1 //===-- Transfer.h ----------------------------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 //  This file defines a transfer function that evaluates a program statement and
10 //  updates an environment accordingly.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_CLANG_ANALYSIS_FLOWSENSITIVE_TRANSFER_H
15 #define LLVM_CLANG_ANALYSIS_FLOWSENSITIVE_TRANSFER_H
16 
17 #include "clang/AST/Stmt.h"
18 #include "clang/Analysis/FlowSensitive/DataflowAnalysisContext.h"
19 #include "clang/Analysis/FlowSensitive/DataflowEnvironment.h"
20 #include "clang/Analysis/FlowSensitive/TypeErasedDataflowAnalysis.h"
21 
22 namespace clang {
23 namespace dataflow {
24 
25 /// Maps statements to the environments of basic blocks that contain them.
26 class StmtToEnvMap {
27 public:
28   StmtToEnvMap(const ControlFlowContext &CFCtx,
29                llvm::ArrayRef<std::optional<TypeErasedDataflowAnalysisState>>
30                    BlockToState)
31       : CFCtx(CFCtx), BlockToState(BlockToState) {}
32 
33   /// Returns the environment of the basic block that contains `S`.
34   /// The result is guaranteed never to be null.
35   const Environment *getEnvironment(const Stmt &S) const;
36 
37 private:
38   const ControlFlowContext &CFCtx;
39   llvm::ArrayRef<std::optional<TypeErasedDataflowAnalysisState>> BlockToState;
40 };
41 
42 /// Evaluates `S` and updates `Env` accordingly.
43 ///
44 /// Requirements:
45 ///
46 ///  `S` must not be `ParenExpr` or `ExprWithCleanups`.
47 void transfer(const StmtToEnvMap &StmtToEnv, const Stmt &S, Environment &Env);
48 
49 } // namespace dataflow
50 } // namespace clang
51 
52 #endif // LLVM_CLANG_ANALYSIS_FLOWSENSITIVE_TRANSFER_H
53