-/****************************** global.h ***************************************
+/* global.h ********************************************************************
Copyright (c) 1997 A. Krall, R. Grafl, M. Gschwind, M. Probst
Contains global definitions which are used in the whole program, includes
some files and contains global used macros.
- Authors: Reinhard Grafl EMAIL: cacao@complang.tuwien.ac.at
- Chages: Andreas Krall EMAIL: cacao@complang.tuwien.ac.at
- Mark Probst EMAIL: cacao@complang.tuwien.ac.at
+ Authors: Reinhard Grafl EMAIL: cacao@complang.tuwien.ac.at
+ Andreas Krall (andi) EMAIL: cacao@complang.tuwien.ac.at
+ Changes: Mark Probst (schani) EMAIL: cacao@complang.tuwien.ac.at
+ Philipp Tomsich (phil) EMAIL: cacao@complang.tuwien.ac.at
- Last Change: 1997/10/28
+ Last Change: $Id: global.h 115 1999-01-20 01:52:45Z phil $
*******************************************************************************/
#ifndef __global_h_
-#define __global_h_ /* schani */
+#define __global_h_
-#define STATISTICS /* andi */
+#define OLD_COMPILER /* if enabled makes old compiler available */
+#define NEW_GC /* if enabled, includes the new gc. -- phil. */
-/***************************** standard includes ******************************/
+#define STATISTICS /* if enabled collects program statistics */
+
+/*
+ * JIT_MARKER_SUPPORT is the define used to toggle Just-in-time generated
+ * marker functions on and off.
+ *
+ * SIZE_FROM_CLASSINFO toggles between the bitmap_based and the new method
+ * of determining the sizes of objects on the heap.
+ */
+#undef JIT_MARKER_SUPPORT /* phil */
+#define SIZE_FROM_CLASSINFO
+
+/* standard includes **********************************************************/
#include <stdio.h>
#include <stdlib.h>
#include "toolbox/list.h"
#include "toolbox/loging.h"
+/* system dependent types *****************************************************/
-/**************************** system dependent types **************************/
-
-#include "sysdep/types.h"
+#include "types.h"
-/**************************** additional data types ***************************/
+/* additional data types ******************************************************/
typedef void *voidptr; /* generic pointer */
-
-typedef u1 bool; /* boolean data type */
+typedef int bool; /* boolean data type */
#define true 1
#define false 0
#define MAX_ALIGN 8 /* most generic alignment for JavaVM values */
-/**************************** shutdown function *******************************/
+/* shutdown function **********************************************************/
void cacao_shutdown(s4 status);
-/**************************** basic data types ********************************/
+/* basic data types ***********************************************************/
#define TYPE_INT 0 /* the JavaVM types must numbered in the */
#define TYPE_LONG 1 /* same order as the ICMD_Ixxx to ICMD_Axxx */
#define TYPE_FLOAT 2 /* instructions (LOAD and STORE) */
#define TYPE_DOUBLE 3 /* integer, long, float, double, address */
-#define TYPE_ADDRESS 4 /* all other types can be numbered arbitrarily*/
+#define TYPE_ADDRESS 4 /* all other types can be numbered arbitrarly */
#define TYPE_VOID 10
-/**************************** Java class file constants ***********************/
+/* Java class file constants **************************************************/
#define MAGIC 0xcafebabe
#define MINOR_VERSION 3
#define MAJOR_VERSION 45
-#define CONSTANT_Class 7
-#define CONSTANT_Fieldref 9
-#define CONSTANT_Methodref 10
-#define CONSTANT_InterfaceMethodref 11
-#define CONSTANT_String 8
-#define CONSTANT_Integer 3
-#define CONSTANT_Float 4
-#define CONSTANT_Long 5
-#define CONSTANT_Double 6
-#define CONSTANT_NameAndType 12
-#define CONSTANT_Utf8 1
-
-#define CONSTANT_Arraydescriptor 13
-#define CONSTANT_UNUSED 0
-
+#define CONSTANT_Class 7
+#define CONSTANT_Fieldref 9
+#define CONSTANT_Methodref 10
+#define CONSTANT_InterfaceMethodref 11
+#define CONSTANT_String 8
+#define CONSTANT_Integer 3
+#define CONSTANT_Float 4
+#define CONSTANT_Long 5
+#define CONSTANT_Double 6
+#define CONSTANT_NameAndType 12
+#define CONSTANT_Utf8 1
+
+#define CONSTANT_Arraydescriptor 13
+#define CONSTANT_UNUSED 0
#define ACC_PUBLIC 0x0001
#define ACC_PRIVATE 0x0002
#define ACC_ABSTRACT 0x0400
-
-/**************************** resolve typedef-cycles **************************/
+/* resolve typedef cycles *****************************************************/
typedef struct unicode unicode;
+typedef struct java_objectheader java_objectheader;
typedef struct classinfo classinfo;
typedef struct vftbl vftbl;
typedef u1* methodptr;
-/********************** data structures of UNICODE symbol *********************/
+/* constant pool entries *******************************************************
-struct unicode {
- unicode *hashlink; /* externe Verkettung f"ur die unicode-Hashtabelle */
- u4 key; /* Hash-Schl"ussel (h"angt nur vom Text ab) */
- int length; /* L"ange des Textes */
- u2 *text; /* Zeiger auf den Text (jeder Buchstabe 16 Bit) */
- classinfo *class; /* gegebenenfalls Referenz auf die Klasse dieses
- Namens (oder NULL, wenn es keine solche gibt) */
- struct java_objectheader *string;
- /* gegebenenfalls Referenz auf einen konstanten
- String mit dem entsprechenden Wert */
-};
+ All constant pool entries need a data structure which contain the entrys
+ value. In some cases this structure exist already, in the remaining cases
+ this structure must be generated:
-/* Alle Unicode-Symbole werden in einer einzigen globalen Tabelle
- (Hashtabelle) verwaltet, jedes Symbol wird nur einmal angelegt.
- -> Speicherersparnis, und "Uberpr"ufung auf Gleichheit durch einfachen
- Zeigervergleich */
+ kind structure generated?
+ ----------------------------------------------------------------------
+ CONSTANT_Class classinfo no
+ CONSTANT_Fieldref constant_FMIref yes
+ CONSTANT_Methodref constant_FMIref yes
+ CONSTANT_InterfaceMethodref constant_FMIref yes
+ CONSTANT_String unicode no
+ CONSTANT_Integer constant_integer yes
+ CONSTANT_Float constant_float yes
+ CONSTANT_Long constant_long yes
+ CONSTANT_Double constant_double yes
+ CONSTANT_NameAndType constant_nameandtype yes
+ CONSTANT_Utf8 unicode no
+ CONSTANT_Arraydescriptor constant_arraydescriptor yes
+ CONSTANT_UNUSED -
+*******************************************************************************/
-/************ data structures of remaining constant pool entries **************/
+/* data structures of Unicode symbol *******************************************
+ All Unicode symbols are stored in one global (hash) table, every symbol
+ exists only once. Equal symbols have identical pointers.
+*/
-typedef struct {
- classinfo *class;
- unicode *name;
- unicode *descriptor;
-} constant_FMIref;
+struct unicode {
+ unicode *hashlink; /* link for external hash chain */
+ u4 key; /* hash key (computed from text) */
+ int length; /* text length */
+ u2 *text; /* pointer to text (each character is 16 Bit) */
+ classinfo *class; /* class pointer if it exists, otherwise NULL */
+ java_objectheader *string; /* string pointer if it exists, otherwise NULL*/
+};
-typedef struct {
- s4 value;
+/* data structures of remaining constant pool entries *************************/
+
+typedef struct { /* Fieldref, Methodref and InterfaceMethodref */
+ classinfo *class; /* class containing this field/method/interface */
+ unicode *name; /* field/method/interface name */
+ unicode *descriptor; /* field/method/interface type descriptor string */
+} constant_FMIref;
+
+typedef struct { /* Integer */
+ s4 value;
} constant_integer;
-typedef struct {
- float value;
+typedef struct { /* Float */
+ float value;
} constant_float;
-typedef struct {
- s8 value;
+typedef struct { /* Long */
+ s8 value;
} constant_long;
-typedef struct {
- double value;
+typedef struct { /* Double */
+ double value;
} constant_double;
-
-typedef struct {
- unicode *name;
- unicode *descriptor;
+typedef struct { /* NameAndType (Field or Method) */
+ unicode *name; /* field/method name */
+ unicode *descriptor; /* field/method type descriptor string */
} constant_nameandtype;
+/* arraydescriptor describes array types. Basic array types contain their
+ type in the arraytype field, objectclass contains a class pointer for
+ arrays of objects (arraytype == ARRAYTYPE_OBJECT), elementdescriptor
+ contains a pointer to an arraydescriptor which describes the element
+ types in the case of arrays of arrays (arraytype == ARRAYTYPE_ARRAY).
+*/
typedef struct constant_arraydescriptor {
- int arraytype;
- classinfo *objectclass;
- struct constant_arraydescriptor *elementdescriptor;
+ int arraytype;
+ classinfo *objectclass;
+ struct constant_arraydescriptor *elementdescriptor;
} constant_arraydescriptor;
-/* Mit einem Arraydescriptor kann ein Array-Typ dargestellt werden.
- Bei normalen Arrays (z.B. Array von Bytes,...) gen"ugt dazu,
- dass das Feld arraytype die entsprechende Kennzahl enth"alt
- (z.B. ARRAYTYPE_BYTE).
- Bei Arrays von Objekten (arraytype=ARRAYTYPE_OBJECT) muss das
- Feld objectclass auf die Klassenstruktur der m"oglichen
- Element-Objekte zeigen.
- Bei Arrays von Arrays (arraytype=ARRAYTYPE_ARRAY) muss das
- Feld elementdescriptor auf eine weiter arraydescriptor-Struktur
- zeigen, die die Element-Typen beschreibt.
- */
-
-
-
-/********* Anmerkungen zum Constant-Pool:
-
- Die Typen der Eintr"age in den Constant-Pool werden durch die oben
- definierten CONSTANT_.. Werte angegeben.
- Bei allen Typen muss zus"atzlich noch eine Datenstruktur hinzugef"ugt
- werden, die den wirklichen Wert angibt.
- Bei manchen Typen reicht es, einen Verweis auf eine schon bereits
- existierende Struktur (z.B. unicode-Texte) einzutragen, bei anderen
- muss diese Struktur erst extra erzeugt werden.
- Ich habe folgende Datenstrukturen f"ur diese Typen verwendet:
-
- Typ Struktur extra erzeugt?
- ----------------------------------------------------------------------
- CONSTANT_Class classinfo nein
- CONSTANT_Fieldref constant_FMIref ja
- CONSTANT_Methodref constant_FMIref ja
- CONSTANT_InterfaceMethodref constant_FMIref ja
- CONSTANT_String unicode nein
- CONSTANT_Integer constant_integer ja
- CONSTANT_Float constant_float ja
- CONSTANT_Long constant_long ja
- CONSTANT_Double constant_double ja
- CONSTANT_NameAndType constant_nameandtype ja
- CONSTANT_Utf8 unicode nein
- CONSTANT_Arraydescriptor constant_arraydescriptor ja
- CONSTANT_UNUSED -
-
-*******************************/
+/* data structures of the runtime system **************************************/
+/* objects *********************************************************************
-/***************** Die Datenstrukturen fuer das Laufzeitsystem ***************/
+ All objects (and arrays) which resides on the heap need the following
+ header at the beginning of the data structure.
+*/
+struct java_objectheader { /* header for all objects */
+ vftbl *vftbl; /* pointer to virtual function table */
+};
- /********* Objekte **********
-
- Alle Objekte (und Arrays), die am Heap gespeichert werden, m"ussen eine
- folgende spezielle Datenstruktur ganz vorne stehen haben:
-
- */
-
-typedef struct java_objectheader { /* Der Header f"ur alle Objekte */
- vftbl *vftbl; /* Zeiger auf die Function Table */
-} java_objectheader;
+/* arrays **********************************************************************
-/********* Arrays ***********
-
- Alle Arrays in Java sind auch gleichzeitig Objekte (d.h. sie haben auch
- den obligatorischen Object-Header und darin einen Verweis auf eine Klasse)
- Es gibt aber (der Einfachheit halber) nur eine einzige Klasse f"ur alle
- m"oglichen Typen von Arrays, deshalb wird der tats"achliche Typ in einem
- Feld im Array-Objekt selbst gespeichert.
- Die Typen sind: */
+ All arrays are objects (they need the object header with a pointer to a
+ vvftbl (array class table). There is only one class for all arrays. The
+ type of an array is stored directly in the array object. Following types
+ are defined:
+*/
#define ARRAYTYPE_INT 0
#define ARRAYTYPE_LONG 1
#define ARRAYTYPE_OBJECT 8
#define ARRAYTYPE_ARRAY 9
-
-/** Der Header f"ur ein Java-Array **/
-
-typedef struct java_arrayheader { /* Der Arrayheader f"ur alle Arrays */
- java_objectheader objheader; /* Der Object-Header */
- s4 size; /* Gr"osse des Arrays */
- s4 arraytype; /* Typ der Elemente */
+typedef struct java_arrayheader { /* header for all arrays */
+ java_objectheader objheader; /* object header */
+ s4 size; /* array size */
+#ifdef SIZE_FROM_CLASSINFO
+ s4 alignedsize; /* phil */
+#endif
+ s4 arraytype; /* array type from previous list */
} java_arrayheader;
-/** Die Unterschiedlichen Strukturen f"ur alle Typen von Arrays **/
+/* structs for all kinds of arrays ********************************************/
typedef struct java_chararray {
- java_arrayheader header;
- u2 data[1];
+ java_arrayheader header;
+ u2 data[1];
} java_chararray;
typedef struct java_floatheader {
- java_arrayheader header;
- float data[1];
+ java_arrayheader header;
+ float data[1];
} java_floatarray;
typedef struct java_doublearray {
- java_arrayheader header;
- double data[1];
+ java_arrayheader header;
+ double data[1];
} java_doublearray;
-
-/* achtung: die beiden Stukturen booleanarray und bytearray m"ussen
- identisches memory-layout haben, weil mit den selben Funktionen
- darauf zugegriffen wird */
+/* booleanarray and bytearray need identical memory layout (access methods
+ use the same machine code */
typedef struct java_booleanarray {
- java_arrayheader header;
- u1 data[1];
+ java_arrayheader header;
+ u1 data[1];
} java_booleanarray;
typedef struct java_bytearray {
- java_arrayheader header;
- s1 data[1];
+ java_arrayheader header;
+ s1 data[1];
} java_bytearray;
typedef struct java_shortarray {
- java_arrayheader header;
- s2 data[1];
+ java_arrayheader header;
+ s2 data[1];
} java_shortarray;
typedef struct java_intarray {
- java_arrayheader header;
- s4 data[1];
+ java_arrayheader header;
+ s4 data[1];
} java_intarray;
typedef struct java_longarray {
- java_arrayheader header;
- s8 data[1];
+ java_arrayheader header;
+ s8 data[1];
} java_longarray;
-
-/* ACHTUNG: die beiden folgenden Strukturen m"ussen unbedingt gleiches
- Memory-Layout haben, weil mit ein und der selben Funktion auf die
- data-Eintr"age beider Typen zugegriffen wird !!!! */
+/* objectarray and arrayarray need identical memory layout (access methods
+ use the same machine code */
typedef struct java_objectarray {
- java_arrayheader header;
- classinfo *elementtype;
- java_objectheader *data[1];
+ java_arrayheader header;
+ classinfo *elementtype;
+ java_objectheader *data[1];
} java_objectarray;
typedef struct java_arrayarray {
- java_arrayheader header;
- constant_arraydescriptor *elementdescriptor;
- java_arrayheader *data[1];
+ java_arrayheader header;
+ constant_arraydescriptor *elementdescriptor;
+ java_arrayheader *data[1];
} java_arrayarray;
+/* field, method and class structures *****************************************/
+/* fieldinfo ******************************************************************/
-/************** Strukturen f"ur Klassen, Felder & Methoden *****************/
-
+typedef struct fieldinfo {/* field of a class */
+ s4 flags; /* ACC flags */
+ s4 type; /* basic data type */
+ unicode *name; /* name of field */
+ unicode *descriptor; /* JavaVM descriptor string of field */
+
+ s4 offset; /* offset from start of object (instance variables) */
- /*** Struktur: fieldinfo ***/
+ union { /* storage for static values (class variables) */
+ s4 i;
+ s8 l;
+ float f;
+ double d;
+ void *a;
+ } value;
-typedef struct fieldinfo { /* Struktur f"ur ein Feld einer Klasse */
- s4 flags; /* die ACC-Flags */
- s4 type; /* Grunddatentyp */
- unicode *name; /* Name des Felds */
- unicode *descriptor; /* Typedescriptor in JavaVM-Form */
-
- s4 offset; /* Offset vom Anfang des Objektes */
- /* (bei Instanzvariablen) */
-
- union { /* Speicher f"ur den Wert */
- s4 i; /* (bei Klassenvariablen) */
- s8 l;
- float f;
- double d;
- void *a;
- } value;
-
} fieldinfo;
-/*** Struktur: exceptiontable ***/
+/* exceptiontable *************************************************************/
-typedef struct exceptiontable { /* Exceptionhandler-Eintrag in einer Methode */
- s4 startpc; /* Anfang des G"ultigkeitsbereichs */
- s4 endpc; /* Ende des Bereichs (exklusive) */
- s4 handlerpc; /* JavaVM-Position des Handlers */
- classinfo *catchtype; /* Typ der behandelten Exceptions (oder
- NULL, wenn alle behandelt werden sollen) */
+typedef struct exceptiontable { /* exceptiontable entry in a method */
+ s4 startpc; /* start pc of guarded area (inclusive) */
+ s4 endpc; /* end pc of guarded area (exklusive) */
+ s4 handlerpc; /* pc of exception handler */
+ classinfo *catchtype; /* catchtype of exception (NULL == catchall) */
} exceptiontable;
+/* methodinfo *****************************************************************/
-/*** Struktur: methodinfo ***/
-
-typedef struct methodinfo { /* Struktur f"ur eine Methode einer Klasse */
- s4 flags; /* die ACC-Flags */
- unicode *name; /* Name der Methode */
- unicode *descriptor; /* der JavaVM-Descriptorstring f"ur Methoden */
- s4 returntype; /* only temporary valid, return type */
- s4 paramcount; /* only temporary valid, number of parameters */
- u1 *paramtypes; /* only temporary valid, parameter types */
- classinfo *class; /* Die Klasse, der die Methode geh"ort */
- u4 vftblindex; /* Index dieser Methode f"ur die Virtual
- Function Table (wenn es keine statische
- Methode ist) */
+typedef struct methodinfo { /* method structure */
+ s4 flags; /* ACC flags */
+ unicode *name; /* name of method */
+ unicode *descriptor; /* JavaVM descriptor string of method */
+ s4 returntype; /* only temporary valid, return type */
+ s4 paramcount; /* only temporary valid, parameter count */
+ u1 *paramtypes; /* only temporary valid, parameter types */
+ classinfo *class; /* class, the method belongs to */
+ s4 vftblindex; /* index of method in virtual function table
+ (if it is a virtual method) */
+ s4 maxstack; /* maximum stack depth of method */
+ s4 maxlocals; /* maximum number of local variables */
+ s4 jcodelength; /* length of JavaVM code */
+ u1 *jcode; /* pointer to JavaVM code */
- s4 maxstack; /* maximale Stacktiefe des JavaVM-Codes */
- s4 maxlocals; /* maximale Anzahl der JavaVM-Variablen */
- u4 jcodelength; /* L"ange des JavaVM-Codes */
- u1 *jcode; /* und Zeiger auf den JavaVM-Code */
+ s4 exceptiontablelength;/* exceptiontable length */
+ exceptiontable *exceptiontable; /* the exceptiontable */
- s4 exceptiontablelength; /* L"ange der Exceptintable */
- exceptiontable *exceptiontable; /* Die Exceptiontable selber */
+ u1 *stubroutine; /* stub for compiling or calling natives */
+ s4 mcodelength; /* legth of generated machine code */
+ u1 *mcode; /* pointer to machine code */
+ u1 *entrypoint; /* entry point in machine code */
- u1 *stubroutine; /* STUB-Routine for compiling or calling
- natives */
- u4 mcodelength; /* L"ange des generierten Maschinencodes */
- u1 *mcode; /* Zeiger auf den Maschinencode */
- u1 *entrypoint; /* Entrypoint to the Maschine-Code */
} methodinfo;
-/*** Struktur: classinfo ***/
+/* classinfo ******************************************************************/
-struct classinfo { /* Datenstruktur f"ur eine Klasse */
- java_objectheader header; /* Weil auch Klassen als Objekte angesprochen
- werden */
+struct classinfo { /* class structure */
+ java_objectheader header; /* classes are also objects */
- s4 flags; /* Die ACC-Flags */
- unicode *name; /* Name der Klasse */
-
- s4 cpcount; /* Anzahl der Eintr"age im Constant-Pool */
- u1 *cptags; /* Die TAGs f"ur den Constant-Pool */
- voidptr *cpinfos; /* Die Zeiger auf die Info-Strukturen */
-
- classinfo *super; /* Zeiger auf die "ubergeordnete Klasse */
-
- s4 interfacescount; /* Anzahl der Interfaces */
- classinfo **interfaces; /* Zeiger auf die Interfaces */
-
- s4 fieldscount; /* Anzahl der Felder */
- fieldinfo *fields; /* Die Tabelle der Felder */
-
- s4 methodscount; /* Anzahl der Methoden */
- methodinfo *methods; /* Die Tabelle der Methoden */
-
-
- listnode listnode; /* Verkettungsstruktur (f"ur Listen) */
+ s4 flags; /* ACC flags */
+ unicode *name; /* class name */
+
+ s4 cpcount; /* number of entries in constant pool */
+ u1 *cptags; /* constant pool tags */
+ voidptr *cpinfos; /* pointer to constant pool info structures */
+
+ classinfo *super; /* super class pointer */
+ classinfo *sub; /* sub class pointer */
+ classinfo *nextsub; /* pointer to next class in sub class list */
+
+ s4 interfacescount; /* number of interfaces */
+ classinfo **interfaces; /* pointer to interfaces */
- bool initialized; /* true, wenn Klasse bereits Initialisiert */
- bool linked; /* wird von `class_link` auf true gesetzt */
- s4 index; /* Hierarchietiefe (bei normalen Klassen)
- oder fortlaufende Nummer (bei Interfaces)*/
- u4 instancesize; /* Gr"osse eines Objektes dieser Klasse */
+ s4 fieldscount; /* number of fields */
+ fieldinfo *fields; /* field table */
- vftbl *vftbl;
+ s4 methodscount; /* number of methods */
+ methodinfo *methods; /* method table */
- methodinfo* finalizer; /* Finalizer-Methode f"ur die Klasse */
+ listnode listnode; /* linkage */
+
+ bool initialized; /* true, if class already initialised */
+ bool linked; /* true, if class already linked */
+ s4 index; /* hierarchy depth (classes) or index
+ (interfaces) */
+ s4 instancesize; /* size of an instance of this class */
+#ifdef SIZE_FROM_CLASSINFO
+ s4 alignedsize; /* size of an instance, aligned to the
+ allocation size on the heap */
+#endif
+
+ vftbl *vftbl; /* pointer to virtual function table */
+
+ methodinfo *finalizer; /* finalizer method */
#ifdef JIT_MARKER_SUPPORT
- methodinfo* marker;
+ methodinfo *marker;
#endif
};
+
+
+/* virtual function table ******************************************************
+
+ The vtbl has a bidirectional layout with open ends at both sides.
+ interfacetablelength gives the number of entries of the interface table at
+ the start of the vftbl. The vftbl pointer points to &interfacetable[0].
+ vftbllength gives the number of entries of table at the end of the vftbl.
+
+ runtime type check (checkcast):
+
+ Different methods are used for runtime type check depending on the
+ argument of checkcast/instanceof.
+ A check against a class is implemented via relative numbering on the class
+ hierachy tree. The tree is numbered in a depth first traversal setting
+ the base field and the diff field. The diff field gets the result of
+ (high - base) so that a range check can be implemented by an unsigned
+ compare. A sub type test is done by checking the inclusion of base of
+ the sub class in the range of the superclass.
+
+ A check against an interface is implemented via the interfacevftbl. If the
+ interfacevftbl contains a nonnull value a class is a subclass of this
+ interface.
+
+ interfacetable:
+
+ Like standard virtual methods interface methods are called using
+ virtual function tables. All interfaces are numbered sequentially
+ (starting with zero). For each class there exist an interface table
+ of virtual function tables for each implemented interface. The length
+ of the interface table is determined by the highest number of an
+ implemented interface.
+
+ The following example assumes a class which implements interface 0 and 3:
+
+ interfacetablelength = 4
+
+ | ... | +----------+
+ +-----------+ | method 2 |---> method z
+ | class | | method 1 |---> method y
+ +-----------+ | method 0 |---> method x
+ | ivftbl 0 |----------> +----------+
+ vftblptr ---> +-----------+
+ | ivftbl -1 |--> NULL +----------+
+ | ivftbl -2 |--> NULL | method 1 |---> method x
+ | ivftbl -3 |-----+ | method 0 |---> method a
+ +-----------+ +----> +----------+
+
+ +---------------+
+ | length 3 = 2 |
+ | length 2 = 0 |
+ | length 1 = 0 |
+ | length 0 = 3 |
+ interfacevftbllength ---> +---------------+
+
+*******************************************************************************/
struct vftbl {
- classinfo *class; /* Class, the function table belongs to */
+ methodptr *interfacetable[1]; /* interface table (access via macro) */
+
+ classinfo *class; /* class, the vtbl belongs to */
- s4 vftbllength; /* L"aenge der Virtual Function Table */
+ s4 vftbllength; /* virtual function table length */
+ s4 interfacetablelength; /* interface table length */
- s4 interfacetablelength; /* L"ange der Interfacetable */
- u4 *interfacevftbllength; /* -> siehe unten */
- methodptr **interfacevftbl;
+ s4 baseval; /* base for runtime type check */
+ s4 diffval; /* high - base for runtime type check */
+
+ s4 *interfacevftbllength; /* length of interface vftbls */
- methodptr table[1];
+ methodptr table[1]; /* class vftbl */
};
-/*********** Anmerkungen zur Interfacetable:
-
- "Ahnlich wie die 'normalen' virtuellen Methoden k"onnen auch die
- Interface-Methoden mit Hilfe einer Art Virtual Function Table
- aufgerufen werden.
- Dazu werden alle Interfaces im System fortlaufend nummeriert (beginnend
- bei 0), und f"ur jede Klasse wird eine ganze Tabelle von
- Virtual Function Tables erzeugt, n"amlich zu jedem Interface, das die
- Klasse implementiert, eine.
-
- z.B. Nehmen wir an, eine Klasse implementiert zwei Interfaces (die durch
- die Nummerierung die Indizes 0 und 3 bekommen haben)
-
- Das sieht dann ungef"ahr so aus:
- -------------- -------------
- interfacevftbl ---> | Eintrag 0 |---------> | Methode 0 |---> Methode X
- | Eintrag 1 |--> NULL | Methode 1 |---> Methode Y
- | Eintrag 2 |--> NULL | Methode 2 |---> Methode Z
- | Eintrag 3 |-----+ -------------
- -------------- |
- +---> -------------
- | Methode 0 |---> Methode X
- | Methode 1 |---> Methode A
- -------------
- ---------------
- interfacevftlblength ---> | Wert 0 = 3 |
- | Wert 1 = 0 |
- | Wert 2 = 0 |
- | Wert 3 = 2 |
- ---------------
-
- Der Aufruf einer Interface-Methode geht dann so vor sich:
- Zur Compilezeit steht der Index (i) des Interfaces und die Stelle (s), wo
- in der entsprechenden Untertabelle die Methode eingetragen ist, schon fest.
- Also muss zur Laufzeit nur mehr der n-te Eintrag aus der Interfacetable
- gelesen werden, von dieser Tabelle aus wird der s-te Eintrag geholt,
- und diese Methode wird angesprungen.
-
-****************/
-
-
-
-/************************* Referenzen auf die wichtigen Systemklassen ********************/
+#define VFTBLINTERFACETABLE(v,i) (v)->interfacetable[-i]
+
+
+/* references to some system classes ******************************************/
extern classinfo *class_java_lang_Object;
extern classinfo *class_java_lang_String;
extern classinfo *class_java_lang_OutOfMemoryError;
extern classinfo *class_java_lang_ArithmeticException;
extern classinfo *class_java_lang_ArrayStoreException;
-extern classinfo *class_java_lang_ThreadDeath; /* schani */
+extern classinfo *class_java_lang_ThreadDeath;
extern classinfo *class_array;
-/********************** Vorgefertigte Instanzen einiger Systemklassen ********************/
+/* instances of some system classes *******************************************/
extern java_objectheader *proto_java_lang_ClassCastException;
extern java_objectheader *proto_java_lang_NullPointerException;
extern java_objectheader *proto_java_lang_OutOfMemoryError;
extern java_objectheader *proto_java_lang_ArithmeticException;
extern java_objectheader *proto_java_lang_ArrayStoreException;
-extern java_objectheader *proto_java_lang_ThreadDeath; /* schani */
+extern java_objectheader *proto_java_lang_ThreadDeath;
-/********************** flag variables *********************/
+/* flag variables *************************************************************/
extern bool compileall;
extern bool runverbose;
extern bool verbose;
-
-/********************** trace variables ********************/
+
+/* statistic variables ********************************************************/
extern int count_class_infos;
extern int count_const_pool_len;
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