diff options
Diffstat (limited to 'contrib/llvm/lib/Support/MemoryBuffer.cpp')
| -rw-r--r-- | contrib/llvm/lib/Support/MemoryBuffer.cpp | 187 |
1 files changed, 83 insertions, 104 deletions
diff --git a/contrib/llvm/lib/Support/MemoryBuffer.cpp b/contrib/llvm/lib/Support/MemoryBuffer.cpp index dcd5529..5f4b7da 100644 --- a/contrib/llvm/lib/Support/MemoryBuffer.cpp +++ b/contrib/llvm/lib/Support/MemoryBuffer.cpp @@ -12,34 +12,26 @@ //===----------------------------------------------------------------------===// #include "llvm/Support/MemoryBuffer.h" -#include "llvm/ADT/OwningPtr.h" #include "llvm/ADT/SmallString.h" #include "llvm/Config/config.h" +#include "llvm/Support/Errc.h" #include "llvm/Support/Errno.h" #include "llvm/Support/FileSystem.h" #include "llvm/Support/MathExtras.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 <cerrno> #include <cstdio> #include <cstring> #include <new> -#include <sys/stat.h> #include <sys/types.h> +#include <system_error> #if !defined(_MSC_VER) && !defined(__MINGW32__) #include <unistd.h> #else #include <io.h> -// Simplistic definitinos of these macros for use in getOpenFile. -#ifndef S_ISREG -#define S_ISREG(x) (1) -#endif -#ifndef S_ISBLK -#define S_ISBLK(x) (0) -#endif #endif using namespace llvm; @@ -91,12 +83,12 @@ public: init(InputData.begin(), InputData.end(), RequiresNullTerminator); } - virtual const char *getBufferIdentifier() const LLVM_OVERRIDE { + const char *getBufferIdentifier() const override { // The name is stored after the class itself. return reinterpret_cast<const char*>(this + 1); } - virtual BufferKind getBufferKind() const LLVM_OVERRIDE { + BufferKind getBufferKind() const override { return MemoryBuffer_Malloc; } }; @@ -117,7 +109,7 @@ MemoryBuffer *MemoryBuffer::getMemBuffer(StringRef InputData, MemoryBuffer *MemoryBuffer::getMemBufferCopy(StringRef InputData, StringRef BufferName) { MemoryBuffer *Buf = getNewUninitMemBuffer(InputData.size(), BufferName); - if (!Buf) return 0; + if (!Buf) return nullptr; memcpy(const_cast<char*>(Buf->getBufferStart()), InputData.data(), InputData.size()); return Buf; @@ -131,12 +123,13 @@ MemoryBuffer *MemoryBuffer::getNewUninitMemBuffer(size_t Size, StringRef BufferName) { // Allocate space for the MemoryBuffer, the data and the name. It is important // that MemoryBuffer and data are aligned so PointerIntPair works with them. + // TODO: Is 16-byte alignment enough? We copy small object files with large + // alignment expectations into this buffer. size_t AlignedStringLen = - RoundUpToAlignment(sizeof(MemoryBufferMem) + BufferName.size() + 1, - sizeof(void*)); // TODO: Is sizeof(void*) enough? + RoundUpToAlignment(sizeof(MemoryBufferMem) + BufferName.size() + 1, 16); size_t RealLen = AlignedStringLen + Size + 1; char *Mem = static_cast<char*>(operator new(RealLen, std::nothrow)); - if (!Mem) return 0; + if (!Mem) return nullptr; // The name is stored after the class itself. CopyStringRef(Mem + sizeof(MemoryBufferMem), BufferName); @@ -154,24 +147,19 @@ MemoryBuffer *MemoryBuffer::getNewUninitMemBuffer(size_t Size, /// the MemoryBuffer object. MemoryBuffer *MemoryBuffer::getNewMemBuffer(size_t Size, StringRef BufferName) { MemoryBuffer *SB = getNewUninitMemBuffer(Size, BufferName); - if (!SB) return 0; + if (!SB) return nullptr; memset(const_cast<char*>(SB->getBufferStart()), 0, Size); return SB; } - -/// getFileOrSTDIN - Open the specified file as a MemoryBuffer, or open stdin -/// if the Filename is "-". If an error occurs, this returns null and fills -/// in *ErrStr with a reason. If stdin is empty, this API (unlike getSTDIN) -/// returns an empty buffer. -error_code MemoryBuffer::getFileOrSTDIN(StringRef Filename, - OwningPtr<MemoryBuffer> &result, - int64_t FileSize) { +ErrorOr<std::unique_ptr<MemoryBuffer>> +MemoryBuffer::getFileOrSTDIN(StringRef Filename, int64_t FileSize) { if (Filename == "-") - return getSTDIN(result); - return getFile(Filename, result, FileSize); + return getSTDIN(); + return getFile(Filename, FileSize); } + //===----------------------------------------------------------------------===// // MemoryBuffer::getFile implementation. //===----------------------------------------------------------------------===// @@ -197,7 +185,7 @@ class MemoryBufferMMapFile : public MemoryBuffer { public: MemoryBufferMMapFile(bool RequiresNullTerminator, int FD, uint64_t Len, - uint64_t Offset, error_code EC) + uint64_t Offset, std::error_code EC) : MFR(FD, false, sys::fs::mapped_file_region::readonly, getLegalMapSize(Len, Offset), getLegalMapOffset(Offset), EC) { if (!EC) { @@ -206,20 +194,19 @@ public: } } - virtual const char *getBufferIdentifier() const LLVM_OVERRIDE { + const char *getBufferIdentifier() const override { // The name is stored after the class itself. return reinterpret_cast<const char *>(this + 1); } - virtual BufferKind getBufferKind() const LLVM_OVERRIDE { + BufferKind getBufferKind() const override { return MemoryBuffer_MMap; } }; } -static error_code getMemoryBufferForStream(int FD, - StringRef BufferName, - OwningPtr<MemoryBuffer> &result) { +static ErrorOr<std::unique_ptr<MemoryBuffer>> +getMemoryBufferForStream(int FD, StringRef BufferName) { const ssize_t ChunkSize = 4096*4; SmallString<ChunkSize> Buffer; ssize_t ReadBytes; @@ -229,47 +216,48 @@ static error_code getMemoryBufferForStream(int FD, ReadBytes = read(FD, Buffer.end(), ChunkSize); if (ReadBytes == -1) { if (errno == EINTR) continue; - return error_code(errno, posix_category()); + return std::error_code(errno, std::generic_category()); } Buffer.set_size(Buffer.size() + ReadBytes); } while (ReadBytes != 0); - result.reset(MemoryBuffer::getMemBufferCopy(Buffer, BufferName)); - return error_code::success(); + std::unique_ptr<MemoryBuffer> Ret( + MemoryBuffer::getMemBufferCopy(Buffer, BufferName)); + return std::move(Ret); } -static error_code getFileAux(const char *Filename, - OwningPtr<MemoryBuffer> &result, int64_t FileSize, - bool RequiresNullTerminator); +static ErrorOr<std::unique_ptr<MemoryBuffer>> +getFileAux(const char *Filename, int64_t FileSize, bool RequiresNullTerminator, + bool IsVolatileSize); -error_code MemoryBuffer::getFile(Twine Filename, - OwningPtr<MemoryBuffer> &result, - int64_t FileSize, - bool RequiresNullTerminator) { +ErrorOr<std::unique_ptr<MemoryBuffer>> +MemoryBuffer::getFile(Twine Filename, int64_t FileSize, + bool RequiresNullTerminator, bool IsVolatileSize) { // Ensure the path is null terminated. SmallString<256> PathBuf; StringRef NullTerminatedName = Filename.toNullTerminatedStringRef(PathBuf); - return getFileAux(NullTerminatedName.data(), result, FileSize, - RequiresNullTerminator); + return getFileAux(NullTerminatedName.data(), FileSize, RequiresNullTerminator, + IsVolatileSize); } -static error_code getOpenFileImpl(int FD, const char *Filename, - OwningPtr<MemoryBuffer> &Result, - uint64_t FileSize, uint64_t MapSize, - int64_t Offset, bool RequiresNullTerminator); +static ErrorOr<std::unique_ptr<MemoryBuffer>> +getOpenFileImpl(int FD, const char *Filename, uint64_t FileSize, + uint64_t MapSize, int64_t Offset, bool RequiresNullTerminator, + bool IsVolatileSize); -static error_code getFileAux(const char *Filename, - OwningPtr<MemoryBuffer> &result, int64_t FileSize, - bool RequiresNullTerminator) { +static ErrorOr<std::unique_ptr<MemoryBuffer>> +getFileAux(const char *Filename, int64_t FileSize, bool RequiresNullTerminator, + bool IsVolatileSize) { int FD; - error_code EC = sys::fs::openFileForRead(Filename, FD); + std::error_code EC = sys::fs::openFileForRead(Filename, FD); if (EC) return EC; - error_code ret = getOpenFileImpl(FD, Filename, result, FileSize, FileSize, 0, - RequiresNullTerminator); + ErrorOr<std::unique_ptr<MemoryBuffer>> Ret = + getOpenFileImpl(FD, Filename, FileSize, FileSize, 0, + RequiresNullTerminator, IsVolatileSize); close(FD); - return ret; + return Ret; } static bool shouldUseMmap(int FD, @@ -277,7 +265,14 @@ static bool shouldUseMmap(int FD, size_t MapSize, off_t Offset, bool RequiresNullTerminator, - int PageSize) { + int PageSize, + bool IsVolatileSize) { + // mmap may leave the buffer without null terminator if the file size changed + // by the time the last page is mapped in, so avoid it if the file size is + // likely to change. + if (IsVolatileSize) + return false; + // We don't use mmap for small files because this can severely fragment our // address space. if (MapSize < 4 * 4096 || MapSize < (unsigned)PageSize) @@ -293,9 +288,8 @@ static bool shouldUseMmap(int FD, // RequiresNullTerminator = false and MapSize != -1. if (FileSize == size_t(-1)) { sys::fs::file_status Status; - error_code EC = sys::fs::status(FD, Status); - if (EC) - return EC; + if (sys::fs::status(FD, Status)) + return false; FileSize = Status.getSize(); } @@ -306,15 +300,6 @@ static bool shouldUseMmap(int FD, if (End != FileSize) return false; -#if defined(_WIN32) || defined(__CYGWIN__) - // Don't peek the next page if file is multiple of *physical* pagesize(4k) - // but is not multiple of AllocationGranularity(64k), - // when a null terminator is required. - // FIXME: It's not good to hardcode 4096 here. dwPageSize shows 4096. - if ((FileSize & (4096 - 1)) == 0) - return false; -#endif - // Don't try to map files that are exactly a multiple of the system page size // if we need a null terminator. if ((FileSize & (PageSize -1)) == 0) @@ -323,10 +308,10 @@ static bool shouldUseMmap(int FD, return true; } -static error_code getOpenFileImpl(int FD, const char *Filename, - OwningPtr<MemoryBuffer> &result, - uint64_t FileSize, uint64_t MapSize, - int64_t Offset, bool RequiresNullTerminator) { +static ErrorOr<std::unique_ptr<MemoryBuffer>> +getOpenFileImpl(int FD, const char *Filename, uint64_t FileSize, + uint64_t MapSize, int64_t Offset, bool RequiresNullTerminator, + bool IsVolatileSize) { static int PageSize = sys::process::get_self()->page_size(); // Default is to map the full file. @@ -335,7 +320,7 @@ static error_code getOpenFileImpl(int FD, const char *Filename, // file descriptor is cheaper than stat on a random path. if (FileSize == uint64_t(-1)) { sys::fs::file_status Status; - error_code EC = sys::fs::status(FD, Status); + std::error_code EC = sys::fs::status(FD, Status); if (EC) return EC; @@ -345,7 +330,7 @@ static error_code getOpenFileImpl(int FD, const char *Filename, sys::fs::file_type Type = Status.type(); if (Type != sys::fs::file_type::regular_file && Type != sys::fs::file_type::block_file) - return getMemoryBufferForStream(FD, Filename, result); + return getMemoryBufferForStream(FD, Filename); FileSize = Status.getSize(); } @@ -353,12 +338,13 @@ static error_code getOpenFileImpl(int FD, const char *Filename, } if (shouldUseMmap(FD, FileSize, MapSize, Offset, RequiresNullTerminator, - PageSize)) { - error_code EC; - result.reset(new (NamedBufferAlloc(Filename)) MemoryBufferMMapFile( - RequiresNullTerminator, FD, MapSize, Offset, EC)); + PageSize, IsVolatileSize)) { + std::error_code EC; + std::unique_ptr<MemoryBuffer> Result( + new (NamedBufferAlloc(Filename)) + MemoryBufferMMapFile(RequiresNullTerminator, FD, MapSize, Offset, EC)); if (!EC) - return error_code::success(); + return std::move(Result); } MemoryBuffer *Buf = MemoryBuffer::getNewUninitMemBuffer(MapSize, Filename); @@ -368,13 +354,13 @@ static error_code getOpenFileImpl(int FD, const char *Filename, return make_error_code(errc::not_enough_memory); } - OwningPtr<MemoryBuffer> SB(Buf); + std::unique_ptr<MemoryBuffer> SB(Buf); char *BufPtr = const_cast<char*>(SB->getBufferStart()); size_t BytesLeft = MapSize; #ifndef HAVE_PREAD if (lseek(FD, Offset, SEEK_SET) == -1) - return error_code(errno, posix_category()); + return std::error_code(errno, std::generic_category()); #endif while (BytesLeft) { @@ -387,46 +373,39 @@ static error_code getOpenFileImpl(int FD, const char *Filename, if (errno == EINTR) continue; // Error while reading. - return error_code(errno, posix_category()); + return std::error_code(errno, std::generic_category()); } if (NumRead == 0) { - assert(0 && "We got inaccurate FileSize value or fstat reported an " - "invalid file size."); - *BufPtr = '\0'; // null-terminate at the actual size. + memset(BufPtr, 0, BytesLeft); // zero-initialize rest of the buffer. break; } BytesLeft -= NumRead; BufPtr += NumRead; } - result.swap(SB); - return error_code::success(); + return std::move(SB); } -error_code MemoryBuffer::getOpenFile(int FD, const char *Filename, - OwningPtr<MemoryBuffer> &Result, - uint64_t FileSize, - bool RequiresNullTerminator) { - return getOpenFileImpl(FD, Filename, Result, FileSize, FileSize, 0, - RequiresNullTerminator); +ErrorOr<std::unique_ptr<MemoryBuffer>> +MemoryBuffer::getOpenFile(int FD, const char *Filename, uint64_t FileSize, + bool RequiresNullTerminator, bool IsVolatileSize) { + return getOpenFileImpl(FD, Filename, FileSize, FileSize, 0, + RequiresNullTerminator, IsVolatileSize); } -error_code MemoryBuffer::getOpenFileSlice(int FD, const char *Filename, - OwningPtr<MemoryBuffer> &Result, - uint64_t MapSize, int64_t Offset) { - return getOpenFileImpl(FD, Filename, Result, -1, MapSize, Offset, false); +ErrorOr<std::unique_ptr<MemoryBuffer>> +MemoryBuffer::getOpenFileSlice(int FD, const char *Filename, uint64_t MapSize, + int64_t Offset, bool IsVolatileSize) { + return getOpenFileImpl(FD, Filename, -1, MapSize, Offset, false, + IsVolatileSize); } -//===----------------------------------------------------------------------===// -// MemoryBuffer::getSTDIN implementation. -//===----------------------------------------------------------------------===// - -error_code MemoryBuffer::getSTDIN(OwningPtr<MemoryBuffer> &result) { +ErrorOr<std::unique_ptr<MemoryBuffer>> MemoryBuffer::getSTDIN() { // 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::ChangeStdinToBinary(); - return getMemoryBufferForStream(0, "<stdin>", result); + return getMemoryBufferForStream(0, "<stdin>"); } |
