lix/subprojects/lix-clang-tidy/CharPtrCast.cc
jade a5f0954c29 clang-tidy: write a lint for charptr_cast
This lets us ensure that nobody is putting in new reinterpret_cast
instances where they could safely use charptr_cast instead.

Change-Id: I6358a3934c8133c7150042635843bdbb6b9218d4
2024-08-08 14:53:17 -07:00

46 lines
1.7 KiB
C++

#include "CharPtrCast.hh"
#include <clang/AST/ExprCXX.h>
#include <clang/Basic/Diagnostic.h>
#include <clang/Tooling/Transformer/SourceCode.h>
namespace nix::clang_tidy {
using namespace clang::ast_matchers;
using namespace clang;
void CharPtrCastCheck::registerMatchers(ast_matchers::MatchFinder *Finder) {
Finder->addMatcher(
traverse(clang::TK_IgnoreUnlessSpelledInSource,
cxxReinterpretCastExpr(allOf(
hasDestinationType(qualType(pointsTo(isAnyCharacter()))),
has(expr(hasType(qualType(pointsTo(isAnyCharacter()))))))))
.bind("reinterpret-cast-expr"),
this);
}
void CharPtrCastCheck::check(
const ast_matchers::MatchFinder::MatchResult &Result) {
const auto ReinterpretCastExpr =
Result.Nodes.getNodeAs<CXXReinterpretCastExpr>("reinterpret-cast-expr");
const auto ToTypeSpan = ReinterpretCastExpr->getAngleBrackets();
const auto & SM = Result.Context->getSourceManager();
auto Diag =
diag(ReinterpretCastExpr->getExprLoc(),
"reinterpret_cast used for trivially safe character pointer cast");
Diag << ReinterpretCastExpr->getSourceRange();
auto Inside = tooling::getText(*ReinterpretCastExpr->getSubExprAsWritten(),
*Result.Context);
Diag << Inserter.createIncludeInsertion(SM.getFileID(ReinterpretCastExpr->getExprLoc()), "charptr-cast.hh");
llvm::Twine Replacement =
"charptr_cast" +
tooling::getText(CharSourceRange(ToTypeSpan, true), *Result.Context) +
"(" + Inside + ")";
Diag << FixItHint::CreateReplacement(ReinterpretCastExpr->getSourceRange(),
Replacement.str());
}
} // namespace nix::clang_tidy