src/JavaLookup.st
branchjk_new_structure
changeset 1356 0dd28400803e
child 1365 cd6fe7944943
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/JavaLookup.st	Sat Feb 11 19:24:18 2012 +0000
@@ -0,0 +1,673 @@
+"
+ Copyright (c) 2010-2011 Jan Vrany, Jan Kurs & Marcel Hlopko,
+                         SWING Research Group, Czech Technical University 
+                         in Prague
+
+ Permission is hereby granted, free of charge, to any person
+ obtaining a copy of this software and associated documentation
+ files (the 'Software'), to deal in the Software without
+ restriction, including without limitation the rights to use,
+ copy, modify, merge, publish, distribute, sublicense, and/or sell
+ copies of the Software, and to permit persons to whom the
+ Software is furnished to do so, subject to the following
+ conditions:
+
+ The above copyright notice and this permission notice shall be
+ included in all copies or substantial portions of the Software.
+
+ THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
+ EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ OTHER DEALINGS IN THE SOFTWARE.
+"
+"{ Package: 'stx:libjava' }"
+
+Lookup subclass:#JavaLookup
+	instanceVariableNames:'s2j j2s'
+	classVariableNames:'Instance'
+	poolDictionaries:''
+	category:'Languages-Java-Interop'
+!
+
+Lookup subclass:#Java2Smalltalk
+	instanceVariableNames:''
+	classVariableNames:''
+	poolDictionaries:''
+	privateIn:JavaLookup
+!
+
+Lookup subclass:#Smalltalk2Java
+	instanceVariableNames:''
+	classVariableNames:''
+	poolDictionaries:''
+	privateIn:JavaLookup
+!
+
+!JavaLookup class methodsFor:'documentation'!
+
+copyright
+"
+ Copyright (c) 2010-2011 Jan Vrany, Jan Kurs & Marcel Hlopko,
+                         SWING Research Group, Czech Technical University 
+                         in Prague
+
+ Permission is hereby granted, free of charge, to any person
+ obtaining a copy of this software and associated documentation
+ files (the 'Software'), to deal in the Software without
+ restriction, including without limitation the rights to use,
+ copy, modify, merge, publish, distribute, sublicense, and/or sell
+ copies of the Software, and to permit persons to whom the
+ Software is furnished to do so, subject to the following
+ conditions:
+
+ The above copyright notice and this permission notice shall be
+ included in all copies or substantial portions of the Software.
+
+ THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
+ EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ OTHER DEALINGS IN THE SOFTWARE.
+
+"
+! !
+
+!JavaLookup class methodsFor:'instance creation'!
+
+cleanup
+
+    Instance := nil.
+
+    "Modified: / 25-02-2011 / 14:45:03 / kursjan <kursjan@fit.cvut.cz>"
+    "Created: / 19-09-2011 / 23:25:08 / Jan Kurs <kursjan@fit.cvut.cz>"
+    "Modified: / 15-12-2011 / 23:05:37 / Jan Vrany <jan.vrany@fit.cvut.cz>"
+!
+
+instance
+
+    Instance isNil ifTrue:[
+        Instance := self basicNew initialize
+    ].
+    ^Instance
+
+    "Modified: / 25-02-2011 / 14:45:03 / kursjan <kursjan@fit.cvut.cz>"
+    "Created: / 19-09-2011 / 23:20:49 / Jan Kurs <kursjan@fit.cvut.cz>"
+    "Modified: / 15-12-2011 / 23:05:29 / Jan Vrany <jan.vrany@fit.cvut.cz>"
+!
+
+new
+    ^ self shouldNeverBeSent.
+
+    "Created: / 25-02-2011 / 14:44:43 / kursjan <kursjan@fit.cvut.cz>"
+    "Modified: / 29-08-2011 / 21:10:12 / Jan Kurs <kursjan@fit.cvut.cz>"
+! !
+
+!JavaLookup methodsFor:'initialization'!
+
+initialize
+    "Invoked when a new instance is created."
+
+    s2j := Smalltalk2Java new.
+    j2s := Java2Smalltalk new.
+
+    "Modified: / 15-12-2011 / 23:06:57 / Jan Vrany <jan.vrany@fit.cvut.cz>"
+! !
+
+!JavaLookup methodsFor:'lookup'!
+
+lookupMethodForSelector:selector directedTo:initialSearchClass for:aReceiver withArguments:argArrayOrNil from:sendingContext ilc: ilcCache
+
+    "Invoked by the VM to ask me for a method to call.
+     The arguments are: the selector, receiver and arguments,
+     the class to start the search in (for here-, super and directed sends)
+     the sending context and the inline/poly cache (instance of
+     PolymorphicInlineCache). "
+
+    | m |
+    m := super lookupMethodForSelector:selector directedTo:initialSearchClass for:aReceiver withArguments:argArrayOrNil from:sendingContext ilc: ilcCache.
+    m notNil ifTrue: [ ^ m ].
+
+    sendingContext programmingLanguage isSmalltalk ifTrue:[
+        aReceiver class theNonMetaclass programmingLanguage isJava ifTrue:[
+            ^s2j lookupMethodForSelector:selector directedTo:initialSearchClass for:aReceiver withArguments:argArrayOrNil from:sendingContext ilc: ilcCache.
+        ]
+    ].
+
+    sendingContext programmingLanguage isJava ifTrue:[
+        aReceiver class programmingLanguage isSmalltalk ifTrue:[
+            ^j2s lookupMethodForSelector:selector directedTo:initialSearchClass for:aReceiver withArguments:argArrayOrNil from:sendingContext ilc: ilcCache.
+        ]
+    ].
+
+    ^nil
+
+    "Created: / 01-10-2011 / 13:18:40 / Jan Kurs <kursjan@fit.cvut.cz>"
+    "Created: / 15-12-2011 / 23:11:45 / Jan Vrany <jan.vrany@fit.cvut.cz>"
+! !
+
+!JavaLookup::Java2Smalltalk methodsFor:'lookup'!
+
+lookupMethodForSelector:selector directedTo:initialSearchClass for:receiver withArguments:argArrayOrNil from:sendingContext ilc: ilc
+
+    | d m |
+
+    d := JavaDescriptor readFrom: (selector readStream skipThrough: $(; backStep; yourself).
+    m := self lookupMethodForSelector: selector directedTo: initialSearchClass numArguments: d numArgs.
+    m notNil ifTrue: [
+        m := self compileProxyWithSelector: selector descriptor: d in: receiver class calling: m.
+        ilc notNil ifTrue:[ilc bindTo: m forClass: receiver class].
+        ^m.
+    ] ifFalse:[
+        ^ nil
+    ]
+
+    "Created: / 06-09-2011 / 22:04:04 / Jan Kurs <kursjan@fit.cvut.cz>"
+    "Modified: / 09-10-2011 / 22:59:18 / kursjan <kursjan@fit.cvut.cz>"
+    "Created: / 19-11-2011 / 12:37:26 / Jan Vrany <jan.vrany@fit.cvut.cz>"
+!
+
+lookupMethodForSelector:jselector directedTo:initialSearchClass numArguments: nArgs
+
+    | name cls |
+
+    name := jselector upTo: $(.
+
+    "Pass 1: Search for explicitly annotated method"
+    cls := initialSearchClass.
+    [ cls notNil ] whileTrue:[
+        cls methodDictionary keysAndValuesDo:[:sel :mthd|
+            | jdescriptor |
+
+            mthd numArgs == nArgs ifTrue:[
+                (jdescriptor := mthd annotationAt: #javaselector:) notNil ifTrue:[
+                    jdescriptor arguments first == jselector ifTrue: [
+                        ^mthd    
+                    ]
+                ].
+            ]
+        ].
+        cls := cls superclass.
+    ].
+
+    "Pass 2: Search for method with matching name"
+    cls := initialSearchClass.
+    [ cls notNil ] whileTrue:[
+        cls methodDictionary keysAndValuesDo:[:sel :mthd|
+            mthd numArgs == nArgs ifTrue:[
+                (sel startsWith: name) ifTrue:[
+                    ^mthd
+                ]
+            ]
+        ].
+        cls := cls superclass.
+    ].
+
+    ^nil
+
+    "Created: / 16-12-2011 / 00:00:31 / Jan Vrany <jan.vrany@fit.cvut.cz>"
+! !
+
+!JavaLookup::Java2Smalltalk methodsFor:'utilities'!
+
+addSelector:selector withMethod:proxy toClass:class 
+
+    ProxyMethod installProxies ifTrue:[
+        Class withoutUpdatingChangesDo:[
+            class addSelector:selector withMethod:proxy.
+        ]
+    ]
+
+    "Modified: / 23-12-2011 / 13:09:06 / Jan Vrany <jan.vrany@fit.cvut.cz>"
+!
+
+compileProxyWithSelector:selector descriptor:descriptor in:class calling:callee 
+    |compiler proxy body|
+
+    compiler := ProxyMethodCompiler new.
+    body := compiler newJavaMethodInvocation:callee.
+    body descriptor:descriptor.
+    proxy := compiler 
+                compile:body 
+                arguments:callee numArgs 
+                selector: selector.
+"/    JK: do nod add here
+"/    self 
+"/        addSelector:selector
+"/        withMethod:proxy
+"/        toClass:class.
+    ^ proxy
+
+    "Created: / 14-12-2011 / 20:48:55 / Jan Vrany <jan.vrany@fit.cvut.cz>"
+    "Modified: / 01-01-2012 / 19:33:45 / kursjan <kursjan@fit.cvut.cz>"
+! !
+
+!JavaLookup::Smalltalk2Java methodsFor:'lookup'!
+
+lookupMethodForSelector:selector directedTo:initialSearchClass for:receiver withArguments:argArrayOrNil from:sendingContext ilc: ilc
+    "
+    As a courtesy to a Smalltalker, try to map smalltalk selectors to a java ones.
+    Returns JavaMethodDescriptor or nil.
+    "
+    | name nameSizePlusOne candidates finder static cls m |
+
+    name := selector upTo: $:.
+    nameSizePlusOne := name size + 1.
+    static := receiver isBehavior.
+    candidates := OrderedCollection new.
+    finder := [:cls|
+        cls methodDictionary keysAndValuesDo:[:sel :mthd|
+            (mthd mclass ~~ ProxyMethod
+                and:[((sel size >= nameSizePlusOne) and:[(sel at: nameSizePlusOne) == $( and:[(sel startsWith: name)]])
+                    and:[mthd descriptor numArgs == argArrayOrNil size]]) ifTrue:[
+                        candidates add: mthd
+                    ]
+        ]
+    ].
+
+    cls := initialSearchClass theNonMetaclass.
+    static ifTrue:[
+        finder value: cls
+    ] ifFalse:[
+        [ cls notNil and:[cls ~~ JavaObject] ] whileTrue:[
+            finder value: cls.
+            cls := cls superclass.
+        ]     
+    ].
+
+    candidates notEmpty ifTrue:[
+        m := self compileProxyWithSelector: selector in: receiver class calling: candidates.
+        ilc notNil ifTrue:[ilc bindTo: m forClass: receiver class].
+
+        "Install the proxy"
+        self addSelector: selector withMethod: m toClass: receiver class.
+
+        ^m.
+    ].
+    ^nil
+
+    "Created: / 21-02-2011 / 13:38:55 / kursjan <kursjan@fit.cvut.cz>"
+    "Modified: / 29-08-2011 / 20:38:21 / kursjan"
+    "Modified: / 20-09-2011 / 00:03:48 / Jan Kurs <kursjan@fit.cvut.cz>"
+    "Modified (format): / 25-09-2011 / 21:08:45 / Jan Kurs <kursjan@fit.cvut.cz>"
+    "Created: / 19-11-2011 / 13:03:39 / Jan Vrany <jan.vrany@fit.cvut.cz>"
+    "Modified: / 01-01-2012 / 17:41:42 / Jan Vrany <jan.vrany@fit.cvut.cz>"
+    "Modified: / 01-01-2012 / 19:58:59 / kursjan <kursjan@fit.cvut.cz>"
+    "Modified (comment): / 02-01-2012 / 10:35:25 / kursjan <kursjan@fit.cvut.cz>"
+! !
+
+!JavaLookup::Smalltalk2Java methodsFor:'lookup (old)'!
+
+old_lookupMethodForSelector:selector directedTo:initialSearchClass for:receiver withArguments:argArrayOrNil from:sendingContext ilc: ilc
+    "
+    As a courtesy to a Smalltalker, try to map smalltalk selectors to a java ones.
+    Returns JavaMethodDescriptor or nil.
+    "
+    |descriptor candidate static cls m |
+
+    static := receiver isBehavior.
+    descriptor := JavaMethodDescriptor 
+            name: (selector upTo:$:) 
+            parameters: (argArrayOrNil ? #() collect:[:a|
+                (a class isString and: [JavaVM booted]) ifTrue:[
+                    JavaFieldDescriptorWithUnionType new
+                        addDescriptor: (JavaFieldDescriptor javaClass: a class);
+                        addDescriptor: (JavaFieldDescriptor javaClass: (Java classForName: 'java.lang.String'));
+                        yourself.
+                ] ifFalse:[
+                    JavaFieldDescriptor javaClass: a class
+                ]
+            ]).
+    cls := initialSearchClass theNonMetaclass.
+    [ cls notNil and:[cls ~~ JavaObject] ] whileTrue:[
+        cls methodsDo:[:mthd|
+            "/(mthd selector startsWith: 'foo') ifTrue:[self breakPoint: #jv]. 
+            (mthd class ~~ ProxyMethod and:[mthd isStatic == static and:[descriptor match: mthd descriptor]]) ifTrue:[
+                candidate isNil ifTrue:[
+                    candidate := mthd
+                ] ifFalse:[
+                    candidate descriptorSymbol ~~ mthd descriptorSymbol ifTrue:[
+                        "Hm, hm, two matching methods with different descriptors means
+                         ambiguity...raise an error"
+
+                        "Bit hacky - NamespaceAwareLookup already has method to generate
+                         ambigouous send trampouline..."
+                        ^NamespaceAwareLookup instance ambiguousMessageSend: selector withArgs: argArrayOrNil
+                    ]
+                ].
+            ]                                                                 
+        ].
+        cls := cls superclass.                
+    ].
+    candidate notNil ifTrue:[
+        m := self compileProxyWithSelector: selector descriptor: descriptor in: receiver class calling: candidate.
+        ilc notNil ifTrue:[ilc bindTo: m forClass: receiver class].
+        ^m.
+    ].
+    ^nil
+
+    "Created: / 21-02-2011 / 13:38:55 / kursjan <kursjan@fit.cvut.cz>"
+    "Modified: / 11-04-2011 / 20:19:50 / kursjan <kursjan@fit.cvut.cz>"
+    "Modified: / 29-08-2011 / 20:38:21 / kursjan"
+    "Modified: / 20-09-2011 / 00:03:48 / Jan Kurs <kursjan@fit.cvut.cz>"
+    "Modified (format): / 25-09-2011 / 21:08:45 / Jan Kurs <kursjan@fit.cvut.cz>"
+    "Created: / 16-12-2011 / 23:05:41 / Jan Vrany <jan.vrany@fit.cvut.cz>"
+! !
+
+!JavaLookup::Smalltalk2Java methodsFor:'matching'!
+
+descriptorForJavaSelector:arg
+    ^ MessageDescription new 
+        parserClass: JavaSelectorParser;
+        selector: arg;
+        yourself.
+
+    "Created: / 29-08-2011 / 20:41:48 / Jan Kurs <kursjan@fit.cvut.cz>"
+!
+
+descriptorForSmalltalkSelector:selector arguments: args
+    ^ MessageDescription new 
+        parserClass: SmalltalkSelectorParser;
+        runtimeArguments: args;
+        selector: selector;
+        yourself.
+
+    "Created: / 29-08-2011 / 21:44:06 / Jan Kurs <kursjan@fit.cvut.cz>"
+!
+
+findBestMatchOf: smalltalkMethod in: javaMethods
+    | methods |
+    javaMethods size = 1 ifTrue: [
+        ^ javaMethods first.    
+    ].
+    javaMethods size = 0 ifTrue: [
+        ^ nil
+    ].
+
+    methods := javaMethods select: [:m |
+        m argSize = smalltalkMethod argSize.
+    ].
+    methods size = 1 ifTrue: [
+        ^ methods first.    
+    ].
+
+    methods := methods select: [:m |
+        self javaMatches: m argTypes to: smalltalkMethod args.
+    ].
+    methods size = 1 ifTrue: [
+        ^ methods first.
+    ].
+
+    methods size = 0 ifTrue: [
+        ^ nil.
+    ].
+
+    ^ Error raiseErrorString: 'Ambiguous selector: ', smalltalkMethod name.
+
+    "Created: / 29-08-2011 / 20:50:14 / Jan Kurs <kursjan@fit.cvut.cz>"
+!
+
+javaMatches: jArgs to: sArgs
+    
+    1 to: jArgs size do: [ :i |
+        ((JavaTypeBox typeBoxForJava: (jArgs at: i)) smalltalkType = ((sArgs at: i) className)) ifFalse: [ ^ false ].
+    ].
+    ^ true.
+
+    "Created: / 29-08-2011 / 21:21:37 / Jan Kurs <kursjan@fit.cvut.cz>"
+!
+
+javaSelectorsFor:class
+    | selectors cls static |
+    cls := class.
+    selectors := IdentitySet new.
+    self breakPoint: #jk info: 'determine static based on class'.
+    static := false.
+
+    [cls = JavaObject] whileFalse: [
+        cls methodDictionary keysAndValuesDo: [:k :v |
+            (v isJavaMethod and: [v isStatic = static]) ifTrue: [
+                selectors add: k.
+            ].
+        ].
+        cls := cls superclass.
+    ].
+    ^ selectors.
+
+    "Created: / 06-09-2011 / 22:20:34 / Jan Kurs <kursjan@fit.cvut.cz>"
+! !
+
+!JavaLookup::Smalltalk2Java methodsFor:'utilities'!
+
+addSelector:selector withMethod:proxy toClass:class 
+
+    ProxyMethod installProxies ifTrue:[
+        Class withoutUpdatingChangesDo:[
+            class addSelector:selector withMethod:proxy.
+        ]
+    ]
+
+    "Modified: / 23-12-2011 / 13:09:14 / Jan Vrany <jan.vrany@fit.cvut.cz>"
+    "Created: / 01-01-2012 / 17:41:46 / Jan Vrany <jan.vrany@fit.cvut.cz>"
+!
+
+compileProxyWithSelector:selector in:class calling:methods 
+    "For given set of methods, create a dispatching proxy with given selector.
+     This method performs typechecks on arguments and dispatch to proper method"
+    
+    |compiler proxy body fallback|
+
+    compiler := ProxyMethodCompiler new.
+    fallback := self 
+                fallbackWithSelector:class
+                in:selector
+                calling:methods
+                compiler:compiler.
+     "Generate and install dispatching tree..."
+    selector numArgs == 0 ifTrue:[
+        "If method has no arguments, no dynamic method dispatch is
+         required. Therefore, no fallback is needed. In theory, there is
+         no need for proxy method at all..."
+        self assert:methods size == 1.
+        body := compiler newJavaMethodInvocation:methods anyOne.
+    ] ifFalse:[
+        "JV@2012-01-01: Based on discussion with JK, if there is no overloaded method
+         DO NOT compile guard, call the method directly. We'll see..."
+        methods size == 1 ifTrue:[
+            body := (compiler newJavaMethodInvocation:methods anElement).
+        ] ifFalse:[
+            "For every method, create a guard and add it"
+            body := fallback.
+        ]
+    ].
+    
+    "/Create and install proxy
+    
+    proxy := compiler 
+                compile:body
+                arguments:methods anyOne descriptor numPhysicalArgs
+                selector:selector.
+    
+"/    self halt.
+"/    JK: do NOT install here, just compile and return the proxy. Let someone else to install
+"/    self 
+"/        addSelector:selector
+"/        withMethod:proxy
+"/        toClasS:class.
+    
+    ^ proxy
+
+    "Created: / 16-12-2011 / 23:21:55 / Jan Vrany <jan.vrany@fit.cvut.cz>"
+    "Modified: / 30-12-2011 / 14:44:11 / kursjan <kursjan@fit.cvut.cz>"
+    "Modified: / 03-01-2012 / 22:15:44 / Jan Vrany <jan.vrany@fit.cvut.cz>"
+!
+
+compileProxyWithSelector: selector in: class calling: methods receiver: receiver arguments: arguments
+    "For given receiver and arguments, selects apropriate method from methods
+     and compile guard"
+
+    | compiler method proxy condition invocation fallback guard |
+
+    compiler := ProxyMethodCompiler new.    
+
+    proxy := class compiledMethodAt: selector.
+    proxy notNil ifTrue:[
+        fallback := proxy body    
+    ] ifFalse:[
+        fallback := self fallbackWithSelector: selector in: class calling: methods compiler: compiler.
+    ].
+
+    method := self selectMethodFrom: methods arguments: arguments.
+    invocation := compiler newJavaMethodInvocation:method.
+
+    condition := nil.
+    arguments withIndexDo:[:arg :index|
+        condition isNil ifTrue:[
+            condition := compiler newTypeCheck: arg class argument: index.
+        ] ifFalse:[
+            condition := condition and: (compiler newTypeCheck: arg class argument: index).
+        ].
+    ].
+
+    guard := compiler newGuard
+                condition: condition;
+                action: invocation; 
+                fallback: fallback;
+                yourself.
+
+    proxy := compiler 
+                compile:guard
+                arguments:methods anyOne descriptor numPhysicalArgs
+                selector:selector.
+
+    self 
+        addSelector:selector
+        withMethod:proxy
+        toClass:class.
+
+    "Created: / 03-01-2012 / 22:14:06 / Jan Vrany <jan.vrany@fit.cvut.cz>"
+!
+
+fallbackWithSelector:selector in:class calling:methods compiler:compiler 
+    ^ compiler 
+        newJavaBlockInvocation:[:receiver :arguments | 
+            self 
+                compileProxyWithSelector:selector
+                in:class
+                calling:methods
+                receiver:receiver
+                arguments:arguments.
+            "/self breakPoint:#jv.
+            receiver perform:selector withArguments:arguments.
+        ]
+
+    "Modified: / 04-01-2012 / 21:35:40 / Jan Vrany <jan.vrany@fit.cvut.cz>"
+!
+
+selectMethodFrom: methods arguments: arguments
+
+    | candidates |
+
+    candidates := methods.
+    arguments withIndexDo:[:arg :index|
+        | cls |
+
+        cls := arg class.
+        candidates := candidates select:[:m|
+            self type: cls matches: (m descriptor parameters at: index) javaClass
+        ].
+    ].
+
+    candidates size == 0 ifTrue:[
+        self halt: 'Unfinished - no matching method'        
+    ].
+    candidates size == 1 ifTrue:[
+        ^candidates anElement
+    ].
+
+    self halt: 'Unfinished - ambiguous'
+
+    "Created: / 03-01-2012 / 21:40:23 / Jan Vrany <jan.vrany@fit.cvut.cz>"
+!
+
+type: actual matches: formal
+    "Return true, if actual (parameter) type matches given formal (parameter) type"
+
+    formal isJavaPrimitiveType ifTrue:[
+        ^ actual == formal.
+    ].
+
+    actual isJavaPrimitiveType ifTrue:[
+        ^ formal isJavaWrapperClass and:[
+            formal javaWrappedClass == actual.
+        ]
+    ].
+
+    ^JavaVM canCast: actual to: formal
+
+    "Created: / 03-01-2012 / 22:36:19 / Jan Vrany <jan.vrany@fit.cvut.cz>"
+! !
+
+!JavaLookup::Smalltalk2Java methodsFor:'utilities (old)'!
+
+old_compileProxyWithSelector: selector descriptor: descriptor in: class calling: callee
+
+    | proxy invocation fallback |
+
+    "This method might (indirectly) be invoked by guarded method itself,
+     when all guards fails and method gets recompiled during fallback action.
+     In that case, we should not throw away existing proxy, but just extend it."
+
+    proxy := class compiledMethodAt: selector.
+    proxy isNil ifTrue:[
+        "No method exists, create one..."
+        proxy := ProxyMethod new.
+        proxy numberOfArgs: callee descriptor numPhysicalArgs.
+        proxy source:'I''m a proxy method, please inspect my body'.
+        "Create default fallback"
+        fallback := ProxyMethod newJavaBlockInvocation: [ self halt: 'Launch recompile, not yet implemented'].
+        "Install it..."
+        Class withoutUpdatingChangesDo:[
+            class addSelector: selector withMethod: proxy.        
+        ]
+    ] ifFalse:[
+        "Method already exists, then the fallback is currently 
+         installed body"
+        fallback := proxy body.
+    ].
+
+    "Now, create and install a node that invokes given method"   
+    callee numArgs == 0 ifTrue:[
+        "If method has no arguments, no dynamic method dispatch is
+        required. Therefore, no fallback is needed. In theory, there is
+        no need for proxy method at all..."
+        self assert: descriptor numArgs size == 0.
+        invocation := ProxyMethod newJavaMethodInvocation: callee.
+        "Install it"
+        proxy body: invocation
+    ] ifFalse:[
+        "Create a guard"
+        invocation := ProxyMethod newGuard.
+        invocation condition: callee descriptor guardCondition.
+        invocation action: (ProxyMethod newJavaMethodInvocation: callee).
+        invocation fallback: fallback.
+        "Install it"
+        proxy addGuard: invocation.
+    ].
+    "/Finally, return the method                                
+    ^ proxy
+
+    "Created: / 16-12-2011 / 23:06:02 / Jan Vrany <jan.vrany@fit.cvut.cz>"
+! !
+
+!JavaLookup class methodsFor:'documentation'!
+
+version_SVN
+    ^ '$Id$'
+! !