-static void upgradeGlobalArray(GlobalVariable *GV) {
- ArrayType *ATy = cast<ArrayType>(GV->getType()->getElementType());
- StructType *OldTy = cast<StructType>(ATy->getElementType());
- assert(OldTy->getNumElements() == 2 && "Expected to upgrade from 2 elements");
-
- // Get the upgraded 3 element type.
- PointerType *VoidPtrTy = Type::getInt8Ty(GV->getContext())->getPointerTo();
- Type *Tys[3] = {OldTy->getElementType(0), OldTy->getElementType(1),
- VoidPtrTy};
- StructType *NewTy = StructType::get(GV->getContext(), Tys, false);
-
- // Build new constants with a null third field filled in.
- Constant *OldInitC = GV->getInitializer();
- ConstantArray *OldInit = dyn_cast<ConstantArray>(OldInitC);
- if (!OldInit && !isa<ConstantAggregateZero>(OldInitC))
- // Invalid initializer; give up.
- return;
- std::vector<Constant *> Initializers;
- if (OldInit && OldInit->getNumOperands()) {
- Value *Null = Constant::getNullValue(VoidPtrTy);
- for (Use &U : OldInit->operands()) {
- ConstantStruct *Init = cast<ConstantStruct>(U.get());
- Initializers.push_back(ConstantStruct::get(
- NewTy, Init->getOperand(0), Init->getOperand(1), Null, nullptr));
- }
- }
- assert(Initializers.size() == ATy->getNumElements() &&
- "Failed to copy all array elements");
-
- // Replace the old GV with a new one.
- ATy = ArrayType::get(NewTy, Initializers.size());
- Constant *NewInit = ConstantArray::get(ATy, Initializers);
- GlobalVariable *NewGV = new GlobalVariable(
- *GV->getParent(), ATy, GV->isConstant(), GV->getLinkage(), NewInit, "",
- GV, GV->getThreadLocalMode(), GV->getType()->getAddressSpace(),
- GV->isExternallyInitialized());
- NewGV->copyAttributesFrom(GV);
- NewGV->takeName(GV);
- assert(GV->use_empty() && "program cannot use initializer list");
- GV->eraseFromParent();
-}
-
-void ModuleLinker::upgradeMismatchedGlobalArray(StringRef Name) {
- // Look for the global arrays.
- auto *DstGV = dyn_cast_or_null<GlobalVariable>(DstM.getNamedValue(Name));
- if (!DstGV)
- return;
- auto *SrcGV = dyn_cast_or_null<GlobalVariable>(SrcM.getNamedValue(Name));
- if (!SrcGV)
- return;
-
- // Check if the types already match.
- auto *DstTy = cast<ArrayType>(DstGV->getType()->getElementType());
- auto *SrcTy =
- cast<ArrayType>(TypeMap.get(SrcGV->getType()->getElementType()));
- if (DstTy == SrcTy)
- return;
-
- // Grab the element types. We can only upgrade an array of a two-field
- // struct. Only bother if the other one has three-fields.
- auto *DstEltTy = cast<StructType>(DstTy->getElementType());
- auto *SrcEltTy = cast<StructType>(SrcTy->getElementType());
- if (DstEltTy->getNumElements() == 2 && SrcEltTy->getNumElements() == 3) {
- upgradeGlobalArray(DstGV);
- return;
- }
- if (DstEltTy->getNumElements() == 3 && SrcEltTy->getNumElements() == 2)
- upgradeGlobalArray(SrcGV);
-
- // We can't upgrade any other differences.
-}
-
-void ModuleLinker::upgradeMismatchedGlobals() {
- upgradeMismatchedGlobalArray("llvm.global_ctors");
- upgradeMismatchedGlobalArray("llvm.global_dtors");
-}
-