text: //===-- 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/System/DataTypes.h"
  #include <vector>
  
  namespace llvm {
  
  class FunctionType;
  class GVMaterializer;
  class LLVMContext;
  
  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.
    static GlobalVariable *createSentinel();
    static void destroySentinel(GlobalVariable *GV) { delete GV; }
  };
  template<> struct ilist_traits<GlobalAlias>
    : public SymbolTableListTraits<GlobalAlias, Module> {
    // createSentinel is used to create a node that marks the end of the list.
    static GlobalAlias *createSentinel();
    static void destroySentinel(GlobalAlias *GA) { delete GA; }
  };
  
  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 type for the list of dependent libraries.
    typedef std::vector<std::string> LibraryListType;
  
    /// 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;
    /// The Library list iterator.
    typedef LibraryListType::const_iterator lib_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 };
  
  /// @}
  /// @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
    LibraryListType LibraryList;    ///< The Libraries needed by the module
    NamedMDListType NamedMDList;    ///< The named metadata in the module
    std::string GlobalScopeAsm;     ///< Inline Asm at global scope.
    ValueSymbolTable *ValSymTab;    ///< Symbol table for values
    TypeSymbolTable *TypeSymTab;    ///< Symbol table for types
    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() const;
  
    /// Get the global data context.
    /// @returns LLVMContext - a container for LLVM's global information
    LLVMContext &getContext() const { return Context; }
  
    /// Get any module-scope inline assembly blocks.
    /// @returns a string containing the module-scope inline assembly blocks.
    const std::string &getModuleInlineAsm() const { return GlobalScopeAsm; }
  
  /// @}
  /// @name Module Level Mutators
  /// @{
  
    /// Set the module identifier.
    void setModuleIdentifier(StringRef ID) { ModuleID = ID; }
  
    /// Set the data layout
    void setDataLayout(StringRef DL) { DataLayout = DL; }
  
    /// Set the target triple.
    void setTargetTriple(StringRef T) { TargetTriple = T; }
  
    /// Set the module-scope inline assembly blocks.
    void setModuleInlineAsm(StringRef Asm) { GlobalScopeAsm = Asm; }
  
    /// Append to the module-scope inline assembly blocks, automatically inserting
    /// a separating newline if necessary.
    void appendModuleInlineAsm(StringRef Asm) {
      if (!GlobalScopeAsm.empty() &&
          GlobalScopeAsm[GlobalScopeAsm.size()-1] != '\n')
        GlobalScopeAsm += '\n';
      GlobalScopeAsm += Asm;
    }
  
  /// @}
  /// @name Generic Value Accessors
  /// @{
  
    /// getNamedValue - Return the first global value in the module with
    /// the specified name, of arbitrary type.  This method returns null
    /// if a global with the specified name is not found.
    GlobalValue *getNamedValue(StringRef Name) const;
  
    /// getMDKindID - Return a unique non-zero ID for the specified metadata kind.
    /// This ID is uniqued across modules in the current LLVMContext.
    unsigned getMDKindID(StringRef Name) const;
  
    /// getMDKindNames - Populate client supplied SmallVector with the name for
    /// custom metadata IDs registered in this LLVMContext.
    void getMDKindNames(SmallVectorImpl<StringRef> &Result) const;
  
  /// @}
  /// @name Function Accessors
  /// @{
  
    /// getOrInsertFunction - Look up the specified function in the module symbol
    /// table.  Four possibilities:
    ///   1. If it does not exist, add a prototype for the function and return it.
    ///   2. If it exists, and has a local linkage, the existing function is
    ///      renamed and a new one is inserted.
    ///   3. Otherwise, if the existing function has the correct prototype, return
    ///      the existing function.
    ///   4. Finally, the function exists but has the wrong prototype: return the
    ///      function with a constantexpr cast to the right prototype.
    Constant *getOrInsertFunction(StringRef Name, const FunctionType *T,
                                  AttrListPtr AttributeList);
  
    Constant *getOrInsertFunction(StringRef Name, const FunctionType *T);
  
    /// getOrInsertFunction - Look up the specified function in the module symbol
    /// table.  If it does not exist, add a prototype for the function and return
    /// it.  This function guarantees to return a constant of pointer to the
    /// specified function type or a ConstantExpr BitCast of that type if the
    /// named function has a different type.  This version of the method takes a
    /// null terminated list of function arguments, which makes it easier for
    /// clients to use.
    Constant *getOrInsertFunction(StringRef Name,
                                  AttrListPtr AttributeList,
                                  const Type *RetTy, ...)  END_WITH_NULL;
  
    /// getOrInsertFunction - Same as above, but without the attributes.
    Constant *getOrInsertFunction(StringRef Name, const Type *RetTy, ...)
      END_WITH_NULL;
  
    Constant *getOrInsertTargetIntrinsic(StringRef Name,
                                         const FunctionType *Ty,
                                         AttrListPtr AttributeList);
  
    /// getFunction - Look up the specified function in the module symbol table.
    /// If it does not exist, return null.
    Function *getFunction(StringRef Name) const;
  
  /// @}
  /// @name Global Variable Accessors
  /// @{
  
    /// getGlobalVariable - Look up the specified global variable in the module
    /// symbol table.  If it does not exist, return null. If AllowInternal is set
    /// to true, this function will return types that have InternalLinkage. By
    /// default, these types are not returned.
    GlobalVariable *getGlobalVariable(StringRef Name,
                                      bool AllowInternal = false) const;
  
    /// getNamedGlobal - Return the first global variable in the module with the
    /// specified name, of arbitrary type.  This method returns null if a global
    /// with the specified name is not found.
    GlobalVariable *getNamedGlobal(StringRef Name) const {
      return getGlobalVariable(Name, true);
    }
  
    /// getOrInsertGlobal - Look up the specified global in the module symbol
    /// table.
    ///   1. If it does not exist, add a declaration of the global and return it.
    ///   2. Else, the global exists but has the wrong type: return the function
    ///      with a constantexpr cast to the right type.
    ///   3. Finally, if the existing global is the correct delclaration, return
    ///      the existing global.
    Constant *getOrInsertGlobal(StringRef Name, const Type *Ty);
  
  /// @}
  /// @name Global Alias Accessors
  /// @{
  
    /// getNamedAlias - Return the first global alias in the module with the
    /// specified name, of arbitrary type.  This method returns null if a global
    /// with the specified name is not found.
    GlobalAlias *getNamedAlias(StringRef Name) const;
  
  /// @}
  /// @name Named Metadata Accessors
  /// @{
  
    /// getNamedMetadata - Return the first NamedMDNode in the module with the
    /// specified name. This method returns null if a NamedMDNode with the
    /// specified name is not found.
    NamedMDNode *getNamedMetadata(const Twine &Name) const;
  
    /// getOrInsertNamedMetadata - Return the first named MDNode in the module
    /// with the specified name. This method returns a new NamedMDNode if a
    /// NamedMDNode with the specified name is not found.
    NamedMDNode *getOrInsertNamedMetadata(StringRef Name);
  
    /// eraseNamedMetadata - Remove the given NamedMDNode from this module
    /// and delete it.
    void eraseNamedMetadata(NamedMDNode *NMD);
  
  /// @}
  /// @name Type Accessors
  /// @{
  
    /// addTypeName - Insert an entry in the symbol table mapping Str to Type.  If
    /// there is already an entry for this name, true is returned and the symbol
    /// table is not modified.
    bool addTypeName(StringRef Name, const Type *Ty);
  
    /// getTypeName - If there is at least one entry in the symbol table for the
    /// specified type, return it.
    std::string getTypeName(const Type *Ty) const;
  
    /// getTypeByName - Return the type with the specified name in this module, or
    /// null if there is none by that name.
    const Type *getTypeByName(StringRef Name) const;
  
  /// @}
  /// @name Materialization
  /// @{
  
    /// setMaterializer - Sets the GVMaterializer to GVM.  This module must not
    /// yet have a Materializer.  To reset the materializer for a module that
    /// already has one, call MaterializeAllPermanently first.  Destroying this
    /// module will destroy its materializer without materializing any more
    /// GlobalValues.  Without destroying the Module, there is no way to detach or
    /// destroy a materializer without materializing all the GVs it controls, to
    /// avoid leaving orphan unmaterialized GVs.
    void setMaterializer(GVMaterializer *GVM);
    /// getMaterializer - Retrieves the GVMaterializer, if any, for this Module.
    GVMaterializer *getMaterializer() const { return Materializer.get(); }
  
    /// isMaterializable - True if the definition of GV has yet to be materialized
    /// from the GVMaterializer.
    bool isMaterializable(const GlobalValue *GV) const;
    /// isDematerializable - Returns true if this GV was loaded from this Module's
    /// GVMaterializer and the GVMaterializer knows how to dematerialize the GV.
    bool isDematerializable(const GlobalValue *GV) const;
  
    /// Materialize - Make sure the GlobalValue is fully read.  If the module is
    /// corrupt, this returns true and fills in the optional string with
    /// information about the problem.  If successful, this returns false.
    bool Materialize(GlobalValue *GV, std::string *ErrInfo = 0);
    /// Dematerialize - If the GlobalValue is read in, and if the GVMaterializer
    /// supports it, release the memory for the function, and set it up to be
    /// materialized lazily.  If !isDematerializable(), this method is a noop.
    void Dematerialize(GlobalValue *GV);
  
    /// MaterializeAll - Make sure all GlobalValues in this Module are fully read.
    /// If the module is corrupt, this returns true and fills in the optional
    /// string with information about the problem.  If successful, this returns
    /// false.
    bool MaterializeAll(std::string *ErrInfo = 0);
  
    /// MaterializeAllPermanently - Make sure all GlobalValues in this Module are
    /// fully read and clear the Materializer.  If the module is corrupt, this
    /// returns true, fills in the optional string with information about the
    /// problem, and DOES NOT clear the old Materializer.  If successful, this
    /// returns false.
    bool MaterializeAllPermanently(std::string *ErrInfo = 0);
  
  /// @}
  /// @name Direct access to the globals list, functions list, and symbol table
  /// @{
  
    /// Get the Module's list of global variables (constant).
    const GlobalListType   &getGlobalList() const       { return GlobalList; }
    /// Get the Module's list of global variables.
    GlobalListType         &getGlobalList()             { return GlobalList; }
    static iplist<GlobalVariable> Module::*getSublistAccess(GlobalVariable*) {
      return &Module::GlobalList;
    }
    /// Get the Module's list of functions (constant).
    const FunctionListType &getFunctionList() const     { return FunctionList; }
    /// Get the Module's list of functions.
    FunctionListType       &getFunctionList()           { return FunctionList; }
    static iplist<Function> Module::*getSublistAccess(Function*) {
      return &Module::FunctionList;
    }
    /// Get the Module's list of aliases (constant).
    const AliasListType    &getAliasList() const        { return AliasList; }
    /// Get the Module's list of aliases.
    AliasListType          &getAliasList()              { return AliasList; }
    static iplist<GlobalAlias> Module::*getSublistAccess(GlobalAlias*) {
      return &Module::AliasList;
    }
    /// Get the symbol table of global variable and function identifiers
    const ValueSymbolTable &getValueSymbolTable() const { return *ValSymTab; }
    /// Get the Module's symbol table of global variable and function identifiers.
    ValueSymbolTable       &getValueSymbolTable()       { return *ValSymTab; }
    /// Get the symbol table of types
    const TypeSymbolTable  &getTypeSymbolTable() const  { return *TypeSymTab; }
    /// Get the Module's symbol table of types
    TypeSymbolTable        &getTypeSymbolTable()        { return *TypeSymTab; }
  
  /// @}
  /// @name Global Variable Iteration
  /// @{
  
    /// Get an iterator to the first global variable
    global_iterator       global_begin()       { return GlobalList.begin(); }
    /// Get a constant iterator to the first global variable
    const_global_iterator global_begin() const { return GlobalList.begin(); }
    /// Get an iterator to the last global variable
    global_iterator       global_end  ()       { return GlobalList.end(); }
    /// Get a constant iterator to the last global variable
    const_global_iterator global_end  () const { return GlobalList.end(); }
    /// Determine if the list of globals is empty.
    bool                  global_empty() const { return GlobalList.empty(); }
  
  /// @}
  /// @name Function Iteration
  /// @{
  
    /// Get an iterator to the first function.
    iterator                begin()       { return FunctionList.begin(); }
    /// Get a constant iterator to the first function.
    const_iterator          begin() const { return FunctionList.begin(); }
    /// Get an iterator to the last function.
    iterator                end  ()       { return FunctionList.end();   }
    /// Get a constant iterator to the last function.
    const_iterator          end  () const { return FunctionList.end();   }
    /// Determine how many functions are in the Module's list of functions.
    size_t                  size() const  { return FunctionList.size(); }
    /// Determine if the list of functions is empty.
    bool                    empty() const { return FunctionList.empty(); }
  
  /// @}
  /// @name Dependent Library Iteration
  /// @{
  
    /// @brief Get a constant iterator to beginning of dependent library list.
    inline lib_iterator lib_begin() const { return LibraryList.begin(); }
    /// @brief Get a constant iterator to end of dependent library list.
    inline lib_iterator lib_end()   const { return LibraryList.end();   }
    /// @brief Returns the number of items in the list of libraries.
    inline size_t       lib_size()  const { return LibraryList.size();  }
    /// @brief Add a library to the list of dependent libraries
    void addLibrary(StringRef Lib);
    /// @brief Remove a library from the list of dependent libraries
    void removeLibrary(StringRef Lib);
    /// @brief Get all the libraries
    inline const LibraryListType& getLibraries() const { return LibraryList; }
  
  /// @}
  /// @name Alias Iteration
  /// @{
  
    /// Get an iterator to the first alias.
    alias_iterator       alias_begin()            { return AliasList.begin(); }
    /// Get a constant iterator to the first alias.
    const_alias_iterator alias_begin() const      { return AliasList.begin(); }
    /// Get an iterator to the last alias.
    alias_iterator       alias_end  ()            { return AliasList.end();   }
    /// Get a constant iterator to the last alias.
    const_alias_iterator alias_end  () const      { return AliasList.end();   }
    /// Determine how many aliases are in the Module's list of aliases.
    size_t               alias_size () const      { return AliasList.size();  }
    /// Determine if the list of aliases is empty.
    bool                 alias_empty() const      { return AliasList.empty(); }
  
  
  /// @}
  /// @name Named Metadata Iteration
  /// @{
  
    /// Get an iterator to the first named metadata.
    named_metadata_iterator named_metadata_begin() { return NamedMDList.begin(); }
    /// Get a constant iterator to the first named metadata.
    const_named_metadata_iterator named_metadata_begin() const {
      return NamedMDList.begin();
    }
  
    /// Get an iterator to the last named metadata.
    named_metadata_iterator named_metadata_end() { return NamedMDList.end(); }
    /// Get a constant iterator to the last named metadata.
    const_named_metadata_iterator named_metadata_end() const {
      return NamedMDList.end();
    }
  
    /// Determine how many NamedMDNodes are in the Module's list of named
    /// metadata.
    size_t named_metadata_size() const { return NamedMDList.size();  }
    /// Determine if the list of named metadata is empty.
    bool named_metadata_empty() const { return NamedMDList.empty(); }
  
  
  /// @}
  /// @name Utility functions for printing and dumping Module objects
  /// @{
  
    /// Print the module to an output stream with AssemblyAnnotationWriter.
    void print(raw_ostream &OS, AssemblyAnnotationWriter *AAW) const;
  
    /// Dump the module to stderr (for debugging).
    void dump() const;
    /// This function causes all the subinstructions to "let go" of all references
    /// that they are maintaining.  This allows one to 'delete' a whole class at
    /// a time, even though there may be circular references... first all
    /// references are dropped, and all use counts go to zero.  Then everything
    /// is delete'd for real.  Note that no operations are valid on an object
    /// that has "dropped all references", except operator delete.
    void dropAllReferences();
  /// @}
  };
  
  /// An raw_ostream inserter for modules.
  inline raw_ostream &operator<<(raw_ostream &O, const Module &M) {
    M.print(O, 0);
    return O;
  }
  
  } // End llvm namespace
  
  #endif
  