ErrorOr<std::unique_ptr<ObjectFile>>
ObjectFile::createELFObjectFile(MemoryBufferRef Obj) {
std::pair<unsigned char, unsigned char> Ident =
getElfArchType(Obj.getBuffer());
std::size_t MaxAlignment =
1ULL << countTrailingZeros(uintptr_t(Obj.getBufferStart()));
if (MaxAlignment < 2)
return object_error::parse_failed;
std::error_code EC;
std::unique_ptr<ObjectFile> R;
if (Ident.first == ELF::ELFCLASS32) {
if (Ident.second == ELF::ELFDATA2LSB)
R.reset(new ELFObjectFile<ELFType<support::little, false>>(Obj, EC));
else if (Ident.second == ELF::ELFDATA2MSB)
R.reset(new ELFObjectFile<ELFType<support::big, false>>(Obj, EC));
else
return object_error::parse_failed;
} else if (Ident.first == ELF::ELFCLASS64) {
if (Ident.second == ELF::ELFDATA2LSB)
R.reset(new ELFObjectFile<ELFType<support::little, true>>(Obj, EC));
else if (Ident.second == ELF::ELFDATA2MSB)
R.reset(new ELFObjectFile<ELFType<support::big, true>>(Obj, EC));
else
return object_error::parse_failed;
} else {
return object_error::parse_failed;
}
if (EC)
return EC;
return std::move(R);
}
Error PDBFile::parseFileHeaders() {
std::error_code EC;
MemoryBufferRef BufferRef = *Context->Buffer;
// Make sure the file is sufficiently large to hold a super block.
// Do this before attempting to read the super block.
if (BufferRef.getBufferSize() < sizeof(SuperBlock))
return make_error<RawError>(raw_error_code::corrupt_file,
"Does not contain superblock");
Context->SB =
reinterpret_cast<const SuperBlock *>(BufferRef.getBufferStart());
const SuperBlock *SB = Context->SB;
// Check the magic bytes.
if (memcmp(SB->MagicBytes, Magic, sizeof(Magic)) != 0)
return make_error<RawError>(raw_error_code::corrupt_file,
"MSF magic header doesn't match");
// We don't support blocksizes which aren't a multiple of four bytes.
if (SB->BlockSize % sizeof(support::ulittle32_t) != 0)
return make_error<RawError>(raw_error_code::corrupt_file,
"Block size is not multiple of 4.");
switch (SB->BlockSize) {
case 512: case 1024: case 2048: case 4096:
break;
default:
// An invalid block size suggests a corrupt PDB file.
return make_error<RawError>(raw_error_code::corrupt_file,
"Unsupported block size.");
}
if (BufferRef.getBufferSize() % SB->BlockSize != 0)
return make_error<RawError>(raw_error_code::corrupt_file,
"File size is not a multiple of block size");
// We don't support directories whose sizes aren't a multiple of four bytes.
if (SB->NumDirectoryBytes % sizeof(support::ulittle32_t) != 0)
return make_error<RawError>(raw_error_code::corrupt_file,
"Directory size is not multiple of 4.");
// The number of blocks which comprise the directory is a simple function of
// the number of bytes it contains.
uint64_t NumDirectoryBlocks = getNumDirectoryBlocks();
// The block map, as we understand it, is a block which consists of a list of
// block numbers.
// It is unclear what would happen if the number of blocks couldn't fit on a
// single block.
if (NumDirectoryBlocks > SB->BlockSize / sizeof(support::ulittle32_t))
return make_error<RawError>(raw_error_code::corrupt_file,
"Too many directory blocks.");
// Make sure the directory block array fits within the file.
if (auto EC = checkOffset(BufferRef, getDirectoryBlockArray()))
return EC;
return Error::success();
}
static std::error_code checkOffset(MemoryBufferRef M, uintptr_t Addr,
const uint64_t Size) {
if (Addr + Size < Addr || Addr + Size < Size ||
Addr + Size > uintptr_t(M.getBufferEnd()) ||
Addr < uintptr_t(M.getBufferStart())) {
return object_error::unexpected_eof;
}
return std::error_code();
}
static std::error_code checkOffset(MemoryBufferRef M, uintptr_t Addr,
const uint64_t Size) {
if (Addr + Size < Addr || Addr + Size < Size ||
Addr + Size > uintptr_t(M.getBufferEnd()) ||
Addr < uintptr_t(M.getBufferStart())) {
return std::make_error_code(std::errc::bad_address);
}
return std::error_code();
}
static Error checkOffset(MemoryBufferRef M, uintptr_t Addr,
const uint64_t Size) {
if (Addr + Size < Addr || Addr + Size < Size ||
Addr + Size > uintptr_t(M.getBufferEnd()) ||
Addr < uintptr_t(M.getBufferStart())) {
return make_error<RawError>(raw_error_code::corrupt_file,
"Invalid buffer address");
}
return Error::success();
}
void notifyObjectCompiled(const Module *M, MemoryBufferRef Obj) override {
const std::string &ModuleID = M->getModuleIdentifier();
std::string CacheName;
if (!getCacheFilename(ModuleID, CacheName))
return;
if (!CacheDir.empty()) { // Create user-defined cache dir.
SmallString<128> dir(sys::path::parent_path(CacheName));
sys::fs::create_directories(Twine(dir));
}
std::error_code EC;
raw_fd_ostream outfile(CacheName, EC, sys::fs::F_None);
outfile.write(Obj.getBufferStart(), Obj.getBufferSize());
outfile.close();
}
std::unique_ptr<Module> llvm::parseIR(MemoryBufferRef Buffer, SMDiagnostic &Err,
LLVMContext &Context) {
NamedRegionTimer T(TimeIRParsingName, TimeIRParsingGroupName,
TimePassesIsEnabled);
if (isBitcode((const unsigned char *)Buffer.getBufferStart(),
(const unsigned char *)Buffer.getBufferEnd())) {
ErrorOr<std::unique_ptr<Module>> ModuleOrErr =
parseBitcodeFile(Buffer, Context);
if (std::error_code EC = ModuleOrErr.getError()) {
Err = SMDiagnostic(Buffer.getBufferIdentifier(), SourceMgr::DK_Error,
EC.message());
return nullptr;
}
return std::move(ModuleOrErr.get());
}
return parseAssembly(Buffer, Err, Context);
}
std::error_code PDBFile::parseFileHeaders() {
std::error_code EC;
MemoryBufferRef BufferRef = *Context->Buffer;
Context->SB =
reinterpret_cast<const SuperBlock *>(BufferRef.getBufferStart());
const SuperBlock *SB = Context->SB;
// Make sure the file is sufficiently large to hold a super block.
if (BufferRef.getBufferSize() < sizeof(SuperBlock))
return std::make_error_code(std::errc::illegal_byte_sequence);
// Check the magic bytes.
if (memcmp(SB->MagicBytes, Magic, sizeof(Magic)) != 0)
return std::make_error_code(std::errc::illegal_byte_sequence);
// We don't support blocksizes which aren't a multiple of four bytes.
if (SB->BlockSize == 0 || SB->BlockSize % sizeof(support::ulittle32_t) != 0)
return std::make_error_code(std::errc::not_supported);
// We don't support directories whose sizes aren't a multiple of four bytes.
if (SB->NumDirectoryBytes % sizeof(support::ulittle32_t) != 0)
return std::make_error_code(std::errc::not_supported);
// The number of blocks which comprise the directory is a simple function of
// the number of bytes it contains.
uint64_t NumDirectoryBlocks = getNumDirectoryBlocks();
// The block map, as we understand it, is a block which consists of a list of
// block numbers.
// It is unclear what would happen if the number of blocks couldn't fit on a
// single block.
if (NumDirectoryBlocks > SB->BlockSize / sizeof(support::ulittle32_t))
return std::make_error_code(std::errc::illegal_byte_sequence);
return std::error_code();
}
Error PDBFile::parseStreamData() {
assert(Context && Context->SB);
bool SeenNumStreams = false;
uint32_t NumStreams = 0;
uint32_t StreamIdx = 0;
uint64_t DirectoryBytesRead = 0;
MemoryBufferRef M = *Context->Buffer;
const SuperBlock *SB = Context->SB;
auto DirectoryBlocks = getDirectoryBlockArray();
// The structure of the directory is as follows:
// struct PDBDirectory {
// uint32_t NumStreams;
// uint32_t StreamSizes[NumStreams];
// uint32_t StreamMap[NumStreams][];
// };
//
// Empty streams don't consume entries in the StreamMap.
for (uint32_t DirectoryBlockAddr : DirectoryBlocks) {
uint64_t DirectoryBlockOffset =
blockToOffset(DirectoryBlockAddr, SB->BlockSize);
auto DirectoryBlock =
makeArrayRef(reinterpret_cast<const support::ulittle32_t *>(
M.getBufferStart() + DirectoryBlockOffset),
SB->BlockSize / sizeof(support::ulittle32_t));
if (auto EC = checkOffset(M, DirectoryBlock))
return EC;
// We read data out of the directory four bytes at a time. Depending on
// where we are in the directory, the contents may be: the number of streams
// in the directory, a stream's size, or a block in the stream map.
for (uint32_t Data : DirectoryBlock) {
// Don't read beyond the end of the directory.
if (DirectoryBytesRead == SB->NumDirectoryBytes)
break;
DirectoryBytesRead += sizeof(Data);
// This data must be the number of streams if we haven't seen it yet.
if (!SeenNumStreams) {
NumStreams = Data;
SeenNumStreams = true;
continue;
}
// This data must be a stream size if we have not seen them all yet.
if (Context->StreamSizes.size() < NumStreams) {
// It seems like some streams have their set to -1 when their contents
// are not present. Treat them like empty streams for now.
if (Data == UINT32_MAX)
Context->StreamSizes.push_back(0);
else
Context->StreamSizes.push_back(Data);
continue;
}
// This data must be a stream block number if we have seen all of the
// stream sizes.
std::vector<uint32_t> *StreamBlocks = nullptr;
// Figure out which stream this block number belongs to.
while (StreamIdx < NumStreams) {
uint64_t NumExpectedStreamBlocks =
bytesToBlocks(Context->StreamSizes[StreamIdx], SB->BlockSize);
StreamBlocks = &Context->StreamMap[StreamIdx];
if (NumExpectedStreamBlocks > StreamBlocks->size())
break;
++StreamIdx;
}
// It seems this block doesn't belong to any stream? The stream is either
// corrupt or something more mysterious is going on.
if (StreamIdx == NumStreams)
return make_error<RawError>(raw_error_code::corrupt_file,
"Orphaned block found?");
StreamBlocks->push_back(Data);
}
}
// We should have read exactly SB->NumDirectoryBytes bytes.
assert(DirectoryBytesRead == SB->NumDirectoryBytes);
return Error::success();
}
Reader::Reader(MemoryBufferRef InputBuffer)
: InputBuffer(InputBuffer), Current(InputBuffer.getBufferStart()),
End(InputBuffer.getBufferEnd()) {}