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//===-- Value.cpp - Implement the Value class -----------------------------===//
//
// This file implements the Value and User classes.
//
//===----------------------------------------------------------------------===//
#include "llvm/InstrTypes.h"
#include "llvm/SymbolTable.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Constant.h"
#include "Support/LeakDetector.h"
#include <algorithm>
//===----------------------------------------------------------------------===//
// 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, ValueTy vty, const std::string &name)
: Name(name), Ty(checkType(ty), this) {
VTy = vty;
}
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 (Uses.begin() != Uses.end()) {
std::cerr << "While deleting: " << Ty << "%" << Name << "\n";
for (use_const_iterator I = Uses.begin(); I != Uses.end(); ++I)
std::cerr << "Use still stuck around after Def is destroyed:"
<< **I << "\n";
}
#endif
assert(Uses.begin() == Uses.end() &&"Uses remain when a value is destroyed!");
// There should be no uses of this object anymore, remove it.
LeakDetector::removeGarbageObject(this);
}
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!");
while (!Uses.empty()) {
User *Use = Uses.back();
// Must handle Constants specially, we cannot call replaceUsesOfWith on a
// constant!
if (Constant *C = dyn_cast<Constant>(Use)) {
C->replaceUsesOfWithOnConstant(this, New);
} else {
Use->replaceUsesOfWith(this, New);
}
}
}
// 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 (!Uses.empty()) {
User *Use = Uses.back();
// Must handle Constants specially, we cannot call replaceUsesOfWith on a
// constant!
if (Constant *C = dyn_cast<Constant>(Use)) {
C->replaceUsesOfWithOnConstant(this, New);
} else {
Use->replaceUsesOfWith(this, New);
}
}
}
// refineAbstractType - This function is implemented because we use
// potentially abstract types, and these types may be resolved to more
// concrete types after we are constructed. For the value class, we simply
// change Ty to point to the right type. :)
//
void Value::refineAbstractType(const DerivedType *OldTy, const Type *NewTy) {
assert(Ty.get() == OldTy && "Can't refine anything but my type!");
if (OldTy == NewTy && !OldTy->isAbstract())
Ty.removeUserFromConcrete();
Ty = NewTy;
}
void Value::killUse(User *U) {
if (U == 0) return;
unsigned i;
// Scan backwards through the uses list looking for the user. We do this
// because vectors like to be accessed on the end. This is incredibly
// important from a performance perspective.
for (i = Uses.size()-1; Uses[i] != U; --i)
/* empty */;
assert(i < Uses.size() && "Use not in uses list!!");
Uses[i] = Uses.back();
Uses.pop_back();
}
//===----------------------------------------------------------------------===//
// User Class
//===----------------------------------------------------------------------===//
User::User(const Type *Ty, ValueTy vty, const std::string &name)
: Value(Ty, vty, name) {
}
// 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) &&
"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...
}
}
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