From 8480a37e146c40e82a93c0ecf6144571516c95c5 Mon Sep 17 00:00:00 2001 From: Simon Marchi Date: Mon, 19 Feb 2024 13:07:47 -0500 Subject: 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 --- gdb/ppc-linux-tdep.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'gdb/ppc-linux-tdep.c') diff --git a/gdb/ppc-linux-tdep.c b/gdb/ppc-linux-tdep.c index a7c1104..2824cb6 100644 --- a/gdb/ppc-linux-tdep.c +++ b/gdb/ppc-linux-tdep.c @@ -338,7 +338,7 @@ powerpc_linux_in_dynsym_resolve_code (CORE_ADDR pc) stub sequence. */ static CORE_ADDR -ppc_skip_trampoline_code (frame_info_ptr frame, CORE_ADDR pc) +ppc_skip_trampoline_code (const frame_info_ptr &frame, CORE_ADDR pc) { unsigned int insnbuf[POWERPC32_PLT_CHECK_LEN]; struct gdbarch *gdbarch = get_frame_arch (frame); @@ -1169,7 +1169,7 @@ ppc_linux_iterate_over_regset_sections (struct gdbarch *gdbarch, } static void -ppc_linux_sigtramp_cache (frame_info_ptr this_frame, +ppc_linux_sigtramp_cache (const frame_info_ptr &this_frame, struct trad_frame_cache *this_cache, CORE_ADDR func, LONGEST offset, int bias) @@ -1241,7 +1241,7 @@ ppc_linux_sigtramp_cache (frame_info_ptr this_frame, static void ppc32_linux_sigaction_cache_init (const struct tramp_frame *self, - frame_info_ptr this_frame, + const frame_info_ptr &this_frame, struct trad_frame_cache *this_cache, CORE_ADDR func) { @@ -1253,7 +1253,7 @@ ppc32_linux_sigaction_cache_init (const struct tramp_frame *self, static void ppc64_linux_sigaction_cache_init (const struct tramp_frame *self, - frame_info_ptr this_frame, + const frame_info_ptr &this_frame, struct trad_frame_cache *this_cache, CORE_ADDR func) { @@ -1265,7 +1265,7 @@ ppc64_linux_sigaction_cache_init (const struct tramp_frame *self, static void ppc32_linux_sighandler_cache_init (const struct tramp_frame *self, - frame_info_ptr this_frame, + const frame_info_ptr &this_frame, struct trad_frame_cache *this_cache, CORE_ADDR func) { @@ -1277,7 +1277,7 @@ ppc32_linux_sighandler_cache_init (const struct tramp_frame *self, static void ppc64_linux_sighandler_cache_init (const struct tramp_frame *self, - frame_info_ptr this_frame, + const frame_info_ptr &this_frame, struct trad_frame_cache *this_cache, CORE_ADDR func) { -- cgit v1.1