/// Walk through the instructions in \p F looking for external
/// calls not already in the \p CalledFunctions set. If any are
/// found they are added to the \p Worklist for importing.
static void findExternalCalls(const Module &DestModule, Function &F,
const FunctionInfoIndex &Index,
StringSet<> &CalledFunctions,
SmallVector<StringRef, 64> &Worklist) {
// We need to suffix internal function calls imported from other modules,
// prepare the suffix ahead of time.
std::string Suffix;
if (F.getParent() != &DestModule)
Suffix =
(Twine(".llvm.") +
Twine(Index.getModuleId(F.getParent()->getModuleIdentifier()))).str();
for (auto &BB : F) {
for (auto &I : BB) {
if (isa<CallInst>(I)) {
auto CalledFunction = cast<CallInst>(I).getCalledFunction();
// Insert any new external calls that have not already been
// added to set/worklist.
if (!CalledFunction || !CalledFunction->hasName())
continue;
// Ignore intrinsics early
if (CalledFunction->isIntrinsic()) {
assert(CalledFunction->getIntrinsicID() != 0);
continue;
}
auto ImportedName = CalledFunction->getName();
auto Renamed = (ImportedName + Suffix).str();
// Rename internal functions
if (CalledFunction->hasInternalLinkage()) {
ImportedName = Renamed;
}
auto It = CalledFunctions.insert(ImportedName);
if (!It.second) {
// This is a call to a function we already considered, skip.
continue;
}
// Ignore functions already present in the destination module
auto *SrcGV = DestModule.getNamedValue(ImportedName);
if (SrcGV) {
assert(isa<Function>(SrcGV) && "Name collision during import");
if (!cast<Function>(SrcGV)->isDeclaration()) {
DEBUG(dbgs() << DestModule.getModuleIdentifier() << ": Ignoring "
<< ImportedName << " already in DestinationModule\n");
continue;
}
}
Worklist.push_back(It.first->getKey());
DEBUG(dbgs() << DestModule.getModuleIdentifier()
<< ": Adding callee for : " << ImportedName << " : "
<< F.getName() << "\n");
}
}
}
}
