| //===-- Value.cpp - Implement the Value 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 implements the Value and User classes. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/Constant.h" |
| #include "llvm/DerivedTypes.h" |
| #include "llvm/InstrTypes.h" |
| #include "llvm/Module.h" |
| #include "llvm/SymbolTable.h" |
| #include "llvm/Support/LeakDetector.h" |
| #include <algorithm> |
| #include <iostream> |
| using namespace llvm; |
| |
| //===----------------------------------------------------------------------===// |
| // Value Class |
| //===----------------------------------------------------------------------===// |
| |
| static inline const Type *checkType(const Type *Ty) { |
| assert(Ty && "Value defined with a null type: Error!"); |
| return Ty; |
| } |
| |
| Value::Value(const Type *ty, unsigned scid, const std::string &name) |
| : SubclassID(scid), SubclassData(0), Ty(checkType(ty)), |
| UseList(0), Name(name) { |
| if (!isa<Constant>(this) && !isa<BasicBlock>(this)) |
| assert((Ty->isFirstClassType() || Ty == Type::VoidTy || |
| isa<OpaqueType>(ty)) && |
| "Cannot create non-first-class values except for constants!"); |
| if (ty == Type::VoidTy) |
| assert(name.empty() && "Cannot have named void values!"); |
| } |
| |
| Value::~Value() { |
| #ifndef NDEBUG // Only in -g mode... |
| // Check to make sure that there are no uses of this value that are still |
| // around when the value is destroyed. If there are, then we have a dangling |
| // reference and something is wrong. This code is here to print out what is |
| // still being referenced. The value in question should be printed as |
| // a <badref> |
| // |
| if (use_begin() != use_end()) { |
| std::cerr << "While deleting: " << *Ty << " %" << Name << "\n"; |
| for (use_iterator I = use_begin(), E = use_end(); I != E; ++I) |
| std::cerr << "Use still stuck around after Def is destroyed:" |
| << **I << "\n"; |
| } |
| #endif |
| assert(use_begin() == use_end() && "Uses remain when a value is destroyed!"); |
| |
| // There should be no uses of this object anymore, remove it. |
| LeakDetector::removeGarbageObject(this); |
| } |
| |
| /// hasNUses - Return true if this Value has exactly N users. |
| /// |
| bool Value::hasNUses(unsigned N) const { |
| use_const_iterator UI = use_begin(), E = use_end(); |
| |
| for (; N; --N, ++UI) |
| if (UI == E) return false; // Too few. |
| return UI == E; |
| } |
| |
| /// hasNUsesOrMore - Return true if this value has N users or more. This is |
| /// logically equivalent to getNumUses() >= N. |
| /// |
| bool Value::hasNUsesOrMore(unsigned N) const { |
| use_const_iterator UI = use_begin(), E = use_end(); |
| |
| for (; N; --N, ++UI) |
| if (UI == E) return false; // Too few. |
| |
| return true; |
| } |
| |
| |
| /// getNumUses - This method computes the number of uses of this Value. This |
| /// is a linear time operation. Use hasOneUse or hasNUses to check for specific |
| /// values. |
| unsigned Value::getNumUses() const { |
| return (unsigned)std::distance(use_begin(), use_end()); |
| } |
| |
| |
| void Value::setName(const std::string &name) { |
| if (Name == name) return; // Name is already set. |
| |
| // Get the symbol table to update for this object. |
| SymbolTable *ST = 0; |
| if (Instruction *I = dyn_cast<Instruction>(this)) { |
| if (BasicBlock *P = I->getParent()) |
| if (Function *PP = P->getParent()) |
| ST = &PP->getSymbolTable(); |
| } else if (BasicBlock *BB = dyn_cast<BasicBlock>(this)) { |
| if (Function *P = BB->getParent()) ST = &P->getSymbolTable(); |
| } else if (GlobalValue *GV = dyn_cast<GlobalValue>(this)) { |
| if (Module *P = GV->getParent()) ST = &P->getSymbolTable(); |
| } else if (Argument *A = dyn_cast<Argument>(this)) { |
| if (Function *P = A->getParent()) ST = &P->getSymbolTable(); |
| } else { |
| assert(isa<Constant>(this) && "Unknown value type!"); |
| return; // no name is setable for this. |
| } |
| |
| if (!ST) // No symbol table to update? Just do the change. |
| Name = name; |
| else if (hasName()) { |
| if (!name.empty()) { // Replacing name. |
| ST->changeName(this, name); |
| } else { // Transitioning from hasName -> noname. |
| ST->remove(this); |
| Name.clear(); |
| } |
| } else { // Transitioning from noname -> hasName. |
| Name = name; |
| ST->insert(this); |
| } |
| } |
| |
| // uncheckedReplaceAllUsesWith - This is exactly the same as replaceAllUsesWith, |
| // except that it doesn't have all of the asserts. The asserts fail because we |
| // are half-way done resolving types, which causes some types to exist as two |
| // different Type*'s at the same time. This is a sledgehammer to work around |
| // this problem. |
| // |
| void Value::uncheckedReplaceAllUsesWith(Value *New) { |
| while (!use_empty()) { |
| Use &U = *UseList; |
| // Must handle Constants specially, we cannot call replaceUsesOfWith on a |
| // constant! |
| if (Constant *C = dyn_cast<Constant>(U.getUser())) { |
| if (!isa<GlobalValue>(C)) |
| C->replaceUsesOfWithOnConstant(this, New, &U); |
| else |
| U.set(New); |
| } else { |
| U.set(New); |
| } |
| } |
| } |
| |
| void Value::replaceAllUsesWith(Value *New) { |
| assert(New && "Value::replaceAllUsesWith(<null>) is invalid!"); |
| assert(New != this && "this->replaceAllUsesWith(this) is NOT valid!"); |
| assert(New->getType() == getType() && |
| "replaceAllUses of value with new value of different type!"); |
| |
| uncheckedReplaceAllUsesWith(New); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // User Class |
| //===----------------------------------------------------------------------===// |
| |
| // replaceUsesOfWith - Replaces all references to the "From" definition with |
| // references to the "To" definition. |
| // |
| void User::replaceUsesOfWith(Value *From, Value *To) { |
| if (From == To) return; // Duh what? |
| |
| assert(!isa<Constant>(this) || isa<GlobalValue>(this) && |
| "Cannot call User::replaceUsesofWith on a constant!"); |
| |
| for (unsigned i = 0, E = getNumOperands(); i != E; ++i) |
| if (getOperand(i) == From) { // Is This operand is pointing to oldval? |
| // The side effects of this setOperand call include linking to |
| // "To", adding "this" to the uses list of To, and |
| // most importantly, removing "this" from the use list of "From". |
| setOperand(i, To); // Fix it now... |
| } |
| } |
| |