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//===- GCStrategy.cpp - Garbage Collector Description ---------------------===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// This file implements the policy object GCStrategy which describes the
// behavior of a given garbage collector.
#include "llvm/IR/GCStrategy.h"
#include "llvm/ADT/Twine.h"
#include "llvm/IR/BuiltinGCs.h"
using namespace llvm;
GCStrategy::GCStrategy() = default;
std::unique_ptr<GCStrategy> llvm::getGCStrategy(const StringRef Name) {
for (auto &S : GCRegistry::entries())
if (S.getName() == Name)
return S.instantiate();
// We need to link all the builtin GCs when LLVM is used as a static library.
// The linker will quite happily remove the static constructors that register
// the builtin GCs if we don't use a function from that object. This function
// does nothing but we need to make sure it is (or at least could be, even
// with all optimisations enabled) called *somewhere*, and this is a good
// place to do that: if the GC strategies are being used then this function
// obviously can't be removed by the linker, and here it won't affect
// performance, since there's about to be a fatal error anyway.
if (GCRegistry::begin() == GCRegistry::end()) {
// In normal operation, the registry should not be empty. There should
// be the builtin GCs if nothing else. The most likely scenario here is
// that we got here without running the initializers used by the Registry
// itself and it's registration mechanism.
const std::string error =
std::string("unsupported GC: ") + Name.str() +
" (did you remember to link and initialize the library?)";
} else
report_fatal_error(Twine(std::string("unsupported GC: ") + Name.str()));