clang-tools 10.0.0

ProBoundsArrayToPointerDecayCheck.cpp
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1 //===--- ProBoundsArrayToPointerDecayCheck.cpp - clang-tidy----------------===//
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 #include "ProBoundsArrayToPointerDecayCheck.h"
10 #include "clang/AST/ASTContext.h"
11 #include "clang/ASTMatchers/ASTMatchFinder.h"
12
13 using namespace clang::ast_matchers;
14
15 namespace clang {
16 namespace tidy {
17 namespace cppcoreguidelines {
18
19 namespace {
20 AST_MATCHER_P(CXXForRangeStmt, hasRangeBeginEndStmt,
21 ast_matchers::internal::Matcher<DeclStmt>, InnerMatcher) {
22 for (const DeclStmt *Stmt : {Node.getBeginStmt(), Node.getEndStmt()})
23 if (Stmt != nullptr && InnerMatcher.matches(*Stmt, Finder, Builder))
24 return true;
25 return false;
26 }
27
28 AST_MATCHER(Stmt, isInsideOfRangeBeginEndStmt) {
29 return stmt(hasAncestor(cxxForRangeStmt(
30 hasRangeBeginEndStmt(hasDescendant(equalsNode(&Node))))))
31 .matches(Node, Finder, Builder);
32 }
33
34 AST_MATCHER_P(Expr, hasParentIgnoringImpCasts,
35 ast_matchers::internal::Matcher<Expr>, InnerMatcher) {
36 const Expr *E = &Node;
37 do {
38 ASTContext::DynTypedNodeList Parents =
39 Finder->getASTContext().getParents(*E);
40 if (Parents.size() != 1)
41 return false;
42 E = Parents[0].get<Expr>();
43 if (!E)
44 return false;
45 } while (isa<ImplicitCastExpr>(E));
46
47 return InnerMatcher.matches(*E, Finder, Builder);
48 }
49 } // namespace
50
51 void ProBoundsArrayToPointerDecayCheck::registerMatchers(MatchFinder *Finder) {
52 if (!getLangOpts().CPlusPlus)
53 return;
54
55 // The only allowed array to pointer decay
56 // 1) just before array subscription
57 // 2) inside a range-for over an array
58 // 3) if it converts a string literal to a pointer
59 Finder->addMatcher(
60 implicitCastExpr(
61 unless(hasParent(arraySubscriptExpr())),
62 unless(hasParentIgnoringImpCasts(explicitCastExpr())),
63 unless(isInsideOfRangeBeginEndStmt()),
64 unless(hasSourceExpression(ignoringParens(stringLiteral()))))
65 .bind("cast"),
66 this);
67 }
68
69 void ProBoundsArrayToPointerDecayCheck::check(
70 const MatchFinder::MatchResult &Result) {
71 const auto *MatchedCast = Result.Nodes.getNodeAs<ImplicitCastExpr>("cast");
72 if (MatchedCast->getCastKind() != CK_ArrayToPointerDecay)
73 return;
74
75 diag(MatchedCast->getExprLoc(), "do not implicitly decay an array into a "
76 "pointer; consider using gsl::array_view or "
77 "an explicit cast instead");
78 }
79
80 } // namespace cppcoreguidelines
81 } // namespace tidy
82 } // namespace clang
clang::ast_matchers
Definition: AbseilMatcher.h:14
clang::clangd::TypeHierarchyDirection::Parents
clang::ast_matchers::AST_MATCHER
AST_MATCHER(Expr, isMacroID)
Definition: PreferIsaOrDynCastInConditionalsCheck.cpp:18
ProBoundsArrayToPointerDecayCheck.h
Builder
CodeCompletionBuilder Builder
Definition: CodeCompletionStringsTests.cpp:35
clang
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
Definition: ApplyReplacements.h:27
E
const Expr * E
Definition: AvoidBindCheck.cpp:82
clang::tidy::readability::AST_MATCHER_P
AST_MATCHER_P(CXXMethodDecl, hasCanonicalDecl, ast_matchers::internal::Matcher< CXXMethodDecl >, InnerMatcher)
Definition: ConvertMemberFunctionsToStatic.cpp:52