| //===-- 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" |
| #include "llvm/Support/raw_ostream.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); |
| |
| // Get the current set of static global constructors and add the new ctor |
| // to the list. |
| SmallVector<Constant *, 16> CurrentCtors; |
| StructType *EltTy; |
| if (GlobalVariable *GVCtor = M.getNamedGlobal(Array)) { |
| // If there is a global_ctors array, use the existing struct type, which can |
| // have 2 or 3 fields. |
| ArrayType *ATy = cast<ArrayType>(GVCtor->getType()->getElementType()); |
| EltTy = cast<StructType>(ATy->getElementType()); |
| 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(); |
| } else { |
| // Use a simple two-field struct if there isn't one already. |
| EltTy = StructType::get(IRB.getInt32Ty(), PointerType::getUnqual(FnTy), |
| nullptr); |
| } |
| |
| // Build a 2 or 3 field global_ctor entry. We don't take a comdat key. |
| Constant *CSVals[3]; |
| CSVals[0] = IRB.getInt32(Priority); |
| CSVals[1] = F; |
| // FIXME: Drop support for the two element form in LLVM 4.0. |
| if (EltTy->getNumElements() >= 3) |
| CSVals[2] = llvm::Constant::getNullValue(IRB.getInt8PtrTy()); |
| Constant *RuntimeCtorInit = |
| ConstantStruct::get(EltTy, makeArrayRef(CSVals, EltTy->getNumElements())); |
| |
| CurrentCtors.push_back(RuntimeCtorInit); |
| |
| // Create a new initializer. |
| ArrayType *AT = ArrayType::get(EltTy, 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, SmallPtrSetImpl<GlobalValue *> &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; |
| } |
| |
| Function *llvm::checkSanitizerInterfaceFunction(Constant *FuncOrBitcast) { |
| if (isa<Function>(FuncOrBitcast)) |
| return cast<Function>(FuncOrBitcast); |
| FuncOrBitcast->dump(); |
| std::string Err; |
| raw_string_ostream Stream(Err); |
| Stream << "Sanitizer interface function redefined: " << *FuncOrBitcast; |
| report_fatal_error(Err); |
| } |