clang-tools  5.0.0
NamespaceCommentCheck.cpp
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1 //===--- NamespaceCommentCheck.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 "NamespaceCommentCheck.h"
11 #include "clang/AST/ASTContext.h"
12 #include "clang/ASTMatchers/ASTMatchers.h"
13 #include "clang/Lex/Lexer.h"
14 #include "llvm/ADT/StringExtras.h"
15 
16 using namespace clang::ast_matchers;
17 
18 namespace clang {
19 namespace tidy {
20 namespace readability {
21 
22 NamespaceCommentCheck::NamespaceCommentCheck(StringRef Name,
24  : ClangTidyCheck(Name, Context),
25  NamespaceCommentPattern("^/[/*] *(end (of )?)? *(anonymous|unnamed)? *"
26  "namespace( +([a-zA-Z0-9_]+))?\\.? *(\\*/)?$",
27  llvm::Regex::IgnoreCase),
28  ShortNamespaceLines(Options.get("ShortNamespaceLines", 1u)),
29  SpacesBeforeComments(Options.get("SpacesBeforeComments", 1u)) {}
30 
31 void NamespaceCommentCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
32  Options.store(Opts, "ShortNamespaceLines", ShortNamespaceLines);
33  Options.store(Opts, "SpacesBeforeComments", SpacesBeforeComments);
34 }
35 
37  // Only register the matchers for C++; the functionality currently does not
38  // provide any benefit to other languages, despite being benign.
39  if (getLangOpts().CPlusPlus)
40  Finder->addMatcher(namespaceDecl().bind("namespace"), this);
41 }
42 
43 static bool locationsInSameFile(const SourceManager &Sources,
44  SourceLocation Loc1, SourceLocation Loc2) {
45  return Loc1.isFileID() && Loc2.isFileID() &&
46  Sources.getFileID(Loc1) == Sources.getFileID(Loc2);
47 }
48 
49 static std::string getNamespaceComment(const NamespaceDecl *ND,
50  bool InsertLineBreak) {
51  std::string Fix = "// namespace";
52  if (!ND->isAnonymousNamespace())
53  Fix.append(" ").append(ND->getNameAsString());
54  if (InsertLineBreak)
55  Fix.append("\n");
56  return Fix;
57 }
58 
59 void NamespaceCommentCheck::check(const MatchFinder::MatchResult &Result) {
60  const auto *ND = Result.Nodes.getNodeAs<NamespaceDecl>("namespace");
61  const SourceManager &Sources = *Result.SourceManager;
62 
63  if (!locationsInSameFile(Sources, ND->getLocStart(), ND->getRBraceLoc()))
64  return;
65 
66  // Don't require closing comments for namespaces spanning less than certain
67  // number of lines.
68  unsigned StartLine = Sources.getSpellingLineNumber(ND->getLocStart());
69  unsigned EndLine = Sources.getSpellingLineNumber(ND->getRBraceLoc());
70  if (EndLine - StartLine + 1 <= ShortNamespaceLines)
71  return;
72 
73  // Find next token after the namespace closing brace.
74  SourceLocation AfterRBrace = ND->getRBraceLoc().getLocWithOffset(1);
75  SourceLocation Loc = AfterRBrace;
76  Token Tok;
77  // Skip whitespace until we find the next token.
78  while (Lexer::getRawToken(Loc, Tok, Sources, getLangOpts()) ||
79  Tok.is(tok::semi)) {
80  Loc = Loc.getLocWithOffset(1);
81  }
82  if (!locationsInSameFile(Sources, ND->getRBraceLoc(), Loc))
83  return;
84 
85  bool NextTokenIsOnSameLine = Sources.getSpellingLineNumber(Loc) == EndLine;
86  // If we insert a line comment before the token in the same line, we need
87  // to insert a line break.
88  bool NeedLineBreak = NextTokenIsOnSameLine && Tok.isNot(tok::eof);
89 
90  SourceRange OldCommentRange(AfterRBrace, AfterRBrace);
91  std::string Message = "%0 not terminated with a closing comment";
92 
93  // Try to find existing namespace closing comment on the same line.
94  if (Tok.is(tok::comment) && NextTokenIsOnSameLine) {
95  StringRef Comment(Sources.getCharacterData(Loc), Tok.getLength());
96  SmallVector<StringRef, 7> Groups;
97  if (NamespaceCommentPattern.match(Comment, &Groups)) {
98  StringRef NamespaceNameInComment = Groups.size() > 5 ? Groups[5] : "";
99  StringRef Anonymous = Groups.size() > 3 ? Groups[3] : "";
100 
101  // Check if the namespace in the comment is the same.
102  if ((ND->isAnonymousNamespace() && NamespaceNameInComment.empty()) ||
103  (ND->getNameAsString() == NamespaceNameInComment &&
104  Anonymous.empty())) {
105  // FIXME: Maybe we need a strict mode, where we always fix namespace
106  // comments with different format.
107  return;
108  }
109 
110  // Otherwise we need to fix the comment.
111  NeedLineBreak = Comment.startswith("/*");
112  OldCommentRange =
113  SourceRange(AfterRBrace, Loc.getLocWithOffset(Tok.getLength()));
114  Message =
115  (llvm::Twine(
116  "%0 ends with a comment that refers to a wrong namespace '") +
117  NamespaceNameInComment + "'")
118  .str();
119  } else if (Comment.startswith("//")) {
120  // Assume that this is an unrecognized form of a namespace closing line
121  // comment. Replace it.
122  NeedLineBreak = false;
123  OldCommentRange =
124  SourceRange(AfterRBrace, Loc.getLocWithOffset(Tok.getLength()));
125  Message = "%0 ends with an unrecognized comment";
126  }
127  // If it's a block comment, just move it to the next line, as it can be
128  // multi-line or there may be other tokens behind it.
129  }
130 
131  std::string NamespaceName =
132  ND->isAnonymousNamespace()
133  ? "anonymous namespace"
134  : ("namespace '" + ND->getNameAsString() + "'");
135 
136  diag(AfterRBrace, Message)
137  << NamespaceName << FixItHint::CreateReplacement(
138  CharSourceRange::getCharRange(OldCommentRange),
139  std::string(SpacesBeforeComments, ' ') +
140  getNamespaceComment(ND, NeedLineBreak));
141  diag(ND->getLocation(), "%0 starts here", DiagnosticIDs::Note)
142  << NamespaceName;
143 }
144 
145 } // namespace readability
146 } // namespace tidy
147 } // namespace clang
SourceLocation Loc
'#' location in the include directive
void registerMatchers(ast_matchers::MatchFinder *Finder) override
Override this to register AST matchers with Finder.
LangOptions getLangOpts() const
Returns the language options from the context.
Definition: ClangTidy.h:187
StringHandle Name
std::unique_ptr< ast_matchers::MatchFinder > Finder
Definition: ClangTidy.cpp:275
Base class for all clang-tidy checks.
Definition: ClangTidy.h:127
void check(const ast_matchers::MatchFinder::MatchResult &Result) override
ClangTidyChecks that register ASTMatchers should do the actual work in here.
static bool locationsInSameFile(const SourceManager &Sources, SourceLocation Loc1, SourceLocation Loc2)
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:449
std::map< std::string, std::string > OptionMap
static std::string getNamespaceComment(const NamespaceDecl *ND, bool InsertLineBreak)
ClangTidyContext & Context
Definition: ClangTidy.cpp:87
Every ClangTidyCheck reports errors through a DiagnosticsEngine provided by this context.
static cl::opt< bool > Fix("fix", cl::desc(R"( Apply suggested fixes. Without -fix-errors clang-tidy will bail out if any compilation errors were found. )"), cl::init(false), cl::cat(ClangTidyCategory))
DiagnosticBuilder diag(SourceLocation Loc, StringRef Description, DiagnosticIDs::Level Level=DiagnosticIDs::Warning)
Add a diagnostic with the check's name.
Definition: ClangTidy.cpp:416