Re: [RFA] Allow setting breakpoints on inline functions (PR 10738)

[Tom Tromey <tromey at redhat dot com>]

>>>>> "Gary" == Gary Benson <gbenson@redhat.com> writes:

Gary> This patch, which applies on top of Tom's ambiguous linespec work,
Gary> allows you to set breakpoints on inlined functions.  Although it
Gary> can't be committed until Tom's stuff goes in, I'm posting it for
Gary> feedback now.

This is super.  Thanks.

I noticed that the manual node "Inline Functions" says:

       There are some ways that GDB does not pretend that inlined function
    calls are the same as normal calls:

       * You cannot set breakpoints on inlined functions.  GDB either
         reports that there is no symbol with that name, or else sets the
         breakpoint only on non-inlined copies of the function.  This
         limitation will be removed in a future version of GDB; until then,
         set a breakpoint by line number on the first line of the inlined
         function instead.
    [...]

I think this needs a small update.

Also I think this feature deserves a NEWS entry.

I checked it out and played with it a little.  I found one little bug.
Using the inline-break test case from the patch:

(gdb) p &func1
$1 = (int (*)(int)) 0x4003d8 <main+8>

That is, it chooses the location of the inline function as the address
of the function when evaluating an expression.  I think this is wrong.
Instead, it should ignore inline instances here, returning the address
of the out-of-line instance.  And, if there is no out-of-line (as in
this case), it should error.

I think one possible way to do this would be to put a flag on symbols,
marking inline instances, and then have ordinary symbol lookup ignore
such symbols.  I am not sure how hard this would be.  There might also
be other approaches.

Tom