[patch v8 14/24] record-btrace: supply register target methods

Markus Metzger
2013-12-12T09:15:57Z

Supply target methods to allow reading the PC. Forbid anything else.

2013-12-12 Markus Metzger <markus.t.metzger@intel.com>

* record-btrace.c (record_btrace_fetch_registers,
record_btrace_store_registers,
record_btrace_to_prepare_to_store): New.
(init_record_btrace_ops): Add the above.

---
gdb/record-btrace.c | 92 +++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 92 insertions(+)

diff --git a/gdb/record-btrace.c b/gdb/record-btrace.c
index fc692aa..26ae6d8 100644
--- a/gdb/record-btrace.c
+++ b/gdb/record-btrace.c
@@ -32,6 +32,7 @@
#include "ui-out.h"
#include "symtab.h"
#include "filenames.h"
+#include "regcache.h"

/* The target_ops of record-btrace. */
static struct target_ops record_btrace_ops;
@@ -751,6 +752,94 @@ record_btrace_is_replaying (void)
return 0;
}

+/* The to_fetch_registers method of target record-btrace. */
+
+static void
+record_btrace_fetch_registers (struct target_ops *ops,
+ struct regcache *regcache, int regno)
+{
+ struct btrace_insn_iterator *replay;
+ struct thread_info *tp;
+
+ tp = find_thread_ptid (inferior_ptid);
+ gdb_assert (tp != NULL);
+
+ replay = tp->btrace.replay;
+ if (replay != NULL)
+ {
+ const struct btrace_insn *insn;
+ struct gdbarch *gdbarch;
+ int pcreg;
+
+ gdbarch = get_regcache_arch (regcache);
+ pcreg = gdbarch_pc_regnum (gdbarch);
+ if (pcreg < 0)
+ return;
+
+ /* We can only provide the PC register. */
+ if (regno >= 0 && regno != pcreg)
+ return;
+
+ insn = btrace_insn_get (replay);
+ gdb_assert (insn != NULL);
+
+ regcache_raw_supply (regcache, regno, &insn->pc);
+ }
+ else
+ {
+ struct target_ops *t;
+
+ for (t = ops->beneath; t != NULL; t = t->beneath)
+ if (t->to_fetch_registers != NULL)
+ {
+ t->to_fetch_registers (t, regcache, regno);
+ break;
+ }
+ }
+}
+
+/* The to_store_registers method of target record-btrace. */
+
+static void
+record_btrace_store_registers (struct target_ops *ops,
+ struct regcache *regcache, int regno)
+{
+ struct target_ops *t;
+
+ if (record_btrace_is_replaying ())
+ error (_("This record target does not allow writing registers."));
+
+ gdb_assert (may_write_registers != 0);
+
+ for (t = ops->beneath; t != NULL; t = t->beneath)
+ if (t->to_store_registers != NULL)
+ {
+ t->to_store_registers (t, regcache, regno);
+ return;
+ }
+
+ noprocess ();
+}
+
+/* The to_prepare_to_store method of target record-btrace. */
+
+static void
+record_btrace_prepare_to_store (struct target_ops *ops,
+ struct regcache *regcache)
+{
+ struct target_ops *t;
+
+ if (record_btrace_is_replaying ())
+ return;
+
+ for (t = ops->beneath; t != NULL; t = t->beneath)
+ if (t->to_prepare_to_store != NULL)
+ {
+ t->to_prepare_to_store (t, regcache);
+ return;
+ }
+}
+
/* Initialize the record-btrace target ops. */

static void
@@ -778,6 +867,9 @@ init_record_btrace_ops (void)
ops->to_call_history_from = record_btrace_call_history_from;
ops->to_call_history_range = record_btrace_call_history_range;
ops->to_record_is_replaying = record_btrace_is_replaying;
+ ops->to_fetch_registers = record_btrace_fetch_registers;
+ ops->to_store_registers = record_btrace_store_registers;
+ ops->to_prepare_to_store = record_btrace_prepare_to_store;
ops->to_stratum = record_stratum;
ops->to_magic = OPS_MAGIC;
}
--
1.8.3.1