X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FGlobalVariable.h;h=79463fbdf0ff9729098f645fec3038527d551040;hb=b09c146b116359616f6cbd4c8b3328607e00ff42;hp=68bd1b3eab151777d9bb2259e2d03403eca7d234;hpb=dc1472b6d9281893771a64eb95b4599dff9aadfd;p=oota-llvm.git diff --git a/include/llvm/GlobalVariable.h b/include/llvm/GlobalVariable.h index 68bd1b3eab1..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. // //===----------------------------------------------------------------------===// @@ -20,9 +20,10 @@ #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 { @@ -33,31 +34,42 @@ template 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, + GlobalVariable(Type *Ty, bool isConstant, LinkageTypes Linkage, Constant *Initializer = 0, const Twine &Name = "", - bool ThreadLocal = false, unsigned AddressSpace = 0); + ThreadLocalMode = NotThreadLocal, unsigned AddressSpace = 0); /// GlobalVariable ctor - This creates a global and inserts it before the /// specified other global. - GlobalVariable(Module &M, const Type *Ty, bool isConstant, + GlobalVariable(Module &M, Type *Ty, bool isConstant, LinkageTypes Linkage, Constant *Initializer, - const Twine &Name, - GlobalVariable *InsertBefore = 0, bool ThreadLocal = false, + const Twine &Name = "", + GlobalVariable *InsertBefore = 0, + ThreadLocalMode = NotThreadLocal, unsigned AddressSpace = 0); ~GlobalVariable() { @@ -67,11 +79,6 @@ 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. @@ -79,7 +86,21 @@ public: inline bool hasInitializer() const { return !isDeclaration(); } /// hasDefinitiveInitializer - Whether the global variable has an initializer, - /// and this is the initializer that will be used in the final executable. + /// 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 @@ -87,11 +108,24 @@ public: !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()); } @@ -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. @@ -134,14 +174,14 @@ public: 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 : public OptionalOperandTraits<> { +struct OperandTraits : + public OptionalOperandTraits { }; DEFINE_TRANSPARENT_OPERAND_ACCESSORS(GlobalVariable, Value)