#include "llvm/Support/MemoryBuffer.h"
#include "llvm/ADT/OwningPtr.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/Errno.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/Process.h"
#include "llvm/Support/Program.h"
#include "llvm/Support/system_error.h"
#include <cassert>
#include <cstdio>
#include <cstring>
#include <cerrno>
#include <new>
#include <sys/types.h>
#include <sys/stat.h>
#if !defined(_MSC_VER) && !defined(__MINGW32__)
#include <unistd.h>
#include <sys/uio.h>
#else
#include <io.h>
#endif
#include <fcntl.h>
using namespace llvm;
namespace { const llvm::error_code success; }
MemoryBuffer::~MemoryBuffer() { }
void MemoryBuffer::init(const char *BufStart, const char *BufEnd,
bool RequiresNullTerminator) {
assert((!RequiresNullTerminator || BufEnd[0] == 0) &&
"Buffer is not null terminated!");
BufferStart = BufStart;
BufferEnd = BufEnd;
}
static void CopyStringRef(char *Memory, StringRef Data) {
memcpy(Memory, Data.data(), Data.size());
Memory[Data.size()] = 0; }
template <typename T>
static T* GetNamedBuffer(StringRef Buffer, StringRef Name,
bool RequiresNullTerminator) {
char *Mem = static_cast<char*>(operator new(sizeof(T) + Name.size() + 1));
CopyStringRef(Mem + sizeof(T), Name);
return new (Mem) T(Buffer, RequiresNullTerminator);
}
namespace {
class MemoryBufferMem : public MemoryBuffer {
public:
MemoryBufferMem(StringRef InputData, bool RequiresNullTerminator) {
init(InputData.begin(), InputData.end(), RequiresNullTerminator);
}
virtual const char *getBufferIdentifier() const {
return reinterpret_cast<const char*>(this + 1);
}
virtual BufferKind getBufferKind() const {
return MemoryBuffer_Malloc;
}
};
}
MemoryBuffer *MemoryBuffer::getMemBuffer(StringRef InputData,
StringRef BufferName,
bool RequiresNullTerminator) {
return GetNamedBuffer<MemoryBufferMem>(InputData, BufferName,
RequiresNullTerminator);
}
MemoryBuffer *MemoryBuffer::getMemBufferCopy(StringRef InputData,
StringRef BufferName) {
MemoryBuffer *Buf = getNewUninitMemBuffer(InputData.size(), BufferName);
if (!Buf) return 0;
memcpy(const_cast<char*>(Buf->getBufferStart()), InputData.data(),
InputData.size());
return Buf;
}
MemoryBuffer *MemoryBuffer::getNewUninitMemBuffer(size_t Size,
StringRef BufferName) {
size_t AlignedStringLen =
RoundUpToAlignment(sizeof(MemoryBufferMem) + BufferName.size() + 1,
sizeof(void*)); size_t RealLen = AlignedStringLen + Size + 1;
char *Mem = static_cast<char*>(operator new(RealLen, std::nothrow));
if (!Mem) return 0;
CopyStringRef(Mem + sizeof(MemoryBufferMem), BufferName);
char *Buf = Mem + AlignedStringLen;
Buf[Size] = 0;
return new (Mem) MemoryBufferMem(StringRef(Buf, Size), true);
}
MemoryBuffer *MemoryBuffer::getNewMemBuffer(size_t Size, StringRef BufferName) {
MemoryBuffer *SB = getNewUninitMemBuffer(Size, BufferName);
if (!SB) return 0;
memset(const_cast<char*>(SB->getBufferStart()), 0, Size);
return SB;
}
error_code MemoryBuffer::getFileOrSTDIN(StringRef Filename,
OwningPtr<MemoryBuffer> &result,
int64_t FileSize) {
if (Filename == "-")
return getSTDIN(result);
return getFile(Filename, result, FileSize);
}
error_code MemoryBuffer::getFileOrSTDIN(const char *Filename,
OwningPtr<MemoryBuffer> &result,
int64_t FileSize) {
if (strcmp(Filename, "-") == 0)
return getSTDIN(result);
return getFile(Filename, result, FileSize);
}
namespace {
class MemoryBufferMMapFile : public MemoryBufferMem {
public:
MemoryBufferMMapFile(StringRef Buffer, bool RequiresNullTerminator)
: MemoryBufferMem(Buffer, RequiresNullTerminator) { }
~MemoryBufferMMapFile() {
static int PageSize = sys::Process::GetPageSize();
uintptr_t Start = reinterpret_cast<uintptr_t>(getBufferStart());
size_t Size = getBufferSize();
uintptr_t RealStart = Start & ~(PageSize - 1);
size_t RealSize = Size + (Start - RealStart);
sys::Path::UnMapFilePages(reinterpret_cast<const char*>(RealStart),
RealSize);
}
virtual BufferKind getBufferKind() const {
return MemoryBuffer_MMap;
}
};
}
error_code MemoryBuffer::getFile(StringRef Filename,
OwningPtr<MemoryBuffer> &result,
int64_t FileSize,
bool RequiresNullTerminator) {
SmallString<256> PathBuf(Filename.begin(), Filename.end());
return MemoryBuffer::getFile(PathBuf.c_str(), result, FileSize,
RequiresNullTerminator);
}
error_code MemoryBuffer::getFile(const char *Filename,
OwningPtr<MemoryBuffer> &result,
int64_t FileSize,
bool RequiresNullTerminator) {
int OpenFlags = O_RDONLY;
#ifdef O_BINARY
OpenFlags |= O_BINARY; #endif
int FD = ::open(Filename, OpenFlags);
if (FD == -1) {
return error_code(errno, posix_category());
}
error_code ret = getOpenFile(FD, Filename, result, FileSize, FileSize,
0, RequiresNullTerminator);
close(FD);
return ret;
}
static bool shouldUseMmap(int FD,
size_t FileSize,
size_t MapSize,
off_t Offset,
bool RequiresNullTerminator,
int PageSize) {
if (MapSize < 4096*4)
return false;
if (!RequiresNullTerminator)
return true;
if (FileSize == size_t(-1)) {
struct stat FileInfo;
if (fstat(FD, &FileInfo) == -1) {
return error_code(errno, posix_category());
}
FileSize = FileInfo.st_size;
}
size_t End = Offset + MapSize;
assert(End <= FileSize);
if (End != FileSize)
return false;
if ((FileSize & (PageSize -1)) == 0)
return false;
return true;
}
error_code MemoryBuffer::getOpenFile(int FD, const char *Filename,
OwningPtr<MemoryBuffer> &result,
size_t FileSize, size_t MapSize,
off_t Offset,
bool RequiresNullTerminator) {
static int PageSize = sys::Process::GetPageSize();
if (MapSize == size_t(-1)) {
if (FileSize == size_t(-1)) {
struct stat FileInfo;
if (fstat(FD, &FileInfo) == -1) {
return error_code(errno, posix_category());
}
FileSize = FileInfo.st_size;
}
MapSize = FileSize;
}
if (shouldUseMmap(FD, FileSize, MapSize, Offset, RequiresNullTerminator,
PageSize)) {
off_t RealMapOffset = Offset & ~(PageSize - 1);
off_t Delta = Offset - RealMapOffset;
size_t RealMapSize = MapSize + Delta;
if (const char *Pages = sys::Path::MapInFilePages(FD,
RealMapSize,
RealMapOffset)) {
result.reset(GetNamedBuffer<MemoryBufferMMapFile>(
StringRef(Pages + Delta, MapSize), Filename, RequiresNullTerminator));
return success;
}
}
MemoryBuffer *Buf = MemoryBuffer::getNewUninitMemBuffer(MapSize, Filename);
if (!Buf) {
return make_error_code(errc::not_enough_memory);
}
OwningPtr<MemoryBuffer> SB(Buf);
char *BufPtr = const_cast<char*>(SB->getBufferStart());
size_t BytesLeft = MapSize;
if (lseek(FD, Offset, SEEK_SET) == -1)
return error_code(errno, posix_category());
while (BytesLeft) {
ssize_t NumRead = ::read(FD, BufPtr, BytesLeft);
if (NumRead == -1) {
if (errno == EINTR)
continue;
return error_code(errno, posix_category());
} else if (NumRead == 0) {
Buf->BufferEnd = BufPtr;
*BufPtr = 0;
result.swap(SB);
return success;
}
BytesLeft -= NumRead;
BufPtr += NumRead;
}
result.swap(SB);
return success;
}
error_code MemoryBuffer::getSTDIN(OwningPtr<MemoryBuffer> &result) {
sys::Program::ChangeStdinToBinary();
const ssize_t ChunkSize = 4096*4;
SmallString<ChunkSize> Buffer;
ssize_t ReadBytes;
do {
Buffer.reserve(Buffer.size() + ChunkSize);
ReadBytes = read(0, Buffer.end(), ChunkSize);
if (ReadBytes == -1) {
if (errno == EINTR) continue;
return error_code(errno, posix_category());
}
Buffer.set_size(Buffer.size() + ReadBytes);
} while (ReadBytes != 0);
result.reset(getMemBufferCopy(Buffer, "<stdin>"));
return success;
}