[llvm-commits] CVS: llvm/lib/Bytecode/Archive/ArchiveWriter.cpp
Reid Spencer
reid at x10sys.com
Sun Nov 14 13:57:36 PST 2004
Changes in directory llvm/lib/Bytecode/Archive:
ArchiveWriter.cpp updated: 1.1 -> 1.2
---
Log message:
First working version
---
Diffs of the changes: (+362 -220)
Index: llvm/lib/Bytecode/Archive/ArchiveWriter.cpp
diff -u llvm/lib/Bytecode/Archive/ArchiveWriter.cpp:1.1 llvm/lib/Bytecode/Archive/ArchiveWriter.cpp:1.2
--- llvm/lib/Bytecode/Archive/ArchiveWriter.cpp:1.1 Sat Nov 6 02:51:45 2004
+++ llvm/lib/Bytecode/Archive/ArchiveWriter.cpp Sun Nov 14 15:56:59 2004
@@ -1,284 +1,426 @@
-//===-- ArchiveWriter.cpp - LLVM archive writing --------------------------===//
+//===-- ArchiveWriter.cpp - Write LLVM archive files ----------------------===//
//
// The LLVM Compiler Infrastructure
//
-// This file was developed by Reid Spencerand is distributed under the
+// This file was developed by Reid Spencer and is distributed under the
// University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
-// Builds up standard unix archive files (.a) containing LLVM bytecode.
+// Builds up an LLVM archive file (.a) containing LLVM bytecode.
//
//===----------------------------------------------------------------------===//
#include "ArchiveInternals.h"
-#include "llvm/Module.h"
#include "llvm/Bytecode/Reader.h"
#include "llvm/Support/FileUtilities.h"
-#include "llvm/ADT/StringExtras.h"
-#include "llvm/System/MappedFile.h"
+#include "llvm/Support/Compressor.h"
+#include "llvm/System/Signals.h"
#include <fstream>
#include <iostream>
+#include <iomanip>
using namespace llvm;
+namespace {
+
+// Write an integer using variable bit rate encoding. This saves a few bytes
+// per entry in the symbol table.
+inline void writeInteger(unsigned num, std::ofstream& ARFile) {
+ while (1) {
+ if (num < 0x80) { // done?
+ ARFile << (unsigned char)num;
+ return;
+ }
+
+ // Nope, we are bigger than a character, output the next 7 bits and set the
+ // high bit to say that there is more coming...
+ ARFile << (unsigned char)(0x80 | ((unsigned char)num & 0x7F));
+ num >>= 7; // Shift out 7 bits now...
+ }
+}
+
+// Compute how many bytes are taken by a given VBR encoded value. This is needed
+// to pre-compute the size of the symbol table.
+inline unsigned numVbrBytes(unsigned num) {
+ if (num < 128) // 2^7
+ return 1;
+ if (num < 16384) // 2^14
+ return 2;
+ if (num < 2097152) // 2^21
+ return 3;
+ if (num < 268435456) // 2^28
+ return 4;
+ return 5; // anything >= 2^28 takes 5 bytes
+}
+
+}
+
+// Create an empty archive.
Archive*
-Archive::CreateEmpty(const sys::Path& Filename) {
- Archive* result = new Archive;
- Archive::ArchiveInternals* impl = result->impl = new Archive::ArchiveInternals;
- impl->fname = Filename;
+Archive::CreateEmpty(const sys::Path& FilePath ) {
+ Archive* result = new Archive(FilePath,false);
return result;
}
-Archive*
-Archive::CreateFromFiles(
- const sys::Path& Filename,
- const PathList& Files,
- const std::string& StripName
-) {
- Archive* result = new Archive;
- Archive::ArchiveInternals* impl = result->impl = new Archive::ArchiveInternals;
- impl->fname = Filename;
+bool
+Archive::fillHeader(const ArchiveMember &mbr, ArchiveMemberHeader& hdr,
+ int sz, bool TruncateNames) const {
+
+ // Set the permissions mode, uid and gid
+ hdr.init();
+ char buffer[32];
+ sprintf(buffer, "%-8o", mbr.getMode());
+ memcpy(hdr.mode,buffer,8);
+ sprintf(buffer, "%-6u", mbr.getUser());
+ memcpy(hdr.uid,buffer,6);
+ sprintf(buffer, "%-6u", mbr.getGroup());
+ memcpy(hdr.gid,buffer,6);
+
+ // Set the size field
+ if (sz < 0 ) {
+ buffer[0] = '-';
+ sprintf(&buffer[1],"%-9u",(unsigned)-sz);
+ } else {
+ sprintf(buffer, "%-10u", (unsigned)sz);
+ }
+ memcpy(hdr.size,buffer,10);
- try {
- size_t strip_len = StripName.length();
- for (PathList::const_iterator P = Files.begin(), E = Files.end(); P != E ;++P)
- {
- if (P->readable()) {
- std::string name(P->get());
- if (strip_len > 0 && StripName == name.substr(0,strip_len)) {
- name.erase(0,strip_len);
- }
- if (P->isBytecodeFile()) {
- std::vector<std::string> syms;
- if (!GetBytecodeSymbols(*P, syms))
- throw std::string("Can not get symbols from: ") + P->get();
- impl->addFileMember(*P, name, &syms);
- } else {
- impl->addFileMember(*P, name);
- }
- }
- else
- throw std::string("Can not read: ") + P->get();
+ // Set the last modification date
+ uint64_t secondsSinceEpoch = mbr.getModTime().toEpochTime();
+ sprintf(buffer,"%-12u", unsigned(secondsSinceEpoch));
+ memcpy(hdr.date,buffer,12);
+
+ // Set the name field in one of its various flavors.
+ bool writeLongName = false;
+ const std::string& mbrPath = mbr.getPath().get();
+ if (mbr.isStringTable()) {
+ memcpy(hdr.name,ARFILE_STRTAB_NAME,16);
+ } else if (mbr.isForeignSymbolTable()) {
+ memcpy(hdr.name,ARFILE_SYMTAB_NAME,16);
+ } else if (mbr.isLLVMSymbolTable()) {
+ memcpy(hdr.name,ARFILE_LLVM_SYMTAB_NAME,16);
+ } else if (TruncateNames) {
+ const char* nm = mbrPath.c_str();
+ unsigned len = mbrPath.length();
+ size_t slashpos = mbrPath.rfind('/');
+ if (slashpos != std::string::npos) {
+ nm += slashpos + 1;
+ len -= slashpos +1;
}
+ if (len >15)
+ len = 15;
+ mbrPath.copy(hdr.name,len);
+ hdr.name[len] = '/';
+ } else if (mbrPath.length() < 16 && mbrPath.find('/') == std::string::npos) {
+ mbrPath.copy(hdr.name,mbrPath.length());
+ hdr.name[mbrPath.length()] = '/';
+ } else {
+ std::string nm = "#1/";
+ nm += utostr(mbrPath.length());
+ nm.copy(hdr.name,nm.length());
+ writeLongName = true;
+ }
+ return writeLongName;
+}
- // Now that we've collected everything, write the archive
- impl->writeArchive();
+void
+Archive::addFileBefore(const sys::Path& filePath, iterator where) {
+ assert(filePath.exists() && "Can't add a non-existent file");
- } catch(...) {
- delete impl;
- result->impl = 0;
- delete result;
- throw;
- }
+ ArchiveMember* mbr = new ArchiveMember(this);
- return result;
+ mbr->data = 0;
+ mbr->path = filePath;
+ mbr->path.getStatusInfo(mbr->info);
+
+ unsigned flags = 0;
+ bool hasSlash = filePath.get().find('/') != std::string::npos;
+ if (hasSlash)
+ flags |= ArchiveMember::HasPathFlag;
+ if (hasSlash || filePath.get().length() > 15)
+ flags |= ArchiveMember::HasLongFilenameFlag;
+ std::string magic;
+ mbr->path.getMagicNumber(magic,4);
+ switch (sys::IdentifyFileType(magic.c_str(),4)) {
+ case sys::BytecodeFileType:
+ flags |= ArchiveMember::BytecodeFlag;
+ break;
+ case sys::CompressedBytecodeFileType:
+ flags |= ArchiveMember::CompressedBytecodeFlag;
+ break;
+ default:
+ break;
+ }
+ mbr->flags = flags;
+ members.insert(where,mbr);
}
void
-Archive::ArchiveInternals::addFileMember(
- const sys::Path& filePath,
- const std::string& memberName,
- const StrTab* symbols
-) {
- MemberInfo info;
- info.path = filePath;
- info.name = memberName;
- filePath.getStatusInfo(info.status);
- if (symbols)
- info.symbols = *symbols;
- info.offset = 0;
- members.push_back(info);
+Archive::moveMemberBefore(iterator target, iterator where) {
+ assert(target != end() && "Target iterator for moveMemberBefore is invalid");
+ ArchiveMember* mbr = members.remove(target);
+ members.insert(where, mbr);
}
void
-Archive::ArchiveInternals::writeInteger(int num, std::ofstream& ARFile) {
- char buff[4];
- buff[0] = (num >> 24) & 255;
- buff[1] = (num >> 16) & 255;
- buff[2] = (num >> 8) & 255;
- buff[3] = num & 255;
- ARFile.write(buff, sizeof(buff));
+Archive::remove(iterator target) {
+ assert(target != end() && "Target iterator for remove is invalid");
+ ArchiveMember* mbr = members.remove(target);
+ delete mbr;
}
-
void
-Archive::ArchiveInternals::writeSymbolTable( std::ofstream& ARFile ) {
-
- // Compute the number of symbols in the symbol table and the
- // total byte size of the string pool. While we're traversing,
- // build the string pool for supporting long file names. Also,
- // build the table of file offsets for the symbol table and
- // the
- typedef std::map<std::string,unsigned> SymbolMap;
- StrTab stringPool;
- SymbolMap symbolTable;
- std::vector<unsigned> fileOffsets;
- std::string symTabStrings;
- unsigned fileOffset = 0;
- unsigned spOffset = 0;
- unsigned numSymbols = 0;
- unsigned numSymBytes = 0;
- for (unsigned i = 0; i < members.size(); i++ ) {
- MemberInfo& mi = members[i];
- StrTab& syms = mi.symbols;
- size_t numSym = syms.size();
- numSymbols += numSym;
- for (unsigned j = 0; j < numSym; j++ ) {
- numSymBytes += syms[j].size() + 1;
- symbolTable[syms[i]] = i;
- }
- if (mi.name.length() > 15 || std::string::npos != mi.name.find('/')) {
- stringPool.push_back(mi.name + "/\n");
- mi.name = std::string("/") + utostr(spOffset);
- spOffset += mi.name.length() + 2;
- } else if (mi.name[mi.name.length()-1] != '/') {
- mi.name += "/";
+Archive::writeMember(
+ const ArchiveMember& member,
+ std::ofstream& ARFile,
+ bool CreateSymbolTable,
+ bool TruncateNames,
+ bool ShouldCompress
+) {
+
+ unsigned filepos = ARFile.tellp();
+ filepos -= 8;
+
+ // Get the data and its size either from the
+ // member's in-memory data or directly from the file.
+ size_t fSize = member.getSize();
+ const char* data = (const char*)member.getData();
+ sys::MappedFile* mFile = 0;
+ if (!data) {
+ mFile = new sys::MappedFile(member.getPath());
+ data = (const char*) mFile->map();
+ fSize = mFile->size();
+ }
+
+ // Now that we have the data in memory, update the
+ // symbol table if its a bytecode file.
+ if (CreateSymbolTable &&
+ (member.isBytecode() || member.isCompressedBytecode())) {
+ std::vector<std::string> symbols;
+ GetBytecodeSymbols((const unsigned char*)data,fSize,member.getPath().get(),
+ symbols);
+ for (std::vector<std::string>::iterator SI = symbols.begin(),
+ SE = symbols.end(); SI != SE; ++SI) {
+
+ std::pair<SymTabType::iterator,bool> Res =
+ symTab.insert(std::make_pair(*SI,filepos));
+
+ if (Res.second) {
+ symTabSize += SI->length() +
+ numVbrBytes(SI->length()) +
+ numVbrBytes(filepos);
+ }
}
- fileOffsets.push_back(fileOffset);
- fileOffset += sizeof(ArchiveMemberHeader) + mi.status.fileSize;
}
+ // Determine if we actually should compress this member
+ bool willCompress =
+ (ShouldCompress &&
+ !member.isForeignSymbolTable() &&
+ !member.isLLVMSymbolTable() &&
+ !member.isCompressed() &&
+ !member.isCompressedBytecode());
+
+ // Perform the compression. Note that if the file is uncompressed bytecode
+ // then we turn the file into compressed bytecode rather than treating it as
+ // compressed data. This is necessary since it allows us to determine that the
+ // file contains bytecode instead of looking like a regular compressed data
+ // member. A compressed bytecode file has its content compressed but has a
+ // magic number of "llvc". This acounts for the +/-4 arithmetic in the code
+ // below.
+ int hdrSize;
+ if (willCompress) {
+ char* output = 0;
+ if (member.isBytecode()) {
+ data +=4;
+ fSize -= 4;
+ }
+ fSize = Compressor::compressToNewBuffer(
+ data,fSize,output,Compressor::COMP_TYPE_ZLIB);
+ data = output;
+ if (member.isBytecode())
+ hdrSize = -fSize-4;
+ else
+ hdrSize = -fSize;
+ } else {
+ hdrSize = fSize;
+ }
- // Compute the size of the symbol table file member
- unsigned symTabSize = 0;
- if (numSymbols != 0)
- symTabSize =
- sizeof(ArchiveMemberHeader) + // Size of the file header
- 4 + // Size of "number of entries"
- (4 * numSymbols) + // Size of member file indices
- numSymBytes; // Size of the string table
-
- // Compute the size of the string pool
- unsigned strPoolSize = 0;
- if (spOffset != 0 )
- strPoolSize =
- sizeof(ArchiveMemberHeader) + // Size of the file header
- spOffset; // Number of bytes in the string pool
-
- // Compute the byte index offset created by symbol table and string pool
- unsigned firstFileOffset = symTabSize + strPoolSize;
-
- // Create header for symbol table. This must be first if there is
- // a symbol table and must have a special name.
- if ( symTabSize > 0 ) {
- ArchiveMemberHeader Hdr;
- Hdr.init();
-
- // Name of symbol table is '/ ' but "" is passed in
- // because the setName method always terminates with a /
- Hdr.setName(ARFILE_SYMTAB_NAME);
- Hdr.setDate();
- Hdr.setSize(symTabSize - sizeof(ArchiveMemberHeader));
- Hdr.setMode(0);
- Hdr.setUid(0);
- Hdr.setGid(0);
-
- // Write header to archive file
- ARFile.write((char*)&Hdr, sizeof(Hdr));
-
- // Write the number of entries in the symbol table
- this->writeInteger(numSymbols, ARFile);
+ // Compute the fields of the header
+ ArchiveMemberHeader Hdr;
+ bool writeLongName = fillHeader(member,Hdr,hdrSize,TruncateNames);
- // Write the file offset indices for each symbol and build the
- // symbol table string pool
- std::string symTabStrPool;
- symTabStrPool.reserve(256 * 1024); // Reserve 256KBytes for symbols
- for (SymbolMap::iterator I = symbolTable.begin(), E = symbolTable.end();
- I != E; ++I ) {
- this->writeInteger(firstFileOffset + fileOffsets[I->second], ARFile);
- symTabStrPool += I->first;
- symTabStrPool += "\0";
- }
+ // Write header to archive file
+ ARFile.write((char*)&Hdr, sizeof(Hdr));
- // Write the symbol table's string pool
- ARFile.write(symTabStrPool.data(), symTabStrPool.size());
+ // Write the long filename if its long
+ if (writeLongName) {
+ ARFile << member.getPath().c_str();
+ ARFile << '\n';
}
- //============== DONE WITH SYMBOL TABLE
+ // Make sure we write the compressed bytecode magic number if we should.
+ if (willCompress && member.isBytecode())
+ ARFile.write("llvc",4);
+
+ // Write the (possibly compressed) member's content to the file.
+ ARFile.write(data,fSize);
+
+ // Make sure the member is an even length
+ if (ARFile.tellp() % 2 != 0)
+ ARFile << ARFILE_PAD;
+
+ // Free the compressed data, if necessary
+ if (willCompress) {
+ free((void*)data);
+ }
- if (strPoolSize > 0) {
- // Initialize the header for the string pool
- ArchiveMemberHeader Hdr;
- Hdr.init();
- Hdr.setName(ARFILE_STRTAB_NAME);
- Hdr.setDate();
- Hdr.setSize(spOffset);
- Hdr.setMode(0);
- Hdr.setUid(0);
- Hdr.setGid(0);
-
- // Write the string pool header
- ARFile.write((char*)&Hdr, sizeof(Hdr));
-
- // Write the string pool
- for (unsigned i = 0; i < stringPool.size(); i++) {
- ARFile.write(stringPool[i].data(), stringPool[i].size());
- }
+ // Close the mapped file if it was opened
+ if (mFile != 0) {
+ mFile->unmap();
+ delete mFile;
}
}
void
-Archive::ArchiveInternals::writeMember(
- const MemberInfo& member,
- std::ofstream& ARFile
-) {
+Archive::writeSymbolTable(std::ofstream& ARFile,bool PrintSymTab ) {
- // Map the file into memory. We do this early for two reasons. First,
- // if there's any kind of error, we want to know about it. Second, we
- // want to ensure we're using the most recent size for this file.
- sys::MappedFile mFile(member.path);
- mFile.map();
-
- // Header for the archive member
+ // Construct the symbol table's header
ArchiveMemberHeader Hdr;
Hdr.init();
+ memcpy(Hdr.name,ARFILE_LLVM_SYMTAB_NAME,16);
+ uint64_t secondsSinceEpoch = sys::TimeValue::now().toEpochTime();
+ char buffer[32];
+ sprintf(buffer,"%-12u", unsigned(secondsSinceEpoch));
+ memcpy(Hdr.date,buffer,12);
+ sprintf(buffer,"%-10u",symTabSize);
+ memcpy(Hdr.size,buffer,10);
- // Set the name. If its longer than 15 chars, it will have already
- // been reduced by the writeSymbolTable.
- Hdr.setName(member.name);
-
- // Set the other header members
- Hdr.setSize( mFile.size() );
- Hdr.setMode( member.status.mode);
- Hdr.setUid ( member.status.user);
- Hdr.setGid ( member.status.group);
- Hdr.setDate( member.status.modTime.ToPosixTime() );
-
- // Write header to archive file
+ // Write the header
ARFile.write((char*)&Hdr, sizeof(Hdr));
-
- //write to archive file
- ARFile.write(mFile.charBase(),mFile.size());
- mFile.unmap();
+ // Save the starting position of the symbol tables data content.
+ unsigned startpos = ARFile.tellp();
+
+ // Print the symbol table header if we're supposed to
+ if (PrintSymTab)
+ std::cout << "Symbol Table:\n";
+
+ // Write out the symbols sequentially
+ for ( Archive::SymTabType::iterator I = symTab.begin(), E = symTab.end();
+ I != E; ++I)
+ {
+ // Write out the file index
+ writeInteger(I->second, ARFile);
+ // Write out the length of the symbol
+ writeInteger(I->first.length(), ARFile);
+ // Write out the symbol
+ ARFile.write(I->first.data(), I->first.length());
+
+ // Print this entry to std::cout if we should
+ if (PrintSymTab) {
+ unsigned filepos = I->second + symTabSize + sizeof(ArchiveMemberHeader) +
+ (symTabSize % 2 != 0) + 8;
+ std::cout << " " << std::setw(9) << filepos << "\t" << I->first << "\n";
+ }
+ }
+
+ // Now that we're done with the symbol table, get the ending file position
+ unsigned endpos = ARFile.tellp();
+
+ // Make sure that the amount we wrote is what we pre-computed. This is
+ // critical for file integrity purposes.
+ assert(endpos - startpos == symTabSize && "Invalid symTabSize computation");
+
+ // Make sure the symbol table is even sized
+ if (symTabSize % 2 != 0 )
+ ARFile << ARFILE_PAD;
}
void
-Archive::ArchiveInternals::writeArchive() {
+Archive::writeToDisk(bool CreateSymbolTable, bool TruncateNames,
+ bool Compress, bool PrintSymTab) {
- // Create archive file for output.
- std::ofstream ArchiveFile(fname.get().c_str());
+ // Make sure they haven't opened up the file, not loaded it,
+ // but are now trying to write it which would wipe out the file.
+ assert(!(members.empty() && mapfile->size() > 8));
+
+ // Create a temporary file to store the archive in
+ sys::Path TmpArchive = archPath;
+ TmpArchive.createTemporaryFile();
+
+ // Make sure the temporary gets removed if we crash
+ sys::RemoveFileOnSignal(TmpArchive);
+
+ // Ensure we can remove the temporary even in the face of an exception
+ try {
+ // Create archive file for output.
+ std::ofstream ArchiveFile(TmpArchive.c_str());
- // Check for errors opening or creating archive file.
- if ( !ArchiveFile.is_open() || ArchiveFile.bad() ) {
- throw std::string("Error opening archive file: ") + fname.get();
- }
+ // Check for errors opening or creating archive file.
+ if ( !ArchiveFile.is_open() || ArchiveFile.bad() ) {
+ throw std::string("Error opening archive file: ") + archPath.get();
+ }
- // Write magic string to archive.
- ArchiveFile << ARFILE_MAGIC;
+ // If we're creating a symbol table, reset it now
+ if (CreateSymbolTable) {
+ symTabSize = 0;
+ symTab.clear();
+ }
- // Write the symbol table and string pool
- writeSymbolTable(ArchiveFile);
+ // Write magic string to archive.
+ ArchiveFile << ARFILE_MAGIC;
- //Loop over all member files, and add to the archive.
- for ( unsigned i = 0; i < members.size(); ++i) {
- if(ArchiveFile.tellp() % 2 != 0)
- ArchiveFile << ARFILE_PAD;
- writeMember(members[i],ArchiveFile);
- }
+ // Loop over all member files, and write them out. Note that this also
+ // builds the symbol table, symTab.
+ for ( MembersList::iterator I = begin(), E = end(); I != E; ++I) {
+ writeMember(*I,ArchiveFile,CreateSymbolTable,TruncateNames,Compress);
+ }
- //Close archive file.
- ArchiveFile.close();
-}
+ // Close archive file.
+ ArchiveFile.close();
-// vim: sw=2 ai
+ // Write the symbol table
+ if (CreateSymbolTable) {
+ // At this point we have written a file that is a legal archive but it
+ // doesn't have a symbol table in it. To aid in faster reading and to
+ // ensure compatibility with other archivers we need to put the symbol
+ // table first in the file. Unfortunately, this means mapping the file
+ // we just wrote back in and copying it to the destination file.
+ sys::MappedFile arch(TmpArchive);
+ const char* base = (const char*) arch.map();
+
+ // Open the final file to write and check it.
+ std::ofstream FinalFile(archPath.c_str());
+ if ( !FinalFile.is_open() || FinalFile.bad() ) {
+ throw std::string("Error opening archive file: ") + archPath.get();
+ }
+
+ // Write the file magic number
+ FinalFile << ARFILE_MAGIC;
+
+ // Put out the symbol table
+ writeSymbolTable(FinalFile,PrintSymTab);
+
+ // Copy the temporary file contents being sure to skip the file's magic
+ // number.
+ FinalFile.write(base + sizeof(ARFILE_MAGIC)-1,
+ arch.size()-sizeof(ARFILE_MAGIC)+1);
+
+ // Close up shop
+ FinalFile.close();
+ arch.unmap();
+ TmpArchive.destroyFile();
+
+ } else {
+ // We don't have to insert the symbol table, so just renaming the temp
+ // file to the correct name will suffice.
+ TmpArchive.renameFile(archPath);
+ }
+ } catch (...) {
+ // Make sure we clean up.
+ if (TmpArchive.exists())
+ TmpArchive.destroyFile();
+ throw;
+ }
+}
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