llvm/lib/VMCore/Value.cpp

121 lines
3.9 KiB
C++
Raw Normal View History

//===-- 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 <algorithm>
#include <iostream>
//===----------------------------------------------------------------------===//
// 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)->dump();
std::cerr << "\n";
}
}
#endif
assert(Uses.begin() == Uses.end());
}
void Value::replaceAllUsesWith(Value *D) {
assert(D && "Value::replaceAllUsesWith(<null>) is invalid!");
assert(D != this && "V->replaceAllUsesWith(V) is NOT valid!");
assert(D->getType() == getType() &&
"replaceAllUses of value with new value of different type!");
while (!Uses.empty()) {
User *Use = Uses.back();
#ifndef NDEBUG
unsigned NumUses = Uses.size();
#endif
Use->replaceUsesOfWith(this, D);
#ifndef NDEBUG // only in -g mode...
if (Uses.size() == NumUses) {
std::cerr << "Use: ";
Use->dump();
std::cerr << "replace with: ";
D->dump();
}
#endif
assert(Uses.size() != NumUses && "Didn't remove definition!");
}
}
// 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 *i) {
if (i == 0) return;
use_iterator I = find(Uses.begin(), Uses.end(), i);
assert(I != Uses.end() && "Use not in uses list!!");
Uses.erase(I);
}
User *Value::use_remove(use_iterator &I) {
assert(I != Uses.end() && "Trying to remove the end of the use list!!!");
User *i = *I;
I = Uses.erase(I);
return i;
}
//===----------------------------------------------------------------------===//
// 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?
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...
}
}