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mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-12-14 11:32:34 +00:00
llvm-6502/lib/Archive/ArchiveWriter.cpp
Jeffrey Yasskin f0356fe140 Kill ModuleProvider and ghost linkage by inverting the relationship between
Modules and ModuleProviders. Because the "ModuleProvider" simply materializes
GlobalValues now, and doesn't provide modules, it's renamed to
"GVMaterializer". Code that used to need a ModuleProvider to materialize
Functions can now materialize the Functions directly. Functions no longer use a
magic linkage to record that they're materializable; they simply ask the
GVMaterializer.

Because the C ABI must never change, we can't remove LLVMModuleProviderRef or
the functions that refer to it. Instead, because Module now exposes the same
functionality ModuleProvider used to, we store a Module* in any
LLVMModuleProviderRef and translate in the wrapper methods.  The bindings to
other languages still use the ModuleProvider concept.  It would probably be
worth some time to update them to follow the C++ more closely, but I don't
intend to do it.

Fixes http://llvm.org/PR5737 and http://llvm.org/PR5735.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94686 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-27 20:34:15 +00:00

482 lines
15 KiB
C++

//===-- 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 "ArchiveInternals.h"
#include "llvm/Module.h"
#include "llvm/ADT/OwningPtr.h"
#include "llvm/Bitcode/ReaderWriter.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/System/Process.h"
#include "llvm/System/Signals.h"
#include <fstream>
#include <ostream>
#include <iomanip>
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 (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;
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) {
if (!filePath.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;
std::string magic;
mbr->path.getMagicNumber(magic,4);
switch (sys::IdentifyFileType(magic.c_str(),4)) {
case sys::Bitcode_FileType:
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,
bool ShouldCompress,
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) {
mFile = MemoryBuffer::getFile(member.getPath().c_str(), ErrMsg);
if (mFile == 0)
return true;
data = mFile->getBufferStart();
fSize = mFile->getBufferSize();
}
// Now that we have the data in memory, update the
// symbol table if its a bitcode file.
if (CreateSymbolTable && member.isBitcode()) {
std::vector<std::string> symbols;
std::string FullMemberName = archPath.str() + "(" + member.getPath().str()
+ ")";
Module* M =
GetBitcodeSymbols((const unsigned char*)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 out the LLVM symbol table as an archive member to the file.
void
Archive::writeSymbolTable(std::ofstream& ARFile) {
// 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, "%-8o", 0644);
memcpy(Hdr.mode,buffer,8);
sprintf(buffer, "%-6u", sys::Process::GetCurrentUserId());
memcpy(Hdr.uid,buffer,6);
sprintf(buffer, "%-6u", sys::Process::GetCurrentGroupId());
memcpy(Hdr.gid,buffer,6);
sprintf(buffer,"%-12u", unsigned(secondsSinceEpoch));
memcpy(Hdr.date,buffer,12);
sprintf(buffer,"%-10u",symTabSize);
memcpy(Hdr.size,buffer,10);
// Write the header
ARFile.write((char*)&Hdr, sizeof(Hdr));
#ifndef NDEBUG
// Save the starting position of the symbol tables data content.
unsigned startpos = ARFile.tellp();
#endif
// 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());
}
#ifndef NDEBUG
// Now that we're done with the symbol table, get the ending file position
unsigned endpos = ARFile.tellp();
#endif
// 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;
}
// 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, bool Compress,
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);
// 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()) {
if (TmpArchive.exists())
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, Compress, ErrMsg)) {
if (TmpArchive.exists())
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(MemoryBuffer::getFile(TmpArchive.c_str()));
if (arch == 0) 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);
std::ofstream FinalFile(FinalFilePath.c_str(), io_mode);
if (!FinalFile.is_open() || FinalFile.bad()) {
if (TmpArchive.exists())
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, false, ErrMsg)) {
FinalFile.close();
if (TmpArchive.exists())
TmpArchive.eraseFromDisk();
return true;
}
}
// Put out the LLVM symbol table now.
writeSymbolTable(FinalFile);
// 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;
}