llvm-6502/include/llvm/IR/GlobalVariable.h
Chandler Carruth 0b8c9a80f2 Move all of the header files which are involved in modelling the LLVM IR
into their new header subdirectory: include/llvm/IR. This matches the
directory structure of lib, and begins to correct a long standing point
of file layout clutter in LLVM.

There are still more header files to move here, but I wanted to handle
them in separate commits to make tracking what files make sense at each
layer easier.

The only really questionable files here are the target intrinsic
tablegen files. But that's a battle I'd rather not fight today.

I've updated both CMake and Makefile build systems (I think, and my
tests think, but I may have missed something).

I've also re-sorted the includes throughout the project. I'll be
committing updates to Clang, DragonEgg, and Polly momentarily.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171366 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-02 11:36:10 +00:00

192 lines
7.3 KiB
C++

//===-- llvm/GlobalVariable.h - GlobalVariable class ------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// 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
// represents a single global variable (or constant) in the VM.
//
// 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 initial value, which is copied into the executables .data
// area. Global Constants are required to have initializers.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_GLOBAL_VARIABLE_H
#define LLVM_GLOBAL_VARIABLE_H
#include "llvm/ADT/Twine.h"
#include "llvm/ADT/ilist_node.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/IR/OperandTraits.h"
namespace llvm {
class Module;
class Constant;
template<typename ValueSubClass, typename ItemParentClass>
class SymbolTableListTraits;
class GlobalVariable : public GlobalValue, public ilist_node<GlobalVariable> {
friend class SymbolTableListTraits<GlobalVariable, Module>;
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?
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(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
}
/// 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
/// 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 Constant *getInitializer() const {
assert(hasInitializer() && "GV doesn't have initializer!");
return static_cast<Constant*>(Op<0>().get());
}
inline Constant *getInitializer() {
assert(hasInitializer() && "GV doesn't have initializer!");
return static_cast<Constant*>(Op<0>().get());
}
/// 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 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>(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 Value *V) {
return V->getValueID() == Value::GlobalVariableVal;
}
};
template <>
struct OperandTraits<GlobalVariable> :
public OptionalOperandTraits<GlobalVariable> {
};
DEFINE_TRANSPARENT_OPERAND_ACCESSORS(GlobalVariable, Value)
} // End llvm namespace
#endif