1 //===--- DataBufferLLVM.cpp -------------------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "lldb/Utility/DataBufferLLVM.h"
11 
12 #include "llvm/ADT/Twine.h"
13 #include "llvm/Support/FileSystem.h"
14 #include "llvm/Support/MemoryBuffer.h"
15 
16 #include <assert.h>    // for assert
17 #include <type_traits> // for move
18 
19 using namespace lldb_private;
20 
21 DataBufferLLVM::DataBufferLLVM(
22     std::unique_ptr<llvm::WritableMemoryBuffer> MemBuffer)
23     : Buffer(std::move(MemBuffer)) {
24   assert(Buffer != nullptr &&
25          "Cannot construct a DataBufferLLVM with a null buffer");
26 }
27 
28 DataBufferLLVM::~DataBufferLLVM() {}
29 
30 std::shared_ptr<DataBufferLLVM>
31 DataBufferLLVM::CreateSliceFromPath(const llvm::Twine &Path, uint64_t Size,
32                                     uint64_t Offset) {
33   // If the file resides non-locally, pass the volatile flag so that we don't
34   // mmap it.
35   bool IsVolatile = !llvm::sys::fs::is_local(Path);
36 
37   auto Buffer =
38       llvm::WritableMemoryBuffer::getFileSlice(Path, Size, Offset, IsVolatile);
39   if (!Buffer)
40     return nullptr;
41   return std::shared_ptr<DataBufferLLVM>(
42       new DataBufferLLVM(std::move(*Buffer)));
43 }
44 
45 std::shared_ptr<DataBufferLLVM>
46 DataBufferLLVM::CreateFromPath(const llvm::Twine &Path) {
47   // If the file resides non-locally, pass the volatile flag so that we don't
48   // mmap it.
49   bool IsVolatile = !llvm::sys::fs::is_local(Path);
50 
51   auto Buffer = llvm::WritableMemoryBuffer::getFile(Path, -1, IsVolatile);
52   if (!Buffer)
53     return nullptr;
54   return std::shared_ptr<DataBufferLLVM>(
55       new DataBufferLLVM(std::move(*Buffer)));
56 }
57 
58 uint8_t *DataBufferLLVM::GetBytes() {
59   return reinterpret_cast<uint8_t *>(Buffer->getBufferStart());
60 }
61 
62 const uint8_t *DataBufferLLVM::GetBytes() const {
63   return reinterpret_cast<const uint8_t *>(Buffer->getBufferStart());
64 }
65 
66 lldb::offset_t DataBufferLLVM::GetByteSize() const {
67   return Buffer->getBufferSize();
68 }
69