1 files changed, 429 insertions, 0 deletions
diff --git a/tools/llvm-ar/ArchiveWriter.cpp b/tools/llvm-ar/ArchiveWriter.cpp
new file mode 100644
index 0000000000..24f5dbc0dc
--- /dev/null
+++ b/tools/llvm-ar/ArchiveWriter.cpp
@@ -0,0 +1,429 @@
+//===-- ArchiveWriter.cpp - Write LLVM archive files ----------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Builds up an LLVM archive file (.a) containing LLVM bitcode.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Archive.h"
+#include "ArchiveInternals.h"
+#include "llvm/ADT/OwningPtr.h"
+#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/Process.h"
+#include "llvm/Support/Signals.h"
+#include "llvm/Support/system_error.h"
+#include <fstream>
+#include <iomanip>
+#include <ostream>
+using namespace llvm;
+
+// Write an integer using variable bit rate encoding. This saves a few bytes
+// per entry in the symbol table.
+static 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.
+static inline unsigned numVbrBytes(unsigned num) {
+
+  // Note that the following nested ifs are somewhat equivalent to a binary
+  // search. We split it in half by comparing against 2^14 first. This allows
+  // most reasonable values to be done in 2 comparisons instead of 1 for
+  // small ones and four for large ones. We expect this to access file offsets
+  // in the 2^10 to 2^24 range and symbol lengths in the 2^0 to 2^8 range,
+  // so this approach is reasonable.
+  if (num < 1<<14) {
+    if (num < 1<<7)
+      return 1;
+    else
+      return 2;
+  }
+  if (num < 1<<21)
+    return 3;
+
+  if (num < 1<<28)
+    return 4;
+  return 5; // anything >= 2^28 takes 5 bytes
+}
+
+// Create an empty archive.
+Archive* Archive::CreateEmpty(const sys::Path& FilePath, LLVMContext& C) {
+  Archive* result = new Archive(FilePath, C);
+  return result;
+}
+
+// Fill the ArchiveMemberHeader with the information from a member. If
+// TruncateNames is true, names are flattened to 15 chars or less. The sz field
+// is provided here instead of coming from the mbr because the member might be
+// stored compressed and the compressed size is not the ArchiveMember's size.
+// Furthermore compressed files have negative size fields to identify them as
+// compressed.
+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 last modification date
+  uint64_t secondsSinceEpoch = mbr.getModTime().toEpochTime();
+  sprintf(buffer,"%-12u", unsigned(secondsSinceEpoch));
+  memcpy(hdr.date,buffer,12);
+
+  // Get rid of trailing blanks in the name
+  std::string mbrPath = mbr.getPath().str();
+  size_t mbrLen = mbrPath.length();
+  while (mbrLen > 0 && mbrPath[mbrLen-1] == ' ') {
+    mbrPath.erase(mbrLen-1,1);
+    mbrLen--;
+  }
+
+  // Set the name field in one of its various flavors.
+  bool writeLongName = false;
+  if (mbr.isStringTable()) {
+    memcpy(hdr.name,ARFILE_STRTAB_NAME,16);
+  } else if (mbr.isSVR4SymbolTable()) {
+    memcpy(hdr.name,ARFILE_SVR4_SYMTAB_NAME,16);
+  } else if (mbr.isBSD4SymbolTable()) {
+    memcpy(hdr.name,ARFILE_BSD4_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;
+    memcpy(hdr.name,nm,len);
+    hdr.name[len] = '/';
+  } else if (mbrPath.length() < 16 && mbrPath.find('/') == std::string::npos) {
+    memcpy(hdr.name,mbrPath.c_str(),mbrPath.length());
+    hdr.name[mbrPath.length()] = '/';
+  } else {
+    std::string nm = "#1/";
+    nm += utostr(mbrPath.length());
+    memcpy(hdr.name,nm.data(),nm.length());
+    if (sz < 0)
+      sz -= mbrPath.length();
+    else
+      sz += mbrPath.length();
+    writeLongName = true;
+  }
+
+  // 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);
+
+  return writeLongName;
+}
+
+// Insert a file into the archive before some other member. This also takes care
+// of extracting the necessary flags and information from the file.
+bool
+Archive::addFileBefore(const sys::Path& filePath, iterator where,
+                        std::string* ErrMsg) {
+  bool Exists;
+  if (sys::fs::exists(filePath.str(), Exists) || !Exists) {
+    if (ErrMsg)
+      *ErrMsg = "Can not add a non-existent file to archive";
+    return true;
+  }
+
+  ArchiveMember* mbr = new ArchiveMember(this);
+
+  mbr->data = 0;
+  mbr->path = filePath;
+  const sys::FileStatus *FSInfo = mbr->path.getFileStatus(false, ErrMsg);
+  if (!FSInfo) {
+    delete mbr;
+    return true;
+  }
+  mbr->info = *FSInfo;
+
+  unsigned flags = 0;
+  bool hasSlash = filePath.str().find('/') != std::string::npos;
+  if (hasSlash)
+    flags |= ArchiveMember::HasPathFlag;
+  if (hasSlash || filePath.str().length() > 15)
+    flags |= ArchiveMember::HasLongFilenameFlag;
+
+  sys::fs::file_magic type;
+  if (sys::fs::identify_magic(mbr->path.str(), type))
+    type = sys::fs::file_magic::unknown;
+  switch (type) {
+    case sys::fs::file_magic::bitcode:
+      flags |= ArchiveMember::BitcodeFlag;
+      break;
+    default:
+      break;
+  }
+  mbr->flags = flags;
+  members.insert(where,mbr);
+  return false;
+}
+
+// Write one member out to the file.
+bool
+Archive::writeMember(
+  const ArchiveMember& member,
+  std::ofstream& ARFile,
+  bool CreateSymbolTable,
+  bool TruncateNames,
+  std::string* ErrMsg
+) {
+
+  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();
+  MemoryBuffer *mFile = 0;
+  if (!data) {
+    OwningPtr<MemoryBuffer> File;
+    if (error_code ec = MemoryBuffer::getFile(member.getPath().c_str(), File)) {
+      if (ErrMsg)
+        *ErrMsg = ec.message();
+      return true;
+    }
+    mFile = File.take();
+    data = mFile->getBufferStart();
+    fSize = mFile->getBufferSize();
+  }
+
+  // Now that we have the data in memory, update the
+  // symbol table if it's a bitcode file.
+  if (CreateSymbolTable && member.isBitcode()) {
+    std::vector<std::string> symbols;
+    std::string FullMemberName = archPath.str() + "(" + member.getPath().str()
+      + ")";
+    Module* M =
+      GetBitcodeSymbols(data, fSize, FullMemberName, Context, symbols, ErrMsg);
+
+    // If the bitcode parsed successfully
+    if ( M ) {
+      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);
+        }
+      }
+      // We don't need this module any more.
+      delete M;
+    } else {
+      delete mFile;
+      if (ErrMsg)
+        *ErrMsg = "Can't parse bitcode member: " + member.getPath().str()
+          + ": " + *ErrMsg;
+      return true;
+    }
+  }
+
+  int hdrSize = fSize;
+
+  // Compute the fields of the header
+  ArchiveMemberHeader Hdr;
+  bool writeLongName = fillHeader(member,Hdr,hdrSize,TruncateNames);
+
+  // Write header to archive file
+  ARFile.write((char*)&Hdr, sizeof(Hdr));
+
+  // Write the long filename if its long
+  if (writeLongName) {
+    ARFile.write(member.getPath().str().data(),
+                 member.getPath().str().length());
+  }
+
+  // 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() & 1) == 1)
+    ARFile << ARFILE_PAD;
+
+  // Close the mapped file if it was opened
+  delete mFile;
+  return false;
+}
+
+// Write the entire archive to the file specified when the archive was created.
+// This writes to a temporary file first. Options are for creating a symbol
+// table, flattening the file names (no directories, 15 chars max) and
+// compressing each archive member.
+bool
+Archive::writeToDisk(bool CreateSymbolTable, bool TruncateNames,
+                     std::string* ErrMsg)
+{
+  // 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.
+  if (members.empty() && mapfile && mapfile->getBufferSize() > 8) {
+    if (ErrMsg)
+      *ErrMsg = "Can't write an archive not opened for writing";
+    return true;
+  }
+
+  // Create a temporary file to store the archive in
+  sys::Path TmpArchive = archPath;
+  if (TmpArchive.createTemporaryFileOnDisk(ErrMsg))
+    return true;
+
+  // Make sure the temporary gets removed if we crash
+  sys::RemoveFileOnSignal(TmpArchive.str());
+
+  // Create archive file for output.
+  std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
+                               std::ios::binary;
+  std::ofstream ArchiveFile(TmpArchive.c_str(), io_mode);
+
+  // Check for errors opening or creating archive file.
+  if (!ArchiveFile.is_open() || ArchiveFile.bad()) {
+    TmpArchive.eraseFromDisk();
+    if (ErrMsg)
+      *ErrMsg = "Error opening archive file: " + archPath.str();
+    return true;
+  }
+
+  // If we're creating a symbol table, reset it now
+  if (CreateSymbolTable) {
+    symTabSize = 0;
+    symTab.clear();
+  }
+
+  // Write magic string to archive.
+  ArchiveFile << ARFILE_MAGIC;
+
+  // 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) {
+    if (writeMember(*I, ArchiveFile, CreateSymbolTable,
+                     TruncateNames, ErrMsg)) {
+      TmpArchive.eraseFromDisk();
+      ArchiveFile.close();
+      return true;
+    }
+  }
+
+  // Close archive file.
+  ArchiveFile.close();
+
+  // 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::Path FinalFilePath = archPath;
+
+    // Map in the archive we just wrote.
+    {
+    OwningPtr<MemoryBuffer> arch;
+    if (error_code ec = MemoryBuffer::getFile(TmpArchive.c_str(), arch)) {
+      if (ErrMsg)
+        *ErrMsg = ec.message();
+      return true;
+    }
+    const char* base = arch->getBufferStart();
+
+    // Open another temporary file in order to avoid invalidating the
+    // mmapped data
+    if (FinalFilePath.createTemporaryFileOnDisk(ErrMsg))
+      return true;
+    sys::RemoveFileOnSignal(FinalFilePath.str());
+
+    std::ofstream FinalFile(FinalFilePath.c_str(), io_mode);
+    if (!FinalFile.is_open() || FinalFile.bad()) {
+      TmpArchive.eraseFromDisk();
+      if (ErrMsg)
+        *ErrMsg = "Error opening archive file: " + FinalFilePath.str();
+      return true;
+    }
+
+    // Write the file magic number
+    FinalFile << ARFILE_MAGIC;
+
+    // If there is a foreign symbol table, put it into the file now. Most
+    // ar(1) implementations require the symbol table to be first but llvm-ar
+    // can deal with it being after a foreign symbol table. This ensures
+    // compatibility with other ar(1) implementations as well as allowing the
+    // archive to store both native .o and LLVM .bc files, both indexed.
+    if (foreignST) {
+      if (writeMember(*foreignST, FinalFile, false, false, ErrMsg)) {
+        FinalFile.close();
+        TmpArchive.eraseFromDisk();
+        return true;
+      }
+    }
+
+    // Copy the temporary file contents being sure to skip the file's magic
+    // number.
+    FinalFile.write(base + sizeof(ARFILE_MAGIC)-1,
+      arch->getBufferSize()-sizeof(ARFILE_MAGIC)+1);
+
+    // Close up shop
+    FinalFile.close();
+    } // free arch.
+
+    // Move the final file over top of TmpArchive
+    if (FinalFilePath.renamePathOnDisk(TmpArchive, ErrMsg))
+      return true;
+  }
+
+  // Before we replace the actual archive, we need to forget all the
+  // members, since they point to data in that old archive. We need to do
+  // this because we cannot replace an open file on Windows.
+  cleanUpMemory();
+
+  if (TmpArchive.renamePathOnDisk(archPath, ErrMsg))
+    return true;
+
+  // Set correct read and write permissions after temporary file is moved
+  // to final destination path.
+  if (archPath.makeReadableOnDisk(ErrMsg))
+    return true;
+  if (archPath.makeWriteableOnDisk(ErrMsg))
+    return true;
+
+  return false;
+}