Re: [PATCH v8] gdb: Add source-tracking breakpoints feature

On Tue, Jul 14, 2026 at 2:41 PM Eli Zaretskii <[email protected]> wrote:

> > From: Alexandra Hájková <[email protected]>
> > Cc: [email protected]
> > Date: Tue, 14 Jul 2026 11:40:52 +0200
> >
> >
> >  gdb/NEWS                                      |  14 +
> >  gdb/breakpoint.c                              | 487 ++++++++++++++++++
> >  gdb/breakpoint.h                              |  16 +-
> >  gdb/doc/gdb.texinfo                           |  45 ++
> >  .../gdb.base/adjust_breakpoint-2.cpp          |  39 ++
> >  .../gdb.base/adjust_breakpoint-3.cpp          |  41 ++
> >  .../gdb.base/adjust_breakpoint-4.cpp          |  37 ++
> >  .../adjust_breakpoint-missing-source.exp      |  55 ++
> >  gdb/testsuite/gdb.base/adjust_breakpoint.cpp  |  40 ++
> >  gdb/testsuite/gdb.base/adjust_breakpoint.exp  | 168 ++++++
> >  .../gdb.base/source-tracking-inline-1.c       |  50 ++
> >  .../gdb.base/source-tracking-inline-2.c       |  49 ++
> >  .../gdb.base/source-tracking-inline.exp       |  80 +++
> >  gdb/testsuite/gdb.base/test_source_tracking.c |  18 +
> >  .../gdb.base/test_source_tracking.exp         |  43 ++
> >  15 files changed, 1181 insertions(+), 1 deletion(-)
> >  create mode 100644 gdb/testsuite/gdb.base/adjust_breakpoint-2.cpp
> >  create mode 100644 gdb/testsuite/gdb.base/adjust_breakpoint-3.cpp
> >  create mode 100644 gdb/testsuite/gdb.base/adjust_breakpoint-4.cpp
> >  create mode 100644
> gdb/testsuite/gdb.base/adjust_breakpoint-missing-source.exp
> >  create mode 100644 gdb/testsuite/gdb.base/adjust_breakpoint.cpp
> >  create mode 100644 gdb/testsuite/gdb.base/adjust_breakpoint.exp
> >  create mode 100644 gdb/testsuite/gdb.base/source-tracking-inline-1.c
> >  create mode 100644 gdb/testsuite/gdb.base/source-tracking-inline-2.c
> >  create mode 100644 gdb/testsuite/gdb.base/source-tracking-inline.exp
> >  create mode 100644 gdb/testsuite/gdb.base/test_source_tracking.c
> >  create mode 100644 gdb/testsuite/gdb.base/test_source_tracking.exp
>
> Thanks.
>
> > diff --git a/gdb/NEWS b/gdb/NEWS
> > index ec9b5a33787..553d8c49ff6 100644
> > --- a/gdb/NEWS
> > +++ b/gdb/NEWS
> > @@ -6,6 +6,13 @@
> >  * Support for the Common Trace Format (CTF) has been removed.  GDB now
> >    saves trace information exclusively in its own "tfile" format.
> >
> > +* GDB now supports source-tracking breakpoints, which automatically
> > +  adjust their location when source code changes between rebuilds.
> > +  When enabled, file and line breakpoints capture the surrounding
> > +  source code context and use it to adjust the breakpoint line if the
> > +  source is modified.  Source tracking can be enabled with 'set
> > +  breakpoint source-tracking enabled on'.
>
> This part is okay, but is this feature available in all builds of GDB?
> For example, is the availability of the 'compile' command or being
> able to rebuild the program while the GDB session is active necessary
> for this to work?
>
> If there are preconditions, we should mention them, so users won't
> expect this to work where it isn't supported.
>
> > +set breakpoint source-tracking enabled [on|off]
> > +show breakpoint source-tracking enabled
> > +  Enable or disable source-tracking for file and line breakpoints.
> > +  When enabled, breakpoints capture surrounding source code and
> > +  automatically adjust their location when the source changes between
> > +  recompilations.
>
> Why aren't the maintenance commands you add called out in NEWS?
>
> > diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
> > index a698b2b8451..d304f885def 100644
> > --- a/gdb/doc/gdb.texinfo
> > +++ b/gdb/doc/gdb.texinfo
>
> This part is okay.
>
> Reviewed-By: Eli Zaretskii <[email protected]>
>

Hi Eli,

This feature works in all GDB builds, it only requires that source files
are accessible and the
binary was compiled with debug info (line numbers). No special dependencies
like `compile`
are needed.

The maintenance command will be added to NEWS in the next version, thanks
for catching that.

Thank you,
Alexandra