INFORMATIONAL: new ELFObjectWriter patch

include/llvm/MC/ELFObjectWriter.h

Index: include/llvm/MC/ELFObjectWriter.h
===================================================================
--- include/llvm/MC/ELFObjectWriter.h	(revision 118813)
+++ include/llvm/MC/ELFObjectWriter.h	(working copy)
@@ -11,20 +11,31 @@
 #define LLVM_MC_ELFOBJECTWRITER_H
 
 #include "llvm/ADT/Triple.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/StringMap.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallString.h"
 #include "llvm/MC/MCObjectWriter.h"
-#include "llvm/Support/raw_ostream.h"
+#include "llvm/MC/MCValue.h"
+#include "llvm/Support/ELF.h"
 #include <cassert>
+#include <vector>
 
 namespace llvm {
 class MCAsmFixup;
 class MCAssembler;
 class MCFragment;
 class MCValue;
+class MCSectionData;
+class MCSymbolData;
+class MCSymbol;
+class MCDataFragment;
+class MCSectionELF;
 class raw_ostream;
 
 class ELFObjectWriter : public MCObjectWriter {
-  void *Impl;
 
+
 public:
   ELFObjectWriter(raw_ostream &OS, bool Is64Bit, Triple::OSType OSType, 
                   uint16_t EMachine, bool IsLittleEndian = true,
@@ -38,7 +49,9 @@
                                 const MCAsmLayout &Layout,
                                 const MCFragment *Fragment,
                                 const MCFixup &Fixup, MCValue Target,
-                                uint64_t &FixedValue);
+                                uint64_t &FixedValue) {
+    assert(0 && "RecordRelocation is not specific enough");
+  }
 
   virtual bool IsFixupFullyResolved(const MCAssembler &Asm,
                                     const MCValue Target,
@@ -46,8 +59,233 @@
                                     const MCFragment *DF) const;
 
   virtual void WriteObject(MCAssembler &Asm, const MCAsmLayout &Layout);
+
+protected:
+
+  /*static bool isFixupKindX86RIPRel(unsigned Kind) {
+    return Kind == X86::reloc_riprel_4byte ||
+    Kind == X86::reloc_riprel_4byte_movq_load;
+    }*/
+
+
+  /// ELFSymbolData - Helper struct for containing some precomputed information
+  /// on symbols.
+  struct ELFSymbolData {
+    MCSymbolData *SymbolData;
+    uint64_t StringIndex;
+    uint32_t SectionIndex;
+
+    // Support lexicographic sorting.
+    bool operator<(const ELFSymbolData &RHS) const ;
+  };
+
+  /// @name Relocation Data
+  /// @{
+
+  struct ELFRelocationEntry {
+    // Make these big enough for both 32-bit and 64-bit
+    uint64_t r_offset;
+    int Index;
+    unsigned Type;
+    const MCSymbol *Symbol;
+    uint64_t r_addend;
+
+    // Support lexicographic sorting.
+    bool operator<(const ELFRelocationEntry &RE) const;
+  };
+
+  SmallPtrSet<const MCSymbol *, 16> UsedInReloc;
+  SmallPtrSet<const MCSymbol *, 16> WeakrefUsedInReloc;
+  DenseMap<const MCSymbol *, const MCSymbol *> Renames;
+
+  llvm::DenseMap<const MCSectionData*,
+                 std::vector<ELFRelocationEntry> > Relocations;
+  DenseMap<const MCSection*, uint64_t> SectionStringTableIndex;
+
+  /// @}
+  /// @name Symbol Table Data
+  /// @{
+
+  SmallString<256> StringTable;
+  std::vector<ELFSymbolData> LocalSymbolData;
+  std::vector<ELFSymbolData> ExternalSymbolData;
+  std::vector<ELFSymbolData> UndefinedSymbolData;
+
+  /// @}
+
+  int NumRegularSections;
+
+  bool NeedsGOT;
+
+  bool NeedsSymtabShndx;
+
+  unsigned Is64Bit : 1;
+
+  bool HasRelocationAddend;
+
+  Triple::OSType OSType;
+
+  uint16_t EMachine;
+
+  // This holds the symbol table index of the last local symbol.
+  unsigned LastLocalSymbolIndex;
+  // This holds the .strtab section index.
+  unsigned StringTableIndex;
+  // This holds the .symtab section index.
+  unsigned SymbolTableIndex;
+
+  unsigned ShstrtabIndex;
+
+public:
+
+  /// @name new nonvirtual helpers
+  /// @{
+
+  void WriteWord(uint64_t W) {
+    if (Is64Bit)
+      Write64(W);
+    else
+      Write32(W);
+  }
+
+  void StringLE16(char *buf, uint16_t Value) {
+    buf[0] = char(Value >> 0);
+    buf[1] = char(Value >> 8);
+  }
+
+  void StringLE32(char *buf, uint32_t Value) {
+    StringLE16(buf, uint16_t(Value >> 0));
+    StringLE16(buf + 2, uint16_t(Value >> 16));
+  }
+
+  void StringLE64(char *buf, uint64_t Value) {
+    StringLE32(buf, uint32_t(Value >> 0));
+    StringLE32(buf + 4, uint32_t(Value >> 32));
+  }
+
+  void StringBE16(char *buf ,uint16_t Value) {
+    buf[0] = char(Value >> 8);
+    buf[1] = char(Value >> 0);
+  }
+
+  void StringBE32(char *buf, uint32_t Value) {
+    StringBE16(buf, uint16_t(Value >> 16));
+    StringBE16(buf + 2, uint16_t(Value >> 0));
+  }
+
+  void StringBE64(char *buf, uint64_t Value) {
+    StringBE32(buf, uint32_t(Value >> 32));
+    StringBE32(buf + 4, uint32_t(Value >> 0));
+  }
+
+  void String8(MCDataFragment &F, uint8_t Value);
+
+  void String16(MCDataFragment &F, uint16_t Value);
+
+  void String32(MCDataFragment &F, uint32_t Value);
+
+  void String64(MCDataFragment &F, uint64_t Value);
+
+  /// @}
+
+  /// @name new virtuals
+  /// @{
+  virtual void WriteHeader(uint64_t SectionDataSize, unsigned NumberOfSections);
+
+  virtual void WriteSymbolEntry(MCDataFragment *SymtabF, MCDataFragment *ShndxF,
+                                uint64_t name, uint8_t info,
+                                uint64_t value, uint64_t size,
+                                uint8_t other, uint32_t shndx,
+                                bool Reserved);
+
+  virtual void WriteSymbol(MCDataFragment *SymtabF,  MCDataFragment *ShndxF,
+                           ELFSymbolData &MSD,
+                           const MCAsmLayout &Layout);
+
+  typedef DenseMap<const MCSectionELF*, uint32_t> SectionIndexMapTy;
+  virtual void WriteSymbolTable(MCDataFragment *SymtabF, MCDataFragment *ShndxF,
+                                const MCAssembler &Asm,
+                                const MCAsmLayout &Layout,
+                                const SectionIndexMapTy &SectionIndexMap);
+
+  virtual uint64_t getSymbolIndexInSymbolTable(const MCAssembler &Asm,
+                                               const MCSymbol *S);
+
+  /// ComputeSymbolTable - Compute the symbol table data
+  ///
+  /// \param StringTable [out] - The string table data.
+  /// \param StringIndexMap [out] - Map from symbol names to offsets in the
+  /// string table.
+  virtual void ComputeSymbolTable(MCAssembler &Asm,
+                                  const SectionIndexMapTy &SectionIndexMap);
+
+  virtual void ComputeIndexMap(MCAssembler &Asm,
+                               SectionIndexMapTy &SectionIndexMap);
+
+  virtual void WriteRelocation(MCAssembler &Asm, MCAsmLayout &Layout,
+                               const MCSectionData &SD);
+
+  virtual void WriteRelocations(MCAssembler &Asm, MCAsmLayout &Layout);
+
+  virtual void CreateMetadataSections(MCAssembler &Asm, MCAsmLayout &Layout,
+                                      const SectionIndexMapTy &SectionIndexMap);
+
+  // Map from a group section to the signature symbol
+  typedef DenseMap<const MCSectionELF*, const MCSymbol*> GroupMapTy;
+  virtual void CreateGroupSections(MCAssembler &Asm, MCAsmLayout &Layout,
+                                   GroupMapTy &GroupMap);
+
+  virtual void WriteSecHdrEntry(uint32_t Name, uint32_t Type, uint64_t Flags,
+                                uint64_t Address, uint64_t Offset,
+                                uint64_t Size, uint32_t Link, uint32_t Info,
+                                uint64_t Alignment, uint64_t EntrySize);
+
+  virtual void WriteRelocationsFragment(const MCAssembler &Asm, MCDataFragment *F,
+                                        const MCSectionData *SD);
+
+  virtual void WriteSection(MCAssembler &Asm,
+                            const SectionIndexMapTy &SectionIndexMap,
+                            uint32_t GroupSymbolIndex,
+                            uint64_t Offset, uint64_t Size, uint64_t Alignment,
+                            const MCSectionELF &Section);
+  /// @}
 };
 
+
+//===- X86ELFObjectWriter -------------------------------------------===//
+
+class X86ELFObjectWriter : public ELFObjectWriter {
+public:
+  X86ELFObjectWriter(raw_ostream &_OS, bool _Is64Bit, Triple::OSType _OSType,
+                     uint16_t _EMachine, bool _IsLittleEndian = true,
+                     bool _HasRelocationAddend = true);
+  
+  virtual ~X86ELFObjectWriter();
+  virtual void RecordRelocation(const MCAssembler &Asm,
+                                const MCAsmLayout &Layout,
+                                const MCFragment *Fragment,
+                                const MCFixup &Fixup, MCValue Target,
+                                uint64_t &FixedValue);
+};
+
+
+//===- ARMELFObjectWriter -------------------------------------------===//
+
+class ARMELFObjectWriter : public ELFObjectWriter {
+
+public:
+  ARMELFObjectWriter(raw_ostream &_OS, bool _Is64Bit, Triple::OSType _OSType,
+                     uint16_t _EMachine, bool _IsLittleEndian = true,
+                     bool _HasRelocationAddend = true);
+
+  virtual ~ARMELFObjectWriter();
+  virtual void RecordRelocation(const MCAssembler &Asm,
+                                const MCAsmLayout &Layout,
+                                const MCFragment *Fragment,
+                                const MCFixup &Fixup, MCValue Target,
+                                uint64_t &FixedValue);
+};
+
 } // End llvm namespace
 
 #endif