[Info-vax] Non-portable code

[Richard Maher]

Hi Marc,

<VAXman- @SendSpamHere.ORG> wrote in message
news:00A971CB.1A391FDB at SendSpamHere.ORG...
> In article <mn.2d1b7da1fb0d0bdb.104627 at brutele.be>, Marc Van Dyck
<marc.vandyck at brutele.be> writes:
> >G'd evening to all...
> >
> >I have a program on my systems, that was written in the VAX ages,
> >and that I use to display which version of layered products, tools,
> >etc,
> >are installed. It simply extracts from the image headers the version
> >info that has been put there by the linker, with the IDENT clause of
> >the link options file.
> >
> >Here is an extract of the code that does it (Pascal) :
> >
> >RESET ( f ) ;
> >buffer := f^ ;
> >CLOSE ( f ) ;
> >
> >addr := IADDRESS (buffer) +
> >        buffer[EIHD$L_IMGIDOFF+1]::$UBYTE +
> >        EIHI$T_IMGID ;
> >image_id.LENGTH := 0 ;
> >
> >LIB$MOVC3 ( word_integer_length := 1 ,
> >            source := %IMMED addr ,
> >            destination := image_id.LENGTH ) ;
> >addr := addr + 1 ;
> >STR$COPY_R ( destination_string := image_id.BODY ,
> >             word_integer_source_length := image_id.LENGTH ,
> >             source_string_address := %IMMED addr ) ;
> >
> >(Assuming that f is an executable image file and image_id the place for
> >the info that I want to obtain)
> >
> >EIHD$L_IMGIDOFF and EIHI$T_IMGID are declared as [EXTERNAL,VALUE]
> >variables and resolved at link time by inserting a .STB file (don't
> >remember which one, I'm at home here) in the link options file.
> >
> >This works perfectly well on VAX and Alpha. On Itanium, it compiles
> >but either gives false results, or even ACCVIOes (I suppose that it
> >happens when what I read in buffer[EIHD$L_IMGIDOFF+1] is absurdly
> >high).
> >
> >So, a few questions :
> >
> >For Integrity images, is the method I used above still valid - but with
> >wrong offsets - or am I completely screwed up ? If positive, what are
> >the offsets that I should use ? If not, how should I do ? Is it
> >documented somewhere ?
>
> This will NOT work on IA64.  You need too study ELF.
>
>
> >If the offsets EIHD$L_IMGIDOFF and EIHI$T_IMGID are wrong on Integrity,
> >why is it possible that the program compiled and linked with no problem
> >at all ? I would have expected that those either have the correct
> >value,
> >or do not exist at all, in which case the link would have failed. Where
> >am I wrong ?
>
> They're not wrong.  The image format was NOT devised by DEC/Compaq/HP and
> VMS engineering.  The chose to go with ELF.  Check $ELFDEF in STARLET.MLB
>
>
> >If I need to have code differences between the VAX/AXP and the I64
> >version, do I need to have two separate source files, or does Pascal
> >provide some way of conditional compiling ?
>
> Pascal specific questions are best left to John Reagan.  I've done
> what you are seeking to do in Macro32 with a common source file.
>
>
> >Many thanks in advance for your help. This is the first time I
> >encouter code which is not source-compatible between the 3 VMS
> >hardware architectures...
>
> You haven't looked very hard! :)
>
> -- 
> VAXman- A Bored Certified VMS Kernel Mode Hacker
VAXman(at)TMESIS(dot)ORG
>
>   http://www.quirkfactory.com/popart/asskey/eqn2.png
>
>   "Well my son, life is like a beanstalk, isn't it?"

Not sure if it helps but Tim Sneddon (pretty sure it was him?) put me onto
the DCL Symbol populating functionality with Analyze/Image.

I'd include the bit from our KITINSTAL.COM (IA64) but I can't get there at
the moment as the IP Address regime is all over the place with
Browser\OS\Hardware versioning Tests :-(

Anyway, IIRC at least for us it was the mut's nuts.

Cheers Richard Maher