clang-tools 10.0.0

ProBoundsConstantArrayIndexCheck.cpp
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1 //===--- ProBoundsConstantArrayIndexCheck.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 "ProBoundsConstantArrayIndexCheck.h"
10 #include "clang/AST/ASTContext.h"
11 #include "clang/ASTMatchers/ASTMatchFinder.h"
12 #include "clang/Frontend/CompilerInstance.h"
13 #include "clang/Lex/Preprocessor.h"
14
15 using namespace clang::ast_matchers;
16
17 namespace clang {
18 namespace tidy {
19 namespace cppcoreguidelines {
20
21 ProBoundsConstantArrayIndexCheck::ProBoundsConstantArrayIndexCheck(
22 StringRef Name, ClangTidyContext *Context)
23 : ClangTidyCheck(Name, Context), GslHeader(Options.get("GslHeader", "")),
24 IncludeStyle(utils::IncludeSorter::parseIncludeStyle(
25 Options.getLocalOrGlobal("IncludeStyle", "llvm"))) {}
26
27 void ProBoundsConstantArrayIndexCheck::storeOptions(
28 ClangTidyOptions::OptionMap &Opts) {
29 Options.store(Opts, "GslHeader", GslHeader);
30 Options.store(Opts, "IncludeStyle", IncludeStyle);
31 }
32
33 void ProBoundsConstantArrayIndexCheck::registerPPCallbacks(
34 const SourceManager &SM, Preprocessor *PP, Preprocessor *ModuleExpanderPP) {
35 if (!getLangOpts().CPlusPlus)
36 return;
37
38 Inserter = std::make_unique<utils::IncludeInserter>(SM, getLangOpts(),
39 IncludeStyle);
40 PP->addPPCallbacks(Inserter->CreatePPCallbacks());
41 }
42
43 void ProBoundsConstantArrayIndexCheck::registerMatchers(MatchFinder *Finder) {
44 if (!getLangOpts().CPlusPlus)
45 return;
46
47 // Note: if a struct contains an array member, the compiler-generated
48 // constructor has an arraySubscriptExpr.
49 Finder->addMatcher(
50 arraySubscriptExpr(
51 hasBase(ignoringImpCasts(hasType(constantArrayType().bind("type")))),
52 hasIndex(expr().bind("index")), unless(hasAncestor(isImplicit())))
53 .bind("expr"),
54 this);
55
56 Finder->addMatcher(
57 cxxOperatorCallExpr(
58 hasOverloadedOperatorName("[]"),
59 hasArgument(
60 0, hasType(cxxRecordDecl(hasName("::std::array")).bind("type"))),
61 hasArgument(1, expr().bind("index")))
62 .bind("expr"),
63 this);
64 }
65
66 void ProBoundsConstantArrayIndexCheck::check(
67 const MatchFinder::MatchResult &Result) {
68 const auto *Matched = Result.Nodes.getNodeAs<Expr>("expr");
69 const auto *IndexExpr = Result.Nodes.getNodeAs<Expr>("index");
70
71 if (IndexExpr->isValueDependent())
72 return; // We check in the specialization.
73
74 llvm::APSInt Index;
75 if (!IndexExpr->isIntegerConstantExpr(Index, *Result.Context, nullptr,
76 /*isEvaluated=*/true)) {
77 SourceRange BaseRange;
78 if (const auto *ArraySubscriptE = dyn_cast<ArraySubscriptExpr>(Matched))
79 BaseRange = ArraySubscriptE->getBase()->getSourceRange();
80 else
81 BaseRange =
82 dyn_cast<CXXOperatorCallExpr>(Matched)->getArg(0)->getSourceRange();
83 SourceRange IndexRange = IndexExpr->getSourceRange();
84
85 auto Diag = diag(Matched->getExprLoc(),
86 "do not use array subscript when the index is "
87 "not an integer constant expression; use gsl::at() "
88 "instead");
89 if (!GslHeader.empty()) {
90 Diag << FixItHint::CreateInsertion(BaseRange.getBegin(), "gsl::at(")
91 << FixItHint::CreateReplacement(
92 SourceRange(BaseRange.getEnd().getLocWithOffset(1),
93 IndexRange.getBegin().getLocWithOffset(-1)),
94 ", ")
95 << FixItHint::CreateReplacement(Matched->getEndLoc(), ")");
96
97 Optional<FixItHint> Insertion = Inserter->CreateIncludeInsertion(
98 Result.SourceManager->getMainFileID(), GslHeader,
99 /*IsAngled=*/false);
100 if (Insertion)
101 Diag << Insertion.getValue();
102 }
103 return;
104 }
105
106 const auto *StdArrayDecl =
107 Result.Nodes.getNodeAs<ClassTemplateSpecializationDecl>("type");
108
109 // For static arrays, this is handled in clang-diagnostic-array-bounds.
110 if (!StdArrayDecl)
111 return;
112
113 if (Index.isSigned() && Index.isNegative()) {
114 diag(Matched->getExprLoc(), "std::array<> index %0 is negative")
115 << Index.toString(10);
116 return;
117 }
118
119 const TemplateArgumentList &TemplateArgs = StdArrayDecl->getTemplateArgs();
120 if (TemplateArgs.size() < 2)
121 return;
122 // First template arg of std::array is the type, second arg is the size.
123 const auto &SizeArg = TemplateArgs[1];
124 if (SizeArg.getKind() != TemplateArgument::Integral)
125 return;
126 llvm::APInt ArraySize = SizeArg.getAsIntegral();
127
128 // Get uint64_t values, because different bitwidths would lead to an assertion
129 // in APInt::uge.
130 if (Index.getZExtValue() >= ArraySize.getZExtValue()) {
131 diag(Matched->getExprLoc(),
132 "std::array<> index %0 is past the end of the array "
133 "(which contains %1 elements)")
134 << Index.toString(10) << ArraySize.toString(10, false);
135 }
136 }
137
138 } // namespace cppcoreguidelines
139 } // namespace tidy
140 } // namespace clang
clang::ast_matchers
Definition: AbseilMatcher.h:14
clang::tidy::cppcoreguidelines::ProBoundsConstantArrayIndexCheck::storeOptions
void storeOptions(ClangTidyOptions::OptionMap &Opts) override
Should store all options supported by this check with their current values or default values for opti...
Definition: ProBoundsConstantArrayIndexCheck.cpp:27
ProBoundsConstantArrayIndexCheck.h
clang::tidy::cppcoreguidelines::ProBoundsConstantArrayIndexCheck::check
void check(const ast_matchers::MatchFinder::MatchResult &Result) override
ClangTidyChecks that register ASTMatchers should do the actual work in here.
Definition: ProBoundsConstantArrayIndexCheck.cpp:66
clang::tidy::ClangTidyCheck
Base class for all clang-tidy checks.
Definition: ClangTidyCheck.h:47
clang::tidy::ClangTidyCheck::getLangOpts
const LangOptions & getLangOpts() const
Returns the language options from the context.
Definition: ClangTidyCheck.h:188
clang::tidy::cppcoreguidelines::ProBoundsConstantArrayIndexCheck::registerPPCallbacks
void registerPPCallbacks(const SourceManager &SM, Preprocessor *PP, Preprocessor *ModuleExpanderPP) override
Override this to register PPCallbacks in the preprocessor.
Definition: ProBoundsConstantArrayIndexCheck.cpp:33
clang::tidy::ClangTidyCheck::Options
OptionsView Options
Definition: ClangTidyCheck.h:184
clang::tidy::ClangTidyCheck::OptionsView::store
void store(ClangTidyOptions::OptionMap &Options, StringRef LocalName, StringRef Value) const
Stores an option with the check-local name LocalName with string value Value to Options.
Definition: ClangTidyCheck.cpp:58
Name
static constexpr llvm::StringLiteral Name
Definition: UppercaseLiteralSuffixCheck.cpp:27
clang::tidy::ClangTidyOptions::OptionMap
std::map< std::string, std::string > OptionMap
Definition: ClangTidyOptions.h:97
clang
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
Definition: ApplyReplacements.h:27
clang::tidy::bugprone::PP
static Preprocessor * PP
Definition: BadSignalToKillThreadCheck.cpp:28
clang::tidy::ClangTidyContext
Every ClangTidyCheck reports errors through a DiagnosticsEngine provided by this context.
Definition: ClangTidyDiagnosticConsumer.h:77
clang::tidy::cppcoreguidelines::ProBoundsConstantArrayIndexCheck::registerMatchers
void registerMatchers(ast_matchers::MatchFinder *Finder) override
Override this to register AST matchers with Finder.
Definition: ProBoundsConstantArrayIndexCheck.cpp:43
clang::tidy::ClangTidyCheck::diag
DiagnosticBuilder diag(SourceLocation Loc, StringRef Description, DiagnosticIDs::Level Level=DiagnosticIDs::Warning)
Add a diagnostic with the check&#39;s name.
Definition: ClangTidyCheck.cpp:21
Index
const SymbolIndex * Index
Definition: Dexp.cpp:84