Analysis/FlowSensitive/Transfer.h

0001 //===-- Transfer.h ----------------------------------------------*- C++ -*-===//
0002 //
0003 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0004 // See https://llvm.org/LICENSE.txt for license information.
0005 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0006 //
0007 //===----------------------------------------------------------------------===//
0008 //
0009 //  This file defines a transfer function that evaluates a program statement and
0010 //  updates an environment accordingly.
0011 //
0012 //===----------------------------------------------------------------------===//
0013
0014 #ifndef LLVM_CLANG_ANALYSIS_FLOWSENSITIVE_TRANSFER_H
0015 #define LLVM_CLANG_ANALYSIS_FLOWSENSITIVE_TRANSFER_H
0016
0017 #include "clang/AST/Stmt.h"
0018 #include "clang/Analysis/FlowSensitive/DataflowAnalysisContext.h"
0019 #include "clang/Analysis/FlowSensitive/DataflowEnvironment.h"
0020 #include "clang/Analysis/FlowSensitive/TypeErasedDataflowAnalysis.h"
0021
0022 namespace clang {
0023 namespace dataflow {
0024
0025 /// Maps statements to the environments of basic blocks that contain them.
0026 class StmtToEnvMap {
0027 public:
0028   // `CurBlockID` is the ID of the block currently being processed, and
0029   // `CurState` is the pending state currently associated with this block. These
0030   // are supplied separately as the pending state for the current block may not
0031   // yet be represented in `BlockToState`.
0032   StmtToEnvMap(const AdornedCFG &ACFG,
0033                llvm::ArrayRef<std::optional<TypeErasedDataflowAnalysisState>>
0034                    BlockToState,
0035                unsigned CurBlockID,
0036                const TypeErasedDataflowAnalysisState &CurState)
0037       : ACFG(ACFG), BlockToState(BlockToState), CurBlockID(CurBlockID),
0038         CurState(CurState) {}
0039
0040   /// Returns the environment of the basic block that contains `S`.
0041   /// The result is guaranteed never to be null.
0042   const Environment *getEnvironment(const Stmt &S) const;
0043
0044 private:
0045   const AdornedCFG &ACFG;
0046   llvm::ArrayRef<std::optional<TypeErasedDataflowAnalysisState>> BlockToState;
0047   unsigned CurBlockID;
0048   const TypeErasedDataflowAnalysisState &CurState;
0049 };
0050
0051 /// Evaluates `S` and updates `Env` accordingly.
0052 ///
0053 /// Requirements:
0054 ///
0055 ///  `S` must not be `ParenExpr` or `ExprWithCleanups`.
0056 void transfer(const StmtToEnvMap &StmtToEnv, const Stmt &S, Environment &Env,
0057               Environment::ValueModel &Model);
0058
0059 } // namespace dataflow
0060 } // namespace clang
0061
0062 #endif // LLVM_CLANG_ANALYSIS_FLOWSENSITIVE_TRANSFER_H