1 //===-- Value.cpp - Implement the Value class -----------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the Value and User classes.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/InstrTypes.h"
15 #include "llvm/SymbolTable.h"
16 #include "llvm/DerivedTypes.h"
17 #include "llvm/Constant.h"
18 #include "llvm/GlobalValue.h"
19 #include "Support/LeakDetector.h"
24 //===----------------------------------------------------------------------===//
26 //===----------------------------------------------------------------------===//
28 static inline const Type *checkType(const Type *Ty) {
29 assert(Ty && "Value defined with a null type: Error!");
33 Value::Value(const Type *ty, unsigned scid, const std::string &name)
34 : SubclassID(scid), Ty(checkType(ty)), Name(name) {
35 if (!isa<Constant>(this) && !isa<BasicBlock>(this))
36 assert((Ty->isFirstClassType() || Ty == Type::VoidTy ||
37 isa<OpaqueType>(ty)) &&
38 "Cannot create non-first-class values except for constants!");
42 #ifndef NDEBUG // Only in -g mode...
43 // Check to make sure that there are no uses of this value that are still
44 // around when the value is destroyed. If there are, then we have a dangling
45 // reference and something is wrong. This code is here to print out what is
46 // still being referenced. The value in question should be printed as
49 if (Uses.begin() != Uses.end()) {
50 std::cerr << "While deleting: " << *Ty << "%" << Name << "\n";
51 for (use_const_iterator I = Uses.begin(), E = Uses.end(); I != E; ++I)
52 std::cerr << "Use still stuck around after Def is destroyed:"
56 assert(Uses.begin() == Uses.end() &&"Uses remain when a value is destroyed!");
58 // There should be no uses of this object anymore, remove it.
59 LeakDetector::removeGarbageObject(this);
63 // uncheckedReplaceAllUsesWith - This is exactly the same as replaceAllUsesWith,
64 // except that it doesn't have all of the asserts. The asserts fail because we
65 // are half-way done resolving types, which causes some types to exist as two
66 // different Type*'s at the same time. This is a sledgehammer to work around
69 void Value::uncheckedReplaceAllUsesWith(Value *New) {
70 while (!Uses.empty()) {
72 // Must handle Constants specially, we cannot call replaceUsesOfWith on a
74 if (Constant *C = dyn_cast<Constant>(U.getUser())) {
75 if (!isa<GlobalValue>(C))
76 C->replaceUsesOfWithOnConstant(this, New, true);
85 void Value::replaceAllUsesWith(Value *New) {
86 assert(New && "Value::replaceAllUsesWith(<null>) is invalid!");
87 assert(New != this && "this->replaceAllUsesWith(this) is NOT valid!");
88 assert(New->getType() == getType() &&
89 "replaceAllUses of value with new value of different type!");
91 uncheckedReplaceAllUsesWith(New);
94 //===----------------------------------------------------------------------===//
96 //===----------------------------------------------------------------------===//
98 // replaceUsesOfWith - Replaces all references to the "From" definition with
99 // references to the "To" definition.
101 void User::replaceUsesOfWith(Value *From, Value *To) {
102 if (From == To) return; // Duh what?
104 assert(!isa<Constant>(this) || isa<GlobalValue>(this) &&
105 "Cannot call User::replaceUsesofWith on a constant!");
107 for (unsigned i = 0, E = getNumOperands(); i != E; ++i)
108 if (getOperand(i) == From) { // Is This operand is pointing to oldval?
109 // The side effects of this setOperand call include linking to
110 // "To", adding "this" to the uses list of To, and
111 // most importantly, removing "this" from the use list of "From".
112 setOperand(i, To); // Fix it now...