| //===-- UncheckedOptionalAccessModel.h --------------------------*- 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 dataflow analysis that detects unsafe uses of optional |
| // values. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef CLANG_ANALYSIS_FLOWSENSITIVE_MODELS_UNCHECKEDOPTIONALACCESSMODEL_H |
| #define CLANG_ANALYSIS_FLOWSENSITIVE_MODELS_UNCHECKEDOPTIONALACCESSMODEL_H |
| |
| #include "clang/AST/ASTContext.h" |
| #include "clang/Analysis/CFG.h" |
| #include "clang/Analysis/FlowSensitive/CFGMatchSwitch.h" |
| #include "clang/Analysis/FlowSensitive/DataflowAnalysis.h" |
| #include "clang/Analysis/FlowSensitive/DataflowEnvironment.h" |
| #include "clang/Analysis/FlowSensitive/NoopLattice.h" |
| #include "clang/Basic/SourceLocation.h" |
| #include <vector> |
| |
| namespace clang { |
| namespace dataflow { |
| |
| // FIXME: Explore using an allowlist-approach, where constructs supported by the |
| // analysis are always enabled and additional constructs are enabled through the |
| // `Options`. |
| struct UncheckedOptionalAccessModelOptions { |
| /// In generating diagnostics, ignore optionals reachable through overloaded |
| /// `operator*` or `operator->` (other than those of the optional type |
| /// itself). The analysis does not equate the results of such calls, so it |
| /// can't identify when their results are used safely (across calls), |
| /// resulting in false positives in all such cases. Note: this option does not |
| /// cover access through `operator[]`. |
| bool IgnoreSmartPointerDereference = false; |
| }; |
| |
| /// Dataflow analysis that models whether optionals hold values or not. |
| /// |
| /// Models the `std::optional`, `absl::optional`, and `base::Optional` types. |
| class UncheckedOptionalAccessModel |
| : public DataflowAnalysis<UncheckedOptionalAccessModel, NoopLattice> { |
| public: |
| UncheckedOptionalAccessModel(ASTContext &Ctx); |
| |
| /// Returns a matcher for the optional classes covered by this model. |
| static ast_matchers::DeclarationMatcher optionalClassDecl(); |
| |
| static NoopLattice initialElement() { return {}; } |
| |
| void transfer(const CFGElement &Elt, NoopLattice &L, Environment &Env); |
| |
| ComparisonResult compare(QualType Type, const Value &Val1, |
| const Environment &Env1, const Value &Val2, |
| const Environment &Env2) override; |
| |
| bool merge(QualType Type, const Value &Val1, const Environment &Env1, |
| const Value &Val2, const Environment &Env2, Value &MergedVal, |
| Environment &MergedEnv) override; |
| |
| Value *widen(QualType Type, Value &Prev, const Environment &PrevEnv, |
| Value &Current, Environment &CurrentEnv) override; |
| |
| private: |
| CFGMatchSwitch<TransferState<NoopLattice>> TransferMatchSwitch; |
| }; |
| |
| class UncheckedOptionalAccessDiagnoser { |
| public: |
| UncheckedOptionalAccessDiagnoser( |
| UncheckedOptionalAccessModelOptions Options = {}); |
| |
| std::vector<SourceLocation> diagnose(ASTContext &Ctx, const CFGElement *Elt, |
| const Environment &Env); |
| |
| private: |
| CFGMatchSwitch<const Environment, std::vector<SourceLocation>> |
| DiagnoseMatchSwitch; |
| }; |
| |
| } // namespace dataflow |
| } // namespace clang |
| |
| #endif // CLANG_ANALYSIS_FLOWSENSITIVE_MODELS_UNCHECKEDOPTIONALACCESSMODEL_H |