[Bug rust/31565] New: "info symbol 0xffffffffffffffff" fails in rust mode with "That operation is not available on integers of more than 8 bytes."

[Bug rust/31565] New: "info symbol 0xffffffffffffffff" fails in rust mode with "That operation is not available on integers of more than 8 bytes."

[sourceware-bugzilla-24 at intrigus dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=31565

            Bug ID: 31565
           Summary: "info symbol 0xffffffffffffffff" fails in rust mode
                    with "That operation is not available on integers of
                    more than 8 bytes."
           Product: gdb
           Version: 14.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: rust
          Assignee: unassigned at sourceware dot org
          Reporter: sourceware-bugzilla-24 at intrigus dot org
  Target Milestone: ---

After running "set language rust"
and then executing "info symbol 0xffffffffffffffff" gdb fails with:
"That operation is not available on integers of more than 8 bytes."

This is indirectly caused by the fix for
https://sourceware.org/bugzilla/show_bug.cgi?id=21185

Previously, gdb would parse "0xffffffffffffffff" as i64, while now "ptype
0xffffffffffffffff" returns i128 which "info symbol" apparently does not
handle.

Bad workaround:
Instead of executing "info symbol 0xffffffffffffffff", execute this:
"info symbol 0xffffffffffffffffi64"
However this has the disadvantage that tools that are scripting gdb have to
explicitly add a special-case when gdb is in rust mode.
(E.g. pwndbg: https://github.com/pwndbg/pwndbg/issues/2080)
This is because the "i64" suffix only works in rust mode and I am not aware of
a suffix that works across all languages.

Changing the parsing of numbers such that 0xffffffffffffffff is not parsed as a
i128 but a u64 would probably not be a solution, because it is also surprising
behavior.
(This is because "ptype 0xffffffff" is currently parsed as i64 and for
consistency this would need to be changed to return u32 or the behavior would
be inconsistent).

So I'd guess that the best solution might be to have "info symbol" support
arguments that are either wider than 64 bit or it should check whether the 128
bit value fits into a 64 bit unsigned type.

Versions tested:
"GNU gdb (GDB; JetBrains IDE bundle; build 185) 14.1"
https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=bb9a951fab7a30cc1209c6b8b1716c13456e8b1a
(master from 2024-03-26)

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[Bug rust/31565] "info symbol 0xffffffffffffffff" fails in rust mode with "That operation is not available on integers of more than 8 bytes."

[tromey at sourceware dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=31565

Tom Tromey <tromey at sourceware dot org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|unassigned at sourceware dot org   |tromey at sourceware dot org
   Last reconfirmed|                            |2024-03-27
                 CC|                            |tromey at sourceware dot org
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW

--- Comment #1 from Tom Tromey <tromey at sourceware dot org> ---
I am testing a patch.

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[Bug rust/31565] "info symbol 0xffffffffffffffff" fails in rust mode with "That operation is not available on integers of more than 8 bytes."

[tromey at sourceware dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=31565

Tom Tromey <tromey at sourceware dot org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |tsng.nullptr at outlook dot com

--- Comment #2 from Tom Tromey <tromey at sourceware dot org> ---
*** Bug 31691 has been marked as a duplicate of this bug. ***

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[Bug rust/31565] "info symbol 0xffffffffffffffff" fails in rust mode with "That operation is not available on integers of more than 8 bytes."

[tromey at sourceware dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=31565

--- Comment #3 from Tom Tromey <tromey at sourceware dot org> ---
My current patch works by changing the scalar-extraction
code to handle over-long byte sequences as long as the
resulting value fits.
However I wonder if instead I should just change the
rust parser to emit u64 in this scenario.
That is a bit weird but maybe not fatally so.

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[Bug rust/31565] "info symbol 0xffffffffffffffff" fails in rust mode with "That operation is not available on integers of more than 8 bytes."

[tromey at sourceware dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=31565

--- Comment #4 from Tom Tromey <tromey at sourceware dot org> ---
Using u64 is weird though, because then using '-' on some
big number will give the wrong answer.
Feeling a bit stuck but probably should go back to the old
approach.  Or maybe just use i64 here.

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