1 //===- OutputSection.h ------------------------------------------*- C++ -*-===//
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 #ifndef LLD_MACHO_MERGED_OUTPUT_SECTION_H
10 #define LLD_MACHO_MERGED_OUTPUT_SECTION_H
11 
12 #include "InputSection.h"
13 #include "OutputSection.h"
14 #include "lld/Common/LLVM.h"
15 #include "llvm/ADT/MapVector.h"
16 
17 namespace lld {
18 namespace macho {
19 
20 // Linking multiple files will inevitably mean resolving sections in different
21 // files that are labeled with the same segment and section name. This class
22 // contains all such sections and writes the data from each section sequentially
23 // in the final binary.
24 class MergedOutputSection : public OutputSection {
25 public:
MergedOutputSection(StringRef name)26   MergedOutputSection(StringRef name) : OutputSection(MergedKind, name) {}
27 
firstSection()28   const InputSection *firstSection() const { return inputs.front(); }
lastSection()29   const InputSection *lastSection() const { return inputs.back(); }
30 
31   // These accessors will only be valid after finalizing the section
getSize()32   uint64_t getSize() const override { return size; }
getFileSize()33   uint64_t getFileSize() const override { return fileSize; }
34 
35   void mergeInput(InputSection *input);
36   void finalize() override;
37 
38   void writeTo(uint8_t *buf) const override;
39 
40   std::vector<InputSection *> inputs;
41 
classof(const OutputSection * sec)42   static bool classof(const OutputSection *sec) {
43     return sec->kind() == MergedKind;
44   }
45 
46 private:
47   void mergeFlags(uint32_t inputFlags);
48 
49   size_t size = 0;
50   uint64_t fileSize = 0;
51 };
52 
53 } // namespace macho
54 } // namespace lld
55 
56 #endif
57