llvm/llvm/include/llvm/PassAnalysisSupport.h

//===- llvm/PassAnalysisSupport.h - Analysis Pass Support code --*- C++ -*-===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// This file defines stuff that is used to define and "use" Analysis Passes.
// This file is automatically #included by Pass.h, so:
//
//           NO .CPP FILES SHOULD INCLUDE THIS FILE DIRECTLY
//
// Instead, #include Pass.h
//
//===----------------------------------------------------------------------===//

#if !defined(LLVM_PASS_H) || defined(LLVM_PASSANALYSISSUPPORT_H)
#error "Do not include <PassAnalysisSupport.h>; include <Pass.h> instead"
#endif

#ifndef LLVM_PASSANALYSISSUPPORT_H
#define LLVM_PASSANALYSISSUPPORT_H

#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallVector.h"
#include <cassert>
#include <tuple>
#include <utility>
#include <vector>

namespace llvm {

class Function;
class Pass;
class PMDataManager;
class StringRef;

//===----------------------------------------------------------------------===//
/// Represent the analysis usage information of a pass.  This tracks analyses
/// that the pass REQUIRES (must be available when the pass runs), REQUIRES
/// TRANSITIVE (must be available throughout the lifetime of the pass), and
/// analyses that the pass PRESERVES (the pass does not invalidate the results
/// of these analyses).  This information is provided by a pass to the Pass
/// infrastructure through the getAnalysisUsage virtual function.
///
class AnalysisUsage { … };

//===----------------------------------------------------------------------===//
/// AnalysisResolver - Simple interface used by Pass objects to pull all
/// analysis information out of pass manager that is responsible to manage
/// the pass.
///
class AnalysisResolver { … };

/// getAnalysisIfAvailable<AnalysisType>() - Subclasses use this function to
/// get analysis information that might be around, for example to update it.
/// This is different than getAnalysis in that it can fail (if the analysis
/// results haven't been computed), so should only be used if you can handle
/// the case when the analysis is not available.  This method is often used by
/// transformation APIs to update analysis results for a pass automatically as
/// the transform is performed.
template<typename AnalysisType>
AnalysisType *Pass::getAnalysisIfAvailable() const { … }

/// getAnalysis<AnalysisType>() - This function is used by subclasses to get
/// to the analysis information that they claim to use by overriding the
/// getAnalysisUsage function.
template<typename AnalysisType>
AnalysisType &Pass::getAnalysis() const { … }

template<typename AnalysisType>
AnalysisType &Pass::getAnalysisID(AnalysisID PI) const { … }

/// getAnalysis<AnalysisType>() - This function is used by subclasses to get
/// to the analysis information that they claim to use by overriding the
/// getAnalysisUsage function. If as part of the dependencies, an IR
/// transformation is triggered (e.g. because the analysis requires
/// BreakCriticalEdges), and Changed is non null, *Changed is updated.
template <typename AnalysisType>
AnalysisType &Pass::getAnalysis(Function &F, bool *Changed) { … }

template <typename AnalysisType>
AnalysisType &Pass::getAnalysisID(AnalysisID PI, Function &F, bool *Changed) { … }

} // end namespace llvm

#endif // LLVM_PASSANALYSISSUPPORT_H