RE: [PATCH 1/1] gdb: Avoid warning for the jump command inside an inline function.

["Willgerodt, Felix" <felix.willgerodt@intel.com>]

> -----Original Message-----
> From: Bruno Larsen <blarsen@redhat.com>
> Sent: Freitag, 17. März 2023 11:14
> To: Willgerodt, Felix <felix.willgerodt@intel.com>; gdb-
> patches@sourceware.org
> Cc: Cristian Sandu <cristian.sandu@intel.com>
> Subject: Re: [PATCH 1/1] gdb: Avoid warning for the jump command inside
> an inline function.
> 
> On 24/01/2023 16:19, Felix Willgerodt via Gdb-patches wrote:
> > When stopped inside an inline function, trying to jump to a different line
> > of the same function currently results in a warning about jumping to
> another
> > function.  Fix this by taking inline functions into account.
> >
> > Before:
> >    Breakpoint 1, function_inline (x=510) at jump-inline.cpp:22
> >    22        a = a + x;             /* inline-funct */
> >    (gdb) j 21
> >    Line 21 is not in `function_inline(int)'.  Jump anyway? (y or n)
> >
> > After:
> >    Breakpoint 2, function_inline (x=510) at jump-inline.cpp:22
> >    22        a = a + x;            /* inline-funct */
> >    (gdb) j 21
> >    Continuing at 0x400679.
> >
> >    Breakpoint 1, function_inline (x=510) at jump-inline.cpp:21
> >    21        a += 1020 + a;                /* increment-funct */
> >
> > This was regression-tested on X86-64 Linux.
> >
> > Co-Authored-by: Cristian Sandu <cristian.sandu@intel.com>
> > ---
> >   gdb/infcmd.c                           |  3 +-
> >   gdb/testsuite/gdb.base/jump-inline.c   | 30 +++++++++++++++++
> >   gdb/testsuite/gdb.base/jump-inline.exp | 45
> ++++++++++++++++++++++++++
> >   3 files changed, 77 insertions(+), 1 deletion(-)
> >   create mode 100644 gdb/testsuite/gdb.base/jump-inline.c
> >   create mode 100644 gdb/testsuite/gdb.base/jump-inline.exp
> >
> > diff --git a/gdb/infcmd.c b/gdb/infcmd.c
> > index fd88b8ca328..40414bc9260 100644
> > --- a/gdb/infcmd.c
> > +++ b/gdb/infcmd.c
> > @@ -1091,7 +1091,8 @@ jump_command (const char *arg, int from_tty)
> >
> >     /* See if we are trying to jump to another function.  */
> >     fn = get_frame_function (get_current_frame ());
> > -  sfn = find_pc_function (sal.pc);
> > +  sfn = find_pc_sect_containing_function (sal.pc,
> > +					  find_pc_mapped_section (sal.pc));
> 
> Hi Felix,
> 
> Thanks for doing this, it is a good improvement, but I don't know if
> this is the best way to go about it. Is there a reason why
> find_pc_function should not return inlined functions?
> 
> I feel like most of the time we want to know the function, knowing if
> we're in an inlined one would be desirable, but I might be wrong. Does
> anyone know?
> 

Hi Bruno,

I don't know the details, but the comments in symtab.h are rather explicit
about it, so I assume there is a reason:


/* lookup the function symbol corresponding to the address.  The
   return value will not be an inlined function; the containing
   function will be returned instead.  */

extern struct symbol *find_pc_function (CORE_ADDR);

/* lookup the function symbol corresponding to the address and
   section.  The return value will be the closest enclosing function,
   which might be an inline function.  */

extern struct symbol *find_pc_sect_containing_function
  (CORE_ADDR pc, struct obj_section *section);


Thanks,
Felix
Intel Deutschland GmbH
Registered Address: Am Campeon 10, 85579 Neubiberg, Germany
Tel: +49 89 99 8853-0, www.intel.de <http://www.intel.de>
Managing Directors: Christin Eisenschmid, Sharon Heck, Tiffany Doon Silva  
Chairperson of the Supervisory Board: Nicole Lau
Registered Office: Munich
Commercial Register: Amtsgericht Muenchen HRB 186928