[PATCHv6,03/10] gdb: change 'if' to gdb_assert in update_dprintf_command_list

Message ID 6dd2d5c964b391a3c5eb44b4c5bdac39dd595ac3.1701513409.git.aburgess@redhat.com
State New
Series [PATCHv6,01/10] gdb: create_breakpoint: add asserts and additional comments |


Context Check Description
linaro-tcwg-bot/tcwg_gdb_build--master-aarch64 success Testing passed
linaro-tcwg-bot/tcwg_gdb_build--master-arm success Testing passed
linaro-tcwg-bot/tcwg_gdb_check--master-aarch64 success Testing passed

Commit Message

Andrew Burgess Dec. 2, 2023, 10:42 a.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(-)


diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index bd28236ce7d..c629d27c4c0 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -8538,8 +8538,9 @@  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);