//===-- llvm/Value.h - Definition of the Value class ------------*- C++ -*-===//
-//
+//
// 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 defines the very important Value class. This is subclassed by a
-// bunch of other important classes, like Instruction, Function, Type, etc...
+//===----------------------------------------------------------------------===//
//
+// This file declares the Value class.
// This file also defines the Use<> template for users of value.
//
//===----------------------------------------------------------------------===//
#include "llvm/AbstractTypeUser.h"
#include "llvm/Use.h"
-#include "Support/Casting.h"
+#include "llvm/Support/Casting.h"
+#include "llvm/Support/Streams.h"
#include <string>
namespace llvm {
class Constant;
class Argument;
class Instruction;
-struct BasicBlock;
+class BasicBlock;
class GlobalValue;
class Function;
class GlobalVariable;
-class SymbolTable;
+class GlobalAlias;
+class InlineAsm;
+class ValueSymbolTable;
+class TypeSymbolTable;
+template<typename ValueTy> class StringMapEntry;
+typedef StringMapEntry<Value*> ValueName;
//===----------------------------------------------------------------------===//
// Value Class
//===----------------------------------------------------------------------===//
-/// Value - The base class of all values computed by a program that may be used
-/// as operands to other values.
+/// This is a very important LLVM class. It is the base class of all values
+/// computed by a program that may be used as operands to other values. Value is
+/// the super class of other important classes such as Instruction and Function.
+/// All Values have a Type. Type is not a subclass of Value. All types can have
+/// a name and they should belong to some Module. Setting the name on the Value
+/// automatically update's the module's symbol table.
///
-struct Value {
+/// Every value has a "use list" that keeps track of which other Values are
+/// using this Value.
+/// @brief LLVM Value Representation
+class Value {
+ const unsigned short SubclassID; // Subclass identifier (for isa/dyn_cast)
+protected:
+ /// SubclassData - This member is defined by this class, but is not used for
+ /// anything. Subclasses can use it to hold whatever state they find useful.
+ /// This field is initialized to zero by the ctor.
+ unsigned short SubclassData;
private:
- unsigned SubclassID; // Subclass identifier (for isa/dyn_cast)
PATypeHolder Ty;
- iplist<Use> Uses;
- std::string Name;
+ Use *UseList;
+
+ friend class ValueSymbolTable; // Allow ValueSymbolTable to directly mod Name.
+ friend class SymbolTable; // Allow SymbolTable to directly poke Name.
+ ValueName *Name;
void operator=(const Value &); // Do not implement
Value(const Value &); // Do not implement
public:
- Value(const Type *Ty, unsigned scid, const std::string &name = "");
+ Value(const Type *Ty, unsigned scid);
virtual ~Value();
-
+
/// dump - Support for debugging, callable in GDB: V->dump()
//
virtual void dump() const;
/// print - Implement operator<< on Value...
///
virtual void print(std::ostream &O) const = 0;
-
+ void print(std::ostream *O) const { if (O) print(*O); }
+
/// All values are typed, get the type of this value.
///
inline const Type *getType() const { return Ty; }
-
+
// All values can potentially be named...
- inline bool hasName() const { return !Name.empty(); }
- inline const std::string &getName() const { return Name; }
+ inline bool hasName() const { return Name != 0; }
+ ValueName *getValueName() const { return Name; }
- virtual void setName(const std::string &name, SymbolTable * = 0) {
- Name = name;
- }
+ /// getNameStart - Return a pointer to a null terminated string for this name.
+ /// Note that names can have null characters within the string as well as at
+ /// their end. This always returns a non-null pointer.
+ const char *getNameStart() const;
+ /// getNameLen - Return the length of the string, correctly handling nul
+ /// characters embedded into them.
+ unsigned getNameLen() const;
+
+ /// getName()/getNameStr() - Return the name of the specified value,
+ /// *constructing a string* to hold it. Because these are guaranteed to
+ /// construct a string, they are very expensive and should be avoided.
+ std::string getName() const { return getNameStr(); }
+ std::string getNameStr() const;
+
+
+ void setName(const std::string &name);
+ void setName(const char *Name, unsigned NameLen);
+ void setName(const char *Name); // Takes a null-terminated string.
+
+
+ /// takeName - transfer the name from V to this value, setting V's name to
+ /// empty. It is an error to call V->takeName(V).
+ void takeName(Value *V);
+
/// replaceAllUsesWith - Go through the uses list for this definition and make
- /// each use point to "V" instead of "this". After this completes, 'this's
+ /// each use point to "V" instead of "this". After this completes, 'this's
/// use list is guaranteed to be empty.
///
void replaceAllUsesWith(Value *V);
//----------------------------------------------------------------------
// Methods for handling the vector of uses of this Value.
//
- typedef UseListIteratorWrapper use_iterator;
- typedef UseListConstIteratorWrapper use_const_iterator;
-
- unsigned use_size() const { return Uses.size(); }
- bool use_empty() const { return Uses.empty(); }
- use_iterator use_begin() { return Uses.begin(); }
- use_const_iterator use_begin() const { return Uses.begin(); }
- use_iterator use_end() { return Uses.end(); }
- use_const_iterator use_end() const { return Uses.end(); }
- User *use_back() { return Uses.back().getUser(); }
- const User *use_back() const { return Uses.back().getUser(); }
+ typedef value_use_iterator<User> use_iterator;
+ typedef value_use_iterator<const User> use_const_iterator;
+
+ bool use_empty() const { return UseList == 0; }
+ use_iterator use_begin() { return use_iterator(UseList); }
+ use_const_iterator use_begin() const { return use_const_iterator(UseList); }
+ use_iterator use_end() { return use_iterator(0); }
+ use_const_iterator use_end() const { return use_const_iterator(0); }
+ User *use_back() { return *use_begin(); }
+ const User *use_back() const { return *use_begin(); }
/// hasOneUse - Return true if there is exactly one user of this value. This
/// is specialized because it is a common request and does not require
/// traversing the whole use list.
///
bool hasOneUse() const {
- iplist<Use>::const_iterator I = Uses.begin(), E = Uses.end();
+ use_const_iterator I = use_begin(), E = use_end();
if (I == E) return false;
return ++I == E;
}
- /// addUse/killUse - These two methods should only be used by the Use class.
+ /// hasNUses - Return true if this Value has exactly N users.
///
- void addUse(Use &U) { Uses.push_back(&U); }
- void killUse(Use &U) { Uses.remove(&U); }
+ bool hasNUses(unsigned N) const;
- /// getValueType - Return an ID for the concrete type of this object. This is
- /// used to implement the classof checks. This should not be used for any
- /// other purpose, as the values may change as LLVM evolves. Also, note that
- /// starting with the InstructionVal value, the value stored is actually the
- /// Instruction opcode, so there are more than just these values possible here
- /// (and Instruction must be last).
+ /// hasNUsesOrMore - Return true if this value has N users or more. This is
+ /// logically equivalent to getNumUses() >= N.
+ ///
+ bool hasNUsesOrMore(unsigned N) const;
+
+ /// getNumUses - This method computes the number of uses of this Value. This
+ /// is a linear time operation. Use hasOneUse, hasNUses, or hasMoreThanNUses
+ /// to check for specific values.
+ unsigned getNumUses() const;
+
+ /// addUse/killUse - These two methods should only be used by the Use class.
///
+ void addUse(Use &U) { U.addToList(&UseList); }
+
+ /// An enumeration for keeping track of the concrete subclass of Value that
+ /// is actually instantiated. Values of this enumeration are kept in the
+ /// Value classes SubclassID field. They are used for concrete type
+ /// identification.
enum ValueTy {
ArgumentVal, // This is an instance of Argument
BasicBlockVal, // This is an instance of BasicBlock
FunctionVal, // This is an instance of Function
+ GlobalAliasVal, // This is an instance of GlobalAlias
GlobalVariableVal, // This is an instance of GlobalVariable
+ UndefValueVal, // This is an instance of UndefValue
ConstantExprVal, // This is an instance of ConstantExpr
ConstantAggregateZeroVal, // This is an instance of ConstantAggregateNull
- SimpleConstantVal, // This is some other type of Constant
+ ConstantIntVal, // This is an instance of ConstantInt
+ ConstantFPVal, // This is an instance of ConstantFP
+ ConstantArrayVal, // This is an instance of ConstantArray
+ ConstantStructVal, // This is an instance of ConstantStruct
+ ConstantVectorVal, // This is an instance of ConstantVector
+ ConstantPointerNullVal, // This is an instance of ConstantPointerNull
+ InlineAsmVal, // This is an instance of InlineAsm
InstructionVal, // This is an instance of Instruction
- ValueListVal // This is for bcreader, a special ValTy
+
+ // Markers:
+ ConstantFirstVal = FunctionVal,
+ ConstantLastVal = ConstantPointerNullVal
};
- unsigned getValueType() const {
+
+ /// getValueID - Return an ID for the concrete type of this object. This is
+ /// used to implement the classof checks. This should not be used for any
+ /// other purpose, as the values may change as LLVM evolves. Also, note that
+ /// for instructions, the Instruction's opcode is added to InstructionVal. So
+ /// this means three things:
+ /// # there is no value with code InstructionVal (no opcode==0).
+ /// # there are more possible values for the value type than in ValueTy enum.
+ /// # the InstructionVal enumerator must be the highest valued enumerator in
+ /// the ValueTy enum.
+ unsigned getValueID() const {
return SubclassID;
}
-private:
- /// FIXME: this is a gross hack, needed by another gross hack. Eliminate!
- void setValueType(unsigned VT) { SubclassID = VT; }
- friend class Instruction;
+ // Methods for support type inquiry through isa, cast, and dyn_cast:
+ static inline bool classof(const Value *) {
+ return true; // Values are always values.
+ }
+
+ /// getRawType - This should only be used to implement the vmcore library.
+ ///
+ const Type *getRawType() const { return Ty.getRawType(); }
};
inline std::ostream &operator<<(std::ostream &OS, const Value &V) {
return OS;
}
-
-inline User *UseListIteratorWrapper::operator*() const {
- return Super::operator*().getUser();
-}
-
-inline const User *UseListConstIteratorWrapper::operator*() const {
- return Super::operator*().getUser();
-}
-
-
-Use::Use(Value *v, User *user) : Val(v), U(user) {
- if (Val) Val->addUse(*this);
-}
-
-Use::Use(const Use &u) : Val(u.Val), U(u.U) {
+void Use::init(Value *v, User *user) {
+ Val = v;
+ U = user;
if (Val) Val->addUse(*this);
}
Use::~Use() {
- if (Val) Val->killUse(*this);
+ if (Val) removeFromList();
}
-void Use::set(Value *V) {
- if (Val) Val->killUse(*this);
+void Use::set(Value *V) {
+ if (Val) removeFromList();
Val = V;
if (V) V->addUse(*this);
}
// isa - Provide some specializations of isa so that we don't have to include
// the subtype header files to test to see if the value is a subclass...
//
-template <> inline bool isa_impl<Constant, Value>(const Value &Val) {
- return Val.getValueType() == Value::ConstantExprVal ||
- Val.getValueType() == Value::SimpleConstantVal ||
- Val.getValueType() == Value::ConstantAggregateZeroVal ||
- Val.getValueType() == Value::FunctionVal ||
- Val.getValueType() == Value::GlobalVariableVal;
+template <> inline bool isa_impl<Constant, Value>(const Value &Val) {
+ return Val.getValueID() >= Value::ConstantFirstVal &&
+ Val.getValueID() <= Value::ConstantLastVal;
+}
+template <> inline bool isa_impl<Argument, Value>(const Value &Val) {
+ return Val.getValueID() == Value::ArgumentVal;
+}
+template <> inline bool isa_impl<InlineAsm, Value>(const Value &Val) {
+ return Val.getValueID() == Value::InlineAsmVal;
}
-template <> inline bool isa_impl<Argument, Value>(const Value &Val) {
- return Val.getValueType() == Value::ArgumentVal;
+template <> inline bool isa_impl<Instruction, Value>(const Value &Val) {
+ return Val.getValueID() >= Value::InstructionVal;
}
-template <> inline bool isa_impl<Instruction, Value>(const Value &Val) {
- return Val.getValueType() >= Value::InstructionVal;
+template <> inline bool isa_impl<BasicBlock, Value>(const Value &Val) {
+ return Val.getValueID() == Value::BasicBlockVal;
}
-template <> inline bool isa_impl<BasicBlock, Value>(const Value &Val) {
- return Val.getValueType() == Value::BasicBlockVal;
+template <> inline bool isa_impl<Function, Value>(const Value &Val) {
+ return Val.getValueID() == Value::FunctionVal;
}
-template <> inline bool isa_impl<Function, Value>(const Value &Val) {
- return Val.getValueType() == Value::FunctionVal;
+template <> inline bool isa_impl<GlobalVariable, Value>(const Value &Val) {
+ return Val.getValueID() == Value::GlobalVariableVal;
}
-template <> inline bool isa_impl<GlobalVariable, Value>(const Value &Val) {
- return Val.getValueType() == Value::GlobalVariableVal;
+template <> inline bool isa_impl<GlobalAlias, Value>(const Value &Val) {
+ return Val.getValueID() == Value::GlobalAliasVal;
}
-template <> inline bool isa_impl<GlobalValue, Value>(const Value &Val) {
- return isa<GlobalVariable>(Val) || isa<Function>(Val);
+template <> inline bool isa_impl<GlobalValue, Value>(const Value &Val) {
+ return isa<GlobalVariable>(Val) || isa<Function>(Val) || isa<GlobalAlias>(Val);
}
} // End llvm namespace
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