From c8ec2f334c3751c28d5f952d07dea9c0558ca0a0 Mon Sep 17 00:00:00 2001 From: Yao Qi Date: Wed, 21 Feb 2018 11:20:03 +0000 Subject: Class detached_regcache jit.c uses the regcache in a slightly different way, the regcache dosen't write through to target, but it has read and write methods. If I apply regcache in record-full.c, it has the similar use pattern. This patch adds a new class detached_regcache, a register buffer, but can be read and written. Since jit.c doesn't want to write registers through to target, it uses regcache as a readonly regcache (because only readonly regcache disconnects from the target), but it adds a hole in regcache (raw_set_cached_value) in order to modify a readonly regcache. This patch fixes this hole completely. regcache inherits detached_regcache, and detached_regcache inherits readable_regcache. The ideal design is that both detached_regcache and readable_regcache inherit reg_buffer, and regcache inherit detached_regcache and regcache_read (virtual inheritance). I concern about the performance overhead of virtual inheritance, so I don't do it in the patch. gdb: 2018-02-21 Yao Qi * jit.c (struct jit_unwind_private) : Change its type to reg_buffer_rw *. (jit_unwind_reg_set_impl): Call raw_supply. (jit_frame_sniffer): Use reg_buffer_rw. * record-full.c (record_full_core_regbuf): Change its type. (record_full_core_open_1): Use reg_buffer_rw. (record_full_close): Likewise. (record_full_core_fetch_registers): Use regcache->raw_supply. (record_full_core_store_registers): Likewise. * regcache.c (regcache::get_register_status): Move it to reg_buffer. (regcache_raw_set_cached_value): Remove. (regcache::raw_set_cached_value): Remove. (regcache::raw_write): Call raw_supply. (regcache::raw_supply): Move it to reg_buffer_rw. * regcache.h (regcache_raw_set_cached_value): Remove. (reg_buffer_rw): New class. --- gdb/jit.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) (limited to 'gdb/jit.c') diff --git a/gdb/jit.c b/gdb/jit.c index 01ead45..62d6634 100644 --- a/gdb/jit.c +++ b/gdb/jit.c @@ -1097,7 +1097,7 @@ struct jit_unwind_private { /* Cached register values. See jit_frame_sniffer to see how this works. */ - struct regcache *regcache; + detached_regcache *regcache; /* The frame being unwound. */ struct frame_info *this_frame; @@ -1126,7 +1126,7 @@ jit_unwind_reg_set_impl (struct gdb_unwind_callbacks *cb, int dwarf_regnum, return; } - regcache_raw_set_cached_value (priv->regcache, gdb_reg, value->value); + priv->regcache->raw_supply (gdb_reg, value->value); value->free (value); } @@ -1188,7 +1188,6 @@ jit_frame_sniffer (const struct frame_unwind *self, struct jit_unwind_private *priv_data; struct gdb_unwind_callbacks callbacks; struct gdb_reader_funcs *funcs; - struct gdbarch *gdbarch; callbacks.reg_get = jit_unwind_reg_get_impl; callbacks.reg_set = jit_unwind_reg_set_impl; @@ -1201,11 +1200,11 @@ jit_frame_sniffer (const struct frame_unwind *self, gdb_assert (!*cache); - gdbarch = get_frame_arch (this_frame); - *cache = XCNEW (struct jit_unwind_private); priv_data = (struct jit_unwind_private *) *cache; - priv_data->regcache = new regcache (gdbarch); + /* Take a snapshot of current regcache. */ + priv_data->regcache = new detached_regcache (get_frame_arch (this_frame), + true); priv_data->this_frame = this_frame; callbacks.priv_data = priv_data; -- cgit v1.1