clang-tools  8.0.0
FunctionNamingCheck.cpp
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1 //===--- FunctionNamingCheck.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 "FunctionNamingCheck.h"
11 #include "clang/AST/ASTContext.h"
12 #include "clang/ASTMatchers/ASTMatchFinder.h"
13 #include "llvm/Support/Regex.h"
14 
15 using namespace clang::ast_matchers;
16 
17 namespace clang {
18 namespace tidy {
19 namespace google {
20 namespace objc {
21 
22 namespace {
23 
24 std::string validFunctionNameRegex(bool RequirePrefix) {
25  // Allow the following name patterns for all functions:
26  // • ABFoo (prefix + UpperCamelCase)
27  // • ABURL (prefix + capitalized acronym/initialism)
28  //
29  // If no prefix is required, additionally allow the following name patterns:
30  // • Foo (UpperCamelCase)
31  // • URL (capitalized acronym/initialism)
32  //
33  // The function name following the prefix can contain standard and
34  // non-standard capitalized character sequences including acronyms,
35  // initialisms, and prefixes of symbols (e.g., UIColorFromNSString). For this
36  // reason, the regex only verifies that the function name after the prefix
37  // begins with a capital letter followed by an arbitrary sequence of
38  // alphanumeric characters.
39  //
40  // If a prefix is required, the regex checks for a capital letter followed by
41  // another capital letter or number that is part of the prefix and another
42  // capital letter or number that begins the name following the prefix.
43  std::string FunctionNameMatcher =
44  std::string(RequirePrefix ? "[A-Z][A-Z0-9]+" : "") + "[A-Z][a-zA-Z0-9]*";
45  return std::string("::(") + FunctionNameMatcher + ")$";
46 }
47 
48 /// For now we will only fix functions of static storage class with names like
49 /// 'functionName' or 'function_name' and convert them to 'FunctionName'. For
50 /// other cases the user must determine an appropriate name on their own.
51 FixItHint generateFixItHint(const FunctionDecl *Decl) {
52  // A fixit can be generated for functions of static storage class but
53  // otherwise the check cannot determine the appropriate function name prefix
54  // to use.
55  if (Decl->getStorageClass() != SC_Static)
56  return FixItHint();
57 
58  StringRef Name = Decl->getName();
59  std::string NewName = Decl->getName().str();
60 
61  size_t Index = 0;
62  bool AtWordBoundary = true;
63  while (Index < NewName.size()) {
64  char ch = NewName[Index];
65  if (isalnum(ch)) {
66  // Capitalize the first letter after every word boundary.
67  if (AtWordBoundary) {
68  NewName[Index] = toupper(NewName[Index]);
69  AtWordBoundary = false;
70  }
71 
72  // Advance the index after every alphanumeric character.
73  Index++;
74  } else {
75  // Strip out any characters other than alphanumeric characters.
76  NewName.erase(Index, 1);
77  AtWordBoundary = true;
78  }
79  }
80 
81  // Generate a fixit hint if the new name is different.
82  if (NewName != Name)
83  return FixItHint::CreateReplacement(
84  CharSourceRange::getTokenRange(SourceRange(Decl->getLocation())),
85  llvm::StringRef(NewName));
86 
87  return FixItHint();
88 }
89 
90 } // namespace
91 
92 void FunctionNamingCheck::registerMatchers(MatchFinder *Finder) {
93  // This check should only be applied to Objective-C sources.
94  if (!getLangOpts().ObjC)
95  return;
96 
97  // Match function declarations that are not in system headers and are not
98  // main.
99  Finder->addMatcher(
100  functionDecl(
101  unless(anyOf(isExpansionInSystemHeader(), cxxMethodDecl(),
102  hasAncestor(namespaceDecl()), isMain(),
103  matchesName(validFunctionNameRegex(true)),
104  allOf(isStaticStorageClass(),
105  matchesName(validFunctionNameRegex(false))))))
106  .bind("function"),
107  this);
108 }
109 
110 void FunctionNamingCheck::check(const MatchFinder::MatchResult &Result) {
111  const auto *MatchedDecl = Result.Nodes.getNodeAs<FunctionDecl>("function");
112 
113  bool IsGlobal = MatchedDecl->getStorageClass() != SC_Static;
114  diag(MatchedDecl->getLocation(),
115  "%select{static function|function in global namespace}1 named %0 must "
116  "%select{be in|have an appropriate prefix followed by}1 Pascal case as "
117  "required by Google Objective-C style guide")
118  << MatchedDecl << IsGlobal << generateFixItHint(MatchedDecl);
119 }
120 
121 } // namespace objc
122 } // namespace google
123 } // namespace tidy
124 } // namespace clang
static constexpr llvm::StringLiteral Name
llvm::Optional< llvm::Expected< tooling::AtomicChanges > > Result
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
const SymbolIndex * Index
Definition: Dexp.cpp:85