clang-tools  7.0.0
GlobalVariableDeclarationCheck.cpp
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1 //===--- GlobalVariableDeclarationCheck.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 "clang/AST/ASTContext.h"
12 #include "clang/ASTMatchers/ASTMatchFinder.h"
13 #include "llvm/ADT/StringExtras.h"
14 #include "llvm/ADT/StringRef.h"
15 
16 #include <string>
17 
18 using namespace clang::ast_matchers;
19 
20 namespace clang {
21 namespace tidy {
22 namespace google {
23 namespace objc {
24 
25 namespace {
26 
27 AST_MATCHER(VarDecl, isLocalVariable) {
28  return Node.isLocalVarDecl();
29 }
30 
31 FixItHint generateFixItHint(const VarDecl *Decl, bool IsConst) {
32  char FC = Decl->getName()[0];
33  if (!llvm::isAlpha(FC) || Decl->getName().size() == 1) {
34  // No fix available if first character is not alphabetical character, or it
35  // is a single-character variable, since it is difficult to determine the
36  // proper fix in this case. Users should create a proper variable name by
37  // their own.
38  return FixItHint();
39  }
40  char SC = Decl->getName()[1];
41  if ((FC == 'k' || FC == 'g') && !llvm::isAlpha(SC)) {
42  // No fix available if the prefix is correct but the second character is not
43  // alphabetical, since it is difficult to determine the proper fix in this
44  // case.
45  return FixItHint();
46  }
47  auto NewName = (IsConst ? "k" : "g") +
48  llvm::StringRef(std::string(1, FC)).upper() +
49  Decl->getName().substr(1).str();
50  return FixItHint::CreateReplacement(
51  CharSourceRange::getTokenRange(SourceRange(Decl->getLocation())),
52  llvm::StringRef(NewName));
53 }
54 } // namespace
55 
56 void GlobalVariableDeclarationCheck::registerMatchers(MatchFinder *Finder) {
57  // The relevant Style Guide rule only applies to Objective-C.
58  if (!getLangOpts().ObjC1 && !getLangOpts().ObjC2) {
59  return;
60  }
61  // need to add two matchers since we need to bind different ids to distinguish
62  // constants and variables. Since bind() can only be called on node matchers,
63  // we cannot make it in one matcher.
64  //
65  // Note that hasGlobalStorage() matches static variables declared locally
66  // inside a function or method, so we need to exclude those with
67  // isLocalVariable().
68  Finder->addMatcher(
69  varDecl(hasGlobalStorage(), unless(hasType(isConstQualified())),
70  unless(isLocalVariable()), unless(matchesName("::g[A-Z]")))
71  .bind("global_var"),
72  this);
73  Finder->addMatcher(varDecl(hasGlobalStorage(), hasType(isConstQualified()),
74  unless(isLocalVariable()),
75  unless(matchesName("::(k[A-Z]|[A-Z]{2,})")))
76  .bind("global_const"),
77  this);
78 }
79 
80 void GlobalVariableDeclarationCheck::check(
81  const MatchFinder::MatchResult &Result) {
82  if (const auto *Decl = Result.Nodes.getNodeAs<VarDecl>("global_var")) {
83  diag(Decl->getLocation(),
84  "non-const global variable '%0' must have a name which starts with "
85  "'g[A-Z]'")
86  << Decl->getName() << generateFixItHint(Decl, false);
87  }
88  if (const auto *Decl = Result.Nodes.getNodeAs<VarDecl>("global_const")) {
89  diag(Decl->getLocation(),
90  "const global variable '%0' must have a name which starts with "
91  "an appropriate prefix")
92  << Decl->getName() << generateFixItHint(Decl, true);
93  }
94 }
95 
96 } // namespace objc
97 } // namespace google
98 } // namespace tidy
99 } // namespace clang
AST_MATCHER(BinaryOperator, isAssignmentOperator)
Definition: Matchers.h:20
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//