X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FVMCore%2FGlobals.cpp;h=94bf3dea9ab3ca05b275286d61dfc476709f6f05;hb=d865e02ea24e92f8fd1d2b49a26ea0676a879ce7;hp=cfecbc91ce064f2bf882553534359848ad8a0783;hpb=8243976b69aee92b26e67ef8a3ec505e924e408b;p=oota-llvm.git diff --git a/lib/VMCore/Globals.cpp b/lib/VMCore/Globals.cpp index cfecbc91ce0..94bf3dea9ab 100644 --- a/lib/VMCore/Globals.cpp +++ b/lib/VMCore/Globals.cpp @@ -1,10 +1,10 @@ -//===-- Globals.cpp - Implement the Global object classes -----------------===// -// +//===-- Globals.cpp - Implement the GlobalValue & GlobalVariable class ----===// +// // The LLVM Compiler Infrastructure // -// This file was developed by the LLVM research group and is distributed under -// the University of Illinois Open Source License. See LICENSE.TXT for details. -// +// 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 VMCore @@ -12,33 +12,34 @@ // //===----------------------------------------------------------------------===// -#include "llvm/DerivedTypes.h" +#include "llvm/Constants.h" #include "llvm/GlobalVariable.h" +#include "llvm/GlobalAlias.h" +#include "llvm/DerivedTypes.h" #include "llvm/Module.h" -#include "llvm/SymbolTable.h" -#include "Support/LeakDetector.h" +#include "llvm/ADT/SmallPtrSet.h" +#include "llvm/Support/ErrorHandling.h" +#include "llvm/Support/LeakDetector.h" using namespace llvm; //===----------------------------------------------------------------------===// // GlobalValue Class //===----------------------------------------------------------------------===// -/// This could be named "SafeToDestroyGlobalValue". It just makes sure that -/// there are no non-constant uses of this GlobalValue. If there aren't then -/// this and the transitive closure of the constants can be deleted. See the -/// destructor for details. -static bool removeDeadConstantUsers(Constant* C) { +/// removeDeadUsersOfConstant - If the specified constantexpr is dead, remove +/// it. This involves recursively eliminating any dead users of the +/// constantexpr. +static bool removeDeadUsersOfConstant(const Constant *C) { if (isa(C)) return false; // Cannot remove this - while (!C->use_empty()) - if (Constant *User = dyn_cast(C->use_back())) { - if (!removeDeadConstantUsers(User)) - return false; // Constant wasn't dead - } else { - return false; // Non-constant usage; - } + while (!C->use_empty()) { + const Constant *User = dyn_cast(C->use_back()); + if (!User) return false; // Non-constant usage; + if (!removeDeadUsersOfConstant(User)) + return false; // Constant wasn't dead + } - C->destroyConstant(); + const_cast(C)->destroyConstant(); return true; } @@ -46,46 +47,92 @@ static bool removeDeadConstantUsers(Constant* C) { /// off of this global value, remove them. This method is useful for clients /// that want to check to see if a global is unused, but don't want to deal /// with potentially dead constants hanging off of the globals. -/// -/// This function returns true if the global value is now dead. If all -/// users of this global are not dead, this method may return false and -/// leave some of them around. -void GlobalValue::removeDeadConstantUsers() { - while(!use_empty()) { - if (Constant* User = dyn_cast(use_back())) { - if (!::removeDeadConstantUsers(User)) - return; // Constant wasn't dead +void GlobalValue::removeDeadConstantUsers() const { + Value::use_const_iterator I = use_begin(), E = use_end(); + Value::use_const_iterator LastNonDeadUser = E; + while (I != E) { + if (const Constant *User = dyn_cast(*I)) { + if (!removeDeadUsersOfConstant(User)) { + // If the constant wasn't dead, remember that this was the last live use + // and move on to the next constant. + LastNonDeadUser = I; + ++I; + } else { + // If the constant was dead, then the iterator is invalidated. + if (LastNonDeadUser == E) { + I = use_begin(); + if (I == E) break; + } else { + I = LastNonDeadUser; + ++I; + } + } } else { - return; // Non-constant usage; + LastNonDeadUser = I; + ++I; } } } -/// Override destroyConstant to make sure it doesn't get called on + +/// 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() { - assert(0 && "You can't GV->destroyConstant()!"); - abort(); + 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()); +} + + //===----------------------------------------------------------------------===// // GlobalVariable Implementation //===----------------------------------------------------------------------===// GlobalVariable::GlobalVariable(const Type *Ty, bool constant, LinkageTypes Link, - Constant *Initializer, - const std::string &Name, Module *ParentModule) - : GlobalValue(PointerType::get(Ty), Value::GlobalVariableVal, Link, Name), - isConstantGlobal(constant) { - if (Initializer) { - assert(Initializer->getType() == Ty && + Constant *InitVal, const Twine &Name, + bool ThreadLocal, unsigned AddressSpace) + : GlobalValue(PointerType::get(Ty, AddressSpace), + Value::GlobalVariableVal, + OperandTraits::op_begin(this), + InitVal != 0, Link, Name), + isConstantGlobal(constant), isThreadLocalSymbol(ThreadLocal) { + if (InitVal) { + assert(InitVal->getType() == Ty && "Initializer should be the same type as the GlobalVariable!"); - Operands.push_back(Use((Value*)Initializer, this)); + Op<0>() = InitVal; } LeakDetector::addGarbageObject(this); +} - if (ParentModule) - ParentModule->getGlobalList().push_back(this); +GlobalVariable::GlobalVariable(Module &M, const Type *Ty, bool constant, + LinkageTypes Link, Constant *InitVal, + const Twine &Name, + GlobalVariable *Before, bool ThreadLocal, + unsigned AddressSpace) + : GlobalValue(PointerType::get(Ty, AddressSpace), + Value::GlobalVariableVal, + OperandTraits::op_begin(this), + InitVal != 0, Link, Name), + isConstantGlobal(constant), isThreadLocalSymbol(ThreadLocal) { + 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) { @@ -96,22 +143,19 @@ void GlobalVariable::setParent(Module *parent) { LeakDetector::removeGarbageObject(this); } -// Specialize setName to take care of symbol table majik -void GlobalVariable::setName(const std::string &name, SymbolTable *ST) { - Module *P; - assert((ST == 0 || (!getParent() || ST == &getParent()->getSymbolTable())) && - "Invalid symtab argument!"); - if ((P = getParent()) && hasName()) P->getSymbolTable().remove(this); - Value::setName(name); - if (P && hasName()) P->getSymbolTable().insert(this); +void GlobalVariable::removeFromParent() { + getParent()->getGlobalList().remove(this); +} + +void GlobalVariable::eraseFromParent() { + getParent()->getGlobalList().erase(this); } void GlobalVariable::replaceUsesOfWithOnConstant(Value *From, Value *To, - bool DisableChecking ) -{ + Use *U) { // If you call this, then you better know this GVar has a constant // initializer worth replacing. Enforce that here. - assert(getNumOperands() == 1 && + 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 @@ -122,10 +166,125 @@ void GlobalVariable::replaceUsesOfWithOnConstant(Value *From, Value *To, // And, you better have a constant for the replacement value assert(isa(To) && "Attempt to replace GVar initializer with non-constant"); - + // Okay, preconditions out of the way, replace the constant initializer. this->setOperand(0, cast(To)); } -// vim: sw=2 ai +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(Src) && "Expected a GlobalVariable!"); + GlobalValue::copyAttributesFrom(Src); + const GlobalVariable *SrcVar = cast(Src); + setThreadLocal(SrcVar->isThreadLocal()); +} + + +//===----------------------------------------------------------------------===// +// GlobalAlias Implementation +//===----------------------------------------------------------------------===// + +GlobalAlias::GlobalAlias(const 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); +} + +bool GlobalAlias::isDeclaration() const { + const GlobalValue* AV = getAliasedGlobal(); + if (AV) + return AV->isDeclaration(); + else + return false; +} + +void GlobalAlias::setAliasee(Constant *Aliasee) +{ + if (Aliasee) + assert(Aliasee->getType() == getType() && + "Alias and aliasee types should match!"); + + setOperand(0, Aliasee); +} + +const GlobalValue *GlobalAlias::getAliasedGlobal() const { + const Constant *C = getAliasee(); + if (C) { + if (const GlobalValue *GV = dyn_cast(C)) + return GV; + else { + const ConstantExpr *CE = 0; + if ((CE = dyn_cast(C)) && + (CE->getOpcode() == Instruction::BitCast || + CE->getOpcode() == Instruction::GetElementPtr)) + return dyn_cast(CE->getOperand(0)); + else + llvm_unreachable("Unsupported aliasee"); + } + } + return 0; +} +const GlobalValue *GlobalAlias::resolveAliasedGlobal(bool stopOnWeak) const { + SmallPtrSet Visited; + + // Check if we need to stop early. + if (stopOnWeak && mayBeOverridden()) + return this; + + const GlobalValue *GV = getAliasedGlobal(); + Visited.insert(GV); + + // Iterate over aliasing chain, stopping on weak alias if necessary. + while (const GlobalAlias *GA = dyn_cast(GV)) { + if (stopOnWeak && GA->mayBeOverridden()) + break; + + GV = GA->getAliasedGlobal(); + + if (!Visited.insert(GV)) + return NULL; + } + + return GV; +}