1 //===-- ModuleUtils.cpp - Functions to manipulate Modules -----------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This family of functions perform manipulations on Modules.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/Transforms/Utils/ModuleUtils.h"
15 #include "llvm/DerivedTypes.h"
16 #include "llvm/Function.h"
17 #include "llvm/Module.h"
18 #include "llvm/Support/IRBuilder.h"
22 void llvm::appendToGlobalCtors(Module &M, Function *F, int Priority) {
23 IRBuilder<> IRB(M.getContext());
24 FunctionType *FnTy = FunctionType::get(IRB.getVoidTy(), false);
25 StructType *Ty = StructType::get(
26 IRB.getInt32Ty(), PointerType::getUnqual(FnTy), NULL);
28 Constant *RuntimeCtorInit = ConstantStruct::get(
29 Ty, IRB.getInt32(Priority), F, NULL);
31 // Get the current set of static global constructors and add the new ctor
33 SmallVector<Constant *, 16> CurrentCtors;
34 if (GlobalVariable * GVCtor = M.getNamedGlobal("llvm.global_ctors")) {
35 if (Constant *Init = GVCtor->getInitializer()) {
36 unsigned n = Init->getNumOperands();
37 CurrentCtors.reserve(n + 1);
38 for (unsigned i = 0; i != n; ++i)
39 CurrentCtors.push_back(cast<Constant>(Init->getOperand(i)));
41 GVCtor->eraseFromParent();
44 CurrentCtors.push_back(RuntimeCtorInit);
46 // Create a new initializer.
47 ArrayType *AT = ArrayType::get(RuntimeCtorInit->getType(),
49 Constant *NewInit = ConstantArray::get(AT, CurrentCtors);
51 // Create the new global variable and replace all uses of
52 // the old global variable with the new one.
53 (void)new GlobalVariable(M, NewInit->getType(), false,
54 GlobalValue::AppendingLinkage, NewInit,