diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/Support/Casting.h | 80 | ||||
| -rw-r--r-- | include/llvm/Support/Casting.h | 80 |
2 files changed, 160 insertions, 0 deletions
diff --git a/include/Support/Casting.h b/include/Support/Casting.h new file mode 100644 index 0000000..e59b7c2 --- /dev/null +++ b/include/Support/Casting.h @@ -0,0 +1,80 @@ +//===-- Support/Casting.h - Allow flexible, checked, casts -------*- C++ -*--=// +// +// 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 + +// real_type - Provide a macro to get the real type of a value that might be +// a use. This provides a typedef 'Type' that is the argument type for all +// non UseTy types, and is the contained pointer type of the use if it is a +// UseTy. +// +template <class X> class real_type { typedef X Type; }; + +//===----------------------------------------------------------------------===// +// Type Checking Templates +//===----------------------------------------------------------------------===// + +// 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 <class X, class Y> +inline bool isa(Y Val) { + assert(Val && "isa<Ty>(NULL) invoked!"); + return X::classof(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() +// cast<const Instruction>(myVal)->getParent() +// +template <class X, class Y> +inline X *cast(Y Val) { + assert(isa<X>(Val) && "cast<Ty>() argument of uncompatible type!"); + return (X*)(real_type<Y>::Type)Val; +} + +// cast_or_null<X> - Functionally identical to cast, except that a null value is +// accepted. +// +template <class X, class Y> +inline X *cast_or_null(Y Val) { + assert((Val == 0 || isa<X>(Val)) && + "cast_or_null<Ty>() argument of uncompatible type!"); + return (X*)(real_type<Y>::Type)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<const Instruction>(myVal)) { ... } +// + +template <class X, class Y> +inline X *dyn_cast(Y Val) { + return isa<X>(Val) ? cast<X>(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 X *dyn_cast_or_null(Y Val) { + return (Val && isa<X>(Val)) ? cast<X>(Val) : 0; +} + +#endif diff --git a/include/llvm/Support/Casting.h b/include/llvm/Support/Casting.h new file mode 100644 index 0000000..e59b7c2 --- /dev/null +++ b/include/llvm/Support/Casting.h @@ -0,0 +1,80 @@ +//===-- Support/Casting.h - Allow flexible, checked, casts -------*- C++ -*--=// +// +// 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 + +// real_type - Provide a macro to get the real type of a value that might be +// a use. This provides a typedef 'Type' that is the argument type for all +// non UseTy types, and is the contained pointer type of the use if it is a +// UseTy. +// +template <class X> class real_type { typedef X Type; }; + +//===----------------------------------------------------------------------===// +// Type Checking Templates +//===----------------------------------------------------------------------===// + +// 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 <class X, class Y> +inline bool isa(Y Val) { + assert(Val && "isa<Ty>(NULL) invoked!"); + return X::classof(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() +// cast<const Instruction>(myVal)->getParent() +// +template <class X, class Y> +inline X *cast(Y Val) { + assert(isa<X>(Val) && "cast<Ty>() argument of uncompatible type!"); + return (X*)(real_type<Y>::Type)Val; +} + +// cast_or_null<X> - Functionally identical to cast, except that a null value is +// accepted. +// +template <class X, class Y> +inline X *cast_or_null(Y Val) { + assert((Val == 0 || isa<X>(Val)) && + "cast_or_null<Ty>() argument of uncompatible type!"); + return (X*)(real_type<Y>::Type)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<const Instruction>(myVal)) { ... } +// + +template <class X, class Y> +inline X *dyn_cast(Y Val) { + return isa<X>(Val) ? cast<X>(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 X *dyn_cast_or_null(Y Val) { + return (Val && isa<X>(Val)) ? cast<X>(Val) : 0; +} + +#endif |