clang-tools  14.0.0git
GlobalVariableDeclarationCheck.cpp
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1 //===--- GlobalVariableDeclarationCheck.cpp - clang-tidy-------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
10 #include "clang/AST/ASTContext.h"
11 #include "clang/ASTMatchers/ASTMatchFinder.h"
12 #include "llvm/ADT/StringExtras.h"
13 #include "llvm/ADT/StringRef.h"
14 
15 #include <string>
16 
17 using namespace clang::ast_matchers;
18 
19 namespace clang {
20 namespace tidy {
21 namespace google {
22 namespace objc {
23 
24 namespace {
25 
26 AST_MATCHER(VarDecl, isLocalVariable) { return Node.isLocalVarDecl(); }
27 
28 FixItHint generateFixItHint(const VarDecl *Decl, bool IsConst) {
29  if (IsConst && (Decl->getStorageClass() != SC_Static)) {
30  // No fix available if it is not a static constant, since it is difficult
31  // to determine the proper fix in this case.
32  return FixItHint();
33  }
34 
35  char FC = Decl->getName()[0];
36  if (!llvm::isAlpha(FC) || Decl->getName().size() == 1) {
37  // No fix available if first character is not alphabetical character, or it
38  // is a single-character variable, since it is difficult to determine the
39  // proper fix in this case. Users should create a proper variable name by
40  // their own.
41  return FixItHint();
42  }
43  char SC = Decl->getName()[1];
44  if ((FC == 'k' || FC == 'g') && !llvm::isAlpha(SC)) {
45  // No fix available if the prefix is correct but the second character is
46  // not alphabetical, since it is difficult to determine the proper fix in
47  // this case.
48  return FixItHint();
49  }
50 
51  auto NewName = (IsConst ? "k" : "g") +
52  llvm::StringRef(std::string(1, FC)).upper() +
53  Decl->getName().substr(1).str();
54 
55  return FixItHint::CreateReplacement(
56  CharSourceRange::getTokenRange(SourceRange(Decl->getLocation())),
57  llvm::StringRef(NewName));
58 }
59 } // namespace
60 
61 void GlobalVariableDeclarationCheck::registerMatchers(MatchFinder *Finder) {
62  // need to add two matchers since we need to bind different ids to distinguish
63  // constants and variables. Since bind() can only be called on node matchers,
64  // we cannot make it in one matcher.
65  //
66  // Note that hasGlobalStorage() matches static variables declared locally
67  // inside a function or method, so we need to exclude those with
68  // isLocalVariable().
69  Finder->addMatcher(
70  varDecl(hasGlobalStorage(), unless(hasType(isConstQualified())),
71  unless(isLocalVariable()), unless(matchesName("::g[A-Z]")))
72  .bind("global_var"),
73  this);
74  Finder->addMatcher(varDecl(hasGlobalStorage(), hasType(isConstQualified()),
75  unless(isLocalVariable()),
76  unless(matchesName("::(k[A-Z])|([A-Z][A-Z0-9])")))
77  .bind("global_const"),
78  this);
79 }
80 
82  const MatchFinder::MatchResult &Result) {
83  if (const auto *Decl = Result.Nodes.getNodeAs<VarDecl>("global_var")) {
84  if (Decl->isStaticDataMember())
85  return;
86  diag(Decl->getLocation(),
87  "non-const global variable '%0' must have a name which starts with "
88  "'g[A-Z]'")
89  << Decl->getName() << generateFixItHint(Decl, false);
90  }
91  if (const auto *Decl = Result.Nodes.getNodeAs<VarDecl>("global_const")) {
92  if (Decl->isStaticDataMember())
93  return;
94  diag(Decl->getLocation(),
95  "const global variable '%0' must have a name which starts with "
96  "an appropriate prefix")
97  << Decl->getName() << generateFixItHint(Decl, true);
98  }
99 }
100 
101 } // namespace objc
102 } // namespace google
103 } // namespace tidy
104 } // namespace clang
clang::ast_matchers
Definition: AbseilMatcher.h:14
Decl
const FunctionDecl * Decl
Definition: AvoidBindCheck.cpp:100
GlobalVariableDeclarationCheck.h
clang::ast_matchers::AST_MATCHER
AST_MATCHER(Expr, isMacroID)
Definition: PreferIsaOrDynCastInConditionalsCheck.cpp:19
clang::clangd::check
bool check(llvm::StringRef File, llvm::function_ref< bool(const Position &)> ShouldCheckLine, const ThreadsafeFS &TFS, const ClangdLSPServer::Options &Opts, bool EnableCodeCompletion)
Definition: Check.cpp:258
clang
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
Definition: ApplyReplacements.h:27