//
// 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.
//
//===----------------------------------------------------------------------===//
#include "llvm/Value.h"
#include <map>
-class SymbolTable : public AbstractTypeUser,
- public std::map<const Type *,
- std::map<const std::string, Value *> > {
+namespace llvm {
+
+/// 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, const 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;
+
+ /// @brief A const_iterator over the type planes
+ typedef PlaneMap::const_iterator plane_const_iterator;
+
+/// @}
+/// @name Constructors
+/// @{
+public:
- inline SymbolTable() : InternallyInconsistent(false) {}
+ SymbolTable() : LastUnique(0) {}
~SymbolTable();
- // lookup - Returns null on failure...
- Value *lookup(const Type *Ty, const std::string &name);
+/// @}
+/// @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;
+
+ /// 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 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(); }
+
+ /// @brief The number of name/type pairs is returned.
+ inline unsigned num_types() const { return (unsigned)tmap.size(); }
+
+ /// 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;
- // 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);
+/// @}
+/// @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();
}
- void remove(Value *N);
- Value *type_remove(const type_iterator &It) {
- return removeEntry(find(It->second->getType()), It);
+ /// 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();
}
- // 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);
+ /// 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();
}
- /// 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));
+ /// 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();
}
- // 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);
+ /// Get an iterator to the start of the name/Type map.
+ inline type_iterator type_begin() { return tmap.begin(); }
- inline unsigned type_size(const Type *TypeID) const {
- return find(TypeID)->second.size();
- }
+ /// @brief Get a const_iterator to the start of the name/Type map.
+ inline type_const_iterator type_begin() const { return tmap.begin(); }
- // 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();
- }
- inline type_const_iterator type_begin(const Type *TypeID) const {
- return find(TypeID)->second.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(); }
- inline type_iterator type_end(const Type *TypeID) {
- return find(TypeID)->second.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);
}
- inline type_const_iterator type_end(const Type *TypeID) const {
- return find(TypeID)->second.end();
+
+ /// This method returns a plane_iterator for iteration over the
+ /// type planes starting at a specific plane, given by \p Ty.
+ /// @brief 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);
}
- void dump() const; // Debug method, print out symbol table
-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;
-
- inline super::value_type operator[](const Type *Ty) {
- assert(0 && "Should not use this operator to access symbol table!");
- return super::value_type();
+/// @}
+/// @name Mutators
+/// @{
+public:
+
+ /// This method will strip the symbol table of its names leaving the type and
+ /// values.
+ /// @brief Strip the symbol table.
+ bool strip();
+
+ /// 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.
+ void insert(const std::string &Name, const Type *Typ);
+
+ /// Remove a type at the specified position in the symbol table.
+ /// @returns the removed Type.
+ Type* remove(type_iterator TI);
+
+/// @}
+/// @name Mutators used by Value::setName and other LLVM internals.
+/// @{
+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);
}
- // insertEntry - Insert a value into the symbol table with the specified
- // name...
- //
- void insertEntry(const std::string &Name, const Type *Ty, Value *V);
+ /// 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);
- // removeEntry - Remove a value from the symbol table...
- //
- Value *removeEntry(iterator Plane, type_iterator Entry);
+ /// changeName - Given a value with a non-empty name, remove its existing
+ /// entry from the symbol table and insert a new one for Name. This is
+ /// equivalent to doing "remove(V), V->Name = Name, insert(V)", but is faster,
+ /// and will not temporarily remove the symbol table plane if V is the last
+ /// value in the symtab with that name (which could invalidate iterators to
+ /// that plane).
+ void changeName(Value *V, const std::string &Name);
- // This function is called when one of the types in the type plane are refined
+/// @}
+/// @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);
+
+ /// 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.
+ /// @brief The mapping of types to names to values.
+ PlaneMap pmap;
+
+ /// This is the type 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;
+
+ /// 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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