diff mbox series

[PATCHv9,03/14] gdb: change 'if' to gdb_assert in update_dprintf_command_list

Message ID 1b59bf3286719bd63e4cc9caaf66e977fdf49e64.1709651994.git.aburgess@redhat.com
State New
Headers
Series thread-specific breakpoints in just some inferiors |

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Commit Message

Andrew Burgess March 5, 2024, 3:21 p.m. UTC 
  I noticed in update_dprintf_command_list that we handle the case where
the bp_dprintf style breakpoint doesn't have a format and args string.

However, I don't believe such a situation is possible.  The obvious
approach certainly already catches this case:

  (gdb) dprintf main
  Format string required

If it is possible to create a dprintf breakpoint without a format and
args string then I think we should be catching this case and handling
it at creation time, rather than having GDB just ignore the situation
later on.

And so, I propose that we change the 'if' that ignores the case where
the format/args string is empty, and instead assert that we do always
have a format/args string.  The original code, that handled an empty
format/args string has existed since commit e7e0cddfb0d4, which is
when dprintf support was added to GDB.

If I'm correct and this situation can't ever happen then there should
be no user visible changes after this commit.
---
 gdb/breakpoint.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Comments

Andrew Burgess March 31, 2024, 10:27 a.m. UTC | #1 
Andrew Burgess <aburgess@redhat.com> writes:

> I noticed in update_dprintf_command_list that we handle the case where
> the bp_dprintf style breakpoint doesn't have a format and args string.
>
> However, I don't believe such a situation is possible.  The obvious
> approach certainly already catches this case:
>
>   (gdb) dprintf main
>   Format string required
>
> If it is possible to create a dprintf breakpoint without a format and
> args string then I think we should be catching this case and handling
> it at creation time, rather than having GDB just ignore the situation
> later on.
>
> And so, I propose that we change the 'if' that ignores the case where
> the format/args string is empty, and instead assert that we do always
> have a format/args string.  The original code, that handled an empty
> format/args string has existed since commit e7e0cddfb0d4, which is
> when dprintf support was added to GDB.
>
> If I'm correct and this situation can't ever happen then there should
> be no user visible changes after this commit.

I've gone ahead and committed this patch.

Thanks,
Andrew
diff mbox series

Patch

diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index 0482064d057..a7b516ab26c 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -8528,8 +8528,9 @@  update_dprintf_command_list (struct breakpoint *b)
   const char *dprintf_args = b->extra_string.get ();
   gdb::unique_xmalloc_ptr<char> printf_line = nullptr;
 
-  if (!dprintf_args)
-    return;
+  /* Trying to create a dprintf breakpoint without a format and args
+     string should be detected at creation time.  */
+  gdb_assert (dprintf_args != nullptr);
 
   dprintf_args = skip_spaces (dprintf_args);