llvm/clang/include/clang/Analysis/Analyses/CalledOnceCheck.h

//===- CalledOnceCheck.h - Check 'called once' parameters -------*- 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 a check for function-like parameters that should be
//  called exactly one time.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_ANALYSIS_ANALYSES_CALLEDONCECHECK_H
#define LLVM_CLANG_ANALYSIS_ANALYSES_CALLEDONCECHECK_H

namespace clang {

class AnalysisDeclContext;
class BlockDecl;
class CFG;
class Decl;
class Expr;
class ParmVarDecl;
class Stmt;

/// Classification of situations when parameter is not called on every path.
/// \enum IfThen -- then branch of the if statement has no call.
/// \enum IfElse -- else branch of the if statement has no call.
/// \enum Switch -- one of the switch cases doesn't have a call.
/// \enum SwitchSkipped -- there is no call if none of the cases applies.
/// \enum LoopEntered -- no call when the loop is entered.
/// \enum LoopSkipped -- no call when the loop is not entered.
/// \enum FallbackReason -- fallback case when we were not able to figure out
/// the reason.
enum class NeverCalledReason { … };

class CalledOnceCheckHandler { … };

/// Check given CFG for 'called once' parameter violations.
///
/// It traverses the function and tracks how such parameters are used.
/// It detects two main violations:
///   * parameter is called twice
///   * parameter is not called
///
/// \param AC -- context.
/// \param Handler -- a handler for found violations.
/// \param CheckConventionalParameters -- true, if we want to check parameters
/// not explicitly marked as 'called once', but having the same requirements
/// according to conventions.
void checkCalledOnceParameters(AnalysisDeclContext &AC,
                               CalledOnceCheckHandler &Handler,
                               bool CheckConventionalParameters);

} // end namespace clang

#endif /* LLVM_CLANG_ANALYSIS_ANALYSES_CALLEDONCECHECK_H */