| 1 | //===- Writer.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_COFF_WRITER_H |
| 10 | #define LLD_COFF_WRITER_H |
| 11 | |
| 12 | #include "Chunks.h" |
| 13 | #include "llvm/ADT/StringRef.h" |
| 14 | #include "llvm/Object/COFF.h" |
| 15 | #include <chrono> |
| 16 | #include <cstdint> |
| 17 | #include <vector> |
| 18 | |
| 19 | namespace lld::coff { |
| 20 | static const int pageSize = 4096; |
| 21 | class COFFLinkerContext; |
| 22 | |
| 23 | void writeResult(COFFLinkerContext &ctx); |
| 24 | |
| 25 | class PartialSection { |
| 26 | public: |
| 27 | PartialSection(StringRef n, uint32_t chars) |
| 28 | : name(n), characteristics(chars) {} |
| 29 | StringRef name; |
| 30 | unsigned characteristics; |
| 31 | std::vector<Chunk *> chunks; |
| 32 | }; |
| 33 | |
| 34 | // OutputSection represents a section in an output file. It's a |
| 35 | // container of chunks. OutputSection and Chunk are 1:N relationship. |
| 36 | // Chunks cannot belong to more than one OutputSections. The writer |
| 37 | // creates multiple OutputSections and assign them unique, |
| 38 | // non-overlapping file offsets and RVAs. |
| 39 | class OutputSection { |
| 40 | public: |
| 41 | OutputSection(llvm::StringRef n, uint32_t chars) : name(n) { |
| 42 | header.Characteristics = chars; |
| 43 | } |
| 44 | void addChunk(Chunk *c); |
| 45 | void insertChunkAtStart(Chunk *c); |
| 46 | void merge(OutputSection *other); |
| 47 | void setPermissions(uint32_t c); |
| 48 | uint64_t getRVA() const { return header.VirtualAddress; } |
| 49 | uint64_t getFileOff() const { return header.PointerToRawData; } |
| 50 | void writeHeaderTo(uint8_t *buf, bool isDebug); |
| 51 | void addContributingPartialSection(PartialSection *sec); |
| 52 | |
| 53 | // Returns the size of this section in an executable memory image. |
| 54 | // This may be smaller than the raw size (the raw size is multiple |
| 55 | // of disk sector size, so there may be padding at end), or may be |
| 56 | // larger (if that's the case, the loader reserves spaces after end |
| 57 | // of raw data). |
| 58 | uint64_t getVirtualSize() { return header.VirtualSize; } |
| 59 | |
| 60 | // Returns the size of the section in the output file. |
| 61 | uint64_t getRawSize() { return header.SizeOfRawData; } |
| 62 | |
| 63 | // Set offset into the string table storing this section name. |
| 64 | // Used only when the name is longer than 8 bytes. |
| 65 | void setStringTableOff(uint32_t v) { stringTableOff = v; } |
| 66 | |
| 67 | bool isCodeSection() const { |
| 68 | return (header.Characteristics & llvm::COFF::IMAGE_SCN_CNT_CODE) && |
| 69 | (header.Characteristics & llvm::COFF::IMAGE_SCN_MEM_READ) && |
| 70 | (header.Characteristics & llvm::COFF::IMAGE_SCN_MEM_EXECUTE); |
| 71 | } |
| 72 | |
| 73 | // N.B. The section index is one based. |
| 74 | uint32_t sectionIndex = 0; |
| 75 | |
| 76 | llvm::StringRef name; |
| 77 | llvm::object::coff_section header = {}; |
| 78 | |
| 79 | std::vector<Chunk *> chunks; |
| 80 | std::vector<Chunk *> origChunks; |
| 81 | |
| 82 | std::vector<PartialSection *> contribSections; |
| 83 | |
| 84 | private: |
| 85 | uint32_t stringTableOff = 0; |
| 86 | }; |
| 87 | |
| 88 | } // namespace lld::coff |
| 89 | |
| 90 | #endif |
| 91 |