Add Elf 32 Support to Courgette.

courgette/disassembler_elf_32_x86.h

+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef COURGETTE_DISASSEMBLER_ELF_32_X86_H_
+#define COURGETTE_DISASSEMBLER_ELF_32_X86_H_
+
+#include "base/basictypes.h"
+#include "courgette/disassembler.h"
+#include "courgette/memory_allocator.h"
+#include "courgette/types_elf.h"
+
+namespace courgette {
+
+class AssemblyProgram;
+
+class DisassemblerElf32X86 : public Disassembler {
+ public:
+  explicit DisassemblerElf32X86(const void* start, size_t length);
+
+  virtual ExecutableType kind() { return EXE_ELF_32_X86; }
+
+  // Returns 'true' if the buffer appears to point to a valid ELF executable
+  // for X86 32 bitWindows 32 bit. If ParseHeader() succeeds, other member
+  // functions may be called.
+  virtual bool ParseHeader();
+
+  virtual bool Disassemble(AssemblyProgram* target);
+
+  // Public for unittests only
+  std::vector<RVA> &Abs32Locations() { return abs32_locations_; }
+  std::vector<RVA> &Rel32Locations() { return rel32_locations_; }
+
+ protected:
+
+  uint32 DiscoverLength();
+
+  // Misc Section Helpers
+
+  const Elf32_Half SectionHeaderCount() const {
+    return section_header_table_size_;
+  }
+
+  const Elf32_Shdr *SectionHeader(int id) const {
+    assert(id >= 0 && id < SectionHeaderCount());
+    return section_header_table_ + id;
+  }
+
+  const uint8 *SectionBody(int id) const {
+    return OffsetToPointer(SectionHeader(id)->sh_offset);
+  }
+
+  const Elf32_Word SectionBodySize(int id) const {
+    return SectionHeader(id)->sh_size;
+  }
+
+  // Misc Segment Helpers
+
+  const Elf32_Half ProgramSegmentHeaderCount() const {
+    return program_header_table_size_;
+  }
+
+  const Elf32_Phdr *ProgramSegmentHeader(int id) const {
+    assert(id >= 0 && id < ProgramSegmentHeaderCount());
+    return program_header_table_ + id;
+  }
+
+  // The virtual memory address at which this program segment will be loaded
+  const Elf32_Addr ProgramSegmentMemoryBegin(int id) const {
+    return ProgramSegmentHeader(id)->p_vaddr;
+  }
+
+  // The number of virtual memory bytes for this program segment
+  const Elf32_Word ProgramSegmentMemorySize(int id) const {
+    return ProgramSegmentHeader(id)->p_memsz;
+  }
+
+  // Pointer into the source file for this program segment
+  const Elf32_Addr ProgramSegmentFileOffset(int id) const {
+    return ProgramSegmentHeader(id)->p_offset;
+  }
+
+  // Number of file bytes for this program segment. Is <= ProgramMemorySize.
+  const Elf32_Word ProgramSegmentFileSize(int id) const {
+    return ProgramSegmentHeader(id)->p_filesz;
+  }
+
+  // Misc address space helpers
+
+  CheckBool IsValidRVA(RVA rva) const WARN_UNUSED_RESULT;
+
+  // Convert an ELF relocation struction into an RVA
+  CheckBool RelToRVA(Elf32_Rel rel, RVA* result) const WARN_UNUSED_RESULT;
+
+  // Returns kNoOffset if there is no file offset corresponding to 'rva'.
+  CheckBool RVAToFileOffset(RVA rva, size_t* result) const WARN_UNUSED_RESULT;
+
+  RVA FileOffsetToRVA(size_t offset) const WARN_UNUSED_RESULT;
+
+  CheckBool RVAsToOffsets(std::vector<RVA>* rvas /*in*/,
+                          std::vector<size_t>* offsets /*out*/);
+
+  // Parsing Code used to really implement Disassemble
+
+  CheckBool ParseFile(AssemblyProgram* target) WARN_UNUSED_RESULT;
+  CheckBool ParseRelocationSection(
+      const Elf32_Shdr *section_header,
+        AssemblyProgram* program) WARN_UNUSED_RESULT;
+  CheckBool ParseProgbitsSection(
+      const Elf32_Shdr *section_header,
+      std::vector<size_t>::iterator* current_abs_offset,
+      std::vector<size_t>::iterator end_abs_offset,
+      std::vector<size_t>::iterator* current_rel_offset,
+      std::vector<size_t>::iterator end_rel_offset,
+      AssemblyProgram* program) WARN_UNUSED_RESULT;
+  CheckBool ParseSimpleRegion(size_t start_file_offset,
+                              size_t end_file_offset,
+                              AssemblyProgram* program) WARN_UNUSED_RESULT;
+
+  CheckBool ParseAbs32Relocs() WARN_UNUSED_RESULT;
+  CheckBool ParseRel32RelocsFromSections() WARN_UNUSED_RESULT;
+  CheckBool ParseRel32RelocsFromSection(
+      const Elf32_Shdr* section) WARN_UNUSED_RESULT;
+
+  Elf32_Ehdr *header_;
+  Elf32_Shdr *section_header_table_;
+  Elf32_Half section_header_table_size_;
+
+  Elf32_Phdr *program_header_table_;
+  Elf32_Half program_header_table_size_;
+
+  // Section header for default
+  const char *default_string_section_;
+
+  std::vector<RVA> abs32_locations_;
+  std::vector<RVA> rel32_locations_;
+
+  DISALLOW_COPY_AND_ASSIGN(DisassemblerElf32X86);
+};
+
+}  // namespace courgette
+
+#endif  // COURGETTE_DISASSEMBLER_ELF_32_X86_H_