#include "llvm/Support/MemoryBuffer.h"
#include "llvm/ADT/OwningPtr.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/System/Errno.h"
#include "llvm/System/Path.h"
#include "llvm/System/Process.h"
#include "llvm/System/Program.h"
#include <cassert>
#include <cstdio>
#include <cstring>
#include <cerrno>
#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;
MemoryBuffer::~MemoryBuffer() { }
void MemoryBuffer::init(const char *BufStart, const char *BufEnd) {
assert(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) {
char *Mem = static_cast<char*>(operator new(sizeof(T) + Name.size() + 1));
CopyStringRef(Mem + sizeof(T), Name);
return new (Mem) T(Buffer);
}
namespace {
class MemoryBufferMem : public MemoryBuffer {
public:
MemoryBufferMem(StringRef InputData) {
init(InputData.begin(), InputData.end());
}
virtual const char *getBufferIdentifier() const {
return reinterpret_cast<const char*>(this + 1);
}
};
}
MemoryBuffer *MemoryBuffer::getMemBuffer(StringRef InputData,
StringRef BufferName) {
return GetNamedBuffer<MemoryBufferMem>(InputData, BufferName);
}
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));
}
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;
}
MemoryBuffer *MemoryBuffer::getFileOrSTDIN(StringRef Filename,
std::string *ErrStr,
int64_t FileSize,
struct stat *FileInfo) {
if (Filename == "-")
return getSTDIN(ErrStr);
return getFile(Filename, ErrStr, FileSize, FileInfo);
}
MemoryBuffer *MemoryBuffer::getFileOrSTDIN(const char *Filename,
std::string *ErrStr,
int64_t FileSize,
struct stat *FileInfo) {
if (strcmp(Filename, "-") == 0)
return getSTDIN(ErrStr);
return getFile(Filename, ErrStr, FileSize, FileInfo);
}
namespace {
class MemoryBufferMMapFile : public MemoryBufferMem {
public:
MemoryBufferMMapFile(StringRef Buffer)
: MemoryBufferMem(Buffer) { }
~MemoryBufferMMapFile() {
sys::Path::UnMapFilePages(getBufferStart(), getBufferSize());
}
};
class FileCloser {
int FD;
public:
explicit FileCloser(int FD) : FD(FD) {}
~FileCloser() { ::close(FD); }
};
}
MemoryBuffer *MemoryBuffer::getFile(StringRef Filename, std::string *ErrStr,
int64_t FileSize, struct stat *FileInfo) {
SmallString<256> PathBuf(Filename.begin(), Filename.end());
return MemoryBuffer::getFile(PathBuf.c_str(), ErrStr, FileSize, FileInfo);
}
MemoryBuffer *MemoryBuffer::getFile(const char *Filename, std::string *ErrStr,
int64_t FileSize, struct stat *FileInfo) {
int OpenFlags = O_RDONLY;
#ifdef O_BINARY
OpenFlags |= O_BINARY; #endif
int FD = ::open(Filename, OpenFlags);
if (FD == -1) {
if (ErrStr) *ErrStr = sys::StrError();
return 0;
}
FileCloser FC(FD);
if (FileSize == -1 || FileInfo) {
struct stat MyFileInfo;
struct stat *FileInfoPtr = FileInfo? FileInfo : &MyFileInfo;
if (fstat(FD, FileInfoPtr) == -1) {
if (ErrStr) *ErrStr = sys::StrError();
return 0;
}
FileSize = FileInfoPtr->st_size;
}
if (FileSize >= 4096*4 &&
(FileSize & (sys::Process::GetPageSize()-1)) != 0) {
if (const char *Pages = sys::Path::MapInFilePages(FD, FileSize)) {
return GetNamedBuffer<MemoryBufferMMapFile>(StringRef(Pages, FileSize),
Filename);
}
}
MemoryBuffer *Buf = MemoryBuffer::getNewUninitMemBuffer(FileSize, Filename);
if (!Buf) {
if (ErrStr) *ErrStr = "could not allocate buffer";
return 0;
}
OwningPtr<MemoryBuffer> SB(Buf);
char *BufPtr = const_cast<char*>(SB->getBufferStart());
size_t BytesLeft = FileSize;
while (BytesLeft) {
ssize_t NumRead = ::read(FD, BufPtr, BytesLeft);
if (NumRead == -1) {
if (errno == EINTR)
continue;
if (ErrStr) *ErrStr = sys::StrError();
return 0;
} else if (NumRead == 0) {
Buf->BufferEnd = BufPtr;
*BufPtr = 0;
return SB.take();
}
BytesLeft -= NumRead;
BufPtr += NumRead;
}
return SB.take();
}
MemoryBuffer *MemoryBuffer::getSTDIN(std::string *ErrStr) {
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;
if (ErrStr) *ErrStr = sys::StrError();
return 0;
}
Buffer.set_size(Buffer.size() + ReadBytes);
} while (ReadBytes != 0);
return getMemBufferCopy(Buffer, "<stdin>");
}