llvm-project/clang-tools-extra/clang-modernize/UseNullptr/NullptrMatchers.cpp

71 lines
2.0 KiB
C++

//===-- UseNullptr/NullptrMatchers.cpp - Matchers for null casts ----------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// \file
/// \brief This file contains the definitions for matcher-generating functions
/// and a custom AST_MATCHER for identifying casts of type CK_NullTo*.
///
//===----------------------------------------------------------------------===//
#include "NullptrMatchers.h"
#include "clang/AST/ASTContext.h"
using namespace clang::ast_matchers;
using namespace clang;
const char *CastSequence = "sequence";
namespace clang {
namespace ast_matchers {
/// \brief Matches cast expressions that have a cast kind of CK_NullToPointer
/// or CK_NullToMemberPointer.
///
/// Given
/// \code
/// int *p = 0;
/// \endcode
/// implicitCastExpr(isNullToPointer()) matches the implicit cast clang adds
/// around \c 0.
AST_MATCHER(CastExpr, isNullToPointer) {
return Node.getCastKind() == CK_NullToPointer ||
Node.getCastKind() == CK_NullToMemberPointer;
}
AST_MATCHER(Type, sugaredNullptrType) {
const Type *DesugaredType = Node.getUnqualifiedDesugaredType();
if (const BuiltinType *BT = dyn_cast<BuiltinType>(DesugaredType))
return BT->getKind() == BuiltinType::NullPtr;
return false;
}
} // end namespace ast_matchers
} // end namespace clang
StatementMatcher makeCastSequenceMatcher() {
StatementMatcher ImplicitCastToNull =
implicitCastExpr(
isNullToPointer(),
unless(
hasSourceExpression(
hasType(sugaredNullptrType())
)
)
);
return castExpr(
anyOf(
ImplicitCastToNull,
explicitCastExpr(
hasDescendant(ImplicitCastToNull)
)
),
unless(hasAncestor(explicitCastExpr()))
).bind(CastSequence);
}