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
9#include "GlobalVariableDeclarationCheck.h"
10#include "clang/ASTMatchers/ASTMatchFinder.h"
11#include "llvm/ADT/StringExtras.h"
12#include "llvm/ADT/StringRef.h"
13
14#include <string>
15
16using namespace clang::ast_matchers;
17
18namespace clang::tidy::google::objc {
19
20namespace {
21
22AST_MATCHER(VarDecl, isLocalVariable) { return Node.isLocalVarDecl(); }
23
24FixItHint generateFixItHint(const VarDecl *Decl, bool IsConst) {
25 if (IsConst && (Decl->getStorageClass() != SC_Static)) {
26 // No fix available if it is not a static constant, since it is difficult
27 // to determine the proper fix in this case.
28 return {};
29 }
30
31 char FC = Decl->getName()[0];
32 if (!llvm::isAlpha(C: FC) || Decl->getName().size() == 1) {
33 // No fix available if first character is not alphabetical character, or it
34 // is a single-character variable, since it is difficult to determine the
35 // proper fix in this case. Users should create a proper variable name by
36 // their own.
37 return {};
38 }
39 char SC = Decl->getName()[1];
40 if ((FC == 'k' || FC == 'g') && !llvm::isAlpha(C: SC)) {
41 // No fix available if the prefix is correct but the second character is
42 // not alphabetical, since it is difficult to determine the proper fix in
43 // this case.
44 return {};
45 }
46
47 auto NewName = (IsConst ? "k" : "g") +
48 llvm::StringRef(std::string(1, FC)).upper() +
49 Decl->getName().substr(1).str();
50
51 return FixItHint::CreateReplacement(
52 RemoveRange: CharSourceRange::getTokenRange(R: SourceRange(Decl->getLocation())),
53 Code: llvm::StringRef(NewName));
54}
55} // namespace
56
57void GlobalVariableDeclarationCheck::registerMatchers(MatchFinder *Finder) {
58 // need to add two matchers since we need to bind different ids to distinguish
59 // constants and variables. Since bind() can only be called on node matchers,
60 // we cannot make it in one matcher.
61 //
62 // Note that hasGlobalStorage() matches static variables declared locally
63 // inside a function or method, so we need to exclude those with
64 // isLocalVariable().
65 Finder->addMatcher(
66 NodeMatch: varDecl(hasGlobalStorage(), unless(hasType(InnerMatcher: isConstQualified())),
67 unless(isLocalVariable()), unless(matchesName(RegExp: "::g[A-Z]")))
68 .bind(ID: "global_var"),
69 Action: this);
70 Finder->addMatcher(NodeMatch: varDecl(hasGlobalStorage(), hasType(InnerMatcher: isConstQualified()),
71 unless(isLocalVariable()),
72 unless(matchesName(RegExp: "::(k[A-Z])|([A-Z][A-Z0-9])")))
73 .bind(ID: "global_const"),
74 Action: this);
75}
76
77void GlobalVariableDeclarationCheck::check(
78 const MatchFinder::MatchResult &Result) {
79 if (const auto *Decl = Result.Nodes.getNodeAs<VarDecl>(ID: "global_var")) {
80 if (Decl->isStaticDataMember())
81 return;
82 diag(Decl->getLocation(),
83 "non-const global variable '%0' must have a name which starts with "
84 "'g[A-Z]'")
85 << Decl->getName() << generateFixItHint(Decl, IsConst: false);
86 }
87 if (const auto *Decl = Result.Nodes.getNodeAs<VarDecl>(ID: "global_const")) {
88 if (Decl->isStaticDataMember())
89 return;
90 diag(Decl->getLocation(),
91 "const global variable '%0' must have a name which starts with "
92 "an appropriate prefix")
93 << Decl->getName() << generateFixItHint(Decl, IsConst: true);
94 }
95}
96
97} // namespace clang::tidy::google::objc
98

source code of clang-tools-extra/clang-tidy/google/GlobalVariableDeclarationCheck.cpp