llvm-project/clang-tools-extra/clang-tidy/google/GlobalVariableDeclarationCh...

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3.5 KiB
C++

//===--- GlobalVariableDeclarationCheck.cpp - clang-tidy-------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "GlobalVariableDeclarationCheck.h"
#include "clang/AST/ASTContext.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringRef.h"
#include <string>
using namespace clang::ast_matchers;
namespace clang {
namespace tidy {
namespace google {
namespace objc {
namespace {
AST_MATCHER(VarDecl, isLocalVariable) {
return Node.isLocalVarDecl();
}
FixItHint generateFixItHint(const VarDecl *Decl, bool IsConst) {
char FC = Decl->getName()[0];
if (!llvm::isAlpha(FC) || Decl->getName().size() == 1) {
// No fix available if first character is not alphabetical character, or it
// is a single-character variable, since it is difficult to determine the
// proper fix in this case. Users should create a proper variable name by
// their own.
return FixItHint();
}
char SC = Decl->getName()[1];
if ((FC == 'k' || FC == 'g') && !llvm::isAlpha(SC)) {
// No fix available if the prefix is correct but the second character is not
// alphabetical, since it is difficult to determine the proper fix in this
// case.
return FixItHint();
}
auto NewName = (IsConst ? "k" : "g") +
llvm::StringRef(std::string(1, FC)).upper() +
Decl->getName().substr(1).str();
return FixItHint::CreateReplacement(
CharSourceRange::getTokenRange(SourceRange(Decl->getLocation())),
llvm::StringRef(NewName));
}
} // namespace
void GlobalVariableDeclarationCheck::registerMatchers(MatchFinder *Finder) {
// The relevant Style Guide rule only applies to Objective-C.
if (!getLangOpts().ObjC)
return;
// need to add two matchers since we need to bind different ids to distinguish
// constants and variables. Since bind() can only be called on node matchers,
// we cannot make it in one matcher.
//
// Note that hasGlobalStorage() matches static variables declared locally
// inside a function or method, so we need to exclude those with
// isLocalVariable().
Finder->addMatcher(
varDecl(hasGlobalStorage(), unless(hasType(isConstQualified())),
unless(isLocalVariable()), unless(matchesName("::g[A-Z]")))
.bind("global_var"),
this);
Finder->addMatcher(varDecl(hasGlobalStorage(), hasType(isConstQualified()),
unless(isLocalVariable()),
unless(matchesName("::(k[A-Z]|[A-Z]{2,})")))
.bind("global_const"),
this);
}
void GlobalVariableDeclarationCheck::check(
const MatchFinder::MatchResult &Result) {
if (const auto *Decl = Result.Nodes.getNodeAs<VarDecl>("global_var")) {
diag(Decl->getLocation(),
"non-const global variable '%0' must have a name which starts with "
"'g[A-Z]'")
<< Decl->getName() << generateFixItHint(Decl, false);
}
if (const auto *Decl = Result.Nodes.getNodeAs<VarDecl>("global_const")) {
diag(Decl->getLocation(),
"const global variable '%0' must have a name which starts with "
"an appropriate prefix")
<< Decl->getName() << generateFixItHint(Decl, true);
}
}
} // namespace objc
} // namespace google
} // namespace tidy
} // namespace clang