MC: Clean up naming in MCObjectWriter. NFC.
[oota-llvm.git] / include / llvm / MC / MCMachObjectWriter.h
index ec51031d0bb3998546226512dea91dfd4bf56b82..712f81e8f61157b5920623d300ffabe3b13ef7a7 100644 (file)
 #ifndef LLVM_MC_MCMACHOBJECTWRITER_H
 #define LLVM_MC_MCMACHOBJECTWRITER_H
 
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCObjectWriter.h"
+#include "llvm/MC/StringTableBuilder.h"
 #include "llvm/Support/DataTypes.h"
+#include "llvm/Support/MachO.h"
+#include <vector>
 
 namespace llvm {
 
+class MachObjectWriter;
+
 class MCMachObjectTargetWriter {
   const unsigned Is64Bit : 1;
   const uint32_t CPUType;
   const uint32_t CPUSubtype;
-  // FIXME: Remove this, we should just always use it once we no longer care
-  // about Darwin 'as' compatibility.
-  const unsigned UseAggressiveSymbolFolding : 1;
   unsigned LocalDifference_RIT;
 
 protected:
   MCMachObjectTargetWriter(bool Is64Bit_, uint32_t CPUType_,
-                           uint32_t CPUSubtype_,
-                           bool UseAggressiveSymbolFolding_ = false);
+                           uint32_t CPUSubtype_);
 
   void setLocalDifferenceRelocationType(unsigned Type) {
     LocalDifference_RIT = Type;
@@ -36,11 +40,17 @@ protected:
 public:
   virtual ~MCMachObjectTargetWriter();
 
-  /// @name Accessors
+  /// \name Lifetime Management
+  /// @{
+
+  virtual void reset() {};
+
+  /// @}
+
+  /// \name Accessors
   /// @{
 
   bool is64Bit() const { return Is64Bit; }
-  bool useAggressiveSymbolFolding() const { return UseAggressiveSymbolFolding; }
   uint32_t getCPUType() const { return CPUType; }
   uint32_t getCPUSubtype() const { return CPUSubtype; }
   unsigned getLocalDifferenceRelocationType() const {
@@ -48,8 +58,211 @@ public:
   }
 
   /// @}
+
+  /// \name API
+  /// @{
+
+  virtual void recordRelocation(MachObjectWriter *Writer, MCAssembler &Asm,
+                                const MCAsmLayout &Layout,
+                                const MCFragment *Fragment,
+                                const MCFixup &Fixup, MCValue Target,
+                                uint64_t &FixedValue) = 0;
+
+  /// @}
 };
 
+class MachObjectWriter : public MCObjectWriter {
+  /// MachSymbolData - Helper struct for containing some precomputed information
+  /// on symbols.
+  struct MachSymbolData {
+    const MCSymbol *Symbol;
+    uint64_t StringIndex;
+    uint8_t SectionIndex;
+
+    // Support lexicographic sorting.
+    bool operator<(const MachSymbolData &RHS) const;
+  };
+
+  /// The target specific Mach-O writer instance.
+  std::unique_ptr<MCMachObjectTargetWriter> TargetObjectWriter;
+
+  /// \name Relocation Data
+  /// @{
+
+  struct RelAndSymbol {
+    const MCSymbol *Sym;
+    MachO::any_relocation_info MRE;
+    RelAndSymbol(const MCSymbol *Sym, const MachO::any_relocation_info &MRE)
+        : Sym(Sym), MRE(MRE) {}
+  };
+
+  llvm::DenseMap<const MCSection *, std::vector<RelAndSymbol>> Relocations;
+  llvm::DenseMap<const MCSection *, unsigned> IndirectSymBase;
+
+  /// @}
+  /// \name Symbol Table Data
+  /// @{
+
+  StringTableBuilder StringTable;
+  std::vector<MachSymbolData> LocalSymbolData;
+  std::vector<MachSymbolData> ExternalSymbolData;
+  std::vector<MachSymbolData> UndefinedSymbolData;
+
+  /// @}
+
+  MachSymbolData *findSymbolData(const MCSymbol &Sym);
+
+public:
+  MachObjectWriter(MCMachObjectTargetWriter *MOTW, raw_pwrite_stream &OS,
+                   bool IsLittleEndian)
+      : MCObjectWriter(OS, IsLittleEndian), TargetObjectWriter(MOTW) {}
+
+  const MCSymbol &findAliasedSymbol(const MCSymbol &Sym) const;
+
+  /// \name Lifetime management Methods
+  /// @{
+
+  void reset() override;
+
+  /// @}
+
+  /// \name Utility Methods
+  /// @{
+
+  bool isFixupKindPCRel(const MCAssembler &Asm, unsigned Kind);
+
+  SectionAddrMap SectionAddress;
+
+  SectionAddrMap &getSectionAddressMap() { return SectionAddress; }
+
+  uint64_t getSectionAddress(const MCSection *Sec) const {
+    return SectionAddress.lookup(Sec);
+  }
+  uint64_t getSymbolAddress(const MCSymbol &S, const MCAsmLayout &Layout) const;
+
+  uint64_t getFragmentAddress(const MCFragment *Fragment,
+                              const MCAsmLayout &Layout) const;
+
+  uint64_t getPaddingSize(const MCSection *SD, const MCAsmLayout &Layout) const;
+
+  bool doesSymbolRequireExternRelocation(const MCSymbol &S);
+
+  /// @}
+
+  /// \name Target Writer Proxy Accessors
+  /// @{
+
+  bool is64Bit() const { return TargetObjectWriter->is64Bit(); }
+  bool isX86_64() const {
+    uint32_t CPUType = TargetObjectWriter->getCPUType();
+    return CPUType == MachO::CPU_TYPE_X86_64;
+  }
+
+  /// @}
+
+  void WriteHeader(unsigned NumLoadCommands, unsigned LoadCommandsSize,
+                   bool SubsectionsViaSymbols);
+
+  /// WriteSegmentLoadCommand - Write a segment load command.
+  ///
+  /// \param NumSections The number of sections in this segment.
+  /// \param SectionDataSize The total size of the sections.
+  void WriteSegmentLoadCommand(unsigned NumSections,
+                               uint64_t VMSize,
+                               uint64_t SectionDataStartOffset,
+                               uint64_t SectionDataSize);
+
+  void WriteSection(const MCAssembler &Asm, const MCAsmLayout &Layout,
+                    const MCSection &Sec, uint64_t FileOffset,
+                    uint64_t RelocationsStart, unsigned NumRelocations);
+
+  void WriteSymtabLoadCommand(uint32_t SymbolOffset, uint32_t NumSymbols,
+                              uint32_t StringTableOffset,
+                              uint32_t StringTableSize);
+
+  void WriteDysymtabLoadCommand(uint32_t FirstLocalSymbol,
+                                uint32_t NumLocalSymbols,
+                                uint32_t FirstExternalSymbol,
+                                uint32_t NumExternalSymbols,
+                                uint32_t FirstUndefinedSymbol,
+                                uint32_t NumUndefinedSymbols,
+                                uint32_t IndirectSymbolOffset,
+                                uint32_t NumIndirectSymbols);
+
+  void WriteNlist(MachSymbolData &MSD, const MCAsmLayout &Layout);
+
+  void WriteLinkeditLoadCommand(uint32_t Type, uint32_t DataOffset,
+                                uint32_t DataSize);
+
+  void WriteLinkerOptionsLoadCommand(const std::vector<std::string> &Options);
+
+  // FIXME: We really need to improve the relocation validation. Basically, we
+  // want to implement a separate computation which evaluates the relocation
+  // entry as the linker would, and verifies that the resultant fixup value is
+  // exactly what the encoder wanted. This will catch several classes of
+  // problems:
+  //
+  //  - Relocation entry bugs, the two algorithms are unlikely to have the same
+  //    exact bug.
+  //
+  //  - Relaxation issues, where we forget to relax something.
+  //
+  //  - Input errors, where something cannot be correctly encoded. 'as' allows
+  //    these through in many cases.
+
+  // Add a relocation to be output in the object file. At the time this is
+  // called, the symbol indexes are not know, so if the relocation refers
+  // to a symbol it should be passed as \p RelSymbol so that it can be updated
+  // afterwards. If the relocation doesn't refer to a symbol, nullptr should be
+  // used.
+  void addRelocation(const MCSymbol *RelSymbol, const MCSection *Sec,
+                     MachO::any_relocation_info &MRE) {
+    RelAndSymbol P(RelSymbol, MRE);
+    Relocations[Sec].push_back(P);
+  }
+
+  void RecordScatteredRelocation(const MCAssembler &Asm,
+                                 const MCAsmLayout &Layout,
+                                 const MCFragment *Fragment,
+                                 const MCFixup &Fixup, MCValue Target,
+                                 unsigned Log2Size,
+                                 uint64_t &FixedValue);
+
+  void RecordTLVPRelocation(const MCAssembler &Asm,
+                            const MCAsmLayout &Layout,
+                            const MCFragment *Fragment,
+                            const MCFixup &Fixup, MCValue Target,
+                            uint64_t &FixedValue);
+
+  void recordRelocation(MCAssembler &Asm, const MCAsmLayout &Layout,
+                        const MCFragment *Fragment, const MCFixup &Fixup,
+                        MCValue Target, bool &IsPCRel,
+                        uint64_t &FixedValue) override;
+
+  void BindIndirectSymbols(MCAssembler &Asm);
+
+  /// ComputeSymbolTable - Compute the symbol table data
+  ///
+  void ComputeSymbolTable(MCAssembler &Asm,
+                          std::vector<MachSymbolData> &LocalSymbolData,
+                          std::vector<MachSymbolData> &ExternalSymbolData,
+                          std::vector<MachSymbolData> &UndefinedSymbolData);
+
+  void computeSectionAddresses(const MCAssembler &Asm,
+                               const MCAsmLayout &Layout);
+
+  void ExecutePostLayoutBinding(MCAssembler &Asm,
+                                const MCAsmLayout &Layout) override;
+
+  bool isSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm,
+                                              const MCSymbol &SymA,
+                                              const MCFragment &FB, bool InSet,
+                                              bool IsPCRel) const override;
+
+  void writeObject(MCAssembler &Asm, const MCAsmLayout &Layout) override;
+};
+
+
 /// \brief Construct a new Mach-O writer instance.
 ///
 /// This routine takes ownership of the target writer subclass.
@@ -58,7 +271,8 @@ public:
 /// \param OS - The stream to write to.
 /// \returns The constructed object writer.
 MCObjectWriter *createMachObjectWriter(MCMachObjectTargetWriter *MOTW,
-                                       raw_ostream &OS, bool IsLittleEndian);
+                                       raw_pwrite_stream &OS,
+                                       bool IsLittleEndian);
 
 } // End llvm namespace