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author | Simon Marchi <simon.marchi@efficios.com> | 2024-02-19 13:07:47 -0500 |
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committer | Simon Marchi <simon.marchi@efficios.com> | 2024-02-20 10:42:25 -0500 |
commit | 8480a37e146c40e82a93c0ecf6144571516c95c5 (patch) | |
tree | bfa5d1e14e5212821ee29ae5099be72399137036 /gdb/infcmd.c | |
parent | 1b2c120daf9e2d935453f9051bbeafbac7f9f14d (diff) | |
download | binutils-8480a37e146c40e82a93c0ecf6144571516c95c5.zip binutils-8480a37e146c40e82a93c0ecf6144571516c95c5.tar.gz binutils-8480a37e146c40e82a93c0ecf6144571516c95c5.tar.bz2 |
gdb: pass frames as `const frame_info_ptr &`
We currently pass frames to function by value, as `frame_info_ptr`.
This is somewhat expensive:
- the size of `frame_info_ptr` is 64 bytes, which is a bit big to pass
by value
- the constructors and destructor link/unlink the object in the global
`frame_info_ptr::frame_list` list. This is an `intrusive_list`, so
it's not so bad: it's just assigning a few points, there's no memory
allocation as if it was `std::list`, but still it's useless to do
that over and over.
As suggested by Tom Tromey, change many function signatures to accept
`const frame_info_ptr &` instead of `frame_info_ptr`.
Some functions reassign their `frame_info_ptr` parameter, like:
void
the_func (frame_info_ptr frame)
{
for (; frame != nullptr; frame = get_prev_frame (frame))
{
...
}
}
I wondered what to do about them, do I leave them as-is or change them
(and need to introduce a separate local variable that can be
re-assigned). I opted for the later for consistency. It might not be
clear why some functions take `const frame_info_ptr &` while others take
`frame_info_ptr`. Also, if a function took a `frame_info_ptr` because
it did re-assign its parameter, I doubt that we would think to change it
to `const frame_info_ptr &` should the implementation change such that
it doesn't need to take `frame_info_ptr` anymore. It seems better to
have a simple rule and apply it everywhere.
Change-Id: I59d10addef687d157f82ccf4d54f5dde9a963fd0
Approved-By: Andrew Burgess <aburgess@redhat.com>
Diffstat (limited to 'gdb/infcmd.c')
-rw-r--r-- | gdb/infcmd.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/gdb/infcmd.c b/gdb/infcmd.c index 4e17a6b..c1fdbb3 100644 --- a/gdb/infcmd.c +++ b/gdb/infcmd.c @@ -1743,7 +1743,7 @@ finish_backward (struct finish_command_fsm *sm) frame that called the function we're about to step out of. */ static void -finish_forward (struct finish_command_fsm *sm, frame_info_ptr frame) +finish_forward (struct finish_command_fsm *sm, const frame_info_ptr &frame) { struct frame_id frame_id = get_frame_id (frame); struct gdbarch *gdbarch = get_frame_arch (frame); @@ -1768,9 +1768,10 @@ finish_forward (struct finish_command_fsm *sm, frame_info_ptr frame) /* Skip frames for "finish". */ static frame_info_ptr -skip_finish_frames (frame_info_ptr frame) +skip_finish_frames (const frame_info_ptr &initial_frame) { frame_info_ptr start; + frame_info_ptr frame = initial_frame; do { @@ -2256,7 +2257,7 @@ default_print_one_register_info (struct ui_file *file, void default_print_registers_info (struct gdbarch *gdbarch, struct ui_file *file, - frame_info_ptr frame, + const frame_info_ptr &frame, int regnum, int print_all) { int i; @@ -2416,7 +2417,7 @@ info_registers_command (const char *addr_exp, int from_tty) static void print_vector_info (struct ui_file *file, - frame_info_ptr frame, const char *args) + const frame_info_ptr &frame, const char *args) { struct gdbarch *gdbarch = get_frame_arch (frame); @@ -2953,7 +2954,7 @@ interrupt_command (const char *args, int from_tty) void default_print_float_info (struct gdbarch *gdbarch, struct ui_file *file, - frame_info_ptr frame, const char *args) + const frame_info_ptr &frame, const char *args) { int regnum; int printed_something = 0; |