clang-tools 6.0.0

RawStringLiteralCheck.cpp
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1 //===--- RawStringLiteralCheck.cpp - clang-tidy----------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9
10 #include "RawStringLiteralCheck.h"
11 #include "clang/AST/ASTContext.h"
12 #include "clang/ASTMatchers/ASTMatchFinder.h"
13 #include "clang/Lex/Lexer.h"
14
15 using namespace clang::ast_matchers;
16
17 namespace clang {
18 namespace tidy {
19 namespace modernize {
20
21 namespace {
22
23 bool containsEscapes(StringRef HayStack, StringRef Escapes) {
24 size_t BackSlash = HayStack.find('\\');
25 if (BackSlash == StringRef::npos)
26 return false;
27
28 while (BackSlash != StringRef::npos) {
29 if (Escapes.find(HayStack[BackSlash + 1]) == StringRef::npos)
30 return false;
31 BackSlash = HayStack.find('\\', BackSlash + 2);
32 }
33
34 return true;
35 }
36
37 bool isRawStringLiteral(StringRef Text) {
38 // Already a raw string literal if R comes before ".
39 const size_t QuotePos = Text.find('"');
40 assert(QuotePos != StringRef::npos);
41 return (QuotePos > 0) && (Text[QuotePos - 1] == 'R');
42 }
43
44 bool containsEscapedCharacters(const MatchFinder::MatchResult &Result,
45 const StringLiteral *Literal) {
46 // FIXME: Handle L"", u8"", u"" and U"" literals.
47 if (!Literal->isAscii())
48 return false;
49
50 StringRef Bytes = Literal->getBytes();
51 // Non-printing characters disqualify this literal:
52 // \007 = \a bell
53 // \010 = \b backspace
54 // \011 = \t horizontal tab
55 // \012 = \n new line
56 // \013 = \v vertical tab
57 // \014 = \f form feed
58 // \015 = \r carriage return
59 // \177 = delete
60 if (Bytes.find_first_of(StringRef("\000\001\002\003\004\005\006\a"
61 "\b\t\n\v\f\r\016\017"
62 "\020\021\022\023\024\025\026\027"
63 "\030\031\032\033\034\035\036\037"
64 "\177",
65 33)) != StringRef::npos)
66 return false;
67
68 CharSourceRange CharRange = Lexer::makeFileCharRange(
69 CharSourceRange::getTokenRange(Literal->getSourceRange()),
70 *Result.SourceManager, Result.Context->getLangOpts());
71 StringRef Text = Lexer::getSourceText(CharRange, *Result.SourceManager,
72 Result.Context->getLangOpts());
73 if (isRawStringLiteral(Text))
74 return false;
75
76 return containsEscapes(Text, R"('\"?x01)");
77 }
78
79 bool containsDelimiter(StringRef Bytes, const std::string &Delimiter) {
80 return Bytes.find(Delimiter.empty()
81 ? std::string(R"lit()")lit")
82 : (")" + Delimiter + R"(")")) != StringRef::npos;
83 }
84
85 std::string asRawStringLiteral(const StringLiteral *Literal,
86 const std::string &DelimiterStem) {
87 const StringRef Bytes = Literal->getBytes();
88 std::string Delimiter;
89 for (int I = 0; containsDelimiter(Bytes, Delimiter); ++I) {
90 Delimiter = (I == 0) ? DelimiterStem : DelimiterStem + std::to_string(I);
91 }
92
93 if (Delimiter.empty())
94 return (R"(R"()" + Bytes + R"lit()")lit").str();
95
96 return (R"(R")" + Delimiter + "(" + Bytes + ")" + Delimiter + R"(")").str();
97 }
98
99 } // namespace
100
101 RawStringLiteralCheck::RawStringLiteralCheck(StringRef Name,
102 ClangTidyContext *Context)
103 : ClangTidyCheck(Name, Context),
104 DelimiterStem(Options.get("DelimiterStem", "lit")),
105 ReplaceShorterLiterals(Options.get("ReplaceShorterLiterals", false)) {}
106
107 void RawStringLiteralCheck::storeOptions(ClangTidyOptions::OptionMap &Options) {
108 ClangTidyCheck::storeOptions(Options);
109 this->Options.store(Options, "ReplaceShorterLiterals",
110 ReplaceShorterLiterals);
111 }
112
113 void RawStringLiteralCheck::registerMatchers(MatchFinder *Finder) {
114 // Raw string literals require C++11 or later.
115 if (!getLangOpts().CPlusPlus11)
116 return;
117
118 Finder->addMatcher(
119 stringLiteral(unless(hasParent(predefinedExpr()))).bind("lit"), this);
120 }
121
122 void RawStringLiteralCheck::check(const MatchFinder::MatchResult &Result) {
123 const auto *Literal = Result.Nodes.getNodeAs<StringLiteral>("lit");
124 if (Literal->getLocStart().isMacroID())
125 return;
126
127 if (containsEscapedCharacters(Result, Literal)) {
128 std::string Replacement = asRawStringLiteral(Literal, DelimiterStem);
129 if (ReplaceShorterLiterals ||
130 Replacement.length() <=
131 Lexer::MeasureTokenLength(Literal->getLocStart(),
132 *Result.SourceManager, getLangOpts()))
133 replaceWithRawStringLiteral(Result, Literal, Replacement);
134 }
135 }
136
137 void RawStringLiteralCheck::replaceWithRawStringLiteral(
138 const MatchFinder::MatchResult &Result, const StringLiteral *Literal,
139 StringRef Replacement) {
140 CharSourceRange CharRange = Lexer::makeFileCharRange(
141 CharSourceRange::getTokenRange(Literal->getSourceRange()),
142 *Result.SourceManager, getLangOpts());
143 diag(Literal->getLocStart(),
144 "escaped string literal can be written as a raw string literal")
145 << FixItHint::CreateReplacement(CharRange, Replacement);
146 }
147
148 } // namespace modernize
149 } // namespace tidy
150 } // namespace clang
clang::ast_matchers
Definition: ClangTidyDiagnosticConsumer.h:27
Name
StringHandle Name
Definition: PreprocessorTracker.cpp:525
clang::tidy::ClangTidyCheck::getLangOpts
LangOptions getLangOpts() const
Returns the language options from the context.
Definition: ClangTidy.h:187
RawStringLiteralCheck.h
clang::tidy::modernize::RawStringLiteralCheck::check
void check(const ast_matchers::MatchFinder::MatchResult &Result) override
ClangTidyChecks that register ASTMatchers should do the actual work in here.
Definition: RawStringLiteralCheck.cpp:122
clang::tidy::ClangTidyCheck
Base class for all clang-tidy checks.
Definition: ClangTidy.h:127
clang::tidy::ClangTidyCheck::Options
OptionsView Options
Definition: ClangTidy.h:183
clang::tidy::ClangTidyOptions::OptionMap
std::map< std::string, std::string > OptionMap
Definition: ClangTidyOptions.h:99
clang::tidy::modernize::RawStringLiteralCheck::storeOptions
void storeOptions(ClangTidyOptions::OptionMap &Options) override
Should store all options supported by this check with their current values or default values for opti...
Definition: RawStringLiteralCheck.cpp:107
clang
Definition: AndroidTidyModule.cpp:28
clang::tidy::ClangTidyContext
Every ClangTidyCheck reports errors through a DiagnosticsEngine provided by this context.
Definition: ClangTidyDiagnosticConsumer.h:104
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: ClangTidy.cpp:416
clang::tidy::ClangTidyCheck::storeOptions
virtual void storeOptions(ClangTidyOptions::OptionMap &Options)
Should store all options supported by this check with their current values or default values for opti...
Definition: ClangTidy.h:174
clang::tidy::modernize::RawStringLiteralCheck::registerMatchers
void registerMatchers(ast_matchers::MatchFinder *Finder) override
Override this to register AST matchers with Finder.
Definition: RawStringLiteralCheck.cpp:113