RSD1901@TAMSIGMA.BITNET (Shane Davis) (01/09/88)
I'm working on a program in VAX C which will be run as a detached process.
Right now it's running as a subprocess, but regardless it is started with
the /DUMP qualifier, which causes a process dump to be created if an exception
occurs which causes abnormal image exit. I can use ANALYZE/PROCESS_DUMP to
find out what exception occurred, but no symbols or source is available when
the debugger is invoked. I cannot LINK the object module with /DEBUG because
then the image cannot be run detached.
Is there any way to allow access to the symbols from the debugger in this
case? I was thinking about LINKing it with /SYMBOL_TABLE, but I cannot find
a command in DEBUG which allows one to specify a symbol table to be used
with the image. I cannot run the image interactively because it requires
an AST via mailbox and then it must perform $GETJPI's on the sender of the AST,
and I am not allowed multiple interactive logins and do not have WORLD
privilege to do GETJPI on any other process.
Any ideas on alternative methods of debugging will also be appreciated.
--Shane Davis
Texas A&M Univ. XPrint programmer
BITnet: XPMAINT@TAMVENUS TEXnet: THOR::XPMAINT
RSD1901@TAMSIGMA ZAC::RSD1901
X222SD@TAMVM1rrk@byuvax.bitnet (01/11/88)
Both are possible. You can invoke the dump analyzer specifying a /debug image for symbols even if the crash wasn't. You can also redefine dbg$input and dbg$output for your detached process (usually in a group table) to debug it directly.
nagy%warner.hepnet@LBL.GOV (Frank J. Nagy, VAX Wizard & Guru) (01/11/88)
Shane Davis <RSD1901%TAMSIGMA.BITNET@CUNYVM.CUNY.EDU> writes: > Is there any way to allow access to the symbols from the debugger in this > case? (ANALYZE/PROCESS_DUMP) Link your program twice, once just like now with /NODEBUG and a second time with /DEBUG and a different /EXECUTABLE name. Then, when you do the ANALYZE/PROCESS_DUMP add /IMAGE=executable-with-symbols and the symbols will be taken from the second image you linked. = Frank J. Nagy "VAX Guru & Wizard" = Fermilab Research Division EED/Controls = HEPNET: WARNER::NAGY (43198::NAGY) or FNAL::NAGY (43009::NAGY) = BitNet: NAGY@FNAL = USnail: Fermilab POB 500 MS/220 Batavia, IL 60510
hydrovax@nmtsun.nmt.edu (M. Warner Losh) (01/12/88)
In article <8801091650.AA08255@ucbvax.Berkeley.EDU>, RSD1901@TAMSIGMA.BITNET (Shane Davis) writes: > I'm working on a program in VAX C which will be run as a detached process. > Right now it's running as a subprocess, but regardless it is started with > the /DUMP qualifier, which causes a process dump to be created if an exception > occurs which causes abnormal image exit. I can use ANALYZE/PROCESS_DUMP to > find out what exception occurred, but no symbols or source is available when > the debugger is invoked. I cannot LINK the object module with /DEBUG because > then the image cannot be run detached. > But you can run detached processes that are linked with the /DEBUG option. There are even TWO WAYS of doing so: i) RUN/NODEBUG/etc Which gives you symbols when the debugger gets invoked (I THINK). ii) DEFINE DBG$INPUT "_TXan:"/GROUP DEFINE DBG$OUTPUT "_TXan:"/GROUP where TXan: is the terminal you wish to use for debugging. A few restrictions apply here: 1) No one else in your group can use the debugger. 2) You MUST be in the same group as the detached process. You can get around 2) by not allowing ANYBODY ELSE ON THE WHOLE SYSTEM to use the debugger by replacing the /GROUP with /SYSTEM. I don't think that you can get around 1) except by doing something like RUN/INPUT=SOME-FILE.COM/etc SYS$SYSTEM:LOGINOUT and having some-file.com look like: $ $ DEFINE DBG$INPUT terminal-name $ DEFINE DBG$OUTPUT terminal-name $ RUN/DEBUG program. $ This is MUCH MUCH better than having to deal with CORE dumps. I found all of this info (at least the DBG$ stuff defined /group) in the SYSTEM SERVICES manual Volume 8A. Utility Routines. pg. PSM-17. These pages are from a 4.4 doc set, so if you are running a higher version (higher than 4.5 which has the same doc set) then they may be in a different place. I discovered this trick while trying to write my own PSM (Print SyMbiot), so look in that section of the manual. -- bitnet: lush@nmt.csnet M. Warner Losh csnet: warner%hydrovax@nmtsun uucp: ...{cmcl2, ihnp4}!lanl!unmvax!nmtsun!warner%hydrovax ...{cmcl2, ihnp4}!lanl!unmvax!nmtsun!hydrovax Warning: Hydrovax is both a machine, and an account, so be careful.