clang-tools  8.0.0
UppercaseLiteralSuffixCheck.cpp
Go to the documentation of this file.
1 //===--- UppercaseLiteralSuffixCheck.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 
11 #include "../utils/ASTUtils.h"
12 #include "../utils/OptionsUtils.h"
13 #include "clang/AST/ASTContext.h"
14 #include "clang/ASTMatchers/ASTMatchFinder.h"
15 #include "llvm/ADT/Optional.h"
16 #include "llvm/ADT/SmallString.h"
17 
18 using namespace clang::ast_matchers;
19 
20 namespace clang {
21 namespace tidy {
22 namespace readability {
23 
24 namespace {
25 
26 struct IntegerLiteralCheck {
27  using type = clang::IntegerLiteral;
28  static constexpr llvm::StringLiteral Name = llvm::StringLiteral("integer");
29  // What should be skipped before looking for the Suffixes? (Nothing here.)
30  static constexpr llvm::StringLiteral SkipFirst = llvm::StringLiteral("");
31  // Suffix can only consist of 'u' and 'l' chars, and can be a complex number
32  // ('i', 'j'). In MS compatibility mode, suffixes like i32 are supported.
33  static constexpr llvm::StringLiteral Suffixes =
34  llvm::StringLiteral("uUlLiIjJ");
35 };
36 constexpr llvm::StringLiteral IntegerLiteralCheck::Name;
37 constexpr llvm::StringLiteral IntegerLiteralCheck::SkipFirst;
38 constexpr llvm::StringLiteral IntegerLiteralCheck::Suffixes;
39 
40 struct FloatingLiteralCheck {
41  using type = clang::FloatingLiteral;
42  static constexpr llvm::StringLiteral Name =
43  llvm::StringLiteral("floating point");
44  // C++17 introduced hexadecimal floating-point literals, and 'f' is both a
45  // valid hexadecimal digit in a hex float literal and a valid floating-point
46  // literal suffix.
47  // So we can't just "skip to the chars that can be in the suffix".
48  // Since the exponent ('p'/'P') is mandatory for hexadecimal floating-point
49  // literals, we first skip everything before the exponent.
50  static constexpr llvm::StringLiteral SkipFirst = llvm::StringLiteral("pP");
51  // Suffix can only consist of 'f', 'l', "f16", 'h', 'q' chars,
52  // and can be a complex number ('i', 'j').
53  static constexpr llvm::StringLiteral Suffixes =
54  llvm::StringLiteral("fFlLhHqQiIjJ");
55 };
56 constexpr llvm::StringLiteral FloatingLiteralCheck::Name;
57 constexpr llvm::StringLiteral FloatingLiteralCheck::SkipFirst;
58 constexpr llvm::StringLiteral FloatingLiteralCheck::Suffixes;
59 
60 struct NewSuffix {
61  SourceRange LiteralLocation;
62  StringRef OldSuffix;
63  llvm::Optional<FixItHint> FixIt;
64 };
65 
66 llvm::Optional<SourceLocation> GetMacroAwareLocation(SourceLocation Loc,
67  const SourceManager &SM) {
68  // Do nothing if the provided location is invalid.
69  if (Loc.isInvalid())
70  return llvm::None;
71  // Look where the location was *actually* written.
72  SourceLocation SpellingLoc = SM.getSpellingLoc(Loc);
73  if (SpellingLoc.isInvalid())
74  return llvm::None;
75  return SpellingLoc;
76 }
77 
78 llvm::Optional<SourceRange> GetMacroAwareSourceRange(SourceRange Loc,
79  const SourceManager &SM) {
80  llvm::Optional<SourceLocation> Begin =
81  GetMacroAwareLocation(Loc.getBegin(), SM);
82  llvm::Optional<SourceLocation> End = GetMacroAwareLocation(Loc.getEnd(), SM);
83  if (!Begin || !End)
84  return llvm::None;
85  return SourceRange(*Begin, *End);
86 }
87 
88 llvm::Optional<std::string>
89 getNewSuffix(llvm::StringRef OldSuffix,
90  const std::vector<std::string> &NewSuffixes) {
91  // If there is no config, just uppercase the entirety of the suffix.
92  if (NewSuffixes.empty())
93  return OldSuffix.upper();
94  // Else, find matching suffix, case-*insensitive*ly.
95  auto NewSuffix = llvm::find_if(
96  NewSuffixes, [OldSuffix](const std::string &PotentialNewSuffix) {
97  return OldSuffix.equals_lower(PotentialNewSuffix);
98  });
99  // Have a match, return it.
100  if (NewSuffix != NewSuffixes.end())
101  return *NewSuffix;
102  // Nope, I guess we have to keep it as-is.
103  return llvm::None;
104 }
105 
106 template <typename LiteralType>
107 llvm::Optional<NewSuffix>
108 shouldReplaceLiteralSuffix(const Expr &Literal,
109  const std::vector<std::string> &NewSuffixes,
110  const SourceManager &SM, const LangOptions &LO) {
111  NewSuffix ReplacementDsc;
112 
113  const auto &L = cast<typename LiteralType::type>(Literal);
114 
115  // The naive location of the literal. Is always valid.
116  ReplacementDsc.LiteralLocation = L.getSourceRange();
117 
118  // Was this literal fully spelled or is it a product of macro expansion?
119  bool RangeCanBeFixed =
120  utils::rangeCanBeFixed(ReplacementDsc.LiteralLocation, &SM);
121 
122  // The literal may have macro expansion, we need the final expanded src range.
123  llvm::Optional<SourceRange> Range =
124  GetMacroAwareSourceRange(ReplacementDsc.LiteralLocation, SM);
125  if (!Range)
126  return llvm::None;
127 
128  if (RangeCanBeFixed)
129  ReplacementDsc.LiteralLocation = *Range;
130  // Else keep the naive literal location!
131 
132  // Get the whole literal from the source buffer.
133  bool Invalid;
134  const StringRef LiteralSourceText = Lexer::getSourceText(
135  CharSourceRange::getTokenRange(*Range), SM, LO, &Invalid);
136  assert(!Invalid && "Failed to retrieve the source text.");
137 
138  size_t Skip = 0;
139 
140  // Do we need to ignore something before actually looking for the suffix?
141  if (!LiteralType::SkipFirst.empty()) {
142  // E.g. we can't look for 'f' suffix in hexadecimal floating-point literals
143  // until after we skip to the exponent (which is mandatory there),
144  // because hex-digit-sequence may contain 'f'.
145  Skip = LiteralSourceText.find_first_of(LiteralType::SkipFirst);
146  // We could be in non-hexadecimal floating-point literal, with no exponent.
147  if (Skip == StringRef::npos)
148  Skip = 0;
149  }
150 
151  // Find the beginning of the suffix by looking for the first char that is
152  // one of these chars that can be in the suffix, potentially starting looking
153  // in the exponent, if we are skipping hex-digit-sequence.
154  Skip = LiteralSourceText.find_first_of(LiteralType::Suffixes, /*From=*/Skip);
155 
156  // We can't check whether the *Literal has any suffix or not without actually
157  // looking for the suffix. So it is totally possible that there is no suffix.
158  if (Skip == StringRef::npos)
159  return llvm::None;
160 
161  // Move the cursor in the source range to the beginning of the suffix.
162  Range->setBegin(Range->getBegin().getLocWithOffset(Skip));
163  // And in our textual representation too.
164  ReplacementDsc.OldSuffix = LiteralSourceText.drop_front(Skip);
165  assert(!ReplacementDsc.OldSuffix.empty() &&
166  "We still should have some chars left.");
167 
168  // And get the replacement suffix.
169  llvm::Optional<std::string> NewSuffix =
170  getNewSuffix(ReplacementDsc.OldSuffix, NewSuffixes);
171  if (!NewSuffix || ReplacementDsc.OldSuffix == *NewSuffix)
172  return llvm::None; // The suffix was already the way it should be.
173 
174  if (RangeCanBeFixed)
175  ReplacementDsc.FixIt = FixItHint::CreateReplacement(*Range, *NewSuffix);
176 
177  return ReplacementDsc;
178 }
179 
180 } // namespace
181 
182 UppercaseLiteralSuffixCheck::UppercaseLiteralSuffixCheck(
183  StringRef Name, ClangTidyContext *Context)
184  : ClangTidyCheck(Name, Context),
185  NewSuffixes(
186  utils::options::parseStringList(Options.get("NewSuffixes", ""))),
187  IgnoreMacros(Options.getLocalOrGlobal("IgnoreMacros", 1) != 0) {}
188 
191  Options.store(Opts, "NewSuffixes",
193  Options.store(Opts, "IgnoreMacros", IgnoreMacros);
194 }
195 
197  // Sadly, we can't check whether the literal has sufix or not.
198  // E.g. i32 suffix still results in 'BuiltinType::Kind::Int'.
199  // And such an info is not stored in the *Literal itself.
200  Finder->addMatcher(
201  stmt(eachOf(integerLiteral().bind(IntegerLiteralCheck::Name),
202  floatLiteral().bind(FloatingLiteralCheck::Name)),
203  unless(anyOf(hasParent(userDefinedLiteral()),
204  hasAncestor(isImplicit()),
205  hasAncestor(substNonTypeTemplateParmExpr())))),
206  this);
207 }
208 
209 template <typename LiteralType>
210 bool UppercaseLiteralSuffixCheck::checkBoundMatch(
211  const MatchFinder::MatchResult &Result) {
212  const auto *Literal =
213  Result.Nodes.getNodeAs<typename LiteralType::type>(LiteralType::Name);
214  if (!Literal)
215  return false;
216 
217  // We won't *always* want to diagnose.
218  // We might have a suffix that is already uppercase.
219  if (auto Details = shouldReplaceLiteralSuffix<LiteralType>(
220  *Literal, NewSuffixes, *Result.SourceManager, getLangOpts())) {
221  if (Details->LiteralLocation.getBegin().isMacroID() && IgnoreMacros)
222  return true;
223  auto Complaint = diag(Details->LiteralLocation.getBegin(),
224  "%0 literal has suffix '%1', which is not uppercase")
225  << LiteralType::Name << Details->OldSuffix;
226  if (Details->FixIt) // Similarly, a fix-it is not always possible.
227  Complaint << *(Details->FixIt);
228  }
229 
230  return true;
231 }
232 
234  const MatchFinder::MatchResult &Result) {
235  if (checkBoundMatch<IntegerLiteralCheck>(Result))
236  return; // If it *was* IntegerLiteral, don't check for FloatingLiteral.
237  checkBoundMatch<FloatingLiteralCheck>(Result);
238 }
239 
240 } // namespace readability
241 } // namespace tidy
242 } // namespace clang
SourceLocation Loc
&#39;#&#39; location in the include directive
void check(const ast_matchers::MatchFinder::MatchResult &Result) override
ClangTidyChecks that register ASTMatchers should do the actual work in here.
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: ClangTidy.cpp:473
std::string serializeStringList(ArrayRef< std::string > Strings)
Serialize a sequence of names that can be parsed by parseStringList.
LangOptions getLangOpts() const
Returns the language options from the context.
Definition: ClangTidy.h:187
Base class for all clang-tidy checks.
Definition: ClangTidy.h:127
void registerMatchers(ast_matchers::MatchFinder *Finder) override
Override this to register AST matchers with Finder.
std::vector< std::string > parseStringList(StringRef Option)
Parse a semicolon separated list of strings.
SourceRange LiteralLocation
static constexpr llvm::StringLiteral Name
std::map< std::string, std::string > OptionMap
llvm::Optional< llvm::Expected< tooling::AtomicChanges > > Result
static constexpr llvm::StringLiteral SkipFirst
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
StringRef OldSuffix
CharSourceRange Range
SourceRange for the file name.
bool rangeCanBeFixed(SourceRange Range, const SourceManager *SM)
Definition: ASTUtils.cpp:91
Every ClangTidyCheck reports errors through a DiagnosticsEngine provided by this context.
llvm::Optional< FixItHint > FixIt
void storeOptions(ClangTidyOptions::OptionMap &Opts) override
Should store all options supported by this check with their current values or default values for opti...
DiagnosticBuilder diag(SourceLocation Loc, StringRef Description, DiagnosticIDs::Level Level=DiagnosticIDs::Warning)
Add a diagnostic with the check&#39;s name.
Definition: ClangTidy.cpp:438
static constexpr llvm::StringLiteral Suffixes