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From: "tromey at sourceware dot org" <sourceware-bugzilla@sourceware.org>
To: gdb-prs@sourceware.org
Subject: [Bug gdb/30278] gdb gives wrong value at -O1
Date: Mon, 27 Mar 2023 14:59:34 +0000	[thread overview]
Message-ID: <bug-30278-4717-q0MKCzVvhj@http.sourceware.org/bugzilla/> (raw)
In-Reply-To: <bug-30278-4717@http.sourceware.org/bugzilla/>

https://sourceware.org/bugzilla/show_bug.cgi?id=30278

--- Comment #2 from Tom Tromey <tromey at sourceware dot org> ---
gdb runs into this code:

      if (low == high && pc == low)
        {
          /* This is entry PC record present only at entry point
             of a function.  Verify it is really the function entry point.  */

in dwarf2_find_location_expression.

In other code paths it does properly check the condition:

      if (pc >= low && pc < high)

It's hard to be sure but maybe this code is some workaround for
a bad compiler case involving entry values, that's then hit by
this particular test case as well.

So right now I'm inclined to say that, while this is a bug, it's
probably better to leave it in place than to try harder to fix it.
The kind of code in the example here isn't really normal or useful.

Maybe one option would be to see if the symbol ("i" in this case)
really could possibly have an entry value.  That would exclude "i"
here since it is not a parameter.

-- 
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  parent reply	other threads:[~2023-03-27 14:59 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-03-27 13:34 [Bug gdb/30278] New: " hluaw at connect dot ust.hk
2023-03-27 14:50 ` [Bug gdb/30278] " tromey at sourceware dot org
2023-03-27 14:59 ` tromey at sourceware dot org [this message]
2023-03-27 15:42 ` ssbssa at sourceware dot org
2023-03-27 20:48 ` tromey at sourceware dot org

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