From ea001bdce2a4442eb556c64514c8ec2473f4c4d1 Mon Sep 17 00:00:00 2001 From: Markus Metzger Date: Mon, 18 Mar 2013 16:43:05 +0100 Subject: [PATCH] frame, backtrace: allow targets to supply a frame unwinder Allow targets to supply their own target-specific frame unwinders; one for normal frames and one for tailcall frames. If a target-specific unwinder is supplied, it will be chosen before any other unwinder. The original patch has been split into this and the next two patches. gdb/ 2013-02-11 Jan Kratochvil * frame-unwind.c: Include target.h. (frame_unwind_try_unwinder): New function with code from ... (frame_unwind_find_by_frame): ... here. New variable unwinder_from_target, call also target_get_unwinder) (target_get_tailcall_unwinder, and frame_unwind_try_unwinder for it. * target.c (target_get_unwinder, target_get_tailcall_unwinder): New. * target.h (struct target_ops): New fields to_get_unwinder and to_get_tailcall_unwinder. (target_get_unwinder, target_get_tailcall_unwinder): New declarations. --- gdb/ChangeLog | 12 ++++++++ gdb/frame-unwind.c | 86 ++++++++++++++++++++++++++++++++++++------------------ gdb/target.c | 28 ++++++++++++++++++ gdb/target.h | 11 +++++++ 4 files changed, 109 insertions(+), 28 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 1bfe4e2..a81516b 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,15 @@ +2014-01-16 Jan Kratochvil + + * frame-unwind.c: Include target.h. + (frame_unwind_try_unwinder): New function with code from ... + (frame_unwind_find_by_frame): ... here. New variable + unwinder_from_target, call also target_get_unwinder) + (target_get_tailcall_unwinder, and frame_unwind_try_unwinder for it. + * target.c (target_get_unwinder, target_get_tailcall_unwinder): New. + * target.h (struct target_ops): New fields to_get_unwinder and + to_get_tailcall_unwinder. + (target_get_unwinder, target_get_tailcall_unwinder): New declarations. + 2014-01-16 Markus Metzger * record-btrace.c (record_btrace_fetch_registers) diff --git a/gdb/frame-unwind.c b/gdb/frame-unwind.c index f17cda9..fdfea6e 100644 --- a/gdb/frame-unwind.c +++ b/gdb/frame-unwind.c @@ -27,6 +27,7 @@ #include "exceptions.h" #include "gdb_assert.h" #include "gdb_obstack.h" +#include "target.h" static struct gdbarch_data *frame_unwind_data; @@ -88,6 +89,48 @@ frame_unwind_append_unwinder (struct gdbarch *gdbarch, (*ip)->unwinder = unwinder; } +/* Call SNIFFER from UNWINDER. If it succeeded set UNWINDER for + THIS_FRAME and return 1. Otherwise the function keeps THIS_FRAME + unchanged and returns 0. */ + +static int +frame_unwind_try_unwinder (struct frame_info *this_frame, void **this_cache, + const struct frame_unwind *unwinder) +{ + struct cleanup *old_cleanup; + volatile struct gdb_exception ex; + int res = 0; + + old_cleanup = frame_prepare_for_sniffer (this_frame, unwinder); + + TRY_CATCH (ex, RETURN_MASK_ERROR) + { + res = unwinder->sniffer (unwinder, this_frame, this_cache); + } + if (ex.reason < 0 && ex.error == NOT_AVAILABLE_ERROR) + { + /* This usually means that not even the PC is available, + thus most unwinders aren't able to determine if they're + the best fit. Keep trying. Fallback prologue unwinders + should always accept the frame. */ + do_cleanups (old_cleanup); + return 0; + } + else if (ex.reason < 0) + throw_exception (ex); + else if (res) + { + discard_cleanups (old_cleanup); + return 1; + } + else + { + do_cleanups (old_cleanup); + return 0; + } + gdb_assert_not_reached ("frame_unwind_try_unwinder"); +} + /* Iterate through sniffers for THIS_FRAME frame until one returns with an unwinder implementation. THIS_FRAME->UNWIND must be NULL, it will get set by this function. Possibly initialize THIS_CACHE. */ @@ -98,37 +141,24 @@ frame_unwind_find_by_frame (struct frame_info *this_frame, void **this_cache) struct gdbarch *gdbarch = get_frame_arch (this_frame); struct frame_unwind_table *table = gdbarch_data (gdbarch, frame_unwind_data); struct frame_unwind_table_entry *entry; + const struct frame_unwind *unwinder_from_target; + + unwinder_from_target = target_get_unwinder (); + if (unwinder_from_target != NULL + && frame_unwind_try_unwinder (this_frame, this_cache, + unwinder_from_target)) + return; + + unwinder_from_target = target_get_tailcall_unwinder (); + if (unwinder_from_target != NULL + && frame_unwind_try_unwinder (this_frame, this_cache, + unwinder_from_target)) + return; for (entry = table->list; entry != NULL; entry = entry->next) - { - struct cleanup *old_cleanup; - volatile struct gdb_exception ex; - int res = 0; - - old_cleanup = frame_prepare_for_sniffer (this_frame, entry->unwinder); - - TRY_CATCH (ex, RETURN_MASK_ERROR) - { - res = entry->unwinder->sniffer (entry->unwinder, this_frame, - this_cache); - } - if (ex.reason < 0 && ex.error == NOT_AVAILABLE_ERROR) - { - /* This usually means that not even the PC is available, - thus most unwinders aren't able to determine if they're - the best fit. Keep trying. Fallback prologue unwinders - should always accept the frame. */ - } - else if (ex.reason < 0) - throw_exception (ex); - else if (res) - { - discard_cleanups (old_cleanup); - return; - } + if (frame_unwind_try_unwinder (this_frame, this_cache, entry->unwinder)) + return; - do_cleanups (old_cleanup); - } internal_error (__FILE__, __LINE__, _("frame_unwind_find_by_frame failed")); } diff --git a/gdb/target.c b/gdb/target.c index bfb0633..5e84288 100644 --- a/gdb/target.c +++ b/gdb/target.c @@ -4471,6 +4471,34 @@ debug_to_prepare_to_store (struct target_ops *self, struct regcache *regcache) fprintf_unfiltered (gdb_stdlog, "target_prepare_to_store ()\n"); } +/* See target.h. */ + +const struct frame_unwind * +target_get_unwinder (void) +{ + struct target_ops *t; + + for (t = current_target.beneath; t != NULL; t = t->beneath) + if (t->to_get_unwinder != NULL) + return t->to_get_unwinder; + + return NULL; +} + +/* See target.h. */ + +const struct frame_unwind * +target_get_tailcall_unwinder (void) +{ + struct target_ops *t; + + for (t = current_target.beneath; t != NULL; t = t->beneath) + if (t->to_get_tailcall_unwinder != NULL) + return t->to_get_tailcall_unwinder; + + return NULL; +} + static int deprecated_debug_xfer_memory (CORE_ADDR memaddr, bfd_byte *myaddr, int len, int write, struct mem_attrib *attrib, diff --git a/gdb/target.h b/gdb/target.h index 18ae6e3..9752259 100644 --- a/gdb/target.h +++ b/gdb/target.h @@ -900,6 +900,11 @@ struct target_ops non-empty annex. */ int (*to_augmented_libraries_svr4_read) (void); + /* Those unwinders are tried before any other arch unwinders. Use NULL if + it is not used. */ + const struct frame_unwind *to_get_unwinder; + const struct frame_unwind *to_get_tailcall_unwinder; + int to_magic; /* Need sub-structure for target machine related rather than comm related? */ @@ -1791,6 +1796,12 @@ extern char *target_fileio_read_stralloc (const char *filename); extern int target_core_of_thread (ptid_t ptid); +/* See to_get_unwinder in struct target_ops. */ +extern const struct frame_unwind *target_get_unwinder (void); + +/* See to_get_tailcall_unwinder in struct target_ops. */ +extern const struct frame_unwind *target_get_tailcall_unwinder (void); + /* Verify that the memory in the [MEMADDR, MEMADDR+SIZE) range matches the contents of [DATA,DATA+SIZE). Returns 1 if there's a match, 0 if there's a mismatch, and -1 if an error is encountered while -- 2.7.4