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| //===--- RawStringLiteralCheck.cpp - clang-tidy----------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
#include "RawStringLiteralCheck.h"
#include "clang/AST/ASTContext.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include "clang/Lex/Lexer.h"
using namespace clang::ast_matchers;
namespace clang {
namespace tidy {
namespace modernize {
namespace {
bool containsEscapes(StringRef HayStack, StringRef Escapes) {
size_t BackSlash = HayStack.find('\\');
if (BackSlash == StringRef::npos)
return false;
while (BackSlash != StringRef::npos) {
if (Escapes.find(HayStack[BackSlash + 1]) == StringRef::npos)
return false;
BackSlash = HayStack.find('\\', BackSlash + 2);
}
return true;
}
bool isRawStringLiteral(StringRef Text) {
// Already a raw string literal if R comes before ".
const size_t QuotePos = Text.find('"');
assert(QuotePos != StringRef::npos);
return (QuotePos > 0) && (Text[QuotePos - 1] == 'R');
}
bool containsEscapedCharacters(const MatchFinder::MatchResult &Result,
const StringLiteral *Literal,
const CharsBitSet &DisallowedChars) {
// FIXME: Handle L"", u8"", u"" and U"" literals.
if (!Literal->isAscii())
return false;
for (const unsigned char C : Literal->getBytes())
if (DisallowedChars.test(C))
return false;
CharSourceRange CharRange = Lexer::makeFileCharRange(
CharSourceRange::getTokenRange(Literal->getSourceRange()),
*Result.SourceManager, Result.Context->getLangOpts());
StringRef Text = Lexer::getSourceText(CharRange, *Result.SourceManager,
Result.Context->getLangOpts());
if (isRawStringLiteral(Text))
return false;
return containsEscapes(Text, R"('\"?x01)");
}
bool containsDelimiter(StringRef Bytes, const std::string &Delimiter) {
return Bytes.find(Delimiter.empty()
? std::string(R"lit()")lit")
: (")" + Delimiter + R"(")")) != StringRef::npos;
}
std::string asRawStringLiteral(const StringLiteral *Literal,
const std::string &DelimiterStem) {
const StringRef Bytes = Literal->getBytes();
std::string Delimiter;
for (int I = 0; containsDelimiter(Bytes, Delimiter); ++I) {
Delimiter = (I == 0) ? DelimiterStem : DelimiterStem + std::to_string(I);
}
if (Delimiter.empty())
return (R"(R"()" + Bytes + R"lit()")lit").str();
return (R"(R")" + Delimiter + "(" + Bytes + ")" + Delimiter + R"(")").str();
}
} // namespace
RawStringLiteralCheck::RawStringLiteralCheck(StringRef Name,
ClangTidyContext *Context)
: ClangTidyCheck(Name, Context),
DelimiterStem(Options.get("DelimiterStem", "lit")),
ReplaceShorterLiterals(Options.get("ReplaceShorterLiterals", false)) {
// Non-printing characters are disallowed:
// \007 = \a bell
// \010 = \b backspace
// \011 = \t horizontal tab
// \012 = \n new line
// \013 = \v vertical tab
// \014 = \f form feed
// \015 = \r carriage return
// \177 = delete
for (const unsigned char C : StringRef("\000\001\002\003\004\005\006\a"
"\b\t\n\v\f\r\016\017"
"\020\021\022\023\024\025\026\027"
"\030\031\032\033\034\035\036\037"
"\177",
33))
DisallowedChars.set(C);
// Non-ASCII are disallowed too.
for (unsigned int C = 0x80u; C <= 0xFFu; ++C)
DisallowedChars.set(static_cast<unsigned char>(C));
}
void RawStringLiteralCheck::storeOptions(ClangTidyOptions::OptionMap &Options) {
ClangTidyCheck::storeOptions(Options);
this->Options.store(Options, "ReplaceShorterLiterals",
ReplaceShorterLiterals);
}
void RawStringLiteralCheck::registerMatchers(MatchFinder *Finder) {
// Raw string literals require C++11 or later.
if (!getLangOpts().CPlusPlus11)
return;
Finder->addMatcher(
stringLiteral(unless(hasParent(predefinedExpr()))).bind("lit"), this);
}
void RawStringLiteralCheck::check(const MatchFinder::MatchResult &Result) {
const auto *Literal = Result.Nodes.getNodeAs<StringLiteral>("lit");
if (Literal->getBeginLoc().isMacroID())
return;
if (containsEscapedCharacters(Result, Literal, DisallowedChars)) {
std::string Replacement = asRawStringLiteral(Literal, DelimiterStem);
if (ReplaceShorterLiterals ||
Replacement.length() <=
Lexer::MeasureTokenLength(Literal->getBeginLoc(),
*Result.SourceManager, getLangOpts()))
replaceWithRawStringLiteral(Result, Literal, Replacement);
}
}
void RawStringLiteralCheck::replaceWithRawStringLiteral(
const MatchFinder::MatchResult &Result, const StringLiteral *Literal,
StringRef Replacement) {
CharSourceRange CharRange = Lexer::makeFileCharRange(
CharSourceRange::getTokenRange(Literal->getSourceRange()),
*Result.SourceManager, getLangOpts());
diag(Literal->getBeginLoc(),
"escaped string literal can be written as a raw string literal")
<< FixItHint::CreateReplacement(CharRange, Replacement);
}
} // namespace modernize
} // namespace tidy
} // namespace clang
|