[squeak-dev] The Inbox: Kernel-ct.1420.mcz

Marcel Taeumel marcel.taeumel at hpi.de
Wed Dec 1 15:22:47 UTC 2021


Hmm... that "-3" looks strange. Like exposing an implementation detail from the VM. There are all kinds of symbols used in combination with #primitiveFailTokenFor:. I agree that "nil" is too generic. But why don't you use a symbol instead of leaking a VM detail?

Best,
Marcel
Am 10.11.2021 14:11:41 schrieb commits at source.squeak.org <commits at source.squeak.org>:
A new version of Kernel was added to project The Inbox:
http://source.squeak.org/inbox/Kernel-ct.1420.mcz

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

Name: Kernel-ct.1420
Author: ct
Time: 10 November 2021, 1:47:10.350242 am
UUID: 8f2e7a27-2c7b-534a-9c78-a90c968e45c5
Ancestors: Kernel-eem.1418

Aligns the error code for primitive 118 during simulation with what the VM returns. See KernelTests-ct.409/#testPrimitive118/{6. 'not a primitive'. {7}},{6. 9. 'not an array'}.

=============== Diff against Kernel-eem.1418 ===============

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'].
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'].
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 ifTrue: "Object>>withArgs:executeMethod:
CompiledMethod class>>receiver:withArguments:executeMethod:
VMMirror>>ifFail:object:with:executeMethod: et al"
[| n args methodArg thisReceiver |
((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'].
methodArg numArgs = args size ifFalse:
[^self class primitiveFailTokenFor: #'bad number of arguments'].
thisReceiver := arguments at: n - 2 ifAbsent: [receiver].
methodArg primitive > 0 ifTrue:
[methodArg isQuick ifTrue:
[^self push: (methodArg valueWithReceiver: thisReceiver arguments: args)].
^self doPrimitive: methodArg primitive method: meth receiver: thisReceiver args: args].
^Context
sender: self
receiver: thisReceiver
method: methodArg
arguments: args].

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: -3].
- [^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]!


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