I think only the first 4 inst vars are actually used by the plugin: http://squeakvm.org/svn/squeak/trunk/platforms/unix/src/plugins/RomePlugin/R... #define CanvasHandleIndex 0 #define CanvasTargetIndex 1 #define CanvasFlagsIndex 2 #define CanvasStrokeColorIndex 3 #define CanvasInstSize 8 So on Linux, Rome does use the "right" size. John appears to have used a Sophie image to generate his Plugin, which makes this fail (though I could not find his Rome plugin in the Mac OS platform code so can't verify that theory). The proper fix would be to modify RomePlugin class>>initializeInstVarIndices to not generate the indices, but simply hard-code only the used ones (setting CanvasInstSize to 4), and change the comparison John mentioned below to <=. Also remove the unused *Index class vars. Now that there are plugins in the wild, hard-coding the indices is a good idea anyway. During development, the flexible generator version was useful, but not anymore. - Bert - On 18.04.2010, at 18:45, Stéphane Ducasse wrote:
John
how can I know the order and the iv that are used by the plugin?
Stef
On Apr 17, 2010, at 4:09 AM, John M McIntosh wrote:
(a) In Sophie RomeCanvas subclass: #RomePluginCanvas instanceVariableNames: 'handle target flags strokeColor stack font fontSize fontMatrix currentFillColor currentBackColor glyphAccuracy cachedGlyphBlt cachedClearBlt drawRunPositions drawRunGlyph drawRunPointY' classVariableNames: 'CachedTarget FlagFill FlagStro
(b) In Pharo
RomeCanvas subclass: #RomePluginCanvas instanceVariableNames: 'handle target flags strokeColor stack font fontSize fontMatrix' classVariableNames: 'FlagFill FlagStroke Registry' poolDictionaries: '' category: 'Rome-PluginCanvas'
Comment warning:
INST VAR ORDER IS KNOWN TO PLUGIN! DO NOT REARRANGE!
So in the plugin we have...
if (interpreterProxy->slotSizeOf(canvasOop)) < CanvasInstSize) fail().
where CanvasInstSize is 13
but as you see in (b) the number of instance slots for the canvas Oops is 8.
8 < 13, oops you fail.
So where did the instance vars currentFillColor currentBackColor glyphAccuracy cachedGlyphBlt cachedClearBlt go? On purpose gone, refactored, old code. etc....
On 2010-04-16, at 1:37 PM, Stéphane Ducasse wrote:
On Apr 16, 2010, at 10:30 PM, John McIntosh wrote:
Well I'm just as puzzled as you since the primitive gets executed and you are using the same binary that was shipped with Sophie years back.
I like to hear that because I feel less idiot. :)