchr(Hdr->name, '/', 16); |
| if (slash == 0) |
| slash = Hdr->name + 16; |
| pathname.assign(Hdr->name, slash - Hdr->name); |
| break; |
| } |
| |
| // Determine if this is a bitcode file |
| switch (sys::IdentifyFileType(At, 4)) { |
| case sys::Bitcode_FileType: |
| flags |= ArchiveMember::BitcodeFlag; |
| break; |
| default: |
| flags &= ~ArchiveMember::BitcodeFlag; |
| break; |
| } |
| |
| // Instantiate the ArchiveMember to be filled |
| ArchiveMember* member = new ArchiveMember(this); |
| |
| // Fill in fields of the ArchiveMember |
| member->parent = this; |
| member->path.set(pathname); |
| member->info.fileSize = MemberSize; |
| member->info.modTime.fromEpochTime(atoi(Hdr->date)); |
| unsigned int mode; |
| sscanf(Hdr->mode, "%o", &mode); |
| member->info.mode = mode; |
| member->info.user = atoi(Hdr->uid); |
| member->info.group = atoi(Hdr->gid); |
| member->flags = flags; |
| member->data = At; |
| |
| return member; |
| } |
| |
| bool |
| Archive::checkSignature(std::string* error) { |
| // Check the magic string at file's header |
| if (mapfile->getBufferSize() < 8 || memcmp(base, ARFILE_MAGIC, 8)) { |
| if (error) |
| *error = "invalid signature for an archive file"; |
| return false; |
| } |
| return true; |
| } |
| |
| // This function loads the entire archive and fully populates its ilist with |
| // the members of the archive file. This is typically used in preparation for |
| // editing the contents of the archive. |
| bool |
| Archive::loadArchive(std::string* error) { |
| |
| // Set up parsing |
| members.clear(); |
| symTab.clear(); |
| const char *At = base; |
| const char *End = mapfile->getBufferEnd(); |
| |
| if (!checkSignature(error)) |
| return false; |
| |
| At += 8; // Skip the magic string. |
| |
| bool seenSymbolTable = false; |
| bool foundFirstFile = false; |
| while (At < End) { |
| // parse the member header |
| const char* Save = At; |
| ArchiveMember* mbr = parseMemberHeader(At, End, error); |
| if (!mbr) |
| return false; |
| |
| // check if this is the foreign symbol table |
| if (mbr->isSVR4SymbolTable() || mbr->isBSD4SymbolTable()) { |
| // We just save this but don't do anything special |
| // with it. It doesn't count as the "first file". |
| if (foreignST) { |
| // What? Multiple foreign symbol tables? Just chuck it |
| // and retain the last one found. |
| delete foreignST; |
| } |
| foreignST = mbr; |
| At += mbr->getSize(); |
| if ((intptr_t(At) & 1) == 1) |
| At++; |
| } else if (mbr->isStringTable()) { |
| // Simply suck the entire string table into a string |
| // variable. This will be used to get the names of the |
| // members that use the "/ddd" format for their names |
| // (SVR4 style long names). |
| strtab.assign(At, mbr->getSize()); |
| At += mbr->getSize(); |
| if ((intptr_t(At) & 1) == 1) |
| At++; |
| delete mbr; |
| } else if (mbr->isLLVMSymbolTable()) { |
| // This is the LLVM symbol table for the archive. If we've seen it |
| // already, its an error. Otherwise, parse the symbol table and move on. |
| if (seenSymbolTable) { |
| if (error) |
| *error = "invalid archive: multiple symbol tables"; |
| return false; |
| } |
| if (!parseSymbolTable(mbr->getData(), mbr->getSize(), error)) |
| return false; |
| seenSymbolTable = true; |
| At += mbr->getSize(); |
| if ((intptr_t(At) & 1) == 1) |
| At++; |
| delete mbr; // We don't need this member in the list of members. |
| } else { |
| // This is just a regular file. If its the first one, save its offset. |
| // Otherwise just push it on the list and move on to the next file. |
| if (!foundFirstFile) { |
| firstFileOffset = Save - base; |
| foundFirstFile = true; |
| } |
| members.push_back(mbr); |
| At += mbr->getSize(); |
| if ((intptr_t(At) & 1) == 1) |
| At++; |
| } |
| } |
| return true; |
| } |
| |
| // Open and completely load the archive file. |
| Archive* |
| Archive::OpenAndLoad(const sys::Path& file, LLVMContext& C, |
| std::string* ErrorMessage) { |
| std::auto_ptr<Archive> result ( new Archive(file, C)); |
| if (result->mapToMemory(ErrorMessage)) |
| return 0; |
| if (!result->loadArchive(ErrorMessage)) |
| return 0; |
| return result.release(); |
| } |
| |
| // Get all the bitcode modules from the archive |
| bool |
| Archive::getAllModules(std::vector<Module*>& Modules, |
| std::string* ErrMessage) { |
| |
| for (iterator I=begin(), E=end(); I != E; ++I) { |
| if (I->isBitcode()) { |
| std::string FullMemberName = archPath.str() + |
| "(" + I->getPath().str() + ")"; |
| MemoryBuffer *Buffer = |
| MemoryBuffer::getMemBufferCopy(StringRef(I->getData(), I->getSize()), |
| FullMemberName.c_str()); |
| |
| Module *M = ParseBitcodeFile(Buffer, Context, ErrMessage); |
| delete Buffer; |
| if (!M) |
| return true; |
| |
| Modules.push_back(M); |
| } |
| } |
| return false; |
| } |
| |
| // Load just the symbol table from the archive file |
| bool |
| Archive::loadSymbolTable(std::string* ErrorMsg) { |
| |
| // Set up parsing |
| members.clear(); |
| symTab.clear(); |
| const char *At = base; |
| const char *End = mapfile->getBufferEnd(); |
| |
| // Make sure we're dealing with an archive |
| if (!checkSignature(ErrorMsg)) |
| return false; |
| |
| At += 8; // Skip signature |
| |
| // Parse the first file member header |
| const char* FirstFile = At; |
| ArchiveMember* mbr = parseMemberHeader(At, End, ErrorMsg); |
| if (!mbr) |
| return false; |
| |
| if (mbr->isSVR4SymbolTable() || mbr->isBSD4SymbolTable()) { |
| // Skip the foreign symbol table, we don't do anything with it |
| At += mbr->getSize(); |
| if ((intptr_t(At) & 1) == 1) |
| At++; |
| delete mbr; |
| |
| // Read the next one |
| FirstFile = At; |
| mbr = parseMemberHeader(At, End, ErrorMsg); |
| if (!mbr) { |
| delete mbr; |
| return false; |
| } |
| } |
| |
| if (mbr->isStringTable()) { |
| // Process the string table entry |
| strtab.assign((const char*)mbr->getData(), mbr->getSize()); |
| At += mbr->getSize(); |
| if ((intptr_t(At) & 1) == 1) |
| At++; |
| delete mbr; |
| // Get the next one |
| FirstFile = At; |
| mbr = parseMemberHeader(At, End, ErrorMsg); |
| if (!mbr) { |
| delete mbr; |
| return false; |
| } |
| } |
| |
| // See if its the symbol table |
| if (mbr->isLLVMSymbolTable()) { |
| if (!parseSymbolTable(mbr->getData(), mbr->getSize(), ErrorMsg)) { |
| delete mbr; |
| return false; |
| } |
| |
| At += mbr->getSize(); |
| if ((intptr_t(At) & 1) == 1) |
| At++; |
| delete mbr; |
| // Can't be any more symtab headers so just advance |
| FirstFile = At; |
| } else { |
| // There's no symbol table in the file. We have to rebuild it from scratch |
| // because the intent of this method is to get the symbol table loaded so |
| // it can be searched efficiently. |
| // Add the member to the members list |
| members.push_back(mbr); |
| } |
| |
| firstFileOffset = FirstFile - base; |
| return true; |
| } |
| |
| // Open the archive and load just the symbol tables |
| Archive* Archive::OpenAndLoadSymbols(const sys::Path& file, |
| LLVMContext& C, |
| std::string* ErrorMessage) { |
| std::auto_ptr<Archive> result ( new Archive(file, C) ); |
| if (result->mapToMemory(ErrorMessage)) |
| return 0; |
| if (!result->loadSymbolTable(ErrorMessage)) |
| return 0; |
| return result.release(); |
| } |
| |
| // Look up one symbol in the symbol table and return the module that defines |
| // that symbol. |
| Module* |
| Archive::findModuleDefiningSymbol(const std::string& symbol, |
| std::string* ErrMsg) { |
| SymTabType::iterator SI = symTab.find(symbol); |
| if (SI == symTab.end()) |
| return 0; |
| |
| // The symbol table was previously constructed assuming that the members were |
| // written without the symbol table header. Because VBR encoding is used, the |
| // values could not be adjusted to account for the offset of the symbol table |
| // because that could affect the size of the symbol table due to VBR encoding. |
| // We now have to account for this by adjusting the offset by the size of the |
| // symbol table and its header. |
| unsigned fileOffset = |
| SI->second + // offset in symbol-table-less file |
| firstFileOffset; // add offset to first "real" file in archive |
| |
| // See if the module is already loaded |
| ModuleMap::iterator MI = modules.find(fileOffset); |
| if (MI != modules.end()) |
| return MI->second.first; |
| |
| // Module hasn't been loaded yet, we need to load it |
| const char* modptr = base + fileOffset; |
| ArchiveMember* mbr = parseMemberHeader(modptr, mapfile->getBufferEnd(), |
| ErrMsg); |
| if (!mbr) |
| return 0; |
| |
| // Now, load the bitcode module to get the Module. |
| std::string FullMemberName = archPath.str() + "(" + |
| mbr->getPath().str() + ")"; |
| MemoryBuffer *Buffer = |
| MemoryBuffer::getMemBufferCopy(StringRef(mbr->getData(), mbr->getSize()), |
| FullMemberName.c_str()); |
| |
| Module *m = getLazyBitcodeModule(Buffer, Context, ErrMsg); |
| if (!m) |
| return 0; |
| |
| modules.insert(std::make_pair(fileOffset, std::make_pair(m, mbr))); |
| |
| return m; |
| } |
| |
| // Look up multiple symbols in the symbol table and return a set of |
| // Modules that define those symbols. |
| bool |
| Archive::findModulesDefiningSymbols(std::set<std::string>& symbols, |
| SmallVectorImpl<Module*>& result, |
| std::string* error) { |
| if (!mapfile || !base) { |
| if (error) |
| *error = "Empty archive invalid for finding modules defining symbols"; |
| return false; |
| } |
| |
| if (symTab.empty()) { |
| // We don't have a symbol table, so we must build it now but lets also |
| // make sure that we populate the modules table as we do this to ensure |
| // that we don't load them twice when findModuleDefiningSymbol is called |
| // below. |
| |
| // Get a pointer to the first file |
| const char* At = base + firstFileOffset; |
| const char* End = mapfile->getBufferEnd(); |
| |
| while ( At < End) { |
| // Compute the offset to be put in the symbol table |
| unsigned offset = At - base - firstFileOffset; |
| |
| // Parse the file's header |
| ArchiveMember* mbr = parseMemberHeader(At, End, error); |
| if (!mbr) |
| return false; |
| |
| // If it contains symbols |
| if (mbr->isBitcode()) { |
| // Get the symbols |
| std::vector<std::string> symbols; |
| std::string FullMemberName = archPath.str() + "(" + |
| mbr->getPath().str() + ")"; |
| Module* M = |
| GetBitcodeSymbols(At, mbr->getSize(), FullMemberName, Context, |
| symbols, error); |
| |
| if (M) { |
| // Insert the module's symbols into the symbol table |
| for (std::vector<std::string>::iterator I = symbols.begin(), |
| E=symbols.end(); I != E; ++I ) { |
| symTab.insert(std::make_pair(*I, offset)); |
| } |
| // Insert the Module and the ArchiveMember into the table of |
| // modules. |
| modules.insert(std::make_pair(offset, std::make_pair(M, mbr))); |
| } else { |
| if (error) |
| *error = "Can't parse bitcode member: " + |
| mbr->getPath().str() + ": " + *error; |
| delete mbr; |
| return false; |
| } |
| } |
| |
| // Go to the next file location |
| At += mbr->getSize(); |
| if ((intptr_t(At) & 1) == 1) |
| At++; |
| } |
| } |
| |
| // At this point we have a valid symbol table (one way or another) so we |
| // just use it to quickly find the symbols requested. |
| |
| SmallPtrSet<Module*, 16> Added; |
| for (std::set<std::string>::iterator I=symbols.begin(), |
| Next = I, |
| E=symbols.end(); I != E; I = Next) { |
| // Increment Next before we invalidate it. |
| ++Next; |
| |
| // See if this symbol exists |
| Module* m = findModuleDefiningSymbol(*I,error); |
| if (!m) |
| continue; |
| bool NewMember = Added.insert(m); |
| if (!NewMember) |
| continue; |
| |
| // The symbol exists, insert the Module into our result. |
| result.push_back(m); |
| |
| // Remove the symbol now that its been resolved. |
| symbols.erase(I); |
| } |
| return true; |
| } |
| |
| bool Archive::isBitcodeArchive() { |
| // Make sure the symTab has been loaded. In most cases this should have been |
| // done when the archive was constructed, but still, this is just in case. |
| if (symTab.empty()) |
| if (!loadSymbolTable(0)) |
| return false; |
| |
| // Now that we know it's been loaded, return true |
| // if it has a size |
| if (symTab.size()) return true; |
| |
| // We still can't be sure it isn't a bitcode archive |
| if (!loadArchive(0)) |
| return false; |
| |
| std::vector<Module *> Modules; |
| std::string ErrorMessage; |
| |
| // Scan the archive, trying to load a bitcode member. We only load one to |
| // see if this works. |
| for (iterator I = begin(), E = end(); I != E; ++I) { |
| if (!I->isBitcode()) |
| continue; |
| |
| std::string FullMemberName = |
| archPath.str() + "(" + I->getPath().str() + ")"; |
| |
| MemoryBuffer *Buffer = |
| MemoryBuffer::getMemBufferCopy(StringRef(I->getData(), I->getSize()), |
| FullMemberName.c_str()); |
| Module *M = ParseBitcodeFile(Buffer, Context); |
| delete Buffer; |
| if (!M) |
| return false; // Couldn't parse bitcode, not a bitcode archive. |
| delete M; |
| return true; |
| } |
| |
| return false; |
| } |
