[squeak-dev] The Inbox: Kernel-ct.1449.mcz

commits at source.squeak.org commits at source.squeak.org
Sat Mar 12 00:51:15 UTC 2022


A new version of Kernel was added to project The Inbox:
http://source.squeak.org/inbox/Kernel-ct.1449.mcz

==================== Summary ====================

Name: Kernel-ct.1449
Author: ct
Time: 12 March 2022, 1:51:11.452359 am
UUID: 75c8b415-7b05-854e-a772-0412e6a1fd60
Ancestors: Kernel-ct.1448

Fixes handling of objects as methods in Object>>#withArgs:executeMethods:. Complements KernelTests-ct.421.

There were actually two issues:
1. The fallback code in Object>>#withArgs:executeMethod: had multiple unexpected side effects because Behavior>>#basicAddSelector:withMethod: would modify the state (selector+methodClass) of the compiledMethod. If compiledMethod was not a valid CompiledMethod or object as method and did not understand #methodClass: and #selector: correctly, the #addSelectorSilently:withMethod: would have failed non-atomatically and left the method dictionary of the receiver class with a dangling auxiliary symbol key that would never be cleaned up.
2. primitive 83 (primitivePerform) and primitive 84 (primitivePerformWithArgs) must not check the arity of the selector but only the arity of the resolved method if that is not an object as method. This patch aligns the simulation of these primitives to the VM behavior so that the fallback code in Object>>#withArgs:executeMethod: also works in the simulator.

=============== Diff against Kernel-ct.1448 ===============

Item was changed:
  ----- Method: Context>>doPrimitive:method:receiver:args: (in category 'private') -----
  doPrimitive: primitiveIndex method: meth receiver: receiver args: arguments
  	"Simulate a primitive method whose index is primitiveIndex.  The simulated receiver and
  	 arguments are given as arguments to this message. If successful, push result and return
  	 resuming context, else ^ {errCode, PrimitiveFailToken}. Any primitive which provokes
  	 execution needs to be intercepted and simulated to avoid execution running away."
  
  	| value |
  	"Judicious use of primitive 19 (a null primitive that doesn't do anything) prevents
  	 the debugger from entering various run-away activities such as spawning a new
  	 process, etc.  Injudicious use results in the debugger not being able to debug
  	 interesting code, such as the debugger itself.  Hence use primitive 19 with care :-)"
  	"SystemNavigation new browseAllSelect: [:m| m primitive = 19]"
  	primitiveIndex = 19 ifTrue: [
  		[self notify: ('The code being simulated is trying to control a process ({1}). Process controlling cannot be simulated. If you proceed, things may happen outside the observable area of the simulator.' translated format: {meth reference})]
  			ifCurtailed: [self push: nil "Cheap fix of the context's internal state"]].
  	
  	((primitiveIndex between: 201 and: 222)
  	 and: [(self objectClass: receiver) includesBehavior: BlockClosure]) ifTrue:
  		[(primitiveIndex = 206
  		  or: [primitiveIndex = 208]) ifTrue:						"[Full]BlockClosure>>valueWithArguments:"
  			[^receiver simulateValueWithArguments: arguments first caller: self].
  		 ((primitiveIndex between: 201 and: 209)			 "[Full]BlockClosure>>value[:value:...]"
  		  or: [primitiveIndex between: 221 and: 222]) ifTrue: "[Full]BlockClosure>>valueNoContextSwitch[:]"
  			[^receiver simulateValueWithArguments: arguments caller: self]].
  
  	primitiveIndex = 83 ifTrue: "afr 9/11/1998 19:50" "Object>>perform:[with:...]"
  		[| selector |
  		selector := arguments at: 1 ifAbsent:
  			[^ self class primitiveFailTokenFor: #'bad argument'].
+ 		((self objectClass: receiver) lookupSelector: selector) ifNotNil: [:methodArg |
+ 			((self objectClass: methodArg) isCompiledCodeClass and: [arguments size - 1 ~= methodArg numArgs])
+ 				ifTrue: [^ self class primitiveFailTokenFor: #'bad number of arguments']].
- 		arguments size - 1 = selector numArgs ifFalse:
- 			[^ self class primitiveFailTokenFor: #'bad number of arguments'].
  		^self send: selector to: receiver with: arguments allButFirst].
  	primitiveIndex = 84 ifTrue: "afr 9/11/1998 19:50 & eem 8/18/2009 17:04" "Object>>perform:withArguments:"
  		[| selector args |
  		arguments size = 2 ifFalse:
  			[^ self class primitiveFailTokenFor: #'bad argument'].
  		selector := arguments first.
  		args := arguments second.
  		args isArray ifFalse:
  			[^ self class primitiveFailTokenFor: #'bad argument'].
+ 		((self objectClass: receiver) lookupSelector: selector) ifNotNil: [:methodArg |
+ 			((self objectClass: methodArg) isCompiledCodeClass and: [args size ~= methodArg numArgs])
+ 				ifTrue: [^ self class primitiveFailTokenFor: #'bad number of arguments']].
- 		args size = selector numArgs ifFalse:
- 			[^ self class primitiveFailTokenFor: #'bad number of arguments'].
  		^self send: selector to: receiver with: args].
  	primitiveIndex = 100 ifTrue: "eem 8/18/2009 16:57" "Object>>perform:withArguments:inSuperclass:"
  		[| rcvr selector args superclass |
  		arguments size
  			caseOf: {
  				[3] -> [
  					rcvr := receiver.
  					selector := arguments first.
  					args := arguments second.
  					superclass := arguments third].
  				[4] -> ["mirror primitive"
  					rcvr := arguments first.
  					selector := arguments second.
  					args := arguments third.
  					superclass := arguments fourth] }
  			otherwise: [^ self class primitiveFailTokenFor: #'bad argument'].
  		args isArray ifFalse:
  			[^ self class primitiveFailTokenFor: #'bad argument'].
  		args size = selector numArgs ifFalse:
  			[^ self class primitiveFailTokenFor: #'bad number of arguments'].
  		((self objectClass: rcvr) includesBehavior: superclass) ifFalse:
  			[^ self class primitiveFailTokenFor: #'bad argument'].
  		^self send: selector to: rcvr with: args lookupIn: superclass].
  
  	"Mutex>>primitiveEnterCriticalSection
  	 Mutex>>primitiveTestAndSetOwnershipOfCriticalSection"
  	(primitiveIndex = 186 or: [primitiveIndex = 187]) ifTrue:
  		[| effective |
  		 effective := Processor activeProcess effectiveProcess.
  		 "active == effective"
  		 value := primitiveIndex = 186
  					ifTrue: [receiver primitiveEnterCriticalSectionOnBehalfOf: effective]
  					ifFalse: [receiver primitiveTestAndSetOwnershipOfCriticalSectionOnBehalfOf: effective].
  		 ^(self isPrimFailToken: value)
  			ifTrue: [value]
  			ifFalse: [self push: value]].
  	
  	(primitiveIndex = 188 or: [primitiveIndex = 189]) ifTrue:
  		[| n args methodArg thisReceiver |
  		 primitiveIndex caseOf:
  			{[188 "primitiveExecuteMethodArgsArray"] ->
  				["Object>>withArgs:executeMethod:
  				  CompiledMethod class>>receiver:withArguments:executeMethod:
  				  VMMirror>>ifFail:object:with:executeMethod: et al"
  				 ((n := arguments size) between: 2 and: 4) ifFalse:
  					[^self class primitiveFailTokenFor: #'unsupported operation'].
  				 ((self objectClass: (args := arguments at: n - 1)) == Array
  				  and: [(self objectClass: (methodArg := arguments at: n)) includesBehavior: CompiledMethod]) ifFalse:
  					[^self class primitiveFailTokenFor: #'bad argument'].
  				 thisReceiver := arguments at: n - 2 ifAbsent: [receiver]].
  			 [189 "primitiveExecuteMethod"] ->
  				["Object>>executeMethod:
  				  Object>>with:...executeMethod:"
  				 (arguments size > 0) ifFalse:
  					[^self class primitiveFailTokenFor: #'bad argument'].
  				 ((self objectClass: (methodArg := arguments atLast: 1)) includesBehavior: CompiledMethod) ifFalse:
  					[^self class primitiveFailTokenFor: #'bad argument'].
  				 args := arguments allButLast.
  				 thisReceiver := receiver]}.
  		 methodArg numArgs = args size ifFalse:
  			[^self class primitiveFailTokenFor: #'bad number of arguments'].
  		 methodArg primitive > 0 ifTrue:
  			[methodArg isQuick ifTrue:
  				[^self push: (methodArg valueWithReceiver: thisReceiver arguments: args)].
  			 ^self doPrimitive: methodArg primitive method: meth receiver: thisReceiver args: args].
  		 ^self
  			activateMethod: methodArg
  			withArgs: args
  			receiver: thisReceiver].
  
  	primitiveIndex = 118 ifTrue: "[receiver:]tryPrimitive:withArgs:; avoid recursing in the VM"
  		[(arguments size = 3
  		  and: [(self objectClass: arguments second) == SmallInteger
  		  and: [(self objectClass: arguments last) == Array]]) ifTrue:
  			[^self doPrimitive: arguments second method: meth receiver: arguments first args: arguments last].
  		 (arguments size = 2
  		 and: [(self objectClass: arguments first) == SmallInteger
  		 and: [(self objectClass: arguments last) == Array]]) ifFalse:
  			[^self class primitiveFailTokenFor: nil].
  		 ^self doPrimitive: arguments first method: meth receiver: receiver args: arguments last].
  
  	value := primitiveIndex = 120 "FFI method"
  				ifTrue: [(meth literalAt: 1) tryInvokeWithArguments: arguments]
  				ifFalse:
  					[primitiveIndex = 117 "named primitives"
  						ifTrue: [self tryNamedPrimitiveIn: meth for: receiver withArgs: arguments]
  						ifFalse: "should use self receiver: receiver tryPrimitive: primitiveIndex withArgs: arguments but this is only in later VMs (and appears to be broken)"
  							[receiver tryPrimitive: primitiveIndex withArgs: arguments]].
  
  	^(self isPrimFailToken: value)
  		ifTrue: [value]
  		ifFalse: [self push: value]!

Item was changed:
  ----- Method: Object>>withArgs:executeMethod: (in category 'message handling') -----
  withArgs: argArray executeMethod: compiledMethod
  	"Execute compiledMethod against the receiver and args in argArray"
  
  	| selector |
  	<primitive: 188>
  	selector := Symbol new.
+ 	self class methodDict at: selector put: compiledMethod.
+ 	^ [self perform: selector flushCache withArguments: argArray]
- 	self class addSelectorSilently: selector withMethod: compiledMethod.
- 	^ [self perform: selector withArguments: argArray]
  		ensure: [self class basicRemoveSelector: selector]!



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