Authors: Edwin Steiner
- $Id: typeinfo.h 870 2004-01-10 22:49:32Z edwin $
+ $Id: typeinfo.h 887 2004-01-19 12:14:39Z edwin $
*/
typedef struct typevector typevector;
typedef struct typeinfo_retaddr_set typeinfo_retaddr_set;
-/* global variables ***********************************************************/
-
-/* XXX move this documentation to global.h */
-/* The following classinfo pointers are used internally by the type system.
- * Please do not use them directly, use the TYPEINFO_ macros instead.
- */
+/* data structures for the type system ****************************************/
-/*
- * pseudo_class_Arraystub
- * (extends Object implements Cloneable, java.io.Serializable)
- *
- * If two arrays of incompatible component types are merged,
- * the resulting reference has no accessible components.
- * The result does, however, implement the interfaces Cloneable
- * and java.io.Serializable. This pseudo class is used internally
- * to represent such results. (They are *not* considered arrays!)
- *
- * pseudo_class_Null
+/* The typeinfo structure stores detailed information on address types.
+ * (stack elements, variables, etc. with type == TYPE_ADR.)
*
- * This pseudo class is used internally to represent the
- * null type.
+ * There are two kinds of address types which can are distinguished by
+ * the value of the typeclass field:
*
- * pseudo_class_New
+ * 1) typeclass == NULL: returnAddress type
+ * use TYPEINFO_IS_PRIMITIVE to test for this
*
- * This pseudo class is used internally to represent the
- * the uninitialized object type.
- */
-
-/* data structures for the type system ****************************************/
-
-/* The typeinfo structure stores detailed information on reference types.
- * (stack elements, variables, etc. with type == TYPE_ADR.)
- * XXX: exclude ReturnAddresses?
+ * 2) typeclass != NULL: reference type
+ * use TYPEINFO_IS_REFERENCE to test for this
*
- * XXX
- * For primitive types either there is no typeinfo allocated or the
- * typeclass pointer in the typeinfo struct is NULL.
+ * Note: For non-address types either there is no typeinfo allocated
+ * or the fields of the typeinfo struct contain undefined values!
*
* CAUTION: The typeinfo structure should be considered opaque outside of
* typeinfo.[ch]. Please use the macros and functions defined here to
*
* A) typeclass == NULL
*
- * In this case the other fields of the structure
- * are INVALID. XXX
+ * This is a returnAddress type. The interpretation of the
+ * elementclass field depends on wether this typeinfo describes
+ * a stack slot or a local variable:
+ *
+ * stack slot: elementclass is a pointer to a
+ * typeinfo_retaddr_set which contains a return target for
+ * every vector in the current set of local variable vectors.
+ * local variable: elementclass is the return target (when cast
+ * to basicblock *)
+ *
+ * Use TYPEINFO_IS_PRIMITIVE to check for this.
+ * Use TYPEINFO_RETURNADDRESS to access the pointer in elementclass.
+ * Don't access other fields of the struct.
*
* B) typeclass == pseudo_class_Null
*
- * XXX
+ * This is the null-reference type. Use TYPEINFO_IS_NULLTYPE to check for this.
+ * Don't access other fields of the struct.
*
* C) typeclass == pseudo_class_New
*
- * XXX
+ * This is a 'uninitialized object' type. elementclass can be
+ * cast to instruction* and points to the NEW instruction
+ * responsible for creating this type.
+ *
+ * Use TYPEINFO_NEWOBJECT_INSTRUCTION to access the pointer in
+ * elementclass.
+ * Don't access other fields of the struct.
*
* D) typeclass == pseudo_class_Arraystub
*
- * XXX
+ * See global.h for a describes of pseudo_class_Arraystub.
+ * Otherwise like a normal class reference type.
+ * Don't access other fields of the struct.
*
* E) typeclass is an array class
*
- * XXX
+ * An array reference.
+ * elementclass...typeclass of the element type
+ * dimension......dimension of the array (>=1)
+ * elementtype....element type (ARRAYTYPE_...)
+ * merged.........mergedlist of the element type
*
* F) typeclass is an interface
*
- * XXX
+ * An interface reference type.
+ * Don't access other fields of the struct.
*
- * G) typeclass is a (non-pseudo-)class != java.lang.Object
+ * G) typeclass is a (non-pseudo-,non-array-)class != java.lang.Object
*
- * XXX
+ * A class reference type.
* All classinfos in u.merged.list (if any) are
- * subclasses of typeclass.
+ * subclasses of typeclass (no interfaces or array classes).
+ * Don't access other fields of the struct.
*
* H) typeclass is java.lang.Object
*
- * XXX
+ * The most general kind of reference type.
* In this case u.merged.count and u.merged.list
* are valid and may be non-zero.
- * The classinfos in u.merged.list (if any) can be
- * classes, interfaces or pseudo classes.
+ * The classinfos in u.merged.list (if any) may be
+ * classes, interfaces and pseudo classes.
+ * Don't access other fields of the struct.
*/
/* The following algorithm is used to determine if the type described
*
* 1) If typeclass is X or a subinterface of X the answer is "yes".
* 2) If typeclass is a (pseudo) class implementing X the answer is "yes".
- * 3) XXX If typeclass is not an array and u.merged.count>0
+ * 3) If typeclass is not an array and u.merged.count>0
* and all classes/interfaces in u.merged.list implement X
* the answer is "yes".
* 4) If none of the above is true the answer is "no".
*/
struct typeinfo {
classinfo *typeclass;
- classinfo *elementclass; /* valid if dimension>0 */ /* XXX various uses */
+ classinfo *elementclass; /* valid if dimension>0 */ /* various uses! */
typeinfo_mergedlist *merged;
u1 dimension;
u1 elementtype; /* valid if dimension>0 */
typeinfo_init_from_descriptor(&(info), \
(fi)->descriptor->text,utf_end((fi)->descriptor));
-/* macros for writing types (destination must have been initialized) ********/
-/* XXX delete them? */
-#if 0
-
-#define TYPEINFO_PUT_NULLTYPE(info) \
- do {(info).typeclass = pseudo_class_Null;} while(0)
-
-#define TYPEINFO_PUT_NON_ARRAY_CLASSINFO(info,cinfo) \
- do {(info).typeclass = (cinfo);} while(0)
-
-#define TYPEINFO_PUT_CLASSINFO(info,cls) \
- do {if (((info).typeclass = (cls))->vftbl->arraydesc) { \
- if ((cls)->vftbl->arraydesc->elementvftbl) \
- (info).elementclass = (cls)->vftbl->arraydesc->elementvftbl->class; \
- (info).dimension = (cls)->vftbl->arraydesc->dimension; \
- (info).elementtype = (cls)->vftbl->arraydesc->elementtype; \
- }} while(0)
-
-/* srcarray must be an array (not checked) */
-#define TYPEINFO_PUT_COMPONENT(srcarray,dst) \
- do {typeinfo_put_component(&(srcarray),&(dst));} while(0)
-
-#endif
-
/* macros for copying types (destinition is not checked or freed) ***********/
/* TYPEINFO_COPY makes a shallow copy, the merged pointer is simply copied. */
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