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//===-- ModuleUtils.cpp - Functions to manipulate Modules -----------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This family of functions perform manipulations on Modules.
//
//===----------------------------------------------------------------------===//
#include "llvm/Transforms/Utils/ModuleUtils.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/Module.h"
using namespace llvm;
static void appendToGlobalArray(const char *Array,
Module &M, Function *F, int Priority) {
IRBuilder<> IRB(M.getContext());
FunctionType *FnTy = FunctionType::get(IRB.getVoidTy(), false);
StructType *Ty = StructType::get(
IRB.getInt32Ty(), PointerType::getUnqual(FnTy), NULL);
Constant *RuntimeCtorInit = ConstantStruct::get(
Ty, IRB.getInt32(Priority), F, NULL);
// Get the current set of static global constructors and add the new ctor
// to the list.
SmallVector<Constant *, 16> CurrentCtors;
if (GlobalVariable * GVCtor = M.getNamedGlobal(Array)) {
if (Constant *Init = GVCtor->getInitializer()) {
unsigned n = Init->getNumOperands();
CurrentCtors.reserve(n + 1);
for (unsigned i = 0; i != n; ++i)
CurrentCtors.push_back(cast<Constant>(Init->getOperand(i)));
}
GVCtor->eraseFromParent();
}
CurrentCtors.push_back(RuntimeCtorInit);
// Create a new initializer.
ArrayType *AT = ArrayType::get(RuntimeCtorInit->getType(),
CurrentCtors.size());
Constant *NewInit = ConstantArray::get(AT, CurrentCtors);
// Create the new global variable and replace all uses of
// the old global variable with the new one.
(void)new GlobalVariable(M, NewInit->getType(), false,
GlobalValue::AppendingLinkage, NewInit, Array);
}
void llvm::appendToGlobalCtors(Module &M, Function *F, int Priority) {
appendToGlobalArray("llvm.global_ctors", M, F, Priority);
}
void llvm::appendToGlobalDtors(Module &M, Function *F, int Priority) {
appendToGlobalArray("llvm.global_dtors", M, F, Priority);
}
GlobalVariable *
llvm::collectUsedGlobalVariables(Module &M, SmallPtrSet<GlobalValue *, 8> &Set,
bool CompilerUsed) {
const char *Name = CompilerUsed ? "llvm.compiler.used" : "llvm.used";
GlobalVariable *GV = M.getGlobalVariable(Name);
if (!GV || !GV->hasInitializer())
return GV;
const ConstantArray *Init = cast<ConstantArray>(GV->getInitializer());
for (unsigned I = 0, E = Init->getNumOperands(); I != E; ++I) {
Value *Op = Init->getOperand(I);
GlobalValue *G = cast<GlobalValue>(Op->stripPointerCastsNoFollowAliases());
Set.insert(G);
}
return GV;
}
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