path: root/include/llvm/Module.h

//===-- llvm/Module.h - C++ class to represent a VM module ------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
/// @file
/// Module.h This file contains the declarations for the Module class.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_MODULE_H
#define LLVM_MODULE_H

#include "llvm/Function.h"
#include "llvm/GlobalVariable.h"
#include "llvm/GlobalAlias.h"
#include "llvm/Metadata.h"
#include "llvm/ADT/OwningPtr.h"
#include "llvm/Support/DataTypes.h"

namespace llvm {

class FunctionType;
class GVMaterializer;
class LLVMContext;
class StructType;
template<typename T> struct DenseMapInfo;
template<typename KeyT, typename ValueT, typename KeyInfoT> class DenseMap;

template<> struct ilist_traits<Function>
  : public SymbolTableListTraits<Function, Module> {

  // createSentinel is used to get hold of the node that marks the end of the
  // list... (same trick used here as in ilist_traits<Instruction>)
  Function *createSentinel() const {
    return static_cast<Function*>(&Sentinel);
  }
  static void destroySentinel(Function*) {}

  Function *provideInitialHead() const { return createSentinel(); }
  Function *ensureHead(Function*) const { return createSentinel(); }
  static void noteHead(Function*, Function*) {}

private:
  mutable ilist_node<Function> Sentinel;
};

template<> struct ilist_traits<GlobalVariable>
  : public SymbolTableListTraits<GlobalVariable, Module> {
  // createSentinel is used to create a node that marks the end of the list.
  GlobalVariable *createSentinel() const {
    return static_cast<GlobalVariable*>(&Sentinel);
  }
  static void destroySentinel(GlobalVariable*) {}

  GlobalVariable *provideInitialHead() const { return createSentinel(); }
  GlobalVariable *ensureHead(GlobalVariable*) const { return createSentinel(); }
  static void noteHead(GlobalVariable*, GlobalVariable*) {}
private:
  mutable ilist_node<GlobalVariable> Sentinel;
};

template<> struct ilist_traits<GlobalAlias>
  : public SymbolTableListTraits<GlobalAlias, Module> {
  // createSentinel is used to create a node that marks the end of the list.
  GlobalAlias *createSentinel() const {
    return static_cast<GlobalAlias*>(&Sentinel);
  }
  static void destroySentinel(GlobalAlias*) {}

  GlobalAlias *provideInitialHead() const { return createSentinel(); }
  GlobalAlias *ensureHead(GlobalAlias*) const { return createSentinel(); }
  static void noteHead(GlobalAlias*, GlobalAlias*) {}
private:
  mutable ilist_node<GlobalAlias> Sentinel;
};

template<> struct ilist_traits<NamedMDNode>
  : public ilist_default_traits<NamedMDNode> {
  // createSentinel is used to get hold of a node that marks the end of
  // the list...
  NamedMDNode *createSentinel() const {
    return static_cast<NamedMDNode*>(&Sentinel);
  }
  static void destroySentinel(NamedMDNode*) {}

  NamedMDNode *provideInitialHead() const { return createSentinel(); }
  NamedMDNode *ensureHead(NamedMDNode*) const { return createSentinel(); }
  static void noteHead(NamedMDNode*, NamedMDNode*) {}
  void addNodeToList(NamedMDNode *) {}
  void removeNodeFromList(NamedMDNode *) {}
private:
  mutable ilist_node<NamedMDNode> Sentinel;
};

/// A Module instance is used to store all the information related to an
/// LLVM module. Modules are the top level container of all other LLVM
/// Intermediate Representation (IR) objects. Each module directly contains a
/// list of globals variables, a list of functions, a list of libraries (or
/// other modules) this module depends on, a symbol table, and various data
/// about the target's characteristics.
///
/// A module maintains a GlobalValRefMap object that is used to hold all
/// constant references to global variables in the module.  When a global
/// variable is destroyed, it should have no entries in the GlobalValueRefMap.
/// @brief The main container class for the LLVM Intermediate Representation.
class Module {
/// @name Types And Enumerations
/// @{
public:
  /// The type for the list of global variables.
  typedef iplist<GlobalVariable> GlobalListType;
  /// The type for the list of functions.
  typedef iplist<Function> FunctionListType;
  /// The type for the list of aliases.
  typedef iplist<GlobalAlias> AliasListType;
  /// The type for the list of named metadata.
  typedef ilist<NamedMDNode> NamedMDListType;

  /// The Global Variable iterator.
  typedef GlobalListType::iterator                      global_iterator;
  /// The Global Variable constant iterator.
  typedef GlobalListType::const_iterator          const_global_iterator;

  /// The Function iterators.
  typedef FunctionListType::iterator                           iterator;
  /// The Function constant iterator
  typedef FunctionListType::const_iterator               const_iterator;

  /// The Global Alias iterators.
  typedef AliasListType::iterator                        alias_iterator;
  /// The Global Alias constant iterator
  typedef AliasListType::const_iterator            const_alias_iterator;

  /// The named metadata iterators.
  typedef NamedMDListType::iterator             named_metadata_iterator;
  /// The named metadata constant interators.
  typedef NamedMDListType::const_iterator const_named_metadata_iterator;

  /// An enumeration for describing the endianess of the target machine.
  enum Endianness  { AnyEndianness, LittleEndian, BigEndian };

  /// An enumeration for describing the size of a pointer on the target machine.
  enum PointerSize { AnyPointerSize, Pointer32, Pointer64 };

  /// An enumeration for the supported behaviors of module flags. The following
  /// module flags behavior values are supported:
  ///
  ///    Value        Behavior
  ///    -----        --------
  ///      1          Error
  ///                   Emits an error if two values disagree.
  ///
  ///      2          Warning
  ///                   Emits a warning if two values disagree.
  ///
  ///      3          Require
  ///                   Emits an error when the specified value is not present
  ///                   or doesn't have the specified value. It is an error for
  ///                   two (or more) llvm.module.flags with the same ID to have
  ///                   the Require behavior but different values. There may be
  ///                   multiple Require flags per ID.
  ///
  ///      4          Override
  ///                   Uses the specified value if the two values disagree. It
  ///                   is an error for two (or more) llvm.module.flags with the
  ///                   same ID to have the Override behavior but different
  ///                   values.
  enum ModFlagBehavior { Error = 1, Warning  = 2, Require = 3, Override = 4 };

  struct ModuleFlagEntry {
    ModFlagBehavior Behavior;
    MDString *Key;
    Value *Val;
    ModuleFlagEntry(ModFlagBehavior B, MDString *K, Value *V)
      : Behavior(B), Key(K), Val(V) {}
  };

/// @}
/// @name Member Variables
/// @{
private:
  LLVMContext &Context;           ///< The LLVMContext from which types and
                                  ///< constants are allocated.
  GlobalListType GlobalList;      ///< The Global Variables in the module
  FunctionListType FunctionList;  ///< The Functions in the module
  AliasListType AliasList;        ///< The Aliases in the module
  NamedMDListType NamedMDList;    ///< The named metadata in the module
  std::string GlobalScopeAsm;     ///< Inline Asm at global scope.
  ValueSymbolTable *ValSymTab;    ///< Symbol table for values
  OwningPtr<GVMaterializer> Materializer;  ///< Used to materialize GlobalValues
  std::string ModuleID;           ///< Human readable identifier for the module
  std::string TargetTriple;       ///< Platform target triple Module compiled on
  std::string DataLayout;         ///< Target data description
  void *NamedMDSymTab;            ///< NamedMDNode names.

  friend class Constant;

/// @}
/// @name Constructors
/// @{
public:
  /// The Module constructor. Note that there is no default constructor. You
  /// must provide a name for the module upon construction.
  explicit Module(StringRef ModuleID, LLVMContext& C);
  /// The module destructor. This will dropAllReferences.
  ~Module();

/// @}
/// @name Module Level Accessors
/// @{

  /// Get the module identifier which is, essentially, the name of the module.
  /// @returns the module identifier as a string
  const std::string &getModuleIdentifier() const { return ModuleID; }

  /// Get the data layout string for the module's target platform.  This encodes
  /// the type sizes and alignments expected by this module.
  /// @returns the data layout as a string
  const std::string &getDataLayout() const { return DataLayout; }

  /// Get the target triple which is a string describing the target host.
  /// @returns a string containing the target triple.
  const std::string &getTargetTriple() const { return TargetTriple; }

  /// Get the target endian information.
  /// @returns Endianess - an enumeration for the endianess of the target
  Endianness getEndianness() const;

  /// Get the target pointer size.
  /// @returns PointerSize - an enumeration for the size of the target's pointer
  PointerSize getPointerSize()