llvm/llvm/lib/Transforms/IPO/BarrierNoopPass.cpp

//===- BarrierNoopPass.cpp - A barrier pass for the pass manager ----------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// NOTE: DO NOT USE THIS IF AVOIDABLE
//
// This pass is a nonce pass intended to allow manipulation of the implicitly
// nesting pass manager. For example, it can be used to cause a CGSCC pass
// manager to be closed prior to running a new collection of function passes.
//
// FIXME: This is a huge HACK. This should be removed when the pass manager's
// nesting is made explicit instead of implicit.
//
//===----------------------------------------------------------------------===//

#include "llvm/InitializePasses.h"
#include "llvm/Pass.h"
#include "llvm/Transforms/IPO.h"
usingnamespacellvm;

namespace {
/// A nonce module pass used to place a barrier in a pass manager.
///
/// There is no mechanism for ending a CGSCC pass manager once one is started.
/// This prevents extension points from having clear deterministic ordering
/// when they are phrased as non-module passes.
class BarrierNoop : public ModulePass { … };
}

ModulePass *llvm::createBarrierNoopPass() { … }

char BarrierNoop::ID = …;
INITIALIZE_PASS(…)