llvm-6502/include/llvm/IR/GlobalValue.h
Mehdi Amini a716c07147 Remove getDataLayout() from Instruction/GlobalValue/BasicBlock/Function
Summary:
This does not conceptually belongs here. Instead provide a shortcut
getModule() that provides access to the DataLayout.

Reviewers: chandlerc, echristo

Reviewed By: echristo

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8027

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231147 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-03 22:01:13 +00:00

360 lines
13 KiB
C++

//===-- llvm/GlobalValue.h - Class to represent a global value --*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file is a common base class of all globally definable objects. As such,
// it is subclassed by GlobalVariable, GlobalAlias and by Function. This is
// used because you can do certain things with these global objects that you
// can't do to anything else. For example, use the address of one as a
// constant.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_IR_GLOBALVALUE_H
#define LLVM_IR_GLOBALVALUE_H
#include "llvm/IR/Constant.h"
#include "llvm/IR/DerivedTypes.h"
#include <system_error>
namespace llvm {
class Comdat;
class PointerType;
class Module;
class GlobalValue : public Constant {
GlobalValue(const GlobalValue &) = delete;
public:
/// @brief An enumeration for the kinds of linkage for global values.
enum LinkageTypes {
ExternalLinkage = 0,///< Externally visible function
AvailableExternallyLinkage, ///< Available for inspection, not emission.
LinkOnceAnyLinkage, ///< Keep one copy of function when linking (inline)
LinkOnceODRLinkage, ///< Same, but only replaced by something equivalent.
WeakAnyLinkage, ///< Keep one copy of named function when linking (weak)
WeakODRLinkage, ///< Same, but only replaced by something equivalent.
AppendingLinkage, ///< Special purpose, only applies to global arrays
InternalLinkage, ///< Rename collisions when linking (static functions).
PrivateLinkage, ///< Like Internal, but omit from symbol table.
ExternalWeakLinkage,///< ExternalWeak linkage description.
CommonLinkage ///< Tentative definitions.
};
/// @brief An enumeration for the kinds of visibility of global values.
enum VisibilityTypes {
DefaultVisibility = 0, ///< The GV is visible
HiddenVisibility, ///< The GV is hidden
ProtectedVisibility ///< The GV is protected
};
/// @brief Storage classes of global values for PE targets.
enum DLLStorageClassTypes {
DefaultStorageClass = 0,
DLLImportStorageClass = 1, ///< Function to be imported from DLL
DLLExportStorageClass = 2 ///< Function to be accessible from DLL.
};
protected:
GlobalValue(Type *Ty, ValueTy VTy, Use *Ops, unsigned NumOps,
LinkageTypes Linkage, const Twine &Name)
: Constant(Ty, VTy, Ops, NumOps), Linkage(Linkage),
Visibility(DefaultVisibility), UnnamedAddr(0),
DllStorageClass(DefaultStorageClass),
ThreadLocal(NotThreadLocal), Parent(nullptr) {
setName(Name);
}
// Note: VC++ treats enums as signed, so an extra bit is required to prevent
// Linkage and Visibility from turning into negative values.
LinkageTypes Linkage : 5; // The linkage of this global
unsigned Visibility : 2; // The visibility style of this global
unsigned UnnamedAddr : 1; // This value's address is not significant
unsigned DllStorageClass : 2; // DLL storage class
unsigned ThreadLocal : 3; // Is this symbol "Thread Local", if so, what is
// the desired model?
private:
// Give subclasses access to what otherwise would be wasted padding.
// (19 + 3 + 2 + 1 + 2 + 5) == 32.
unsigned SubClassData : 19;
protected:
static const unsigned GlobalValueSubClassDataBits = 19;
unsigned getGlobalValueSubClassData() const {
return SubClassData;
}
void setGlobalValueSubClassData(unsigned V) {
assert(V < (1 << 19) && "It will not fit");
SubClassData = V;
}
Module *Parent; // The containing module.
public:
enum ThreadLocalMode {
NotThreadLocal = 0,
GeneralDynamicTLSModel,
LocalDynamicTLSModel,
InitialExecTLSModel,
LocalExecTLSModel
};
~GlobalValue() {
removeDeadConstantUsers(); // remove any dead constants using this.
}
unsigned getAlignment() const;
bool hasUnnamedAddr() const { return UnnamedAddr; }
void setUnnamedAddr(bool Val) { UnnamedAddr = Val; }
bool hasComdat() const { return getComdat() != nullptr; }
Comdat *getComdat();
const Comdat *getComdat() const {
return const_cast<GlobalValue *>(this)->getComdat();
}
VisibilityTypes getVisibility() const { return VisibilityTypes(Visibility); }
bool hasDefaultVisibility() const { return Visibility == DefaultVisibility; }
bool hasHiddenVisibility() const { return Visibility == HiddenVisibility; }
bool hasProtectedVisibility() const {
return Visibility == ProtectedVisibility;
}
void setVisibility(VisibilityTypes V) {
assert((!hasLocalLinkage() || V == DefaultVisibility) &&
"local linkage requires default visibility");
Visibility = V;
}
/// If the value is "Thread Local", its value isn't shared by the threads.
bool isThreadLocal() const { return getThreadLocalMode() != NotThreadLocal; }
void setThreadLocal(bool Val) {
setThreadLocalMode(Val ? GeneralDynamicTLSModel : NotThreadLocal);
}
void setThreadLocalMode(ThreadLocalMode Val) {
assert(Val == NotThreadLocal || getValueID() != Value::FunctionVal);
ThreadLocal = Val;
}
ThreadLocalMode getThreadLocalMode() const {
return static_cast<ThreadLocalMode>(ThreadLocal);
}
DLLStorageClassTypes getDLLStorageClass() const {
return DLLStorageClassTypes(DllStorageClass);
}
bool hasDLLImportStorageClass() const {
return DllStorageClass == DLLImportStorageClass;
}
bool hasDLLExportStorageClass() const {
return DllStorageClass == DLLExportStorageClass;
}
void setDLLStorageClass(DLLStorageClassTypes C) { DllStorageClass = C; }
bool hasSection() const { return !StringRef(getSection()).empty(); }
// It is unfortunate that we have to use "char *" in here since this is
// always non NULL, but:
// * The C API expects a null terminated string, so we cannot use StringRef.
// * The C API expects us to own it, so we cannot use a std:string.
// * For GlobalAliases we can fail to find the section and we have to
// return "", so we cannot use a "const std::string &".
const char *getSection() const;
/// Global values are always pointers.
inline PointerType *getType() const {
return cast<PointerType>(User::getType());
}
static LinkageTypes getLinkOnceLinkage(bool ODR) {
return ODR ? LinkOnceODRLinkage : LinkOnceAnyLinkage;
}
static LinkageTypes getWeakLinkage(bool ODR) {
return ODR ? WeakODRLinkage : WeakAnyLinkage;
}
static bool isExternalLinkage(LinkageTypes Linkage) {
return Linkage == ExternalLinkage;
}
static bool isAvailableExternallyLinkage(LinkageTypes Linkage) {
return Linkage == AvailableExternallyLinkage;
}
static bool isLinkOnceODRLinkage(LinkageTypes Linkage) {
return Linkage == LinkOnceODRLinkage;
}
static bool isLinkOnceLinkage(LinkageTypes Linkage) {
return Linkage == LinkOnceAnyLinkage || Linkage == LinkOnceODRLinkage;
}
static bool isWeakAnyLinkage(LinkageTypes Linkage) {
return Linkage == WeakAnyLinkage;
}
static bool isWeakODRLinkage(LinkageTypes Linkage) {
return Linkage == WeakODRLinkage;
}
static bool isWeakLinkage(LinkageTypes Linkage) {
return isWeakAnyLinkage(Linkage) || isWeakODRLinkage(Linkage);
}
static bool isAppendingLinkage(LinkageTypes Linkage) {
return Linkage == AppendingLinkage;
}
static bool isInternalLinkage(LinkageTypes Linkage) {
return Linkage == InternalLinkage;
}
static bool isPrivateLinkage(LinkageTypes Linkage) {
return Linkage == PrivateLinkage;
}
static bool isLocalLinkage(LinkageTypes Linkage) {
return isInternalLinkage(Linkage) || isPrivateLinkage(Linkage);
}
static bool isExternalWeakLinkage(LinkageTypes Linkage) {
return Linkage == ExternalWeakLinkage;
}
static bool isCommonLinkage(LinkageTypes Linkage) {
return Linkage == CommonLinkage;
}
/// Whether the definition of this global may be discarded if it is not used
/// in its compilation unit.
static bool isDiscardableIfUnused(LinkageTypes Linkage) {
return isLinkOnceLinkage(Linkage) || isLocalLinkage(Linkage);
}
/// Whether the definition of this global may be replaced by something
/// non-equivalent at link time. For example, if a function has weak linkage
/// then the code defining it may be replaced by different code.
static bool mayBeOverridden(LinkageTypes Linkage) {
return Linkage == WeakAnyLinkage || Linkage == LinkOnceAnyLinkage ||
Linkage == CommonLinkage || Linkage == ExternalWeakLinkage;
}
/// Whether the definition of this global may be replaced at link time. NB:
/// Using this method outside of the code generators is almost always a
/// mistake: when working at the IR level use mayBeOverridden instead as it
/// knows about ODR semantics.
static bool isWeakForLinker(LinkageTypes Linkage) {
return Linkage == AvailableExternallyLinkage || Linkage == WeakAnyLinkage ||
Linkage == WeakODRLinkage || Linkage == LinkOnceAnyLinkage ||
Linkage == LinkOnceODRLinkage || Linkage == CommonLinkage ||
Linkage == ExternalWeakLinkage;
}
bool hasExternalLinkage() const { return isExternalLinkage(Linkage); }
bool hasAvailableExternallyLinkage() const {
return isAvailableExternallyLinkage(Linkage);
}
bool hasLinkOnceLinkage() const {
return isLinkOnceLinkage(Linkage);
}
bool hasLinkOnceODRLinkage() const { return isLinkOnceODRLinkage(Linkage); }
bool hasWeakLinkage() const {
return isWeakLinkage(Linkage);
}
bool hasWeakAnyLinkage() const {
return isWeakAnyLinkage(Linkage);
}
bool hasWeakODRLinkage() const {
return isWeakODRLinkage(Linkage);
}
bool hasAppendingLinkage() const { return isAppendingLinkage(Linkage); }
bool hasInternalLinkage() const { return isInternalLinkage(Linkage); }
bool hasPrivateLinkage() const { return isPrivateLinkage(Linkage); }
bool hasLocalLinkage() const { return isLocalLinkage(Linkage); }
bool hasExternalWeakLinkage() const { return isExternalWeakLinkage(Linkage); }
bool hasCommonLinkage() const { return isCommonLinkage(Linkage); }
void setLinkage(LinkageTypes LT) {
if (isLocalLinkage(LT))
Visibility = DefaultVisibility;
Linkage = LT;
}
LinkageTypes getLinkage() const { return Linkage; }
bool isDiscardableIfUnused() const {
return isDiscardableIfUnused(Linkage);
}
bool mayBeOverridden() const { return mayBeOverridden(Linkage); }
bool isWeakForLinker() const { return isWeakForLinker(Linkage); }
/// Copy all additional attributes (those not needed to create a GlobalValue)
/// from the GlobalValue Src to this one.
virtual void copyAttributesFrom(const GlobalValue *Src);
/// If special LLVM prefix that is used to inform the asm printer to not emit
/// usual symbol prefix before the symbol name is used then return linkage
/// name after skipping this special LLVM prefix.
static StringRef getRealLinkageName(StringRef Name) {
if (!Name.empty() && Name[0] == '\1')
return Name.substr(1);
return Name;
}
/// @name Materialization
/// Materialization is used to construct functions only as they're needed. This
/// is useful to reduce memory usage in LLVM or parsing work done by the
/// BitcodeReader to load the Module.
/// @{
/// If this function's Module is being lazily streamed in functions from disk
/// or some other source, this method can be used to check to see if the
/// function has been read in yet or not.
bool isMaterializable() const;
/// Returns true if this function was loaded from a GVMaterializer that's
/// still attached to its Module and that knows how to dematerialize the
/// function.
bool isDematerializable() const;
/// Make sure this GlobalValue is fully read. If the module is corrupt, this
/// returns true and fills in the optional string with information about the
/// problem. If successful, this returns false.
std::error_code materialize();
/// If this GlobalValue is read in, and if the GVMaterializer supports it,
/// release the memory for the function, and set it up to be materialized
/// lazily. If !isDematerializable(), this method is a noop.
void Dematerialize();
/// @}
/// Override from Constant class.
void destroyConstant() override;
/// Return true if the primary definition of this global value is outside of
/// the current translation unit.
bool isDeclaration() const;
bool isDeclarationForLinker() const {
if (hasAvailableExternallyLinkage())
return true;
return isDeclaration();
}
/// This method unlinks 'this' from the containing module, but does not delete
/// it.
virtual void removeFromParent() = 0;
/// This method unlinks 'this' from the containing module and deletes it.
virtual void eraseFromParent() = 0;
/// Get the module that this global value is contained inside of...
inline Module *getParent() { return Parent; }
inline const Module *getParent() const { return Parent; }
// Methods for support type inquiry through isa, cast, and dyn_cast:
static inline bool classof(const Value *V) {
return V->getValueID() == Value::FunctionVal ||
V->getValueID() == Value::GlobalVariableVal ||
V->getValueID() == Value::GlobalAliasVal;
}
};
} // End llvm namespace
#endif