mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-11-24 11:42:57 +01:00
128 lines
4.7 KiB
C++
128 lines
4.7 KiB
C++
//===-- Globals.cpp - Implement the Global object classes -----------------===//
|
|
//
|
|
// 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 GlobalValue & GlobalVariable classes for the VMCore
|
|
// library.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "llvm/DerivedTypes.h"
|
|
#include "llvm/GlobalVariable.h"
|
|
#include "llvm/Module.h"
|
|
#include "llvm/SymbolTable.h"
|
|
#include "Support/LeakDetector.h"
|
|
using namespace llvm;
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// GlobalValue Class
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
/// This could be named "SafeToDestroyGlobalValue". It just makes sure that
|
|
/// there are no non-constant uses of this GlobalValue. If there aren't then
|
|
/// this and the transitive closure of the constants can be deleted. See the
|
|
/// destructor for details.
|
|
static bool removeDeadConstantUsers(Constant* C) {
|
|
if (isa<GlobalValue>(C)) return false; // Cannot remove this
|
|
|
|
while (!C->use_empty())
|
|
if (Constant *User = dyn_cast<Constant>(C->use_back())) {
|
|
if (!removeDeadConstantUsers(User))
|
|
return false; // Constant wasn't dead
|
|
} else {
|
|
return false; // Non-constant usage;
|
|
}
|
|
|
|
C->destroyConstant();
|
|
return true;
|
|
}
|
|
|
|
/// removeDeadConstantUsers - If there are any dead constant users dangling
|
|
/// off of this global value, remove them. This method is useful for clients
|
|
/// that want to check to see if a global is unused, but don't want to deal
|
|
/// with potentially dead constants hanging off of the globals.
|
|
///
|
|
/// This function returns true if the global value is now dead. If all
|
|
/// users of this global are not dead, this method may return false and
|
|
/// leave some of them around.
|
|
void GlobalValue::removeDeadConstantUsers() {
|
|
while(!use_empty()) {
|
|
if (Constant* User = dyn_cast<Constant>(use_back())) {
|
|
if (!::removeDeadConstantUsers(User))
|
|
return; // Constant wasn't dead
|
|
} else {
|
|
return; // Non-constant usage;
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Override destroyConstant to make sure it doesn't get called on
|
|
/// GlobalValue's because they shouldn't be treated like other constants.
|
|
void GlobalValue::destroyConstant() {
|
|
assert(0 && "You can't GV->destroyConstant()!");
|
|
abort();
|
|
}
|
|
//===----------------------------------------------------------------------===//
|
|
// GlobalVariable Implementation
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
GlobalVariable::GlobalVariable(const Type *Ty, bool constant, LinkageTypes Link,
|
|
Constant *Initializer,
|
|
const std::string &Name, Module *ParentModule)
|
|
: GlobalValue(PointerType::get(Ty), Value::GlobalVariableVal, Link, Name),
|
|
isConstantGlobal(constant) {
|
|
if (Initializer) Operands.push_back(Use((Value*)Initializer, this));
|
|
|
|
LeakDetector::addGarbageObject(this);
|
|
|
|
if (ParentModule)
|
|
ParentModule->getGlobalList().push_back(this);
|
|
}
|
|
|
|
void GlobalVariable::setParent(Module *parent) {
|
|
if (getParent())
|
|
LeakDetector::addGarbageObject(this);
|
|
Parent = parent;
|
|
if (getParent())
|
|
LeakDetector::removeGarbageObject(this);
|
|
}
|
|
|
|
// Specialize setName to take care of symbol table majik
|
|
void GlobalVariable::setName(const std::string &name, SymbolTable *ST) {
|
|
Module *P;
|
|
assert((ST == 0 || (!getParent() || ST == &getParent()->getSymbolTable())) &&
|
|
"Invalid symtab argument!");
|
|
if ((P = getParent()) && hasName()) P->getSymbolTable().remove(this);
|
|
Value::setName(name);
|
|
if (P && hasName()) P->getSymbolTable().insert(this);
|
|
}
|
|
|
|
void GlobalVariable::replaceUsesOfWithOnConstant(Value *From, Value *To,
|
|
bool DisableChecking )
|
|
{
|
|
// If you call this, then you better know this GVar has a constant
|
|
// initializer worth replacing. Enforce that here.
|
|
assert(getNumOperands() == 1 &&
|
|
"Attempt to replace uses of Constants on a GVar with no initializer");
|
|
|
|
// And, since you know it has an initializer, the From value better be
|
|
// the initializer :)
|
|
assert(getOperand(0) == From &&
|
|
"Attempt to replace wrong constant initializer in GVar");
|
|
|
|
// And, you better have a constant for the replacement value
|
|
assert(isa<Constant>(To) &&
|
|
"Attempt to replace GVar initializer with non-constant");
|
|
|
|
// Okay, preconditions out of the way, replace the constant initializer.
|
|
this->setOperand(0,To);
|
|
}
|
|
|
|
// vim: sw=2 ai
|
|
|