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- //===-- 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/Bitcode/ReaderWriter.h"
- #include "llvm/Support/MemoryBuffer.h"
- #include "llvm/Module.h"
- #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]);
- pathname.assign(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, std::string* ErrorMessage)
- {
- std::auto_ptr<Archive> result ( new Archive(file));
- 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.toString() +
- "(" + I->getPath().toString() + ")";
- MemoryBuffer *Buffer =
- MemoryBuffer::getNewMemBuffer(I->getSize(), FullMemberName.c_str());
- memcpy((char*)Buffer->getBufferStart(), I->getData(), I->getSize());
-
- Module *M = ParseBitcodeFile(Buffer, 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, std::string* ErrorMessage) {
- std::auto_ptr<Archive> result ( new Archive(file) );
- 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 a ModuleProvider for the
- // module that defines that symbol.
- ModuleProvider*
- 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 ModuleProvider
- std::string FullMemberName = archPath.toString() + "(" +
- mbr->getPath().toString() + ")";
- MemoryBuffer *Buffer =MemoryBuffer::getNewMemBuffer(mbr->getSize(),
- FullMemberName.c_str());
- memcpy((char*)Buffer->getBufferStart(), mbr->getData(), mbr->getSize());
-
- ModuleProvider *mp = getBitcodeModuleProvider(Buffer, ErrMsg);
- if (!mp)
- return 0;
- modules.insert(std::make_pair(fileOffset, std::make_pair(mp, mbr)));
- return mp;
- }
- // Look up multiple symbols in the symbol table and return a set of
- // ModuleProviders that define those symbols.
- bool
- Archive::findModulesDefiningSymbols(std::set<std::string>& symbols,
- std::set<ModuleProvider*>& 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.toString() + "(" +
- mbr->getPath().toString() + ")";
- ModuleProvider* MP =
- GetBitcodeSymbols((const unsigned char*)At, mbr->getSize(),
- FullMemberName, symbols, error);
- if (MP) {
- // 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 ModuleProvider and the ArchiveMember into the table of
- // modules.
- modules.insert(std::make_pair(offset, std::make_pair(MP, mbr)));
- } else {
- if (error)
- *error = "Can't parse bitcode member: " +
- mbr->getPath().toString() + ": " + *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.
- for (std::set<std::string>::iterator I=symbols.begin(),
- E=symbols.end(); I != E;) {
- // See if this symbol exists
- ModuleProvider* mp = findModuleDefiningSymbol(*I,error);
- if (mp) {
- // The symbol exists, insert the ModuleProvider into our result,
- // duplicates wil be ignored
- result.insert(mp);
- // Remove the symbol now that its been resolved, being careful to
- // post-increment the iterator.
- symbols.erase(I++);
- } else {
- ++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.toString() + "(" + I->getPath().toString() + ")";
- MemoryBuffer *Buffer =
- MemoryBuffer::getNewMemBuffer(I->getSize(), FullMemberName.c_str());
- memcpy((char*)Buffer->getBufferStart(), I->getData(), I->getSize());
- Module *M = ParseBitcodeFile(Buffer);
- delete Buffer;
- if (!M)
- return false; // Couldn't parse bitcode, not a bitcode archive.
- delete M;
- return true;
- }
-
- return false;
- }
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