1 //===- DXContainer.cpp - DXContainer object file implementation -----------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "llvm/Object/DXContainer.h"
10 #include "llvm/BinaryFormat/DXContainer.h"
11 #include "llvm/Object/Error.h"
12 
13 using namespace llvm;
14 using namespace llvm::object;
15 
16 static Error parseFailed(const Twine &Msg) {
17   return make_error<GenericBinaryError>(Msg.str(), object_error::parse_failed);
18 }
19 
20 template <typename T>
21 static Error readStruct(StringRef Buffer, const char *P, T &Struct) {
22   // Don't read before the beginning or past the end of the file
23   if (P < Buffer.begin() || P + sizeof(T) > Buffer.end())
24     return parseFailed("Reading structure out of file bounds");
25 
26   memcpy(&Struct, P, sizeof(T));
27   // DXContainer is always little endian
28   if (sys::IsBigEndianHost)
29     Struct.byteSwap();
30   return Error::success();
31 }
32 
33 DXContainer::DXContainer(MemoryBufferRef O) : Data(O) {}
34 
35 Error DXContainer::parseHeader() {
36   return readStruct(Data.getBuffer(), Data.getBuffer().data(), Header);
37 }
38 
39 Expected<DXContainer> DXContainer::create(MemoryBufferRef Object) {
40   DXContainer Container(Object);
41   if (Error Err = Container.parseHeader())
42     return std::move(Err);
43   return Container;
44 }
45