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"
21 void llvm::appendToGlobalCtors(Module &M, Function *F, int Priority) {
22 IRBuilder<> IRB(M.getContext());
23 FunctionType *FnTy = FunctionType::get(IRB.getVoidTy(), false);
24 StructType *Ty = StructType::get(
25 IRB.getInt32Ty(), PointerType::getUnqual(FnTy), NULL);
27 Constant *RuntimeCtorInit = ConstantStruct::get(
28 Ty, IRB.getInt32(Priority), F, NULL);
30 // Get the current set of static global constructors and add the new ctor
32 SmallVector<Constant *, 16> CurrentCtors;
33 if (GlobalVariable * GVCtor = M.getNamedGlobal("llvm.global_ctors")) {
34 if (Constant *Init = GVCtor->getInitializer()) {
35 unsigned n = Init->getNumOperands();
36 CurrentCtors.reserve(n + 1);
37 for (unsigned i = 0; i != n; ++i)
38 CurrentCtors.push_back(cast<Constant>(Init->getOperand(i)));
40 GVCtor->eraseFromParent();
43 CurrentCtors.push_back(RuntimeCtorInit);
45 // Create a new initializer.
46 ArrayType *AT = ArrayType::get(RuntimeCtorInit->getType(),
48 Constant *NewInit = ConstantArray::get(AT, CurrentCtors);
50 // Create the new global variable and replace all uses of
51 // the old global variable with the new one.
52 (void)new GlobalVariable(M, NewInit->getType(), false,
53 GlobalValue::AppendingLinkage, NewInit,