[llvm-commits] CVS: llvm/include/llvm/SymbolTable.h

LLVM llvm at cs.uiuc.edu
Tue May 25 07:22:32 PDT 2004


Changes in directory llvm/include/llvm:

SymbolTable.h updated: 1.30 -> 1.31

---
Log message:

Completely rewrote the class. SymbolTable now separates Type* from Value* in preparation\
for making Type not derive from Value. There are now separate interfaces \
for looking up, finding, and inserting Types and Values. There are also \
three separate iterator interfaces, one for type planes, one for the types \
(type type plane), and one for values within a type plane. See the \
documentation in the Header file.

---
Diffs of the changes:  (+336 -83)

Index: llvm/include/llvm/SymbolTable.h
diff -u llvm/include/llvm/SymbolTable.h:1.30 llvm/include/llvm/SymbolTable.h:1.31
--- llvm/include/llvm/SymbolTable.h:1.30	Wed Dec 31 01:08:19 2003
+++ llvm/include/llvm/SymbolTable.h	Tue May 25 03:45:53 2004
@@ -2,21 +2,13 @@
 // 
 //                     The LLVM Compiler Infrastructure
 //
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file was developed by the LLVM research group and re-written by Reid
+// Spencer. It is distributed under the University of Illinois Open Source 
+// License. See LICENSE.TXT for details.
 // 
 //===----------------------------------------------------------------------===//
 //
-// This file implements a symbol table that has planes broken up by type.  
-// Identical types may have overlapping symbol names as long as they are 
-// distinct.
-//
-// Note that this implements a chained symbol table.  If a name being 'lookup'd
-// isn't found in the current symbol table, then the parent symbol table is 
-// searched.
-//
-// This chaining behavior does NOT affect iterators though: only the lookup 
-// method.
+// This file implements the main symbol table for LLVM.
 //
 //===----------------------------------------------------------------------===//
 
@@ -28,112 +20,373 @@
 
 namespace llvm {
 
-class SymbolTable : public AbstractTypeUser,
-		    public std::map<const Type *, 
-                                    std::map<const std::string, Value *> > {
+/// This class provides a symbol table of name/value pairs that is broken
+/// up by type. For each Type* there is a "plane" of name/value pairs in 
+/// the symbol table.  Identical types may have overlapping symbol names as 
+/// long as they are distinct. The SymbolTable also tracks,  separately, a 
+/// map of name/type pairs. This allows types to be named. Types are treated 
+/// distinctly from Values.
+/// 
+/// The SymbolTable provides several utility functions for answering common
+/// questions about its contents as well as an iterator interface for
+/// directly iterating over the contents. To reduce confusion, the terms 
+/// "type", "value", and "plane" are used consistently. For example,
+/// There is a TypeMap typedef that is the mapping of names to Types. 
+/// Similarly there is a ValueMap typedef that is the mapping of 
+/// names to Values. Finally, there is a PlaneMap typedef that is the
+/// mapping of types to planes of ValueMap. THis is the basic structure
+/// of the symbol table. When you call type_begin() you're asking
+/// for an iterator at the start of the TypeMap. When you call
+/// plane_begin(), you're asking for an iterator at the start of 
+/// the PlaneMap. Finally, when you call value_begin(), you're asking
+/// for an iterator at the start of a ValueMap for a specific type
+/// plane.
+class SymbolTable : public AbstractTypeUser {
+
+/// @name Types
+/// @{
 public:
-  typedef std::map<const std::string, Value *> VarMap;
-  typedef std::map<const Type *, VarMap> super;
 
-  typedef VarMap::iterator type_iterator;
-  typedef VarMap::const_iterator type_const_iterator;
+  /// @brief A mapping of names to types.
+  typedef std::map<const std::string, Type*> TypeMap;
+
+  /// @brief An iterator over the TypeMap.
+  typedef TypeMap::iterator type_iterator;
+
+  /// @brief A const_iterator over the TypeMap.
+  typedef TypeMap::const_iterator type_const_iterator;
+
+  /// @brief A mapping of names to values.
+  typedef std::map<const std::string, Value *> ValueMap;
+
+  /// @brief An iterator over a ValueMap.
+  typedef ValueMap::iterator value_iterator;
+
+  /// @brief A const_iterator over a ValueMap.
+  typedef ValueMap::const_iterator value_const_iterator;
+
+  /// @brief A mapping of types to names to values (type planes).
+  typedef std::map<const Type *, ValueMap> PlaneMap;
+
+  /// @brief An iterator over the type planes.
+  typedef PlaneMap::iterator plane_iterator;
 
-  inline SymbolTable() : InternallyInconsistent(false), LastUnique(0) {}
+  /// @brief A const_iterator over the type planes
+  typedef PlaneMap::const_iterator plane_const_iterator;
+
+/// @}
+/// @name Constructors
+/// @{
+public:
+
+  inline SymbolTable() 
+    : pmap(), tmap(), InternallyInconsistent(false), LastUnique(0) {}
   ~SymbolTable();
 
-  // lookup - Returns null on failure...
+/// @}
+/// @name Accessors
+/// @{
+public:
+
+  /// This method finds the value with the given \p name in the
+  /// type plane \p Ty and returns it. This method will not find any
+  /// Types, only Values. Use lookupType to find Types by name.
+  /// @returns null on failure, otherwise the Value associated with
+  /// the \p name in type plane \p Ty.
+  /// @brief Lookup a named, typed value.
   Value *lookup(const Type *Ty, const std::string &name) const;
 
-  // insert - Add named definition to the symbol table...
-  inline void insert(Value *N) {
-    assert(N->hasName() && "Value must be named to go into symbol table!");
-    insertEntry(N->getName(), N->getType(), N);
+  /// This method finds the type with the given \p name in the
+  /// type  map and returns it.
+  /// @returns null if the name is not found, otherwise the Type
+  /// associated with the \p name.
+  /// @brief Lookup a type by name.
+  Type* lookupType( const std::string& name ) const;
+
+  /// @returns true iff the type map is not empty.
+  /// @brief Determine if there are types in the symbol table
+  inline bool hasTypes() const { return ! tmap.empty(); }
+
+  /// @returns true iff the type map and the type plane are both not 
+  /// empty.
+  /// @brief Determine if the symbol table is empty
+  inline bool isEmpty() const { return pmap.empty() && tmap.empty(); }
+
+  /// The plane associated with the \p TypeID parameter is found
+  /// and the number of entries in the plane is returned.
+  /// @returns Number of entries in the specified type plane or 0.
+  /// @brief Get the size of a type plane.
+  unsigned type_size(const Type *TypeID) const;
+
+  /// @brief The number of name/type pairs is returned.
+  inline unsigned num_types() const { return tmap.size(); }
+
+  /// Finds the value \p val in the symbol table and returns its
+  /// name. Only the type plane associated with the type of \p val
+  /// is searched.
+  /// @brief Return the name of a value
+  std::string get_name( const Value* Val ) const;
+
+  /// Finds the type \p Ty in the symbol table and returns its name.
+  /// @brief Return the name of a type
+  std::string get_name( const Type* Ty ) const;
+
+  /// Given a base name, return a string that is either equal to it or 
+  /// derived from it that does not already occur in the symbol table 
+  /// for the specified type.
+  /// @brief Get a name unique to this symbol table
+  std::string getUniqueName(const Type *Ty, 
+    const std::string &BaseName) const;
+
+  /// This function can be used from the debugger to display the
+  /// content of the symbol table while debugging.
+  /// @brief Print out symbol table on stderr
+  void dump() const;  
+
+/// @}
+/// @name Mutators
+/// @{
+public:
+
+  /// This method adds the provided value \p N to the symbol table. 
+  /// The Value must have both a name and a type which are extracted 
+  /// and used to place the value in the correct type plane under 
+  /// the value's name.
+  /// @brief Add a named value to the symbol table
+  inline void insert(Value *Val) {
+    assert(Val && "Can't insert null type into symbol table!");
+    assert(Val->hasName() && "Value must be named to go into symbol table!");
+    insertEntry(Val->getName(), Val->getType(), Val);
   }
 
-  void remove(Value *N);
-  Value *type_remove(const type_iterator &It) {
-    return removeEntry(find(It->second->getType()), It);
+  /// Inserts a constant or type into the symbol table with the specified
+  /// name. There can be a many to one mapping between names and constants
+  /// or types.
+  /// @brief Insert a constant or type.
+  inline void insert(const std::string &Name, Value *Val) {
+    assert(Val && "Can't insert null type into symbol table!");
+    assert((isa<Type>(Val) || isa<Constant>(Val)) &&
+           "Can only insert types and constants into a symbol table!");
+    insertEntry(Name, Val->getType(), Val);
   }
 
-  // insert - Insert a constant or type into the symbol table with the specified
-  // name...  There can be a many to one mapping between names and
-  // (constant/type)s.
-  //
-  inline void insert(const std::string &Name, Value *V) {
-    assert((isa<Type>(V) || isa<Constant>(V)) &&
-	   "Can only insert types and constants here!");
-    insertEntry(Name, V->getType(), V);
+  /// Inserts a type into the symbol table with the specified name. There
+  /// can be a many-to-one mapping between names and types. This method
+  /// allows a type with an existing entry in the symbol table to get
+  /// a new name.
+  /// @brief Insert a type under a new name.
+  inline void insert(const std::string &Name, Type *Typ) {
+    assert(Typ && "Can't insert null type into symbol table!");
+    insertEntry(Name, Typ );
   }
 
-  /// remove - Remove a constant or type from the symbol table with the
-  /// specified name.
-  Value *remove(const std::string &Name, Value *V) {
-    iterator TI = find(V->getType());
-    return removeEntry(TI, TI->second.find(Name));
+  /// This method removes a named value from the symbol table. The
+  /// type and name of the Value are extracted from \p N and used to
+  /// lookup the Value in the correct type plane. If the Value is
+  /// not in the symbol table, this method silently ignores the
+  /// request.
+  /// @brief Remove a named value from the symbol table.
+  void remove(Value* Val);
+
+  /// This method removes a named type from the symbol table. The
+  /// name of the type is extracted from \P T and used to look up
+  /// the Type in the type map. If the Type is not in the symbol
+  /// table, this method silently ignores the request.
+  /// @brief Remove a named type from the symbol table.
+  void remove(Type* Typ );
+
+  /// Remove a constant or type with the specified name from the 
+  /// symbol table.
+  /// @returns the removed Value.
+  /// @brief Remove a constant or type from the symbol table.
+  inline Value* remove(const std::string &Name, Value *Val) {
+    assert(Val && "Can't remove null value from symbol table!");
+    plane_iterator PI = pmap.find(Val->getType());
+    return removeEntry(PI, PI->second.find(Name));
   }
 
-  // getUniqueName - Given a base name, return a string that is either equal to
-  // it (or derived from it) that does not already occur in the symbol table for
-  // the specified type.
-  //
-  std::string getUniqueName(const Type *Ty, const std::string &BaseName);
+  /// Remove a type with the specified name from the symbol table.
+  /// @returns the removed Type.
+  /// @brief Remove a named tyep from the symbol table.
+  inline Type* remove(const std::string& Name, Type* T ) {
+    return removeEntry( tmap.find(Name) );
+  }
 
-  inline unsigned type_size(const Type *TypeID) const {
-    return find(TypeID)->second.size();
+  /// Removes a specific value from the symbol table. 
+  /// @returns the removed value.
+  /// @brief Remove a specific value given by an iterator
+  inline Value *value_remove(const value_iterator &It) {
+    return this->removeEntry(pmap.find(It->second->getType()), It);
   }
 
-  // Note that type_begin / type_end only work if you know that an element of 
-  // TypeID is already in the symbol table!!!
-  //
-  inline type_iterator type_begin(const Type *TypeID) { 
-    return find(TypeID)->second.begin(); 
+  /// This method will strip the symbol table of its names leaving
+  /// the type and values. 
+  /// @brief Strip the symbol table. 
+  bool strip();
+
+  /// @brief Empty the symbol table completely.
+  inline void clear() { pmap.clear(); tmap.clear(); }
+
+/// @}
+/// @name Iteration
+/// @{
+public:
+
+  /// Get an iterator that starts at the beginning of the type planes.
+  /// The iterator will iterate over the Type/ValueMap pairs in the
+  /// type planes. 
+  inline plane_iterator plane_begin() { return pmap.begin(); }
+
+  /// Get a const_iterator that starts at the beginning of the type 
+  /// planes.  The iterator will iterate over the Type/ValueMap pairs 
+  /// in the type planes. 
+  inline plane_const_iterator plane_begin() const { return pmap.begin(); }
+
+  /// Get an iterator at the end of the type planes. This serves as
+  /// the marker for end of iteration over the type planes.
+  inline plane_iterator plane_end() { return pmap.end(); }
+
+  /// Get a const_iterator at the end of the type planes. This serves as
+  /// the marker for end of iteration over the type planes.
+  inline plane_const_iterator plane_end() const { return pmap.end(); }
+
+  /// Get an iterator that starts at the beginning of a type plane.
+  /// The iterator will iterate over the name/value pairs in the type plane.
+  /// @note The type plane must already exist before using this.
+  inline value_iterator value_begin(const Type *Typ) { 
+    assert(Typ && "Can't get value iterator with null type!");
+    return pmap.find(Typ)->second.begin(); 
   }
-  inline type_const_iterator type_begin(const Type *TypeID) const {
-    return find(TypeID)->second.begin(); 
+
+  /// Get a const_iterator that starts at the beginning of a type plane.
+  /// The iterator will iterate over the name/value pairs in the type plane.
+  /// @note The type plane must already exist before using this.
+  inline value_const_iterator value_begin(const Type *Typ) const {
+    assert(Typ && "Can't get value iterator with null type!");
+    return pmap.find(Typ)->second.begin(); 
   }
 
-  inline type_iterator type_end(const Type *TypeID) { 
-    return find(TypeID)->second.end(); 
+  /// Get an iterator to the end of a type plane. This serves as the marker
+  /// for end of iteration of the type plane.
+  /// @note The type plane must already exist before using this.
+  inline value_iterator value_end(const Type *Typ) { 
+    assert(Typ && "Can't get value iterator with null type!");
+    return pmap.find(Typ)->second.end(); 
   }
-  inline type_const_iterator type_end(const Type *TypeID) const { 
-    return find(TypeID)->second.end(); 
+
+  /// Get a const_iterator to the end of a type plane. This serves as the
+  /// marker for end of iteration of the type plane.
+  /// @note The type plane must already exist before using this.
+  inline value_const_iterator value_end(const Type *Typ) const { 
+    assert(Typ && "Can't get value iterator with null type!");
+    return pmap.find(Typ)->second.end(); 
   }
 
-  void dump() const;  // Debug method, print out symbol table
+  /// Get an iterator to the start of the name/Type map.
+  inline type_iterator type_begin() { return tmap.begin(); }
 
-private:
-  // InternallyInconsistent - There are times when the symbol table is
-  // internally inconsistent with the rest of the program.  In this one case, a
-  // value exists with a Name, and it's not in the symbol table.  When we call
-  // V->setName(""), it tries to remove itself from the symbol table and dies.
-  // We know this is happening, and so if the flag InternallyInconsistent is
-  // set, removal from the symbol table is a noop.
-  //
-  bool InternallyInconsistent;
+  /// @brief Get a const_iterator to the start of the name/Type map.
+  inline type_const_iterator type_begin() const { return tmap.begin(); }
+
+  /// Get an iterator to the end of the name/Type map. This serves as the
+  /// marker for end of iteration of the types.
+  inline type_iterator type_end() { return tmap.end(); }
+
+  /// Get a const-iterator to the end of the name/Type map. This serves 
+  /// as the marker for end of iteration of the types.
+  inline type_const_iterator type_end() const { return tmap.end(); }
+
+  /// This method returns a plane_const_iterator for iteration over
+  /// the type planes starting at a specific plane, given by \p Ty.
+  /// @brief Find a type plane.
+  inline plane_const_iterator find(const Type* Typ ) const {
+    assert(Typ && "Can't find type plane with null type!");
+    return pmap.find( Typ );
+  }
+
+  /// This method returns a plane_iterator for iteration over the
+  /// type planes starting at a specific plane, given by \p Ty.
+  /// @breif Find a type plane.
+  inline plane_iterator find( const Type* Typ ) { 
+    assert(Typ && "Can't find type plane with null type!");
+    return pmap.find(Typ); 
+  }
 
-  // LastUnique - This value is used to retain the last unique value used
-  // by getUniqueName to generate unique names.
-  unsigned long LastUnique;
-
-  inline super::value_type operator[](const Type *Ty) {
-    assert(0 && "Should not use this operator to access symbol table!");
-    return super::value_type();
+  /// This method returns a ValueMap* for a specific type plane. This
+  /// interface is deprecated and may go away in the future.
+  /// @deprecated
+  /// @brief Find a type plane
+  inline const ValueMap* findPlane( const Type* Typ ) const {
+    assert(Typ && "Can't find type plane with null type!");
+    plane_const_iterator I = pmap.find( Typ );
+    if ( I == pmap.end() ) return 0;
+    return &I->second;
   }
 
-  // insertEntry - Insert a value into the symbol table with the specified
-  // name...
-  //
+/// @}
+/// @name Internal Methods
+/// @{
+private:
+  /// @brief Insert a value into the symbol table with the specified name.
   void insertEntry(const std::string &Name, const Type *Ty, Value *V);
 
-  // removeEntry - Remove a value from the symbol table...
-  //
-  Value *removeEntry(iterator Plane, type_iterator Entry);
+  /// @brief Insert a type into the symbol table with the specified name.
+  void insertEntry(const std::string &Name, Type *T);
+
+  /// Remove a specific value from a specific plane in the SymbolTable.
+  /// @returns the removed Value.
+  Value* removeEntry(plane_iterator Plane, value_iterator Entry);
+
+  /// Remove a specific type from the SymbolTable.
+  /// @returns the removed Type.
+  Type*  removeEntry(type_iterator Entry);
 
-  // This function is called when one of the types in the type plane are refined
+  /// This function is called when one of the types in the type plane 
+  /// is refined.
   virtual void refineAbstractType(const DerivedType *OldTy, const Type *NewTy);
+
+  /// This function markes a type as being concrete (defined).
   virtual void typeBecameConcrete(const DerivedType *AbsTy);
+
+/// @}
+/// @name Internal Data 
+/// @{
+private:
+
+  /// This is the main content of the symbol table. It provides
+  /// separate type planes for named values. That is, each named
+  /// value is organized into a separate dictionary based on 
+  /// Type. This means that the same name can be used for different
+  /// types without conflict. Note that the Type::TypeTy plane is
+  /// not stored in this map but is in tmap.
+  /// @brief The mapping of types to names to values.
+  PlaneMap pmap;
+
+  /// This is the Type::TypeTy plane. It is separated from the pmap
+  /// because the elements of the map are name/Type pairs not 
+  /// name/Value pairs and Type is not a Value.
+  TypeMap tmap;
+
+  /// There are times when the symbol table is internally inconsistent with 
+  /// the rest of the program.  In this one case, a value exists with a Name, 
+  /// and it's not in the symbol table.  When we call V->setName(""), it 
+  /// tries to remove itself from the symbol table and dies.  We know this 
+  /// is happening, and so if the flag InternallyInconsistent is set, 
+  /// removal from the symbol table is a noop.
+  /// @brief Indicator of symbol table internal inconsistency.
+  bool InternallyInconsistent;
+
+  /// This value is used to retain the last unique value used
+  /// by getUniqueName to generate unique names.
+  mutable unsigned long LastUnique;
+
+/// @}
+
 };
 
 } // End llvm namespace
 
+// vim: sw=2
+
 #endif
+





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