#221: rb_objc_ocval_to_rval crashing when returning Modal Panel Return values
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Reporter: parzi...@… | Owner: lsansone...@…
Type: defect | Status: new
Priority: major | Milestone:
Component: MacRuby | Keywords:
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My guess is that this is a problem in rb_objc_method_get_type, or in
rb_objc_ocval_to_rval when dealing with objects of unknown type.
It's causing my code to crash when trying to call the selector from an
NSOpenPanel sheet.
Here's a bit of the MacRuby code I'm working on:
{{{
oPanel.beginSheetForDirectory(nil, file: nil, types: nil, modalForWindow:
spWindow, modalDelegate: self, didEndSelector:
"mediaSourceSheetDidEnd:returnCode:contextInfo:", contextInfo: nil)
end
# Delegate (from modal sheet)
def mediaSourceSheetDidEnd(oPanel, returnCode: rCode, contextInfo: cInfo)
p oPanel # <NSOpenPanel:0x1321300>
p rCode # nil, but only if 'cancel' was selected
p cInfo # nil
end
}}}
Whenever a file is selected & 'Open' is pressed, it crashes with
EXC_BAD_ACCESS. If 'Cancel' is pressed, it proceeds but rcode is nil.
Here's the trace of the crash:
{{{
Thread 1 (process 665 local thread 0x2d03):
#0 0x002df287 in rb_objc_ocval_to_rval (ocval=0xbfffe0ac,
octype=0xbfffdf4c "@", rbval=0xbfffdfcc) at objc.m:882
#1 0x002e48d6 in rb_ruby_to_objc_closure_handler_main (ctx=0x12) at
objc.m:1546
#2 0x002e4bcb in rb_ruby_to_objc_closure_handler (cif=0x31d404,
resp=0x31d404, args=0x31d404, userdata=0x31d404) at objc.m:1607
#3 0x911af424 in ffi_closure_SYSV ()
#4 0x92f0d2ae in -[NSSavePanel(NSSavePanelRuntime)
_didEndSheet:returnCode:contextInfo:] ()
#5 0x92d15233 in -[NSApplication endSheet:returnCode:] ()
#6 0x92e5f7e1 in -[NSSavePanel(NSSavePanelRuntime) dismissWindow:] ()
#7 0x92e5f69d in -[NSSavePanel(NSSavePanelRuntime) ok:] ()
#8 0x92cd353b in -[NSApplication sendAction:to:from:] ()
#9 0x92cd3478 in -[NSControl sendAction:to:] ()
#10 0x92cd32fe in -[NSCell _sendActionFrom:] ()
#11 0x92cd2957 in -[NSCell trackMouse:inRect:ofView:untilMouseUp:] ()
#12 0x92cd21aa in -[NSButtonCell trackMouse:inRect:ofView:untilMouseUp:]
()
#13 0x92cd1a64 in -[NSControl mouseDown:] ()
#14 0x92cd01a3 in -[NSWindow sendEvent:] ()
#15 0x92c9cd49 in -[NSApplication sendEvent:] ()
#16 0x92bfa69f in -[NSApplication run] ()
#17 0x92bc78a4 in NSApplicationMain ()
#18 0x911af1dd in .LCFI1 ()
#19 0x911af771 in ffi_call ()
#20 0x002e45f0 in rb_bsfunc_call (bs_func=0x93bc1a0, sym=0x92bc7666,
argc=2, argv=0x690050) at objc.m:1967
#21 0x002d0b12 in vm_call_method (th=0x1013e50, cfp=0x70ff88, num=2,
blockptr=0x1, flag=2145, id=<value temporarily unavailable, due to
optimizations>, recv=16879904, klass=4267712, mcache=0x10a29c0) at
vm_insnhelper.c:680
#22 0x002c552e in vm_eval (th=0x1013e50, initial=<value temporarily
unavailable, due to optimizations>) at insns.def:1067
#23 0x002cbaab in vm_eval_body (th=0x1013e50) at vm.c:1032
#24 0x002cbd14 in rb_iseq_eval (iseqval=17439584) at vm.c:1236
#25 0x001f79d9 in ruby_exec_node (n=0x10a1b60, file=0x0) at eval.c:252
#26 0x001fa9d0 in ruby_run_node (n=0x10a1b60) at eval.c:280
#27 0x002de84b in macruby_main (path=0x1ff3 "rb_main.rb", argc=3,
argv=0x4094a0) at objc.m:2834
#28 0x00001fed in main (argc=1, argv=0xbffff788) at
/Users/parzival/devo/buried/sinker/main.m:13
Program received signal: “EXC_BAD_ACCESS”.
}}}
Examining memory in the debugger, I can see that the memory holding the
args in rb_ruby_to_objc_closure_handler_main is as follows:
0xbfffe0a0: 01075510 093f5290 0134e070 00000001 00000000
The last three are the arguments to be converted in rb_objc_ocval_to_rval,
and the problem comes on the second one (when i=1), which is the return
code from the panel. It's being treated as type 'id', and then the crash
comes when attempting to dereference it as a'Class *'.
I can also add that *ocval = 0x40. The fact that NULL is treated as a
special case in ocval_to_rval likely explains why it doesn't crash when
'Cancel' is selected, since NSCancelButton = 0 by definition.
I haven't looked at rb_objc_method_get_type so I can't say for sure that's
it, but I would expect that NSCancel & NSOK ought to come back as
integers.
Thinking about it a bit more, it may be that hard to know what type these
ought to be since it's not declared. Is there a way to work that in to
the beginSheet call?
Substituting this function fails as well, however :
{{{
def mediaSourceSheetDidEnd(oPanel, returnCode: rCode, contextInfo: cInfo)
if rCode == NSCancelButton
puts "Canceled."
end
if rCode == NSOKButton
puts "OK!"
end
p oPanel
p rCode
p cInfo
end
}}}
--
Ticket URL: <http://www.macruby.org/trac/ticket/221>
MacRuby <http://macruby.org/>
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