X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FSupport%2FMemoryBuffer.cpp;h=faee10bb07cf3e7da138c8568fb9eb15262be25b;hb=HEAD;hp=ecae7695e1fd539bde1249737938ae04ba710d57;hpb=629b96cb4f278cc78bfd5679e91315cb6e1ed164;p=oota-llvm.git diff --git a/lib/Support/MemoryBuffer.cpp b/lib/Support/MemoryBuffer.cpp index ecae7695e1f..faee10bb07c 100644 --- a/lib/Support/MemoryBuffer.cpp +++ b/lib/Support/MemoryBuffer.cpp @@ -12,34 +12,25 @@ //===----------------------------------------------------------------------===// #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 #include -#include #include #include -#include #include +#include #if !defined(_MSC_VER) && !defined(__MINGW32__) #include #else #include -// 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; @@ -66,20 +57,24 @@ void MemoryBuffer::init(const char *BufStart, const char *BufEnd, /// 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()); + if (!Data.empty()) + memcpy(Memory, Data.data(), Data.size()); Memory[Data.size()] = 0; // Null terminate string. } namespace { struct NamedBufferAlloc { - StringRef Name; - NamedBufferAlloc(StringRef Name) : Name(Name) {} + const Twine &Name; + NamedBufferAlloc(const Twine &Name) : Name(Name) {} }; } void *operator new(size_t N, const NamedBufferAlloc &Alloc) { - char *Mem = static_cast(operator new(N + Alloc.Name.size() + 1)); - CopyStringRef(Mem + N, Alloc.Name); + SmallString<256> NameBuf; + StringRef NameRef = Alloc.Name.toStringRef(NameBuf); + + char *Mem = static_cast(operator new(N + NameRef.size() + 1)); + CopyStringRef(Mem + N, NameRef); return Mem; } @@ -91,88 +86,99 @@ public: init(InputData.begin(), InputData.end(), RequiresNullTerminator); } - virtual const char *getBufferIdentifier() const override { + const char *getBufferIdentifier() const override { // The name is stored after the class itself. return reinterpret_cast(this + 1); } - virtual BufferKind getBufferKind() const override { + BufferKind getBufferKind() const override { return MemoryBuffer_Malloc; } }; } -/// getMemBuffer - Open the specified memory range as a MemoryBuffer. Note -/// that InputData must be a null terminated if RequiresNullTerminator is true! -MemoryBuffer *MemoryBuffer::getMemBuffer(StringRef InputData, - StringRef BufferName, - bool RequiresNullTerminator) { - return new (NamedBufferAlloc(BufferName)) +static ErrorOr> +getFileAux(const Twine &Filename, int64_t FileSize, uint64_t MapSize, + uint64_t Offset, bool RequiresNullTerminator, bool IsVolatileSize); + +std::unique_ptr +MemoryBuffer::getMemBuffer(StringRef InputData, StringRef BufferName, + bool RequiresNullTerminator) { + auto *Ret = new (NamedBufferAlloc(BufferName)) MemoryBufferMem(InputData, RequiresNullTerminator); + return std::unique_ptr(Ret); } -/// 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, - StringRef BufferName) { - MemoryBuffer *Buf = getNewUninitMemBuffer(InputData.size(), BufferName); - if (!Buf) return 0; +std::unique_ptr +MemoryBuffer::getMemBuffer(MemoryBufferRef Ref, bool RequiresNullTerminator) { + return std::unique_ptr(getMemBuffer( + Ref.getBuffer(), Ref.getBufferIdentifier(), RequiresNullTerminator)); +} + +std::unique_ptr +MemoryBuffer::getMemBufferCopy(StringRef InputData, const Twine &BufferName) { + std::unique_ptr Buf = + getNewUninitMemBuffer(InputData.size(), BufferName); + if (!Buf) + return nullptr; memcpy(const_cast(Buf->getBufferStart()), InputData.data(), InputData.size()); return Buf; } -/// getNewUninitMemBuffer - Allocate a new MemoryBuffer of the specified size -/// 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) { +std::unique_ptr +MemoryBuffer::getNewUninitMemBuffer(size_t Size, const Twine &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. + SmallString<256> NameBuf; + StringRef NameRef = BufferName.toStringRef(NameBuf); size_t AlignedStringLen = - RoundUpToAlignment(sizeof(MemoryBufferMem) + BufferName.size() + 1, 16); + RoundUpToAlignment(sizeof(MemoryBufferMem) + NameRef.size() + 1, 16); size_t RealLen = AlignedStringLen + Size + 1; char *Mem = static_cast(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); + CopyStringRef(Mem + sizeof(MemoryBufferMem), NameRef); // 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), true); + auto *Ret = new (Mem) MemoryBufferMem(StringRef(Buf, Size), true); + return std::unique_ptr(Ret); } -/// 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, StringRef BufferName) { - MemoryBuffer *SB = getNewUninitMemBuffer(Size, BufferName); - if (!SB) return 0; +std::unique_ptr +MemoryBuffer::getNewMemBuffer(size_t Size, StringRef BufferName) { + std::unique_ptr SB = getNewUninitMemBuffer(Size, BufferName); + if (!SB) + return nullptr; memset(const_cast(SB->getBufferStart()), 0, Size); return SB; } +ErrorOr> +MemoryBuffer::getFileOrSTDIN(const Twine &Filename, int64_t FileSize, + bool RequiresNullTerminator) { + SmallString<256> NameBuf; + StringRef NameRef = Filename.toStringRef(NameBuf); + + if (NameRef == "-") + return getSTDIN(); + return getFile(Filename, FileSize, RequiresNullTerminator); +} -/// 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 &result, - int64_t FileSize) { - if (Filename == "-") - return getSTDIN(result); - return getFile(Filename, result, FileSize); +ErrorOr> +MemoryBuffer::getFileSlice(const Twine &FilePath, uint64_t MapSize, + uint64_t Offset) { + return getFileAux(FilePath, -1, MapSize, Offset, false, false); } + //===----------------------------------------------------------------------===// // MemoryBuffer::getFile implementation. //===----------------------------------------------------------------------===// @@ -198,8 +204,8 @@ class MemoryBufferMMapFile : public MemoryBuffer { public: MemoryBufferMMapFile(bool RequiresNullTerminator, int FD, uint64_t Len, - uint64_t Offset, error_code EC) - : MFR(FD, false, sys::fs::mapped_file_region::readonly, + uint64_t Offset, std::error_code &EC) + : MFR(FD, sys::fs::mapped_file_region::readonly, getLegalMapSize(Len, Offset), getLegalMapOffset(Offset), EC) { if (!EC) { const char *Start = getStart(Len, Offset); @@ -207,20 +213,19 @@ public: } } - virtual const char *getBufferIdentifier() const override { + const char *getBufferIdentifier() const override { // The name is stored after the class itself. return reinterpret_cast(this + 1); } - virtual BufferKind getBufferKind() const override { + BufferKind getBufferKind() const override { return MemoryBuffer_MMap; } }; } -static error_code getMemoryBufferForStream(int FD, - StringRef BufferName, - OwningPtr &result) { +static ErrorOr> +getMemoryBufferForStream(int FD, const Twine &BufferName) { const ssize_t ChunkSize = 4096*4; SmallString Buffer; ssize_t ReadBytes; @@ -230,47 +235,40 @@ 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(); + return MemoryBuffer::getMemBufferCopy(Buffer, BufferName); } -static error_code getFileAux(const char *Filename, - OwningPtr &result, int64_t FileSize, - bool RequiresNullTerminator); - -error_code MemoryBuffer::getFile(Twine Filename, - OwningPtr &result, - int64_t FileSize, - bool RequiresNullTerminator) { - // Ensure the path is null terminated. - SmallString<256> PathBuf; - StringRef NullTerminatedName = Filename.toNullTerminatedStringRef(PathBuf); - return getFileAux(NullTerminatedName.data(), result, FileSize, - RequiresNullTerminator); + +ErrorOr> +MemoryBuffer::getFile(const Twine &Filename, int64_t FileSize, + bool RequiresNullTerminator, bool IsVolatileSize) { + return getFileAux(Filename, FileSize, FileSize, 0, + RequiresNullTerminator, IsVolatileSize); } -static error_code getOpenFileImpl(int FD, const char *Filename, - OwningPtr &Result, - uint64_t FileSize, uint64_t MapSize, - int64_t Offset, bool RequiresNullTerminator); +static ErrorOr> +getOpenFileImpl(int FD, const Twine &Filename, uint64_t FileSize, + uint64_t MapSize, int64_t Offset, bool RequiresNullTerminator, + bool IsVolatileSize); -static error_code getFileAux(const char *Filename, - OwningPtr &result, int64_t FileSize, - bool RequiresNullTerminator) { +static ErrorOr> +getFileAux(const Twine &Filename, int64_t FileSize, uint64_t MapSize, + uint64_t Offset, 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> Ret = + getOpenFileImpl(FD, Filename, FileSize, MapSize, Offset, + RequiresNullTerminator, IsVolatileSize); close(FD); - return ret; + return Ret; } static bool shouldUseMmap(int FD, @@ -278,7 +276,14 @@ 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) @@ -294,9 +299,8 @@ 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(); } @@ -307,28 +311,27 @@ 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) return false; +#if defined(__CYGWIN__) + // Don't try to map files that are exactly a multiple of the physical page size + // if we need a null terminator. + // FIXME: We should reorganize again getPageSize() on Win32. + if ((FileSize & (4096 - 1)) == 0) + return false; +#endif + return true; } -static error_code getOpenFileImpl(int FD, const char *Filename, - OwningPtr &result, - uint64_t FileSize, uint64_t MapSize, - int64_t Offset, bool RequiresNullTerminator) { - static int PageSize = sys::process::get_self()->page_size(); +static ErrorOr> +getOpenFileImpl(int FD, const Twine &Filename, uint64_t FileSize, + uint64_t MapSize, int64_t Offset, bool RequiresNullTerminator, + bool IsVolatileSize) { + static int PageSize = sys::Process::getPageSize(); // Default is to map the full file. if (MapSize == uint64_t(-1)) { @@ -336,7 +339,7 @@ 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; @@ -346,7 +349,7 @@ 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(); } @@ -354,28 +357,29 @@ 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 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); + std::unique_ptr Buf = + MemoryBuffer::getNewUninitMemBuffer(MapSize, Filename); if (!Buf) { // Failed to create a buffer. The only way it can fail is if // new(std::nothrow) returns 0. return make_error_code(errc::not_enough_memory); } - OwningPtr SB(Buf); - char *BufPtr = const_cast(SB->getBufferStart()); + char *BufPtr = const_cast(Buf->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) { @@ -388,46 +392,46 @@ 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(Buf); } -error_code MemoryBuffer::getOpenFile(int FD, const char *Filename, - OwningPtr &Result, - uint64_t FileSize, - bool RequiresNullTerminator) { - return getOpenFileImpl(FD, Filename, Result, FileSize, FileSize, 0, - RequiresNullTerminator); +ErrorOr> +MemoryBuffer::getOpenFile(int FD, const Twine &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 &Result, - uint64_t MapSize, int64_t Offset) { - return getOpenFileImpl(FD, Filename, Result, -1, MapSize, Offset, false); +ErrorOr> +MemoryBuffer::getOpenFileSlice(int FD, const Twine &Filename, uint64_t MapSize, + int64_t Offset) { + assert(MapSize != uint64_t(-1)); + return getOpenFileImpl(FD, Filename, -1, MapSize, Offset, false, + /*IsVolatileSize*/ false); } -//===----------------------------------------------------------------------===// -// MemoryBuffer::getSTDIN implementation. -//===----------------------------------------------------------------------===// - -error_code MemoryBuffer::getSTDIN(OwningPtr &result) { +ErrorOr> 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, "", result); + return getMemoryBufferForStream(0, ""); +} + +MemoryBufferRef MemoryBuffer::getMemBufferRef() const { + StringRef Data = getBuffer(); + StringRef Identifier = getBufferIdentifier(); + return MemoryBufferRef(Data, Identifier); }