llvm-project/clang-tools-extra/clang-tidy/readability/AvoidConstParamsInDecls.cpp

86 lines
2.6 KiB
C++

//===--- AvoidConstParamsInDecls.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 "AvoidConstParamsInDecls.h"
#include "../utils/LexerUtils.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include "clang/ASTMatchers/ASTMatchers.h"
#include "clang/Lex/Lexer.h"
#include "llvm/ADT/Optional.h"
using namespace clang::ast_matchers;
namespace clang {
namespace tidy {
namespace readability {
namespace {
SourceRange getTypeRange(const ParmVarDecl &Param) {
return SourceRange(Param.getBeginLoc(),
Param.getLocation().getLocWithOffset(-1));
}
} // namespace
void AvoidConstParamsInDecls::registerMatchers(MatchFinder *Finder) {
const auto ConstParamDecl =
parmVarDecl(hasType(qualType(isConstQualified()))).bind("param");
Finder->addMatcher(
functionDecl(unless(isDefinition()),
has(typeLoc(forEach(ConstParamDecl))))
.bind("func"),
this);
}
void AvoidConstParamsInDecls::check(const MatchFinder::MatchResult &Result) {
const auto *Func = Result.Nodes.getNodeAs<FunctionDecl>("func");
const auto *Param = Result.Nodes.getNodeAs<ParmVarDecl>("param");
if (!Param->getType().isLocalConstQualified())
return;
auto Diag = diag(Param->getBeginLoc(),
"parameter %0 is const-qualified in the function "
"declaration; const-qualification of parameters only has an "
"effect in function definitions");
if (Param->getName().empty()) {
for (unsigned int I = 0; I < Func->getNumParams(); ++I) {
if (Param == Func->getParamDecl(I)) {
Diag << (I + 1);
break;
}
}
} else {
Diag << Param;
}
if (Param->getBeginLoc().isMacroID() != Param->getEndLoc().isMacroID()) {
// Do not offer a suggestion if the part of the variable declaration comes
// from a macro.
return;
}
CharSourceRange FileRange = Lexer::makeFileCharRange(
CharSourceRange::getTokenRange(getTypeRange(*Param)),
*Result.SourceManager, getLangOpts());
if (!FileRange.isValid())
return;
auto Tok = tidy::utils::lexer::getQualifyingToken(
tok::kw_const, FileRange, *Result.Context, *Result.SourceManager);
if (!Tok)
return;
Diag << FixItHint::CreateRemoval(
CharSourceRange::getTokenRange(Tok->getLocation(), Tok->getLocation()));
}
} // namespace readability
} // namespace tidy
} // namespace clang