I have defined a method, i.e.,
someMethod anInstVariable := anotherInstVariable1 + anotherInstVariable2.
I would like to intercept the acceptance of this method by the browser and programatically determine what instance variables this method is using so that I can grab these names for other processing tasks.
Additionally, I would really like to be able to determine what instance variables are being assigned to, for instance, anInstVariable in this case and which ones are the "independent" instance variables, anotherInstVariable1 and anotherInstVariable2 in this case.
How can I do this?
Thanks
On Tue, Aug 25, 2009 at 2:16 PM, rdmerrio rdmerrio@gmail.com wrote:
I have defined a method, i.e.,
someMethod anInstVariable := anotherInstVariable1 + anotherInstVariable2.
I would like to intercept the acceptance of this method by the browser and programatically determine what instance variables this method is using so that I can grab these names for other processing tasks.
Additionally, I would really like to be able to determine what instance variables are being assigned to, for instance, anInstVariable in this case and which ones are the "independent" instance variables, anotherInstVariable1 and anotherInstVariable2 in this case.
How can I do this?
Why? What are you trying to achieve? You're talking about some pretty intrusive techniques. Unless you're developing a code analyser of some sort, you probably should be looking at a better way of doing what you're doing.
To capture the acceptance of a method (assuming you mean the action that happens when you press alt+s), you insert a bit of code into PluggableTextMorph>>accept.
To determine which instance variables are being assigned to, you'll need to somehow look at the bytecodes. They're not too hard to analyse, but it can be a bit of work. Alternatively, maybe the refactory browser can help, or maybe you can look at the intermediate code that the compiler generates.
The bytecodes are described here: http://burks.bton.ac.uk/burks/language/smaltalk/goldberg/blueb003.htm. They're in the "Blue book chapter 28" if you need to Google it. You'll want the "store" bytecodes.
To see real bytecodes, either inspect "Morph>>#basicInitialize" to see a CompiledMethod, or use the "byteCodes" view in a Browser (hidden behind the "source" button).
Gulik.
At Mon, 24 Aug 2009 21:16:16 -0500, rdmerrio wrote:
I have defined a method, i.e.,
someMethod anInstVariable := anotherInstVariable1 + anotherInstVariable2.
I would like to intercept the acceptance of this method by the browser and programatically determine what instance variables this method is using so that I can grab these names for other processing tasks.
Additionally, I would really like to be able to determine what instance variables are being assigned to, for instance, anInstVariable in this case and which ones are the "independent" instance variables, anotherInstVariable1 and anotherInstVariable2 in this case.
How can I do this?
The "why" question Michael asked is an interesting one, but I can see many potential use of it. (I've been writing a few automatic inst var access rewriting compilers and friends with similar techniques.)
During the compilation, the Compiler uses Encoder to support the compilation and Encoder keeps track of the accesses of variables.
Encoder>>init:context:notifying:
populates "scopeTable" inst var with VariableNodes. When an assignment to the variable is encountered, #nowHasDef message is sent to the node. When a reference is encountered, #nowHasRef message is sent to the node. The default behavior is do nothing, but you can define methods like (in the latest image, the actual class name varies based on the Squeak version):
InstanceVariableNode nowHasRef Transcript show: 'ref: '; show: self printString; cr.
InstanceVariableNode nowHasDef Transcript show: 'def: '; show: self printString; cr.
and you get the list of these accesses.
To be less intrusive, you can store these info into somewhere and analyze it.
-- Yoshiki
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Michael van der Gulik -
rdmerrio -
Yoshiki Ohshima