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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/arch-utils.c | |
parent | 1b2c120daf9e2d935453f9051bbeafbac7f9f14d (diff) | |
download | gdb-8480a37e146c40e82a93c0ecf6144571516c95c5.zip gdb-8480a37e146c40e82a93c0ecf6144571516c95c5.tar.gz gdb-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/arch-utils.c')
-rw-r--r-- | gdb/arch-utils.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/gdb/arch-utils.c b/gdb/arch-utils.c index 1faa013..ae3354f 100644 --- a/gdb/arch-utils.c +++ b/gdb/arch-utils.c @@ -140,7 +140,7 @@ default_get_memtag (struct gdbarch *gdbarch, struct value *address, } CORE_ADDR -generic_skip_trampoline_code (frame_info_ptr frame, CORE_ADDR pc) +generic_skip_trampoline_code (const frame_info_ptr &frame, CORE_ADDR pc) { return 0; } @@ -166,7 +166,7 @@ generic_stack_frame_destroyed_p (struct gdbarch *gdbarch, CORE_ADDR pc) int default_code_of_frame_writable (struct gdbarch *gdbarch, - frame_info_ptr frame) + const frame_info_ptr &frame) { return 1; } @@ -1079,7 +1079,7 @@ default_type_align (struct gdbarch *gdbarch, struct type *type) /* See arch-utils.h. */ std::string -default_get_pc_address_flags (frame_info_ptr frame, CORE_ADDR pc) +default_get_pc_address_flags (const frame_info_ptr &frame, CORE_ADDR pc) { return ""; } @@ -1105,7 +1105,8 @@ default_use_target_description_from_corefile_notes (struct gdbarch *gdbarch, } CORE_ADDR -default_get_return_buf_addr (struct type *val_type, frame_info_ptr cur_frame) +default_get_return_buf_addr (struct type *val_type, + const frame_info_ptr &cur_frame) { return 0; } |