* Shortcomings of HPD '#' identifier qualification syntax
@ 2008-04-07 2:06 Petr Machata
2008-04-08 13:45 ` Andrew Cagney
0 siblings, 1 reply; 4+ messages in thread
From: Petr Machata @ 2008-04-07 2:06 UTC (permalink / raw)
To: frysk
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HPD syntax misses certain features that I'd like to use in ftrace (and
who knows, maybe fhpd users would appreciate them, too). So here goes
my bikeshed problem:
1) You can't specify ELF symbol version,
2) You can't specify PLT entry
Number 1 can be solved by simply allowing the symbol name to have a form
of "symbolname@version". "@" is good for that purpose, because it's
non-ambiguous, and already used by readelf to refer to symbol versions.
Number 2 can be resolved in any number of ways. In ftrace, I currently
output traced PLT entries like "#soname#plt:symbolname". This looks
nice, seems to be easy to remember, but would be hard to parse in the
context of ?: ternary expression. objdump uses notation of the form of
"symbol@PLT", which would collide with symbol version syntax. Maybe
something along the lines of ".plt:symbol"?
Opinions? Ideas?
PM
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^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Shortcomings of HPD '#' identifier qualification syntax
2008-04-07 2:06 Shortcomings of HPD '#' identifier qualification syntax Petr Machata
@ 2008-04-08 13:45 ` Andrew Cagney
2008-04-08 14:56 ` Petr Machata
2008-04-28 11:55 ` Sami Wagiaalla
0 siblings, 2 replies; 4+ messages in thread
From: Andrew Cagney @ 2008-04-08 13:45 UTC (permalink / raw)
To: Petr Machata; +Cc: frysk
Sami and I were brainstorming some #-parsing vs lexing problems friday
We came up with a rough rule of thumb that given a #, everything until
until a space (and a finite small set of characters) would be included
in the token. Without this something like:
(fhpd) print #libc#environ + #libc.co#errno
would not end how you'd expect. Similarly, this gives us a way to
handle the "." in
(fhpd) print #solib#astruct .member
(fhpd) print #solib#afile.c#10
The consequence is that extra tokens such as "@" and ":" can be made to
work.
Andrew
Petr Machata wrote:
> HPD syntax misses certain features that I'd like to use in ftrace (and
> who knows, maybe fhpd users would appreciate them, too). So here goes
> my bikeshed problem:
>
> 1) You can't specify ELF symbol version,
> 2) You can't specify PLT entry
>
> Number 1 can be solved by simply allowing the symbol name to have a form
> of "symbolname@version". "@" is good for that purpose, because it's
> non-ambiguous, and already used by readelf to refer to symbol versions.
>
>
i noticed, will help with cut/paste.
> Number 2 can be resolved in any number of ways. In ftrace, I currently
> output traced PLT entries like "#soname#plt:symbolname". This looks
> nice, seems to be easy to remember, but would be hard to parse in the
> context of ?: ternary expression. objdump uses notation of the form of
> "symbol@PLT", which would collide with symbol version syntax. Maybe
> something along the lines of ".plt:symbol"?
>
> Opinions? Ideas?
>
> PM
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Shortcomings of HPD '#' identifier qualification syntax
2008-04-08 13:45 ` Andrew Cagney
@ 2008-04-08 14:56 ` Petr Machata
2008-04-28 11:55 ` Sami Wagiaalla
1 sibling, 0 replies; 4+ messages in thread
From: Petr Machata @ 2008-04-08 14:56 UTC (permalink / raw)
To: Andrew Cagney; +Cc: frysk
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On Tue, Apr 08, 2008 at 09:16:41AM -0400, Andrew Cagney wrote:
> Sami and I were brainstorming some #-parsing vs lexing problems friday
> (fhpd) print #solib#astruct .member
Hmm, the necessity to insert spaces into expressions to disambiguate
parsing is nasty. Unfortunately I have no better idea.
Anyway, in that case I'm leaving the #-output of ftrace as it is with
plt: for designation of plt entries.
PM
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^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Shortcomings of HPD '#' identifier qualification syntax
2008-04-08 13:45 ` Andrew Cagney
2008-04-08 14:56 ` Petr Machata
@ 2008-04-28 11:55 ` Sami Wagiaalla
1 sibling, 0 replies; 4+ messages in thread
From: Sami Wagiaalla @ 2008-04-28 11:55 UTC (permalink / raw)
To: Andrew Cagney; +Cc: Petr Machata, frysk
I am now starting to implement # parsing in the search engine.
I would like to generate a list of all possible queries that
the search engine can be asked for.
Here is what I have so far:
- #lib#file#symbol
- #lib#file#symbol@version ?
- #lib#file#plt:symbol ?
- #lib#symbol
- #lib#symbol@version ?
- #lib#plt:symbol ?
- #file#symbol
- #file#line
Any additions, corrections, comments ?
Sami Wagiaalla
^ permalink raw reply [flat|nested] 4+ messages in thread
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2008-04-07 2:06 Shortcomings of HPD '#' identifier qualification syntax Petr Machata
2008-04-08 13:45 ` Andrew Cagney
2008-04-08 14:56 ` Petr Machata
2008-04-28 11:55 ` Sami Wagiaalla
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