[Laszlo-dev] For Review: Change 20090327-dda-z Summary: Turn off catcherrors for functions with no free references

[Donald Anderson]

Okay, it's in.  Take it away Max.

On Mar 27, 2009, at 5:11 PM, P T Withington wrote:

> Approved.  Lets get this in so Max can try it.
>
> On 2009-03-27, at 16:21EDT, Donald Anderson wrote:
>
>> Change 20090327-dda-z by dda at lester-2.local on 2009-03-27 13:47:17  
>> EDT
>>   in /Users/dda/laszlo/src/svn/openlaszlo/trunk-b
>>   for http://svn.openlaszlo.org/openlaszlo/trunk
>>
>> Summary: Turn off catcherrors for functions with no free references
>>
>> New Features:
>>
>> Bugs Fixed: LPP-7985: catcherrors needs optimization
>>
>> Technical Reviewer: ptw (pending)
>> QA Reviewer: (pending)
>> Doc Reviewer: (pending)
>>
>> Documentation:
>>
>> Release Notes:
>>
>> Details:
>>   As discussed in JIRA, we need a lighter weight implementation of  
>> catcherrors.
>>   This changeset turns off catcherrors for any function that has no  
>> free references.
>>   Such functions tend to be smaller, more self contained, and  
>> because of that much less
>>   likely to generate an exception.  We expect that this should give  
>> very close to the
>>   same results but with substantially less overhead.
>>
>>   Catcherrors is implemented in the compiler by inserting extra  
>> statements into lists
>>   that hold statements for the prefix (before the try statement),  
>> the errors clause
>>   (the catch block) and the suffix (the finally block).
>>
>>   This change moves the variable analyzer to run before the  
>> catcherrors statements are
>>   inserted.  Running the variable analyzer allows us to see if  
>> there are free variables,
>>   and if so (and catcherrors is enabled), then to insert the needed  
>> statements.
>>
>> Tests:
>>   Same small tests as used for LPP-7824
>>   Modified tests to have functions that reference external  
>> variables and some without references.
>>   Examined generated code to verify that the expected functions  
>> have try/catch blocks.
>>
>>   regression: swf9/swf8/dhtml x smokecheck/weather/lzpix
>>
>> Files:
>> M      WEB-INF/lps/server/src/org/openlaszlo/sc/ 
>> JavascriptGenerator.java
>>
>> Changeset: http://svn.openlaszlo.org/openlaszlo/patches/20090327-dda-z.tar
>>
>>
>>
>> --
>>
>> Don Anderson
>> Java/C/C++, Berkeley DB, systems consultant
>>
>> voice: 617-306-2057
>> email: dda at ddanderson.com
>> www: http://www.ddanderson.com
>>
>>
>>
>>
>>
>


--

Don Anderson
Java/C/C++, Berkeley DB, systems consultant

voice: 617-306-2057
email: dda at ddanderson.com
www: http://www.ddanderson.com





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