X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FGlobalVariable.h;h=79463fbdf0ff9729098f645fec3038527d551040;hb=b09c146b116359616f6cbd4c8b3328607e00ff42;hp=aae17e409daf7792904c146fa7b02454f0e236f7;hpb=944fac71e082cc2664cc71b4d3f6c72bab7143fb;p=oota-llvm.git diff --git a/include/llvm/GlobalVariable.h b/include/llvm/GlobalVariable.h index aae17e409da..79463fbdf0f 100644 --- a/include/llvm/GlobalVariable.h +++ b/include/llvm/GlobalVariable.h @@ -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. // //===----------------------------------------------------------------------===// @@ -20,45 +20,56 @@ #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" -#include "llvm/ADT/ilist_node.h" namespace llvm { class Module; class Constant; -class PointerType; template class SymbolTableListTraits; class GlobalVariable : public GlobalValue, public ilist_node { friend class SymbolTableListTraits; - void *operator new(size_t, unsigned); // Do not implement - void operator=(const GlobalVariable &); // Do not implement - GlobalVariable(const GlobalVariable &); // Do not implement + 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); bool isConstantGlobal : 1; // Is this a global constant? - bool isThreadLocalSymbol : 1; // Is this symbol "Thread Local"? + unsigned threadLocalMode : 3; // Is this symbol "Thread Local", + // if so, what is the desired model? 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, bool ThreadLocal = false, - unsigned AddressSpace = 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(const Type *Ty, bool isConstant, LinkageTypes Linkage, - Constant *Initializer, const std::string &Name, - GlobalVariable *InsertBefore, bool ThreadLocal = false, + GlobalVariable(Module &M, Type *Ty, bool isConstant, + LinkageTypes Linkage, Constant *Initializer, + const Twine &Name = "", + GlobalVariable *InsertBefore = 0, + ThreadLocalMode = NotThreadLocal, unsigned AddressSpace = 0); ~GlobalVariable() { @@ -68,22 +79,53 @@ public: /// Provide fast operand accessors DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value); - /// isDeclaration - Is this global variable lacking an initializer? If so, - /// the global variable is defined in some other translation unit, and is thus - /// only a declaration here. - virtual bool isDeclaration() const { return getNumOperands() == 0; } - /// hasInitializer - Unless a global variable isExternal(), it has an /// initializer. The initializer for the global variable/constant is held by /// 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. + /// + /// @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 /*const FIXME*/ Constant *getInitializer() const { + inline const Constant *getInitializer() const { assert(hasInitializer() && "GV doesn't have initializer!"); return static_cast(Op<0>().get()); } @@ -91,18 +133,10 @@ public: assert(hasInitializer() && "GV doesn't have initializer!"); return static_cast(Op<0>().get()); } - inline void setInitializer(Constant *CPV) { - if (CPV == 0) { - if (hasInitializer()) { - Op<0>().set(0); - NumOperands = 0; - } - } else { - if (!hasInitializer()) - NumOperands = 1; - Op<0>().set(CPV); - } - } + /// 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 @@ -112,8 +146,14 @@ public: void setConstant(bool Val) { isConstantGlobal = Val; } /// If the value is "Thread Local", its value isn't shared by the threads. - bool isThreadLocal() const { return isThreadLocalSymbol; } - void setThreadLocal(bool Val) { isThreadLocalSymbol = Val; } + 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. @@ -122,26 +162,26 @@ public: /// removeFromParent - This method unlinks 'this' from the containing module, /// but does not delete it. /// - void removeFromParent(); + virtual void removeFromParent(); /// eraseFromParent - This method unlinks 'this' from the containing module /// and deletes it. /// - void eraseFromParent(); + 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->getValueID() == Value::GlobalVariableVal; } }; template <> -struct OperandTraits : OptionalOperandTraits<> { +struct OperandTraits : + public OptionalOperandTraits { }; DEFINE_TRANSPARENT_OPERAND_ACCESSORS(GlobalVariable, Value)