Subversion Repositories QNX 8.QNX8 LLVM/Clang compiler suite

//===- SymbolicFile.h - Interface that only provides symbols ----*- C++ -*-===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

//

// This file declares the SymbolicFile interface.

//

//===----------------------------------------------------------------------===//

#ifndef LLVM_OBJECT_SYMBOLICFILE_H

#define LLVM_OBJECT_SYMBOLICFILE_H

#include "llvm/ADT/iterator_range.h"

#include "llvm/BinaryFormat/Magic.h"

#include "llvm/Object/Binary.h"

#include "llvm/Support/Error.h"

#include "llvm/Support/Format.h"

#include "llvm/Support/MemoryBufferRef.h"

#include <cinttypes>

#include <cstdint>

#include <cstring>

#include <iterator>

#include <memory>

namespace llvm {

class LLVMContext;

class raw_ostream;

namespace object {

union DataRefImpl {

  // This entire union should probably be a

  // char[max(8, sizeof(uintptr_t))] and require the impl to cast.

  struct {

    uint32_t a, b;

  } d;

  uintptr_t p;

  DataRefImpl() { std::memset(this, 0, sizeof(DataRefImpl)); }

};

template <typename OStream>

OStream& operator<<(OStream &OS, const DataRefImpl &D) {

  OS << "(" << format("0x%08" PRIxPTR, D.p) << " (" << format("0x%08x", D.d.a)

     << ", " << format("0x%08x", D.d.b) << "))";

  return OS;

}

inline bool operator==(const DataRefImpl &a, const DataRefImpl &b) {

  // Check bitwise identical. This is the only legal way to compare a union w/o

  // knowing which member is in use.

  return std::memcmp(&a, &b, sizeof(DataRefImpl)) == 0;

}

inline bool operator!=(const DataRefImpl &a, const DataRefImpl &b) {

  return !operator==(a, b);

}

inline bool operator<(const DataRefImpl &a, const DataRefImpl &b) {

  // Check bitwise identical. This is the only legal way to compare a union w/o

  // knowing which member is in use.

  return std::memcmp(&a, &b, sizeof(DataRefImpl)) < 0;

}

template <class content_type> class content_iterator {

  content_type Current;

public:

  using iterator_category = std::forward_iterator_tag;

  using value_type = content_type;

  using difference_type = std::ptrdiff_t;

  using pointer = value_type *;

  using reference = value_type &;

  content_iterator(content_type symb) : Current(std::move(symb)) {}

  const content_type *operator->() const { return &Current; }

  const content_type &operator*() const { return Current; }

  bool operator==(const content_iterator &other) const {

    return Current == other.Current;

  }

  bool operator!=(const content_iterator &other) const {

    return !(*this == other);

  }

  content_iterator &operator++() { // preincrement

    Current.moveNext();

    return *this;

  }

};

class SymbolicFile;

/// This is a value type class that represents a single symbol in the list of

/// symbols in the object file.

class BasicSymbolRef {

  DataRefImpl SymbolPimpl;

  const SymbolicFile *OwningObject = nullptr;

public:

  enum Flags : unsigned {

    SF_None = 0,

    SF_Undefined = 1U << 0,      // Symbol is defined in another object file

    SF_Global = 1U << 1,         // Global symbol

    SF_Weak = 1U << 2,           // Weak symbol

    SF_Absolute = 1U << 3,       // Absolute symbol

    SF_Common = 1U << 4,         // Symbol has common linkage

    SF_Indirect = 1U << 5,       // Symbol is an alias to another symbol

    SF_Exported = 1U << 6,       // Symbol is visible to other DSOs

    SF_FormatSpecific = 1U << 7, // Specific to the object file format

                                 // (e.g. section symbols)

    SF_Thumb = 1U << 8,          // Thumb symbol in a 32-bit ARM binary

    SF_Hidden = 1U << 9,         // Symbol has hidden visibility

    SF_Const = 1U << 10,         // Symbol value is constant

    SF_Executable = 1U << 11,    // Symbol points to an executable section

                                 // (IR only)

  };

  BasicSymbolRef() = default;

  BasicSymbolRef(DataRefImpl SymbolP, const SymbolicFile *Owner);

  bool operator==(const BasicSymbolRef &Other) const;

  bool operator<(const BasicSymbolRef &Other) const;

  void moveNext();

  Error printName(raw_ostream &OS) const;

  /// Get symbol flags (bitwise OR of SymbolRef::Flags)

  Expected<uint32_t> getFlags() const;

  DataRefImpl getRawDataRefImpl() const;

  const SymbolicFile *getObject() const;

};

using basic_symbol_iterator = content_iterator<BasicSymbolRef>;

class SymbolicFile : public Binary {

public:

  SymbolicFile(unsigned int Type, MemoryBufferRef Source);

  ~SymbolicFile() override;

  // virtual interface.

  virtual void moveSymbolNext(DataRefImpl &Symb) const = 0;

  virtual Error printSymbolName(raw_ostream &OS, DataRefImpl Symb) const = 0;

  virtual Expected<uint32_t> getSymbolFlags(DataRefImpl Symb) const = 0;

  virtual basic_symbol_iterator symbol_begin() const = 0;

  virtual basic_symbol_iterator symbol_end() const = 0;

  // convenience wrappers.

  using basic_symbol_iterator_range = iterator_range<basic_symbol_iterator>;

  basic_symbol_iterator_range symbols() const {

    return basic_symbol_iterator_range(symbol_begin(), symbol_end());

  }

  // construction aux.

  static Expected<std::unique_ptr<SymbolicFile>>

  createSymbolicFile(MemoryBufferRef Object, llvm::file_magic Type,

                     LLVMContext *Context, bool InitContent = true);

  static Expected<std::unique_ptr<SymbolicFile>>

  createSymbolicFile(MemoryBufferRef Object) {

    return createSymbolicFile(Object, llvm::file_magic::unknown, nullptr);

  }

  static bool classof(const Binary *v) {

    return v->isSymbolic();

  }

  static bool isSymbolicFile(file_magic Type, const LLVMContext *Context);

};

inline BasicSymbolRef::BasicSymbolRef(DataRefImpl SymbolP,

                                      const SymbolicFile *Owner)

    : SymbolPimpl(SymbolP), OwningObject(Owner) {}

inline bool BasicSymbolRef::operator==(const BasicSymbolRef &Other) const {

  return SymbolPimpl == Other.SymbolPimpl;

}

inline bool BasicSymbolRef::operator<(const BasicSymbolRef &Other) const {

  return SymbolPimpl < Other.SymbolPimpl;

}

inline void BasicSymbolRef::moveNext() {

  return OwningObject->moveSymbolNext(SymbolPimpl);

}

inline Error BasicSymbolRef::printName(raw_ostream &OS) const {

  return OwningObject->printSymbolName(OS, SymbolPimpl);

}

inline Expected<uint32_t> BasicSymbolRef::getFlags() const {

  return OwningObject->getSymbolFlags(SymbolPimpl);

}

inline DataRefImpl BasicSymbolRef::getRawDataRefImpl() const {

  return SymbolPimpl;

}

inline const SymbolicFile *BasicSymbolRef::getObject() const {

  return OwningObject;

}

} // end namespace object

} // end namespace llvm

#endif // LLVM_OBJECT_SYMBOLICFILE_H