bug#39962: 27.0.90; Crash in Emacs 27.0.90

[Pieter van Oostrum]

Paul Eggert <eggert@cs.ucla.edu> writes:

> On 3/8/20 4:58 PM, Pieter van Oostrum wrote:
>> Can I get this activated in a running gdb, or must I start a new gdb session?
>
> You can type the 'define xgetsym' into a running GDB. Something like this:
>
> (gdb) define xgetsym
> Redefine command "xgetsym"? (y or n) y
> Type commands for definition of "xgetsym".
> End with a line saying just "end".
>>xgetptr $arg0
>>set $ptr = ((struct Lisp_Symbol *) ((char *) &lispsym + $ptr))
>>end
> (gdb)
>

OK, with this change I get sensible information:

(gdb) f 9
#9  0x0000000100314bfe in Ffuncall (nargs=2, args=0x7ffeefbf6e78)
    at eval.c:2796
2796        val = funcall_lambda (fun, numargs, args + 1);
(gdb) p args[0]
$50 = XIL(0xcfeb420)
(gdb) xtype
Lisp_Symbol
(gdb) xsymbol
$51 = (struct Lisp_Symbol *) 0x10da24150
"vm-set-summary-pointer"
(gdb) f 12
#12 0x0000000100314bfe in Ffuncall (nargs=1, args=0x7ffeefbf7e48)
    at eval.c:2796
2796        val = funcall_lambda (fun, numargs, args + 1);
(gdb) p args[0]
$52 = XIL(0x3e349a0)
(gdb) xtype
Lisp_Symbol
(gdb) xsymbol
$53 = (struct Lisp_Symbol *) 0x10486d6d0
"vm-do-needed-summary-rebuild"
(gdb) f 15
#15 0x0000000100314bfe in Ffuncall (nargs=2, args=0x7ffeefbf8e48)
    at eval.c:2796
2796        val = funcall_lambda (fun, numargs, args + 1);
(gdb) p args[0]
$54 = XIL(0x105c5b465)
(gdb) xtype
Lisp_Vectorlike
PVEC_COMPILED
(gdb) f 21
#21 0x0000000100314bae in Ffuncall (nargs=3, args=0x7ffeefbf9198)
    at eval.c:2794
2794        val = funcall_subr (XSUBR (fun), numargs, args + 1);
(gdb) p args[0]
$55 = XIL(0x5fb6d60)
(gdb) xtype
Lisp_Symbol
(gdb) xsymbol
$56 = (struct Lisp_Symbol *) 0x1069efa90
"mapatoms"
(gdb) f 24
#24 0x0000000100314bfe in Ffuncall (nargs=1, args=0x7ffeefbfa1b8)
    at eval.c:2796
2796        val = funcall_lambda (fun, numargs, args + 1);
(gdb) p args[0]
$57 = XIL(0x3e34910)
(gdb) xtype
Lisp_Symbol
(gdb) xsymbol
$58 = (struct Lisp_Symbol *) 0x10486d640
"vm-update-summary-and-mode-line"
(gdb) f 27
#27 0x0000000100314bfe in Ffuncall (nargs=10, args=0x7ffeefbfb608)
    at eval.c:2796
2796        val = funcall_lambda (fun, numargs, args + 1);
(gdb) p args[0]
$59 = XIL(0x56c6a00)
(gdb) xtype
Lisp_Symbol
(gdb) xsymbol
$60 = (struct Lisp_Symbol *) 0x1060ff730
"vm"
(gdb) f 30
#30 0x0000000100314bfe in Ffuncall (nargs=3, args=0x7ffeefbfc958)
    at eval.c:2796
2796        val = funcall_lambda (fun, numargs, args + 1);
(gdb) p args[0]
$61 = XIL(0x4a62fc0)
(gdb) xtype
Lisp_Symbol
(gdb) xsymbol
$62 = (struct Lisp_Symbol *) 0x10549bcf0
"vm-visit-folder"
(gdb) f 31
#31 0x00000001002fd9ca in Ffuncall_interactively (nargs=3, args=0x7ffeefbfc958)
    at callint.c:254
254       return unbind_to (speccount, Ffuncall (nargs, args));
(gdb) p args[0]
$63 = XIL(0x4a62fc0)
(gdb) xtype
Lisp_Symbol
(gdb) xsymbol
$64 = (struct Lisp_Symbol *) 0x10549bcf0
"vm-visit-folder"
(gdb) f 33
#33 0x0000000100314bae in Ffuncall (nargs=4, args=0x7ffeefbfc950)
    at eval.c:2794
2794        val = funcall_subr (XSUBR (fun), numargs, args + 1);
(gdb) p args[0]
$65 = XIL(0x62a0)
(gdb) xtype
Lisp_Symbol
(gdb) xsymbol
$66 = (struct Lisp_Symbol *) 0x100a3efd0
"funcall-interactively"
(gdb) f 37
#37 0x0000000100314bae in Ffuncall (nargs=4, args=0x7ffeefbfd9b8)
    at eval.c:2794
2794        val = funcall_subr (XSUBR (fun), numargs, args + 1);
(gdb) p args[0]
$67 = XIL(0x5f592d0)
(gdb) xtype
Lisp_Symbol
(gdb) xsymbol
$68 = (struct Lisp_Symbol *) 0x106992000
"call-interactively"
(gdb) f 40
#40 0x0000000100314bfe in Ffuncall (nargs=2, args=0x7ffeefbfea18)
    at eval.c:2796
2796        val = funcall_lambda (fun, numargs, args + 1);
(gdb) p args[0]
$69 = XIL(0x3960)
(gdb) xtype
Lisp_Symbol
(gdb) xsymbol
$70 = (struct Lisp_Symbol *) 0x100a3c690
"command-execute"
(gdb) 

-- 
Pieter van Oostrum
www: http://pieter.vanoostrum.org/
PGP key: [8DAE142BE17999C4]