diff options
Diffstat (limited to 'llvm/lib/Support/MemoryBuffer.cpp')
| -rw-r--r-- | llvm/lib/Support/MemoryBuffer.cpp | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/llvm/lib/Support/MemoryBuffer.cpp b/llvm/lib/Support/MemoryBuffer.cpp index e4027ca7bbfd..248fb72c4968 100644 --- a/llvm/lib/Support/MemoryBuffer.cpp +++ b/llvm/lib/Support/MemoryBuffer.cpp @@ -162,6 +162,20 @@ MemoryBuffer::getFileSlice(const Twine &FilePath, uint64_t MapSize, //===----------------------------------------------------------------------===// namespace { + +template <typename MB> +constexpr sys::fs::mapped_file_region::mapmode Mapmode = + sys::fs::mapped_file_region::readonly; +template <> +constexpr sys::fs::mapped_file_region::mapmode Mapmode<MemoryBuffer> = + sys::fs::mapped_file_region::readonly; +template <> +constexpr sys::fs::mapped_file_region::mapmode Mapmode<WritableMemoryBuffer> = + sys::fs::mapped_file_region::priv; +template <> +constexpr sys::fs::mapped_file_region::mapmode + Mapmode<WriteThroughMemoryBuffer> = sys::fs::mapped_file_region::readwrite; + /// Memory maps a file descriptor using sys::fs::mapped_file_region. /// /// This handles converting the offset into a legal offset on the platform. @@ -184,7 +198,7 @@ class MemoryBufferMMapFile : public MB { public: MemoryBufferMMapFile(bool RequiresNullTerminator, sys::fs::file_t FD, uint64_t Len, uint64_t Offset, std::error_code &EC) - : MFR(FD, MB::Mapmode, getLegalMapSize(Len, Offset), + : MFR(FD, Mapmode<MB>, getLegalMapSize(Len, Offset), getLegalMapOffset(Offset), EC) { if (!EC) { const char *Start = getStart(Len, Offset); @@ -315,7 +329,7 @@ static bool shouldUseMmap(sys::fs::file_t FD, // 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 (IsVolatile) + if (IsVolatile && RequiresNullTerminator) return false; // We don't use mmap for small files because this can severely fragment our |