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codeql/swift/extractor/visitors/VisitorBase.h
2022-10-17 12:57:44 +02:00

118 lines
5.3 KiB
C++

#pragma once
#include <swift/AST/ASTVisitor.h>
#include <swift/AST/TypeVisitor.h>
#include "swift/extractor/infra/SwiftDispatcher.h"
namespace codeql {
namespace detail {
class VisitorBase {
protected:
SwiftDispatcher& dispatcher_;
public:
// SwiftDispatcher should outlive this instance
VisitorBase(SwiftDispatcher& dispatcher) : dispatcher_{dispatcher} {}
};
// define by macro metaprogramming member checkers
// see https://fekir.info/post/detect-member-variables/ for technical details
#define DEFINE_TRANSLATE_CHECKER(KIND, CLASS, PARENT) \
template <typename T, typename = void> \
struct HasTranslate##CLASS##KIND : std::false_type {}; \
\
template <typename T> \
struct HasTranslate##CLASS##KIND<T, decltype((void)std::declval<T>().translate##CLASS##KIND( \
std::declval<swift::CLASS##KIND&>()), \
void())> : std::true_type {};
DEFINE_TRANSLATE_CHECKER(Decl, , )
#define DECL(CLASS, PARENT) DEFINE_TRANSLATE_CHECKER(Decl, CLASS, PARENT)
#define ABSTRACT_DECL(CLASS, PARENT) DEFINE_TRANSLATE_CHECKER(Decl, CLASS, PARENT)
#include "swift/AST/DeclNodes.def"
DEFINE_TRANSLATE_CHECKER(Stmt, , )
#define STMT(CLASS, PARENT) DEFINE_TRANSLATE_CHECKER(Stmt, CLASS, PARENT)
#define ABSTRACT_STMT(CLASS, PARENT) DEFINE_TRANSLATE_CHECKER(Stmt, CLASS, PARENT)
#include "swift/AST/StmtNodes.def"
DEFINE_TRANSLATE_CHECKER(Expr, , )
#define EXPR(CLASS, PARENT) DEFINE_TRANSLATE_CHECKER(Expr, CLASS, PARENT)
#define ABSTRACT_EXPR(CLASS, PARENT) DEFINE_TRANSLATE_CHECKER(Expr, CLASS, PARENT)
#include "swift/AST/ExprNodes.def"
DEFINE_TRANSLATE_CHECKER(Pattern, , )
#define PATTERN(CLASS, PARENT) DEFINE_TRANSLATE_CHECKER(Pattern, CLASS, PARENT)
#include "swift/AST/PatternNodes.def"
DEFINE_TRANSLATE_CHECKER(Type, , )
#define TYPE(CLASS, PARENT) DEFINE_TRANSLATE_CHECKER(Type, CLASS, PARENT)
#define ABSTRACT_TYPE(CLASS, PARENT) DEFINE_TRANSLATE_CHECKER(Type, CLASS, PARENT)
#include "swift/AST/TypeNodes.def"
DEFINE_TRANSLATE_CHECKER(TypeRepr, , )
#define TYPEREPR(CLASS, PARENT) DEFINE_TRANSLATE_CHECKER(TypeRepr, CLASS, PARENT)
#define ABSTRACT_TYPEREPR(CLASS, PARENT) DEFINE_TRANSLATE_CHECKER(TypeRepr, CLASS, PARENT)
#include "swift/AST/TypeReprNodes.def"
} // namespace detail
// we want to override the default swift visitor behaviour of chaining calls to immediate
// superclasses by default and instead provide our own TBD default (using the exact type).
// Moreover, if the implementation class has translate##CLASS##KIND (that uses generated C++
// classes), for the class of for a parent thereof, we want to use that. We detect that by using the
// type traits HasTranslate##CLASS##KIND defined above
#define DEFINE_VISIT(KIND, CLASS, PARENT) \
public: \
void visit##CLASS##KIND(swift::CLASS##KIND* e) { \
if constexpr (detail::HasTranslate##CLASS##KIND<CrtpSubclass>::value) { \
dispatcher_.emit(static_cast<CrtpSubclass*>(this)->translate##CLASS##KIND(*e)); \
} else if constexpr (detail::HasTranslate##PARENT<CrtpSubclass>::value) { \
dispatcher_.emit(static_cast<CrtpSubclass*>(this)->translate##PARENT(*e)); \
} else { \
dispatcher_.emitUnknown(e); \
} \
}
// base class for our AST visitors, getting a SwiftDispatcher member and define_visit emission for
// unknown/TBD entities. Like `swift::ASTVisitor`, this uses CRTP (the Curiously Recurring Template
// Pattern)
template <typename CrtpSubclass>
class AstVisitorBase : public swift::ASTVisitor<CrtpSubclass>, protected detail::VisitorBase {
public:
using VisitorBase::VisitorBase;
#define DECL(CLASS, PARENT) DEFINE_VISIT(Decl, CLASS, PARENT)
#include "swift/AST/DeclNodes.def"
#define STMT(CLASS, PARENT) DEFINE_VISIT(Stmt, CLASS, PARENT)
#include "swift/AST/StmtNodes.def"
#define EXPR(CLASS, PARENT) DEFINE_VISIT(Expr, CLASS, PARENT)
#include "swift/AST/ExprNodes.def"
#define PATTERN(CLASS, PARENT) DEFINE_VISIT(Pattern, CLASS, PARENT)
#include "swift/AST/PatternNodes.def"
#define TYPEREPR(CLASS, PARENT) DEFINE_VISIT(TypeRepr, CLASS, PARENT)
#include "swift/AST/TypeReprNodes.def"
};
// base class for our type visitor, getting a SwiftDispatcher member and define_visit emission for
// unknown/TBD types. Like `swift::TypeVisitor`, this uses CRTP (the Curiously Recurring Template
// Pattern)
template <typename CrtpSubclass>
class TypeVisitorBase : public swift::TypeVisitor<CrtpSubclass>, protected detail::VisitorBase {
public:
using VisitorBase::VisitorBase;
#define TYPE(CLASS, PARENT) DEFINE_VISIT(Type, CLASS, PARENT)
#include "swift/AST/TypeNodes.def"
};
#undef DEFINE_TRANSLATE_CHECKER
#undef DEFINE_VISIT
} // namespace codeql