diff options
Diffstat (limited to 'lib/Support/MemoryBuffer.cpp')
| -rw-r--r-- | lib/Support/MemoryBuffer.cpp | 180 |
1 files changed, 95 insertions, 85 deletions
diff --git a/lib/Support/MemoryBuffer.cpp b/lib/Support/MemoryBuffer.cpp index 2b95089..542162d 100644 --- a/lib/Support/MemoryBuffer.cpp +++ b/lib/Support/MemoryBuffer.cpp @@ -14,6 +14,7 @@ #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" @@ -37,22 +38,7 @@ using namespace llvm; // MemoryBuffer implementation itself. //===----------------------------------------------------------------------===// -MemoryBuffer::~MemoryBuffer() { - if (MustDeleteBuffer) - free((void*)BufferStart); -} - -/// initCopyOf - Initialize this source buffer with a copy of the specified -/// memory range. We make the copy so that we can null terminate it -/// successfully. -void MemoryBuffer::initCopyOf(const char *BufStart, const char *BufEnd) { - size_t Size = BufEnd-BufStart; - BufferStart = (char *)malloc(Size+1); - BufferEnd = BufferStart+Size; - memcpy(const_cast<char*>(BufferStart), BufStart, Size); - *const_cast<char*>(BufferEnd) = 0; // Null terminate buffer. - MustDeleteBuffer = true; -} +MemoryBuffer::~MemoryBuffer() { } /// init - Initialize this MemoryBuffer as a reference to externally allocated /// memory, memory that we know is already null terminated. @@ -60,27 +46,38 @@ void MemoryBuffer::init(const char *BufStart, const char *BufEnd) { assert(BufEnd[0] == 0 && "Buffer is not null terminated!"); BufferStart = BufStart; BufferEnd = BufEnd; - MustDeleteBuffer = false; } //===----------------------------------------------------------------------===// // MemoryBufferMem implementation. //===----------------------------------------------------------------------===// +/// CopyStringRef - Copies contents of a StringRef into a block of memory and +/// null-terminates it. +static void CopyStringRef(char *Memory, StringRef Data) { + memcpy(Memory, Data.data(), Data.size()); + Memory[Data.size()] = 0; // Null terminate string. +} + +/// GetNamedBuffer - Allocates a new MemoryBuffer with Name copied after it. +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 { +/// MemoryBufferMem - Named MemoryBuffer pointing to a block of memory. class MemoryBufferMem : public MemoryBuffer { - std::string FileID; public: - MemoryBufferMem(StringRef InputData, StringRef FID, bool Copy = false) - : FileID(FID) { - if (!Copy) - init(InputData.data(), InputData.data()+InputData.size()); - else - initCopyOf(InputData.data(), InputData.data()+InputData.size()); + MemoryBufferMem(StringRef InputData) { + init(InputData.begin(), InputData.end()); } - + virtual const char *getBufferIdentifier() const { - return FileID.c_str(); + // The name is stored after the class itself. + return reinterpret_cast<const char*>(this + 1); } }; } @@ -88,42 +85,55 @@ public: /// getMemBuffer - Open the specified memory range as a MemoryBuffer. Note /// that EndPtr[0] must be a null byte and be accessible! MemoryBuffer *MemoryBuffer::getMemBuffer(StringRef InputData, - const char *BufferName) { - return new MemoryBufferMem(InputData, BufferName); + StringRef BufferName) { + return GetNamedBuffer<MemoryBufferMem>(InputData, BufferName); } /// getMemBufferCopy - Open the specified memory range as a MemoryBuffer, /// copying the contents and taking ownership of it. This has no requirements /// on EndPtr[0]. MemoryBuffer *MemoryBuffer::getMemBufferCopy(StringRef InputData, - const char *BufferName) { - return new MemoryBufferMem(InputData, BufferName, true); + StringRef BufferName) { + MemoryBuffer *Buf = getNewUninitMemBuffer(InputData.size(), BufferName); + if (!Buf) return 0; + memcpy(const_cast<char*>(Buf->getBufferStart()), InputData.data(), + InputData.size()); + return Buf; } /// getNewUninitMemBuffer - Allocate a new MemoryBuffer of the specified size -/// that is completely initialized to zeros. Note that the caller should -/// initialize the memory allocated by this method. The memory is owned by -/// the MemoryBuffer object. +/// that is not initialized. Note that the caller should initialize the +/// memory allocated by this method. The memory is owned by the MemoryBuffer +/// object. MemoryBuffer *MemoryBuffer::getNewUninitMemBuffer(size_t Size, StringRef BufferName) { - char *Buf = (char *)malloc(Size+1); - if (!Buf) return 0; - Buf[Size] = 0; - MemoryBufferMem *SB = new MemoryBufferMem(StringRef(Buf, Size), BufferName); - // The memory for this buffer is owned by the MemoryBuffer. - SB->MustDeleteBuffer = true; - return SB; + // Allocate space for the MemoryBuffer, the data and the name. It is important + // that MemoryBuffer and data are aligned so PointerIntPair works with them. + size_t AlignedStringLen = + RoundUpToAlignment(sizeof(MemoryBufferMem) + BufferName.size() + 1, + sizeof(void*)); // TODO: Is sizeof(void*) enough? + size_t RealLen = AlignedStringLen + Size + 1; + char *Mem = static_cast<char*>(operator new(RealLen, std::nothrow)); + if (!Mem) return 0; + + // The name is stored after the class itself. + CopyStringRef(Mem + sizeof(MemoryBufferMem), BufferName); + + // The buffer begins after the name and must be aligned. + char *Buf = Mem + AlignedStringLen; + Buf[Size] = 0; // Null terminate buffer. + + return new (Mem) MemoryBufferMem(StringRef(Buf, Size)); } /// getNewMemBuffer - Allocate a new MemoryBuffer of the specified size that /// is completely initialized to zeros. Note that the caller should /// initialize the memory allocated by this method. The memory is owned by /// the MemoryBuffer object. -MemoryBuffer *MemoryBuffer::getNewMemBuffer(size_t Size, - const char *BufferName) { +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+1); + memset(const_cast<char*>(SB->getBufferStart()), 0, Size); return SB; } @@ -137,7 +147,16 @@ MemoryBuffer *MemoryBuffer::getFileOrSTDIN(StringRef Filename, int64_t FileSize, struct stat *FileInfo) { if (Filename == "-") - return getSTDIN(); + 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); } @@ -149,18 +168,11 @@ namespace { /// MemoryBufferMMapFile - This represents a file that was mapped in with the /// sys::Path::MapInFilePages method. When destroyed, it calls the /// sys::Path::UnMapFilePages method. -class MemoryBufferMMapFile : public MemoryBuffer { - std::string Filename; +class MemoryBufferMMapFile : public MemoryBufferMem { public: - MemoryBufferMMapFile(StringRef filename, const char *Pages, uint64_t Size) - : Filename(filename) { - init(Pages, Pages+Size); - } - - virtual const char *getBufferIdentifier() const { - return Filename.c_str(); - } - + MemoryBufferMMapFile(StringRef Buffer) + : MemoryBufferMem(Buffer) { } + ~MemoryBufferMMapFile() { sys::Path::UnMapFilePages(getBufferStart(), getBufferSize()); } @@ -170,19 +182,24 @@ public: class FileCloser { int FD; public: - FileCloser(int FD) : FD(FD) {} + explicit FileCloser(int FD) : FD(FD) {} ~FileCloser() { ::close(FD); } }; } MemoryBuffer *MemoryBuffer::getFile(StringRef Filename, std::string *ErrStr, int64_t FileSize, struct stat *FileInfo) { - int OpenFlags = 0; + 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; // Open input file in binary mode on win32. #endif - SmallString<256> PathBuf(Filename.begin(), Filename.end()); - int FD = ::open(PathBuf.c_str(), O_RDONLY|OpenFlags); + int FD = ::open(Filename, OpenFlags); if (FD == -1) { if (ErrStr) *ErrStr = sys::StrError(); return 0; @@ -213,8 +230,8 @@ MemoryBuffer *MemoryBuffer::getFile(StringRef Filename, std::string *ErrStr, if (FileSize >= 4096*4 && (FileSize & (sys::Process::GetPageSize()-1)) != 0) { if (const char *Pages = sys::Path::MapInFilePages(FD, FileSize)) { - // Close the file descriptor, now that the whole file is in memory. - return new MemoryBufferMMapFile(Filename, Pages, FileSize); + return GetNamedBuffer<MemoryBufferMMapFile>(StringRef(Pages, FileSize), + Filename); } } @@ -254,34 +271,27 @@ MemoryBuffer *MemoryBuffer::getFile(StringRef Filename, std::string *ErrStr, // MemoryBuffer::getSTDIN implementation. //===----------------------------------------------------------------------===// -namespace { -class STDINBufferFile : public MemoryBuffer { -public: - virtual const char *getBufferIdentifier() const { - return "<stdin>"; - } -}; -} - -MemoryBuffer *MemoryBuffer::getSTDIN() { - char Buffer[4096*4]; - - std::vector<char> FileData; - +MemoryBuffer *MemoryBuffer::getSTDIN(std::string *ErrStr) { // Read in all of the data from stdin, we cannot mmap stdin. // // FIXME: That isn't necessarily true, we should try to mmap stdin and // fallback if it fails. sys::Program::ChangeStdinToBinary(); - size_t ReadBytes; + + const ssize_t ChunkSize = 4096*4; + SmallString<ChunkSize> Buffer; + ssize_t ReadBytes; + // Read into Buffer until we hit EOF. do { - ReadBytes = fread(Buffer, sizeof(char), sizeof(Buffer), stdin); - FileData.insert(FileData.end(), Buffer, Buffer+ReadBytes); - } while (ReadBytes == sizeof(Buffer)); - - FileData.push_back(0); // &FileData[Size] is invalid. So is &*FileData.end(). - size_t Size = FileData.size(); - MemoryBuffer *B = new STDINBufferFile(); - B->initCopyOf(&FileData[0], &FileData[Size-1]); - return B; + 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>"); } |
