lld/COFF/Writer.h

   1 //===- Writer.h -------------------------------------------------*- C++ -*-===//
   2 //
   3 //                             The LLVM Linker
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #ifndef LLD_COFF_WRITER_H
  11 #define LLD_COFF_WRITER_H
  12
  13 #include "Chunks.h"
  14 #include "llvm/ADT/StringRef.h"
  15 #include "llvm/Object/COFF.h"
  16 #include <cstdint>
  17 #include <vector>
  18
  19 namespace lld {
  20 namespace coff {
  21 class SymbolTable;
  22
  23 static const int PageSize = 4096;
  24
  25 void writeResult(SymbolTable *T);
  26
  27 // OutputSection represents a section in an output file. It's a
  28 // container of chunks. OutputSection and Chunk are 1:N relationship.
  29 // Chunks cannot belong to more than one OutputSections. The writer
  30 // creates multiple OutputSections and assign them unique,
  31 // non-overlapping file offsets and RVAs.
  32 class OutputSection {
  33 public:
  34   OutputSection(llvm::StringRef N) : Name(N), Header({}) {}
  35   void setRVA(uint64_t);
  36   void setFileOffset(uint64_t);
  37   void addChunk(Chunk *C);
  38   llvm::StringRef getName() { return Name; }
  39   std::vector<Chunk *> &getChunks() { return Chunks; }
  40   void addPermissions(uint32_t C);
  41   void setPermissions(uint32_t C);
  42   uint32_t getPermissions() { return Header.Characteristics & PermMask; }
  43   uint32_t getCharacteristics() { return Header.Characteristics; }
  44   uint64_t getRVA() { return Header.VirtualAddress; }
  45   uint64_t getFileOff() { return Header.PointerToRawData; }
  46   void writeHeaderTo(uint8_t *Buf);
  47
  48   // Returns the size of this section in an executable memory image.
  49   // This may be smaller than the raw size (the raw size is multiple
  50   // of disk sector size, so there may be padding at end), or may be
  51   // larger (if that's the case, the loader reserves spaces after end
  52   // of raw data).
  53   uint64_t getVirtualSize() { return Header.VirtualSize; }
  54
  55   // Returns the size of the section in the output file.
  56   uint64_t getRawSize() { return Header.SizeOfRawData; }
  57
  58   // Set offset into the string table storing this section name.
  59   // Used only when the name is longer than 8 bytes.
  60   void setStringTableOff(uint32_t V) { StringTableOff = V; }
  61
  62   // N.B. The section index is one based.
  63   uint32_t SectionIndex = 0;
  64
  65 private:
  66   llvm::StringRef Name;
  67   llvm::object::coff_section Header;
  68   uint32_t StringTableOff = 0;
  69   std::vector<Chunk *> Chunks;
  70 };
  71
  72 }
  73 }
  74
  75 #endif