Re: [Cygwin-ports-general] Ncview

[Marco Atzeri <marco.atzeri@gmail.com>]

On 01/10/2015 19:35, Yaakov Selkowitz wrote:
> On Mon, 2015-09-28 at 17:33 +0200, Marco Atzeri wrote:
>> On 28/09/2015 16:07, Vasileios Anagnostopoulos wrote:

>>
>> 2) the 64 bit crashes inside X libs.
>>      I never succeeded to identify the root cause
>
> Confirmed.  Often 64-bit-only issues come down to one or more of the
> following:
>
> * implicit function declarations.  Per the C standard, argument types
> are assumed to match whatever is given (which may be wrong if e.g. 0 is
> used instead of 0L or (PointerType)0 or NULL etc.) and the return type
> is assumed to be int (which will truncate the actual return value when
> it is actually a long/pointer).

This is not. The only two implicit declaration are of type int
and declaring them changes noting.

>
> * vararg types.  Because these types aren't declared, the compiler can't
> automatically cast values to the correct type, so literal values and
> symbolic constants must be explicitly cast if they are not meant to be
> an int and are not obviously a long/pointer.

I don't find any case.

> In the case of ncview, I strongly suspect the latter should anyone be
> interested in fixing this.

The hard issue is that only cygwin 64 bit seems impacted,
while other 64 platform are fine,
and that the crash is well deep X libraries during the
destruction phase of graphical elements

#0  LayoutChild (w=w@entry=0x60065ef80)
     at /usr/src/debug/libXaw-1.0.12-2/src/Form.c:693
#1  0x00000003cabefc26 in LayoutChild (w=w@entry=0x60064e8a0)
     at /usr/src/debug/libXaw-1.0.12-2/src/Form.c:702
#2  0x00000003cabefc26 in LayoutChild (w=<optimized out>)
     at /usr/src/debug/libXaw-1.0.12-2/src/Form.c:702
#3  0x00000003cabf04ed in Layout (fw=0x60011a2e0, width=<optimized out>,
     height=<optimized out>, force_relayout=1)
     at /usr/src/debug/libXaw-1.0.12-2/src/Form.c:565
#4  0x00000003cabefb2b in XawFormChangeManaged (w=0x60011a2e0)
     at /usr/src/debug/libXaw-1.0.12-2/src/Form.c:1022
#5  0x00000003ca758f5c in XtUnmanageChildren (children=0x22c8d0,
     num_children=1) at /usr/src/debug/libXt-1.1.4-2/src/Manage.c:184
#6  0x00000003ca759038 in XtUnmanageChild (child=0x60065ef70,
     child@entry=0x60064e8a0) at 
/usr/src/debug/libXt-1.1.4-2/src/Manage.c:204
#7  0x00000003ca74b1db in XtPhase2Destroy (widget=0x60064e8a0)
     at /usr/src/debug/libXt-1.1.4-2/src/Destroy.c:228
#8  0x00000003ca74b4e8 in _XtDoPhase2Destroy (app=app@entry=0x60003c030,
     dispatch_level=dispatch_level@entry=1)
     at /usr/src/debug/libXt-1.1.4-2/src/Destroy.c:322
#9  0x00000003ca75018b in XtDispatchEvent (event=0x100632a80 <event>)
     at /usr/src/debug/libXt-1.1.4-2/src/Event.c:1432
#10 0x00000001004257af in x_process_user_input ()
     at /usr/src/debug/ncview-2.1.5-1/src/interface/x_interface.c:2492
#11 0x000000010041f75a in in_process_user_input ()
     at /usr/src/debug/ncview-2.1.5-1/src/interface/interface.c:149
#12 0x00000001004031e5 in process_user_input ()
     at /usr/src/debug/ncview-2.1.5-1/src/ncview.c:718
#13 0x00000001004012f4 in main (argc=2, argv=0x22cb30)
     at /usr/src/debug/ncview-2.1.5-1/src/ncview.c:149

as the X graphics elements are not correctly destroyed in sequence.

If someone more knowledgeable in X is interested I can provide the 
program and a test case.

Regards
Marco

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