llvm-project/clang-tools-extra/clang-tidy/modernize/UseUsingCheck.cpp

121 lines
4.8 KiB
C++

//===--- UseUsingCheck.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 "UseUsingCheck.h"
#include "clang/AST/ASTContext.h"
#include "clang/Lex/Lexer.h"
using namespace clang::ast_matchers;
namespace clang {
namespace tidy {
namespace modernize {
UseUsingCheck::UseUsingCheck(StringRef Name, ClangTidyContext *Context)
: ClangTidyCheck(Name, Context),
IgnoreMacros(Options.getLocalOrGlobal("IgnoreMacros", true)) {}
void UseUsingCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
Options.store(Opts, "IgnoreMacros", IgnoreMacros);
}
void UseUsingCheck::registerMatchers(MatchFinder *Finder) {
Finder->addMatcher(typedefDecl(unless(isInstantiated())).bind("typedef"),
this);
// This matcher used to find tag declarations in source code within typedefs.
// They appear in the AST just *prior* to the typedefs.
Finder->addMatcher(tagDecl(unless(isImplicit())).bind("tagdecl"), this);
}
void UseUsingCheck::check(const MatchFinder::MatchResult &Result) {
// Match CXXRecordDecl only to store the range of the last non-implicit full
// declaration, to later check whether it's within the typdef itself.
const auto *MatchedTagDecl = Result.Nodes.getNodeAs<TagDecl>("tagdecl");
if (MatchedTagDecl) {
LastTagDeclRange = MatchedTagDecl->getSourceRange();
return;
}
const auto *MatchedDecl = Result.Nodes.getNodeAs<TypedefDecl>("typedef");
if (MatchedDecl->getLocation().isInvalid())
return;
SourceLocation StartLoc = MatchedDecl->getBeginLoc();
if (StartLoc.isMacroID() && IgnoreMacros)
return;
static const char *UseUsingWarning = "use 'using' instead of 'typedef'";
// Warn at StartLoc but do not fix if there is macro or array.
if (MatchedDecl->getUnderlyingType()->isArrayType() || StartLoc.isMacroID()) {
diag(StartLoc, UseUsingWarning);
return;
}
PrintingPolicy PrintPolicy(getLangOpts());
PrintPolicy.SuppressScope = true;
PrintPolicy.ConstantArraySizeAsWritten = true;
PrintPolicy.UseVoidForZeroParams = false;
PrintPolicy.PrintInjectedClassNameWithArguments = false;
std::string Type = MatchedDecl->getUnderlyingType().getAsString(PrintPolicy);
std::string Name = MatchedDecl->getNameAsString();
SourceRange ReplaceRange = MatchedDecl->getSourceRange();
// typedefs with multiple comma-separated definitions produce multiple
// consecutive TypedefDecl nodes whose SourceRanges overlap. Each range starts
// at the "typedef" and then continues *across* previous definitions through
// the end of the current TypedefDecl definition.
// But also we need to check that the ranges belong to the same file because
// different files may contain overlapping ranges.
std::string Using = "using ";
if (ReplaceRange.getBegin().isMacroID() ||
(Result.SourceManager->getFileID(ReplaceRange.getBegin()) !=
Result.SourceManager->getFileID(LastReplacementEnd)) ||
(ReplaceRange.getBegin() >= LastReplacementEnd)) {
// This is the first (and possibly the only) TypedefDecl in a typedef. Save
// Type and Name in case we find subsequent TypedefDecl's in this typedef.
FirstTypedefType = Type;
FirstTypedefName = Name;
} else {
// This is additional TypedefDecl in a comma-separated typedef declaration.
// Start replacement *after* prior replacement and separate with semicolon.
ReplaceRange.setBegin(LastReplacementEnd);
Using = ";\nusing ";
// If this additional TypedefDecl's Type starts with the first TypedefDecl's
// type, make this using statement refer back to the first type, e.g. make
// "typedef int Foo, *Foo_p;" -> "using Foo = int;\nusing Foo_p = Foo*;"
if (Type.size() > FirstTypedefType.size() &&
Type.substr(0, FirstTypedefType.size()) == FirstTypedefType)
Type = FirstTypedefName + Type.substr(FirstTypedefType.size() + 1);
}
if (!ReplaceRange.getEnd().isMacroID())
LastReplacementEnd = ReplaceRange.getEnd().getLocWithOffset(Name.size());
auto Diag = diag(ReplaceRange.getBegin(), UseUsingWarning);
// If typedef contains a full tag declaration, extract its full text.
if (LastTagDeclRange.isValid() &&
ReplaceRange.fullyContains(LastTagDeclRange)) {
bool Invalid;
Type = std::string(
Lexer::getSourceText(CharSourceRange::getTokenRange(LastTagDeclRange),
*Result.SourceManager, getLangOpts(), &Invalid));
if (Invalid)
return;
}
std::string Replacement = Using + Name + " = " + Type;
Diag << FixItHint::CreateReplacement(ReplaceRange, Replacement);
}
} // namespace modernize
} // namespace tidy
} // namespace clang