We have some code in production that is working fine for thousands of
customers. However, one customer can consistently reproduce a problem
which has me stumped.
We're using BDS 2006 (Update 2) and the madExcept report is below. As
you can see, it raises an exception when the FastCode Move code is
called when a string is added to a list. The call that triggers this is
a simple TStringList.AddObject('string', TObject(ptr)).
We're using a TTntStringList class instead of TStringList, but the code
for TTntStringList.AddObject and TTntStringList.InsertItem is identical
to that for TStringList (the only difference is WideString is used
instead of String).
The report below shows the exception being raised on line 334 of
System.pas, but that cannot be correct and I believe it is actually line
3698.
Anyone got any ideas?
operating system : Windows XP Service Pack 2 build 2600
system language : English
system up time : 2 days 16 hours
program up time : 1 day 23 hours
processors : 2x Intel(R) Pentium(R) 4 CPU 3.20GHz
physical memory : 1757/3071 MB (free/total)
free disk space : (C:) 4.16 GB
display mode : 1600x1200, 32 bit
process id : $390
allocated memory : 199.95 MB
madExcept version : 3.0b
callstack crc : $fedba0ff, $6f7cf041, $8d116dcc
exception number : 5
exception class : EInvalidOp
exception message : Invalid floating point operation.
x ($b9c):
00403363 x.exe System 334 +0 Move
0048120b x.exe TntClasses 1269 +4 TTntStringList.InsertItem
00480d9f x.exe TntClasses 1109 +9 TTntStringList.AddObject
005befd8 x.exe TreeScanBase 537 +51 TBaseTreeScanner.AddToFileList
[snip]
cpu registers:
eax = 7f8d7f58
ebx = 010602b0
ecx = 00055198
edx = 7f8d7f60
esi = 00000fe9
edi = 10e27084
eip = 00403360
esp = 0e4edb24
ebp = 0e4edb38
stack dump:
0e4edb24 c0 07 08 00 10 12 48 00 - 08 67 3a 0d 84 70 e2 10
......H..g:..p..
0e4edb34 ac b7 52 00 ac b7 52 00 - a5 0d 48 00 08 67 3a 0d
..R...R...H..g:.
0e4edb44 e9 0f 00 00 80 db 4e 0e - 28 48 5c 00 ac b7 52 00
......N.(H\...R.
0e4edb54 30 cb f9 00 db ef 5b 00 - 8c db 4e 0e 54 4f 40 00
0.....[...N.TO@.
0e4edb64 80 db 4e 0e 18 e9 3a 0d - 00 00 00 00 00 00 00 00
..N...:.........
0e4edb74 ff ff ff ff 18 e9 3a 0d - 00 00 00 00 08 df 4e 0e
......:.......N.
0e4edb84 33 57 5c 00 ac de 4e 0e - 98 db 4e 0e 54 4f 40 00
3W\...N...N.TO@.
0e4edb94 08 df 4e 0e 24 df 4e 0e - 54 4f 40 00 08 df 4e 0e
..N.$.N.TO@...N.
0e4edba4 28 48 5c 00 0c 00 00 00 - 01 00 00 00 00 00 00 00
(H\.............
0e4edbb4 00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00
................
0e4edbc4 00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00
................
0e4edbd4 00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00
................
0e4edbe4 00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00
................
0e4edbf4 00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00
................
0e4edc04 00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00
................
0e4edc14 00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00
................
0e4edc24 00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00
................
0e4edc34 00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00
................
0e4edc44 00 00 00 00 00 00 00 00 - 00 00 00 00 10 00 00 00
................
0e4edc54 00 98 77 17 44 a5 c5 01 - f2 bb 80 53 c3 19 c7 01
..w.D......S....
disassembling:
[...]
00403357 fild qword ptr [eax]
00403359 add ecx, edx
0040335b and ecx, -8
0040335e sub ecx, edx
00403360 fild qword ptr [ecx+eax]
00403363 > fistp qword ptr [ecx+edx]
00403366 sub ecx, 8
00403369 jg loc_403360
0040336b pop ecx
0040336c fistp qword ptr [edx]
0040336e fistp qword ptr [ecx+edx]
[...]
