clang 20.0.0git
UncheckedOptionalAccessModel.h
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1//===-- UncheckedOptionalAccessModel.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 dataflow analysis that detects unsafe uses of optional
10// values.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef CLANG_ANALYSIS_FLOWSENSITIVE_MODELS_UNCHECKEDOPTIONALACCESSMODEL_H
15#define CLANG_ANALYSIS_FLOWSENSITIVE_MODELS_UNCHECKEDOPTIONALACCESSMODEL_H
16
18#include "clang/Analysis/CFG.h"
25#include "llvm/ADT/SmallVector.h"
26
27namespace clang {
28namespace dataflow {
29
30// FIXME: Explore using an allowlist-approach, where constructs supported by the
31// analysis are always enabled and additional constructs are enabled through the
32// `Options`.
34 /// In generating diagnostics, ignore optionals reachable through overloaded
35 /// `operator*` or `operator->` (other than those of the optional type
36 /// itself). The analysis does not equate the results of such calls, so it
37 /// can't identify when their results are used safely (across calls),
38 /// resulting in false positives in all such cases. Note: this option does not
39 /// cover access through `operator[]`.
40 ///
41 /// FIXME: we now cache and equate the result of const accessors
42 /// that look like unique_ptr, have both `->` (returning a pointer type) and
43 /// `*` (returning a reference type). This includes mixing `->` and
44 /// `*` in a sequence of calls as long as the object is not modified. Once we
45 /// are confident in this const accessor caching, we shouldn't need the
46 /// IgnoreSmartPointerDereference option anymore.
48};
49
51
52/// Dataflow analysis that models whether optionals hold values or not.
53///
54/// Models the `std::optional`, `absl::optional`, and `base::Optional` types.
56 : public DataflowAnalysis<UncheckedOptionalAccessModel,
57 UncheckedOptionalAccessLattice> {
58public:
60
61 /// Returns a matcher for the optional classes covered by this model.
63
65
68
69private:
71 TransferMatchSwitch;
72};
73
75public:
78
82 &State) {
83 return DiagnoseMatchSwitch(Elt, Ctx, State.Env);
84 }
85
86private:
88 DiagnoseMatchSwitch;
89};
90
91} // namespace dataflow
92} // namespace clang
93
94#endif // CLANG_ANALYSIS_FLOWSENSITIVE_MODELS_UNCHECKEDOPTIONALACCESSMODEL_H
Defines the clang::ASTContext interface.
const Environment & Env
Definition: HTMLLogger.cpp:147
Defines the clang::SourceLocation class and associated facilities.
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:188
Represents a top-level expression in a basic block.
Definition: CFG.h:55
A mixin for a lattice that additionally maintains a cache of stable method call return values to mode...
Base class template for dataflow analyses built on a single lattice type.
Holds the state of the program (store and heap) at a given program point.
llvm::SmallVector< SourceLocation > operator()(const CFGElement &Elt, ASTContext &Ctx, const TransferStateForDiagnostics< UncheckedOptionalAccessLattice > &State)
Dataflow analysis that models whether optionals hold values or not.
void transfer(const CFGElement &Elt, UncheckedOptionalAccessLattice &L, Environment &Env)
static UncheckedOptionalAccessLattice initialElement()
static ast_matchers::DeclarationMatcher optionalClassDecl()
Returns a matcher for the optional classes covered by this model.
internal::Matcher< Decl > DeclarationMatcher
Types of matchers for the top-level classes in the AST class hierarchy.
Definition: ASTMatchers.h:143
std::function< Result(const CFGElement &, ASTContext &, State &)> CFGMatchSwitch
The JSON file list parser is used to communicate input to InstallAPI.
A read-only version of TransferState.
Definition: MatchSwitch.h:55
bool IgnoreSmartPointerDereference
In generating diagnostics, ignore optionals reachable through overloaded operator* or operator-> (oth...