llvm/lib/IR/Globals.cpp
Rafael Espindola 356deb5ecd Use DataLayout from the module when easily available.
Eventually DataLayoutPass should go away, but for now that is the only easy
way to get a DataLayout in some APIs. This patch only changes the ones that
have easy access to a Module.

One interesting issue with sometimes using DataLayoutPass and sometimes
fetching it from the Module is that we have to make sure they are equivalent.
We can get most of the way there by always constructing the pass with a Module.
In fact, the pass could be changed to point to an external DataLayout instead
of owning one to make this stricter.

Unfortunately, the C api passes a DataLayout, so it has to be up to the caller
to make sure the pass and the module are in sync.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202204 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-25 23:25:17 +00:00

278 lines
9.2 KiB
C++

//===-- Globals.cpp - Implement the GlobalValue & GlobalVariable class ----===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the GlobalValue & GlobalVariable classes for the IR
// library.
//
//===----------------------------------------------------------------------===//
#include "llvm/IR/GlobalValue.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/GlobalAlias.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/LeakDetector.h"
using namespace llvm;
//===----------------------------------------------------------------------===//
// GlobalValue Class
//===----------------------------------------------------------------------===//
bool GlobalValue::isMaterializable() const {
return getParent() && getParent()->isMaterializable(this);
}
bool GlobalValue::isDematerializable() const {
return getParent() && getParent()->isDematerializable(this);
}
bool GlobalValue::Materialize(std::string *ErrInfo) {
return getParent()->Materialize(this, ErrInfo);
}
void GlobalValue::Dematerialize() {
getParent()->Dematerialize(this);
}
const DataLayout *GlobalValue::getDataLayout() const {
return getParent()->getDataLayout();
}
/// Override destroyConstant to make sure it doesn't get called on
/// GlobalValue's because they shouldn't be treated like other constants.
void GlobalValue::destroyConstant() {
llvm_unreachable("You can't GV->destroyConstant()!");
}
/// copyAttributesFrom - copy all additional attributes (those not needed to
/// create a GlobalValue) from the GlobalValue Src to this one.
void GlobalValue::copyAttributesFrom(const GlobalValue *Src) {
setAlignment(Src->getAlignment());
setSection(Src->getSection());
setVisibility(Src->getVisibility());
setUnnamedAddr(Src->hasUnnamedAddr());
setDLLStorageClass(Src->getDLLStorageClass());
}
void GlobalValue::setAlignment(unsigned Align) {
assert((!isa<GlobalAlias>(this) || !Align) &&
"GlobalAlias should not have an alignment!");
assert((Align & (Align-1)) == 0 && "Alignment is not a power of 2!");
assert(Align <= MaximumAlignment &&
"Alignment is greater than MaximumAlignment!");
Alignment = Log2_32(Align) + 1;
assert(getAlignment() == Align && "Alignment representation error!");
}
bool GlobalValue::isDeclaration() const {
// Globals are definitions if they have an initializer.
if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(this))
return GV->getNumOperands() == 0;
// Functions are definitions if they have a body.
if (const Function *F = dyn_cast<Function>(this))
return F->empty();
// Aliases are always definitions.
assert(isa<GlobalAlias>(this));
return false;
}
//===----------------------------------------------------------------------===//
// GlobalVariable Implementation
//===----------------------------------------------------------------------===//
GlobalVariable::GlobalVariable(Type *Ty, bool constant, LinkageTypes Link,
Constant *InitVal,
const Twine &Name, ThreadLocalMode TLMode,
unsigned AddressSpace,
bool isExternallyInitialized)
: GlobalValue(PointerType::get(Ty, AddressSpace),
Value::GlobalVariableVal,
OperandTraits<GlobalVariable>::op_begin(this),
InitVal != 0, Link, Name),
isConstantGlobal(constant), threadLocalMode(TLMode),
isExternallyInitializedConstant(isExternallyInitialized) {
if (InitVal) {
assert(InitVal->getType() == Ty &&
"Initializer should be the same type as the GlobalVariable!");
Op<0>() = InitVal;
}
LeakDetector::addGarbageObject(this);
}
GlobalVariable::GlobalVariable(Module &M, Type *Ty, bool constant,
LinkageTypes Link, Constant *InitVal,
const Twine &Name,
GlobalVariable *Before, ThreadLocalMode TLMode,
unsigned AddressSpace,
bool isExternallyInitialized)
: GlobalValue(PointerType::get(Ty, AddressSpace),
Value::GlobalVariableVal,
OperandTraits<GlobalVariable>::op_begin(this),
InitVal != 0, Link, Name),
isConstantGlobal(constant), threadLocalMode(TLMode),
isExternallyInitializedConstant(isExternallyInitialized) {
if (InitVal) {
assert(InitVal->getType() == Ty &&
"Initializer should be the same type as the GlobalVariable!");
Op<0>() = InitVal;
}
LeakDetector::addGarbageObject(this);
if (Before)
Before->getParent()->getGlobalList().insert(Before, this);
else
M.getGlobalList().push_back(this);
}
void GlobalVariable::setParent(Module *parent) {
if (getParent())
LeakDetector::addGarbageObject(this);
Parent = parent;
if (getParent())
LeakDetector::removeGarbageObject(this);
}
void GlobalVariable::removeFromParent() {
getParent()->getGlobalList().remove(this);
}
void GlobalVariable::eraseFromParent() {
getParent()->getGlobalList().erase(this);
}
void GlobalVariable::replaceUsesOfWithOnConstant(Value *From, Value *To,
Use *U) {
// If you call this, then you better know this GVar has a constant
// initializer worth replacing. Enforce that here.
assert(getNumOperands() == 1 &&
"Attempt to replace uses of Constants on a GVar with no initializer");
// And, since you know it has an initializer, the From value better be
// the initializer :)
assert(getOperand(0) == From &&
"Attempt to replace wrong constant initializer in GVar");
// And, you better have a constant for the replacement value
assert(isa<Constant>(To) &&
"Attempt to replace GVar initializer with non-constant");
// Okay, preconditions out of the way, replace the constant initializer.
this->setOperand(0, cast<Constant>(To));
}
void GlobalVariable::setInitializer(Constant *InitVal) {
if (InitVal == 0) {
if (hasInitializer()) {
Op<0>().set(0);
NumOperands = 0;
}
} else {
assert(InitVal->getType() == getType()->getElementType() &&
"Initializer type must match GlobalVariable type");
if (!hasInitializer())
NumOperands = 1;
Op<0>().set(InitVal);
}
}
/// copyAttributesFrom - copy all additional attributes (those not needed to
/// create a GlobalVariable) from the GlobalVariable Src to this one.
void GlobalVariable::copyAttributesFrom(const GlobalValue *Src) {
assert(isa<GlobalVariable>(Src) && "Expected a GlobalVariable!");
GlobalValue::copyAttributesFrom(Src);
const GlobalVariable *SrcVar = cast<GlobalVariable>(Src);
setThreadLocalMode(SrcVar->getThreadLocalMode());
}
//===----------------------------------------------------------------------===//
// GlobalAlias Implementation
//===----------------------------------------------------------------------===//
GlobalAlias::GlobalAlias(Type *Ty, LinkageTypes Link,
const Twine &Name, Constant* aliasee,
Module *ParentModule)
: GlobalValue(Ty, Value::GlobalAliasVal, &Op<0>(), 1, Link, Name) {
LeakDetector::addGarbageObject(this);
if (aliasee)
assert(aliasee->getType() == Ty && "Alias and aliasee types should match!");
Op<0>() = aliasee;
if (ParentModule)
ParentModule->getAliasList().push_back(this);
}
void GlobalAlias::setParent(Module *parent) {
if (getParent())
LeakDetector::addGarbageObject(this);
Parent = parent;
if (getParent())
LeakDetector::removeGarbageObject(this);
}
void GlobalAlias::removeFromParent() {
getParent()->getAliasList().remove(this);
}
void GlobalAlias::eraseFromParent() {
getParent()->getAliasList().erase(this);
}
void GlobalAlias::setAliasee(Constant *Aliasee) {
assert((!Aliasee || Aliasee->getType() == getType()) &&
"Alias and aliasee types should match!");
setOperand(0, Aliasee);
}
GlobalValue *GlobalAlias::getAliasedGlobal() {
Constant *C = getAliasee();
if (C == 0) return 0;
if (GlobalValue *GV = dyn_cast<GlobalValue>(C))
return GV;
ConstantExpr *CE = cast<ConstantExpr>(C);
assert((CE->getOpcode() == Instruction::BitCast ||
CE->getOpcode() == Instruction::AddrSpaceCast ||
CE->getOpcode() == Instruction::GetElementPtr) &&
"Unsupported aliasee");
return cast<GlobalValue>(CE->getOperand(0));
}
GlobalValue *GlobalAlias::resolveAliasedGlobal(bool stopOnWeak) {
SmallPtrSet<GlobalValue*, 3> Visited;
// Check if we need to stop early.
if (stopOnWeak && mayBeOverridden())
return this;
GlobalValue *GV = getAliasedGlobal();
Visited.insert(GV);
// Iterate over aliasing chain, stopping on weak alias if necessary.
while (GlobalAlias *GA = dyn_cast<GlobalAlias>(GV)) {
if (stopOnWeak && GA->mayBeOverridden())
break;
GV = GA->getAliasedGlobal();
if (!Visited.insert(GV))
return 0;
}
return GV;
}