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!");
39 if (ty == Type::VoidTy)
40 assert(name.empty() && "Cannot have named void values!");
44 #ifndef NDEBUG // Only in -g mode...
45 // Check to make sure that there are no uses of this value that are still
46 // around when the value is destroyed. If there are, then we have a dangling
47 // reference and something is wrong. This code is here to print out what is
48 // still being referenced. The value in question should be printed as
51 if (Uses.begin() != Uses.end()) {
52 std::cerr << "While deleting: " << *Ty << "%" << Name << "\n";
53 for (use_const_iterator I = Uses.begin(), E = Uses.end(); I != E; ++I)
54 std::cerr << "Use still stuck around after Def is destroyed:"
58 assert(Uses.begin() == Uses.end() &&"Uses remain when a value is destroyed!");
60 // There should be no uses of this object anymore, remove it.
61 LeakDetector::removeGarbageObject(this);
65 // uncheckedReplaceAllUsesWith - This is exactly the same as replaceAllUsesWith,
66 // except that it doesn't have all of the asserts. The asserts fail because we
67 // are half-way done resolving types, which causes some types to exist as two
68 // different Type*'s at the same time. This is a sledgehammer to work around
71 void Value::uncheckedReplaceAllUsesWith(Value *New) {
72 while (!Uses.empty()) {
74 // Must handle Constants specially, we cannot call replaceUsesOfWith on a
76 if (Constant *C = dyn_cast<Constant>(U.getUser())) {
77 if (!isa<GlobalValue>(C))
78 C->replaceUsesOfWithOnConstant(this, New, true);
87 void Value::replaceAllUsesWith(Value *New) {
88 assert(New && "Value::replaceAllUsesWith(<null>) is invalid!");
89 assert(New != this && "this->replaceAllUsesWith(this) is NOT valid!");
90 assert(New->getType() == getType() &&
91 "replaceAllUses of value with new value of different type!");
93 uncheckedReplaceAllUsesWith(New);
96 //===----------------------------------------------------------------------===//
98 //===----------------------------------------------------------------------===//
100 // replaceUsesOfWith - Replaces all references to the "From" definition with
101 // references to the "To" definition.
103 void User::replaceUsesOfWith(Value *From, Value *To) {
104 if (From == To) return; // Duh what?
106 assert(!isa<Constant>(this) || isa<GlobalValue>(this) &&
107 "Cannot call User::replaceUsesofWith on a constant!");
109 for (unsigned i = 0, E = getNumOperands(); i != E; ++i)
110 if (getOperand(i) == From) { // Is This operand is pointing to oldval?
111 // The side effects of this setOperand call include linking to
112 // "To", adding "this" to the uses list of To, and
113 // most importantly, removing "this" from the use list of "From".
114 setOperand(i, To); // Fix it now...