X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FGlobalVariable.h;h=79463fbdf0ff9729098f645fec3038527d551040;hb=b09c146b116359616f6cbd4c8b3328607e00ff42;hp=b09bf40f05904da6346f032c799dfb7492153a54;hpb=8b70b78ba489b090d9866e6a4084ab1e8613b527;p=oota-llvm.git diff --git a/include/llvm/GlobalVariable.h b/include/llvm/GlobalVariable.h index b09bf40f059..79463fbdf0f 100644 --- a/include/llvm/GlobalVariable.h +++ b/include/llvm/GlobalVariable.h @@ -1,10 +1,10 @@ -//===-- llvm/Global.h - Class to represent a global variable ----*- C++ -*-===// -// +//===-- llvm/GlobalVariable.h - GlobalVariable 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 is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// //===----------------------------------------------------------------------===// // // This file contains the declaration of the GlobalVariable class, which @@ -12,7 +12,7 @@ // // Global variables are constant pointers that refer to hunks of space that are // allocated by either the VM, or by the linker in a static compiler. A global -// variable may have an intial value, which is copied into the executables .data +// variable may have an initial value, which is copied into the executables .data // area. Global Constants are required to have initializers. // //===----------------------------------------------------------------------===// @@ -20,93 +20,172 @@ #ifndef LLVM_GLOBAL_VARIABLE_H #define LLVM_GLOBAL_VARIABLE_H +#include "llvm/ADT/Twine.h" +#include "llvm/ADT/ilist_node.h" #include "llvm/GlobalValue.h" +#include "llvm/OperandTraits.h" namespace llvm { class Module; class Constant; -class PointerType; -template struct ilist_traits; -template class SymbolTableListTraits; - -class GlobalVariable : public GlobalValue { - friend class SymbolTableListTraits >; +template + class SymbolTableListTraits; + +class GlobalVariable : public GlobalValue, public ilist_node { + friend class SymbolTableListTraits; + void *operator new(size_t, unsigned) LLVM_DELETED_FUNCTION; + void operator=(const GlobalVariable &) LLVM_DELETED_FUNCTION; + GlobalVariable(const GlobalVariable &) LLVM_DELETED_FUNCTION; + void setParent(Module *parent); - GlobalVariable *Prev, *Next; - void setNext(GlobalVariable *N) { Next = N; } - void setPrev(GlobalVariable *N) { Prev = N; } + bool isConstantGlobal : 1; // Is this a global constant? + unsigned threadLocalMode : 3; // Is this symbol "Thread Local", + // if so, what is the desired model? - bool isConstantGlobal; // Is this a global constant? public: + // allocate space for exactly one operand + void *operator new(size_t s) { + return User::operator new(s, 1); + } + + enum ThreadLocalMode { + NotThreadLocal = 0, + GeneralDynamicTLSModel, + LocalDynamicTLSModel, + InitialExecTLSModel, + LocalExecTLSModel + }; + /// GlobalVariable ctor - If a parent module is specified, the global is /// automatically inserted into the end of the specified modules global list. - /// - GlobalVariable(const Type *Ty, bool isConstant, LinkageTypes Linkage, - Constant *Initializer = 0, const std::string &Name = "", - Module *Parent = 0); - - // Specialize setName to handle symbol table majik... - virtual void setName(const std::string &name, SymbolTable *ST = 0); + GlobalVariable(Type *Ty, bool isConstant, LinkageTypes Linkage, + Constant *Initializer = 0, const Twine &Name = "", + ThreadLocalMode = NotThreadLocal, unsigned AddressSpace = 0); + /// GlobalVariable ctor - This creates a global and inserts it before the + /// specified other global. + GlobalVariable(Module &M, Type *Ty, bool isConstant, + LinkageTypes Linkage, Constant *Initializer, + const Twine &Name = "", + GlobalVariable *InsertBefore = 0, + ThreadLocalMode = NotThreadLocal, + unsigned AddressSpace = 0); + + ~GlobalVariable() { + NumOperands = 1; // FIXME: needed by operator delete + } - /// isExternal - Is this global variable lacking an initializer? If so, the - /// global variable is defined in some other translation unit, and is thus - /// externally defined here. - /// - virtual bool isExternal() const { return Operands.empty(); } + /// Provide fast operand accessors + DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value); /// hasInitializer - Unless a global variable isExternal(), it has an /// initializer. The initializer for the global variable/constant is held by - /// Operands[0] if an initializer is specified. + /// Initializer if an initializer is specified. + /// + inline bool hasInitializer() const { return !isDeclaration(); } + + /// hasDefinitiveInitializer - Whether the global variable has an initializer, + /// and any other instances of the global (this can happen due to weak + /// linkage) are guaranteed to have the same initializer. + /// + /// Note that if you want to transform a global, you must use + /// hasUniqueInitializer() instead, because of the *_odr linkage type. + /// + /// Example: + /// + /// @a = global SomeType* null - Initializer is both definitive and unique. + /// + /// @b = global weak SomeType* null - Initializer is neither definitive nor + /// unique. /// - inline bool hasInitializer() const { return !isExternal(); } + /// @c = global weak_odr SomeType* null - Initializer is definitive, but not + /// unique. + inline bool hasDefinitiveInitializer() const { + return hasInitializer() && + // The initializer of a global variable with weak linkage may change at + // link time. + !mayBeOverridden(); + } + + /// hasUniqueInitializer - Whether the global variable has an initializer, and + /// any changes made to the initializer will turn up in the final executable. + inline bool hasUniqueInitializer() const { + return hasInitializer() && + // It's not safe to modify initializers of global variables with weak + // linkage, because the linker might choose to discard the initializer and + // use the initializer from another instance of the global variable + // instead. It is wrong to modify the initializer of a global variable + // with *_odr linkage because then different instances of the global may + // have different initializers, breaking the One Definition Rule. + !isWeakForLinker(); + } /// getInitializer - Return the initializer for this global variable. It is /// illegal to call this method if the global is external, because we cannot /// tell what the value is initialized to! /// - inline Constant *getInitializer() const { + inline const Constant *getInitializer() const { assert(hasInitializer() && "GV doesn't have initializer!"); - return reinterpret_cast(Operands[0].get()); + return static_cast(Op<0>().get()); } inline Constant *getInitializer() { assert(hasInitializer() && "GV doesn't have initializer!"); - return reinterpret_cast(Operands[0].get()); + return static_cast(Op<0>().get()); } - inline void setInitializer(Constant *CPV) { - if (CPV == 0) { - if (hasInitializer()) Operands.pop_back(); - } else { - if (!hasInitializer()) Operands.push_back(Use(0, this)); - Operands[0] = reinterpret_cast(CPV); - } - } - - // getNext/Prev - Return the next or previous global variable in the list. - GlobalVariable *getNext() { return Next; } - const GlobalVariable *getNext() const { return Next; } - GlobalVariable *getPrev() { return Prev; } - const GlobalVariable *getPrev() const { return Prev; } + /// setInitializer - Sets the initializer for this global variable, removing + /// any existing initializer if InitVal==NULL. If this GV has type T*, the + /// initializer must have type T. + void setInitializer(Constant *InitVal); /// If the value is a global constant, its value is immutable throughout the /// runtime execution of the program. Assigning a value into the constant /// leads to undefined behavior. /// bool isConstant() const { return isConstantGlobal; } - void setConstant(bool Value) { isConstantGlobal = Value; } - - virtual void print(std::ostream &OS) const; + void setConstant(bool Val) { isConstantGlobal = Val; } + + /// If the value is "Thread Local", its value isn't shared by the threads. + bool isThreadLocal() const { return threadLocalMode != NotThreadLocal; } + void setThreadLocal(bool Val) { + threadLocalMode = Val ? GeneralDynamicTLSModel : NotThreadLocal; + } + void setThreadLocalMode(ThreadLocalMode Val) { threadLocalMode = Val; } + ThreadLocalMode getThreadLocalMode() const { + return static_cast(threadLocalMode); + } + + /// copyAttributesFrom - copy all additional attributes (those not needed to + /// create a GlobalVariable) from the GlobalVariable Src to this one. + void copyAttributesFrom(const GlobalValue *Src); + + /// removeFromParent - This method unlinks 'this' from the containing module, + /// but does not delete it. + /// + virtual void removeFromParent(); + + /// eraseFromParent - This method unlinks 'this' from the containing module + /// and deletes it. + /// + virtual void eraseFromParent(); + + /// Override Constant's implementation of this method so we can + /// replace constant initializers. + virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U); // Methods for support type inquiry through isa, cast, and dyn_cast: - static inline bool classof(const GlobalVariable *) { return true; } static inline bool classof(const Value *V) { - return V->getValueType() == Value::GlobalVariableVal; + return V->getValueID() == Value::GlobalVariableVal; } }; +template <> +struct OperandTraits : + public OptionalOperandTraits { +}; + +DEFINE_TRANSPARENT_OPERAND_ACCESSORS(GlobalVariable, Value) + } // End llvm namespace #endif