diff options
Diffstat (limited to 'gdb/frame.c')
| -rw-r--r-- | gdb/frame.c | 101 |
1 files changed, 86 insertions, 15 deletions
diff --git a/gdb/frame.c b/gdb/frame.c index 8d4e2c8..d52c26a 100644 --- a/gdb/frame.c +++ b/gdb/frame.c @@ -43,6 +43,7 @@ #include "block.h" #include "inline-frame.h" #include "tracepoint.h" +#include "hashtab.h" static struct frame_info *get_prev_frame_1 (struct frame_info *this_frame); static struct frame_info *get_prev_frame_raw (struct frame_info *this_frame); @@ -128,38 +129,107 @@ struct frame_info enum unwind_stop_reason stop_reason; }; -/* A frame stash used to speed up frame lookups. */ +/* A frame stash used to speed up frame lookups. Create a hash table + to stash frames previously accessed from the frame cache for + quicker subsequent retrieval. The hash table is emptied whenever + the frame cache is invalidated. */ -/* We currently only stash one frame at a time, as this seems to be - sufficient for now. */ -static struct frame_info *frame_stash = NULL; +static htab_t frame_stash; -/* Add the following FRAME to the frame stash. */ +/* Internal function to calculate a hash from the frame_id addresses, + using as many valid addresses as possible. Frames below level 0 + are not stored in the hash table. */ + +static hashval_t +frame_addr_hash (const void *ap) +{ + const struct frame_info *frame = ap; + const struct frame_id f_id = frame->this_id.value; + hashval_t hash = 0; + + gdb_assert (f_id.stack_addr_p || f_id.code_addr_p + || f_id.special_addr_p); + + if (f_id.stack_addr_p) + hash = iterative_hash (&f_id.stack_addr, + sizeof (f_id.stack_addr), hash); + if (f_id.code_addr_p) + hash = iterative_hash (&f_id.code_addr, + sizeof (f_id.code_addr), hash); + if (f_id.special_addr_p) + hash = iterative_hash (&f_id.special_addr, + sizeof (f_id.special_addr), hash); + + return hash; +} + +/* Internal equality function for the hash table. This function + defers equality operations to frame_id_eq. */ + +static int +frame_addr_hash_eq (const void *a, const void *b) +{ + const struct frame_info *f_entry = a; + const struct frame_info *f_element = b; + + return frame_id_eq (f_entry->this_id.value, + f_element->this_id.value); +} + +/* Internal function to create the frame_stash hash table. 100 seems + to be a good compromise to start the hash table at. */ + +static void +frame_stash_create (void) +{ + frame_stash = htab_create (100, + frame_addr_hash, + frame_addr_hash_eq, + NULL); +} + +/* Internal function to add a frame to the frame_stash hash table. Do + not store frames below 0 as they may not have any addresses to + calculate a hash. */ static void frame_stash_add (struct frame_info *frame) { - frame_stash = frame; + /* Do not stash frames below level 0. */ + if (frame->level >= 0) + { + struct frame_info **slot; + + slot = (struct frame_info **) htab_find_slot (frame_stash, + frame, + INSERT); + *slot = frame; + } } -/* Search the frame stash for an entry with the given frame ID. - If found, return that frame. Otherwise return NULL. */ +/* Internal function to search the frame stash for an entry with the + given frame ID. If found, return that frame. Otherwise return + NULL. */ static struct frame_info * frame_stash_find (struct frame_id id) { - if (frame_stash && frame_id_eq (frame_stash->this_id.value, id)) - return frame_stash; + struct frame_info dummy; + struct frame_info *frame; - return NULL; + dummy.this_id.value = id; + frame = htab_find (frame_stash, &dummy); + return frame; } -/* Invalidate the frame stash by removing all entries in it. */ +/* Internal function to invalidate the frame stash by removing all + entries in it. This only occurs when the frame cache is + invalidated. */ static void frame_stash_invalidate (void) { - frame_stash = NULL; + htab_empty (frame_stash); } /* Flag to control debugging. */ @@ -345,10 +415,9 @@ get_frame_id (struct frame_info *fi) fprint_frame_id (gdb_stdlog, fi->this_id.value); fprintf_unfiltered (gdb_stdlog, " }\n"); } + frame_stash_add (fi); } - frame_stash_add (fi); - return fi->this_id.value; } @@ -2451,6 +2520,8 @@ _initialize_frame (void) { obstack_init (&frame_cache_obstack); + frame_stash_create (); + observer_attach_target_changed (frame_observer_target_changed); add_prefix_cmd ("backtrace", class_maintenance, set_backtrace_cmd, _("\ |