[Laszlo-dev] For Review: Change 20070919-dda-f Summary: generatePredictableTemps option for script compiler

[Donald Anderson]

Change 20070919-dda-f by dda at freddie.local on 2007-09-19 13:41:48 EDT
     in /Users/dda/laszlo/src/svn/openlaszlo/trunk/WEB-INF/lps/server/ 
src/org/openlaszlo/sc
     for http://svn.openlaszlo.org/openlaszlo/trunk/WEB-INF/lps/ 
server/src/org/openlaszlo/sc

Summary: generatePredictableTemps option for script compiler

New Features:
   added new option generatePredictableTemps that allows for direct  
comparison
   of compiler outputs.

Bugs Fixed:

Technical Reviewer: ptw
QA Reviewer: (pending)
Doc Reviewer: (pending)

Documentation:

Release Notes:

Details:
   The new option, is specified to the compiler like this:
    --option generatePredictableTemps=true

   Note that this option is *not* the default, nor is it recommended  
for anyone
   that is not doing side-by-side tests of the compiler.  When used,  
it may
   in fact *break* functionality.  It provides some capabilities to  
assist
   in internal testing, and specifically for testing the refactoring  
work.

   When this is option is set, variables that normally use a UUID- 
like naming (for uniqueness between runs)
   are changed to have predictable names, that is names that will be  
identical each time
   the compiler is rerun.  Such predictable names (like "$lzsc$1",  
"$lzsc$2", etc.) will
   collide with the same names used in other compilations that appear  
in the same applications,
   which may cause problems at runtime.  This option uses a simple  
increment to generate
   names.  Seeding the random number generator with a fixed value,  
like 0, would also work
   but the output will appear more obfuscated.

   The intention is that this option can be used when making an  
architectural or 'cleanup'
   change to the compiler that is not intended to change any  
behavior.  When this change
   is done, a suitably complete test input can be fed to the old and  
new compiler, both
   with the generatePredictableTemps option, and comparisons of  
outputs can be made directly.


Tests:

Files:
M      Compiler.java
M      JavascriptGenerator.java
M      CodeGenerator.java

Changeset: http://svn.openlaszlo.org/openlaszlo/patches/20070919-dda- 
f.tar



--

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

Voice:  617-547-7881
Email:  dda at ddanderson.com
WWW:    http://www.ddanderson.com