path: root/include/llvm/Target/TargetAsmInfo.h

//===-- llvm/Target/TargetAsmInfo.h - Asm info ------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains a class to be used as the basis for target specific
// asm writers.  This class primarily takes care of global printing constants,
// which are used in very similar ways across all targets.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_TARGET_ASM_INFO_H
#define LLVM_TARGET_ASM_INFO_H

#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/Support/DataTypes.h"
#include <string>

namespace llvm {
  // DWARF encoding query type
  namespace DwarfEncoding {
    enum Target {
      Data       = 0,
      CodeLabels = 1,
      Functions  = 2
    };
  }

  namespace SectionKind {
    enum Kind {
      Unknown = 0,      ///< Custom section
      Text,             ///< Text section
      Data,             ///< Data section
      BSS,              ///< BSS section
      ROData,           ///< Readonly data section
      RODataMergeStr,   ///< Readonly data section (mergeable strings)
      RODataMergeConst, ///< Readonly data section (mergeable constants)
      SmallData,        ///< Small data section
      SmallBSS,         ///< Small bss section
      SmallROData,      ///< Small readonly section
      ThreadData,       ///< Initialized TLS data objects
      ThreadBSS         ///< Uninitialized TLS data objects
    };

    static inline bool isReadOnly(Kind K) {
      return (K == SectionKind::ROData ||
              K == SectionKind::RODataMergeConst ||
              K == SectionKind::RODataMergeStr ||
              K == SectionKind::SmallROData);
    }

    static inline bool isBSS(Kind K) {
      return (K == SectionKind::BSS ||
              K == SectionKind::SmallBSS);
    }
  }

  namespace SectionFlags {
    const unsigned Invalid    = -1U;
    const unsigned None       = 0;
    const unsigned Code       = 1 << 0;  ///< Section contains code
    const unsigned Writeable  = 1 << 1;  ///< Section is writeable
    const unsigned BSS        = 1 << 2;  ///< Section contains only zeroes
    const unsigned Mergeable  = 1 << 3;  ///< Section contains mergeable data
    const unsigned Strings    = 1 << 4;  ///< Section contains C-type strings
    const unsigned TLS        = 1 << 5;  ///< Section contains thread-local data
    const unsigned Debug      = 1 << 6;  ///< Section contains debug data
    const unsigned Linkonce   = 1 << 7;  ///< Section is linkonce
    const unsigned Small      = 1 << 8;  ///< Section is small
    const unsigned TypeFlags  = 0xFF;
    // Some gap for future flags
    const unsigned Named      = 1 << 23; ///< Section is named
    const unsigned EntitySize = 0xFF << 24; ///< Entity size for mergeable stuff

    static inline unsigned getEntitySize(unsigned Flags) {
      return (Flags >> 24) & 0xFF;
    }

    static inline unsigned setEntitySize(unsigned Flags, unsigned Size) {
      return ((Flags & ~EntitySize) | ((Size & 0xFF) << 24));
    }

    struct KeyInfo {
      static inline unsigned getEmptyKey() { return Invalid; }
      static inline unsigned getTombstoneKey() { return Invalid - 1; }
      static unsigned getHashValue(const unsigned &Key) { return Key; }
      static bool isEqual(unsigned LHS, unsigned RHS) { return LHS == RHS; }
      static bool isPod() { return true; }
    };

    typedef DenseMap<unsigned, std::string, KeyInfo> FlagsStringsMapType;
  }

  class TargetMachine;
  class CallInst;
  class GlobalValue;
  class Type;
  class Mangler;

  class Section {
    friend class TargetAsmInfo;
    friend class StringMapEntry<Section>;
    friend class StringMap<Section>;

    std::string Name;
    unsigned Flags;
    explicit Section(unsigned F = SectionFlags::Invalid):Flags(F) { }

  public:
    
    bool isNamed() const { return Flags & SectionFlags::Named; }
    unsigned getEntitySize() const { return (Flags >> 24) & 0xFF; }

    const std::string& getName() const { return Name; }
    unsigned getFlags() const { return Flags; }
  };

  /// TargetAsmInfo - This class is intended to be used as a base class for asm
  /// properties and features specific to the target.
  class TargetAsmInfo {
  private:
    mutable StringMap<Section> Sections;
    mutable SectionFlags::FlagsStringsMapType FlagsStrings;
    void fillDefaultValues();
  protected:
    /// TM - The current TargetMachine.
    const TargetMachine &TM;