mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-11-25 04:02:41 +01:00
302 lines
9.3 KiB
C++
302 lines
9.3 KiB
C++
//===-- Support/Casting.h - Allow flexible, checked, casts ------*- C++ -*-===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file was developed by the LLVM research group and is distributed under
|
|
// the University of Illinois Open Source License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file defines the isa<X>(), cast<X>(), dyn_cast<X>(), cast_or_null<X>(),
|
|
// and dyn_cast_or_null<X>() templates.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef SUPPORT_CASTING_H
|
|
#define SUPPORT_CASTING_H
|
|
|
|
namespace llvm {
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// isa<x> Support Templates
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
template<typename FromCl> struct isa_impl_cl;
|
|
|
|
// Define a template that can be specialized by smart pointers to reflect the
|
|
// fact that they are automatically dereferenced, and are not involved with the
|
|
// template selection process... the default implementation is a noop.
|
|
//
|
|
template<typename From> struct simplify_type {
|
|
typedef From SimpleType; // The real type this represents...
|
|
|
|
// An accessor to get the real value...
|
|
static SimpleType &getSimplifiedValue(From &Val) { return Val; }
|
|
};
|
|
|
|
template<typename From> struct simplify_type<const From> {
|
|
typedef const From SimpleType;
|
|
static SimpleType &getSimplifiedValue(const From &Val) {
|
|
return simplify_type<From>::getSimplifiedValue(static_cast<From&>(Val));
|
|
}
|
|
};
|
|
|
|
|
|
// isa<X> - Return true if the parameter to the template is an instance of the
|
|
// template type argument. Used like this:
|
|
//
|
|
// if (isa<Type*>(myVal)) { ... }
|
|
//
|
|
template <typename To, typename From>
|
|
inline bool isa_impl(const From &Val) {
|
|
return To::classof(&Val);
|
|
}
|
|
|
|
template<typename To, typename From, typename SimpleType>
|
|
struct isa_impl_wrap {
|
|
// When From != SimplifiedType, we can simplify the type some more by using
|
|
// the simplify_type template.
|
|
static bool doit(const From &Val) {
|
|
return isa_impl_cl<const SimpleType>::template
|
|
isa<To>(simplify_type<const From>::getSimplifiedValue(Val));
|
|
}
|
|
};
|
|
|
|
template<typename To, typename FromTy>
|
|
struct isa_impl_wrap<To, const FromTy, const FromTy> {
|
|
// When From == SimpleType, we are as simple as we are going to get.
|
|
static bool doit(const FromTy &Val) {
|
|
return isa_impl<To,FromTy>(Val);
|
|
}
|
|
};
|
|
|
|
// isa_impl_cl - Use class partial specialization to transform types to a single
|
|
// canonical form for isa_impl.
|
|
//
|
|
template<typename FromCl>
|
|
struct isa_impl_cl {
|
|
template<class ToCl>
|
|
static bool isa(const FromCl &Val) {
|
|
return isa_impl_wrap<ToCl,const FromCl,
|
|
typename simplify_type<const FromCl>::SimpleType>::doit(Val);
|
|
}
|
|
};
|
|
|
|
// Specialization used to strip const qualifiers off of the FromCl type...
|
|
template<typename FromCl>
|
|
struct isa_impl_cl<const FromCl> {
|
|
template<class ToCl>
|
|
static bool isa(const FromCl &Val) {
|
|
return isa_impl_cl<FromCl>::template isa<ToCl>(Val);
|
|
}
|
|
};
|
|
|
|
// Define pointer traits in terms of base traits...
|
|
template<class FromCl>
|
|
struct isa_impl_cl<FromCl*> {
|
|
template<class ToCl>
|
|
static bool isa(FromCl *Val) {
|
|
return isa_impl_cl<FromCl>::template isa<ToCl>(*Val);
|
|
}
|
|
};
|
|
|
|
// Define reference traits in terms of base traits...
|
|
template<class FromCl>
|
|
struct isa_impl_cl<FromCl&> {
|
|
template<class ToCl>
|
|
static bool isa(FromCl &Val) {
|
|
return isa_impl_cl<FromCl>::template isa<ToCl>(&Val);
|
|
}
|
|
};
|
|
|
|
template <class X, class Y>
|
|
inline bool isa(const Y &Val) {
|
|
return isa_impl_cl<Y>::template isa<X>(Val);
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// cast<x> Support Templates
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
template<class To, class From> struct cast_retty;
|
|
|
|
|
|
// Calculate what type the 'cast' function should return, based on a requested
|
|
// type of To and a source type of From.
|
|
template<class To, class From> struct cast_retty_impl {
|
|
typedef To& ret_type; // Normal case, return Ty&
|
|
};
|
|
template<class To, class From> struct cast_retty_impl<To, const From> {
|
|
typedef const To &ret_type; // Normal case, return Ty&
|
|
};
|
|
|
|
template<class To, class From> struct cast_retty_impl<To, From*> {
|
|
typedef To* ret_type; // Pointer arg case, return Ty*
|
|
};
|
|
|
|
template<class To, class From> struct cast_retty_impl<To, const From*> {
|
|
typedef const To* ret_type; // Constant pointer arg case, return const Ty*
|
|
};
|
|
|
|
template<class To, class From> struct cast_retty_impl<To, const From*const> {
|
|
typedef const To* ret_type; // Constant pointer arg case, return const Ty*
|
|
};
|
|
|
|
|
|
template<class To, class From, class SimpleFrom>
|
|
struct cast_retty_wrap {
|
|
// When the simplified type and the from type are not the same, use the type
|
|
// simplifier to reduce the type, then reuse cast_retty_impl to get the
|
|
// resultant type.
|
|
typedef typename cast_retty<To, SimpleFrom>::ret_type ret_type;
|
|
};
|
|
|
|
template<class To, class FromTy>
|
|
struct cast_retty_wrap<To, FromTy, FromTy> {
|
|
// When the simplified type is equal to the from type, use it directly.
|
|
typedef typename cast_retty_impl<To,FromTy>::ret_type ret_type;
|
|
};
|
|
|
|
template<class To, class From>
|
|
struct cast_retty {
|
|
typedef typename cast_retty_wrap<To, From,
|
|
typename simplify_type<From>::SimpleType>::ret_type ret_type;
|
|
};
|
|
|
|
// Ensure the non-simple values are converted using the simplify_type template
|
|
// that may be specialized by smart pointers...
|
|
//
|
|
template<class To, class From, class SimpleFrom> struct cast_convert_val {
|
|
// This is not a simple type, use the template to simplify it...
|
|
static typename cast_retty<To, From>::ret_type doit(const From &Val) {
|
|
return cast_convert_val<To, SimpleFrom,
|
|
typename simplify_type<SimpleFrom>::SimpleType>::doit(
|
|
simplify_type<From>::getSimplifiedValue(Val));
|
|
}
|
|
};
|
|
|
|
template<class To, class FromTy> struct cast_convert_val<To,FromTy,FromTy> {
|
|
// This _is_ a simple type, just cast it.
|
|
static typename cast_retty<To, FromTy>::ret_type doit(const FromTy &Val) {
|
|
return reinterpret_cast<typename cast_retty<To, FromTy>::ret_type>(
|
|
const_cast<FromTy&>(Val));
|
|
}
|
|
};
|
|
|
|
|
|
|
|
// cast<X> - Return the argument parameter cast to the specified type. This
|
|
// casting operator asserts that the type is correct, so it does not return null
|
|
// on failure. But it will correctly return NULL when the input is NULL.
|
|
// Used Like this:
|
|
//
|
|
// cast<Instruction>(myVal)->getParent()
|
|
//
|
|
template <class X, class Y>
|
|
inline typename cast_retty<X, Y>::ret_type cast(const Y &Val) {
|
|
assert(isa<X>(Val) && "cast<Ty>() argument of incompatible type!");
|
|
return cast_convert_val<X, Y,
|
|
typename simplify_type<Y>::SimpleType>::doit(Val);
|
|
}
|
|
|
|
// cast_or_null<X> - Functionally identical to cast, except that a null value is
|
|
// accepted.
|
|
//
|
|
template <class X, class Y>
|
|
inline typename cast_retty<X, Y*>::ret_type cast_or_null(Y *Val) {
|
|
if (Val == 0) return 0;
|
|
assert(isa<X>(Val) && "cast_or_null<Ty>() argument of incompatible type!");
|
|
return cast<X>(Val);
|
|
}
|
|
|
|
|
|
// dyn_cast<X> - Return the argument parameter cast to the specified type. This
|
|
// casting operator returns null if the argument is of the wrong type, so it can
|
|
// be used to test for a type as well as cast if successful. This should be
|
|
// used in the context of an if statement like this:
|
|
//
|
|
// if (const Instruction *I = dyn_cast<Instruction>(myVal)) { ... }
|
|
//
|
|
|
|
template <class X, class Y>
|
|
inline typename cast_retty<X, Y>::ret_type dyn_cast(Y Val) {
|
|
return isa<X>(Val) ? cast<X, Y>(Val) : 0;
|
|
}
|
|
|
|
// dyn_cast_or_null<X> - Functionally identical to dyn_cast, except that a null
|
|
// value is accepted.
|
|
//
|
|
template <class X, class Y>
|
|
inline typename cast_retty<X, Y>::ret_type dyn_cast_or_null(Y Val) {
|
|
return (Val && isa<X>(Val)) ? cast<X, Y>(Val) : 0;
|
|
}
|
|
|
|
|
|
#ifdef DEBUG_CAST_OPERATORS
|
|
#include <iostream>
|
|
|
|
struct bar {
|
|
bar() {}
|
|
private:
|
|
bar(const bar &);
|
|
};
|
|
struct foo {
|
|
void ext() const;
|
|
/* static bool classof(const bar *X) {
|
|
cerr << "Classof: " << X << "\n";
|
|
return true;
|
|
}*/
|
|
};
|
|
|
|
template <> inline bool isa_impl<foo,bar>(const bar &Val) {
|
|
cerr << "Classof: " << &Val << "\n";
|
|
return true;
|
|
}
|
|
|
|
|
|
bar *fub();
|
|
void test(bar &B1, const bar *B2) {
|
|
// test various configurations of const
|
|
const bar &B3 = B1;
|
|
const bar *const B4 = B2;
|
|
|
|
// test isa
|
|
if (!isa<foo>(B1)) return;
|
|
if (!isa<foo>(B2)) return;
|
|
if (!isa<foo>(B3)) return;
|
|
if (!isa<foo>(B4)) return;
|
|
|
|
// test cast
|
|
foo &F1 = cast<foo>(B1);
|
|
const foo *F3 = cast<foo>(B2);
|
|
const foo *F4 = cast<foo>(B2);
|
|
const foo &F8 = cast<foo>(B3);
|
|
const foo *F9 = cast<foo>(B4);
|
|
foo *F10 = cast<foo>(fub());
|
|
|
|
// test cast_or_null
|
|
const foo *F11 = cast_or_null<foo>(B2);
|
|
const foo *F12 = cast_or_null<foo>(B2);
|
|
const foo *F13 = cast_or_null<foo>(B4);
|
|
const foo *F14 = cast_or_null<foo>(fub()); // Shouldn't print.
|
|
|
|
// These lines are errors...
|
|
//foo *F20 = cast<foo>(B2); // Yields const foo*
|
|
//foo &F21 = cast<foo>(B3); // Yields const foo&
|
|
//foo *F22 = cast<foo>(B4); // Yields const foo*
|
|
//foo &F23 = cast_or_null<foo>(B1);
|
|
//const foo &F24 = cast_or_null<foo>(B3);
|
|
}
|
|
|
|
bar *fub() { return 0; }
|
|
void main() {
|
|
bar B;
|
|
test(B, &B);
|
|
}
|
|
|
|
#endif
|
|
|
|
} // End llvm namespace
|
|
|
|
#endif
|