Add target method for converting thread handle to thread_info struct pointer

This patch adds a target method named `to_thread_handle_to_thread_info'.
It is intended to map a thread library specific thread handle (such as
pthread_t for the pthread library) to the corresponding GDB internal
thread_info struct (pointer).

An implementation is provided for Linux pthreads; see linux-thread-db.c.

gdb/ChangeLog:

	* target.h (struct target_ops): Add to_thread_handle_to_thread_info.
	(target_thread_handle_to_thread_info): Declare.
	* target.c (target_thread_handle_to_thread_info): New function.
	* target-delegates.c: Regenerate.
	* gdbthread.h (find_thread_by_handle): Declare.
	* thread.c (find_thread_by_handle): New function.
	* linux-thread-db.c (thread_db_thread_handle_to_thread_info): New
	function.
	(init_thread_db_ops): Register thread_db_thread_handle_to_thread_info.

1 files changed, 37 insertions, 0 deletions

diff --git a/gdb/target-delegates.c b/gdb/target-delegates.c
index 4fc06ea..c981796 100644
--- a/gdb/target-delegates.c
+++ b/gdb/target-delegates.c
@@ -1583,6 +1583,39 @@ debug_thread_name (struct target_ops *self, struct thread_info *arg1)
   return result;
 }
 
+static struct thread_info *
+delegate_thread_handle_to_thread_info (struct target_ops *self, const gdb_byte *arg1, int arg2, struct inferior *arg3)
+{
+  self = self->beneath;
+  return self->to_thread_handle_to_thread_info (self, arg1, arg2, arg3);
+}
+
+static struct thread_info *
+tdefault_thread_handle_to_thread_info (struct target_ops *self, const gdb_byte *arg1, int arg2, struct inferior *arg3)
+{
+  return NULL;
+}
+
+static struct thread_info *
+debug_thread_handle_to_thread_info (struct target_ops *self, const gdb_byte *arg1, int arg2, struct inferior *arg3)
+{
+  struct thread_info * result;
+  fprintf_unfiltered (gdb_stdlog, "-> %s->to_thread_handle_to_thread_info (...)\n", debug_target.to_shortname);
+  result = debug_target.to_thread_handle_to_thread_info (&debug_target, arg1, arg2, arg3);
+  fprintf_unfiltered (gdb_stdlog, "<- %s->to_thread_handle_to_thread_info (", debug_target.to_shortname);
+  target_debug_print_struct_target_ops_p (&debug_target);
+  fputs_unfiltered (", ", gdb_stdlog);
+  target_debug_print_const_gdb_byte_p (arg1);
+  fputs_unfiltered (", ", gdb_stdlog);
+  target_debug_print_int (arg2);
+  fputs_unfiltered (", ", gdb_stdlog);
+  target_debug_print_struct_inferior_p (arg3);
+  fputs_unfiltered (") = ", gdb_stdlog);
+  target_debug_print_struct_thread_info_p (result);
+  fputs_unfiltered ("\n", gdb_stdlog);
+  return result;
+}
+
 static void
 delegate_stop (struct target_ops *self, ptid_t arg1)
 {
@@ -4267,6 +4300,8 @@ install_delegators (struct target_ops *ops)
     ops->to_extra_thread_info = delegate_extra_thread_info;
   if (ops->to_thread_name == NULL)
     ops->to_thread_name = delegate_thread_name;
+  if (ops->to_thread_handle_to_thread_info == NULL)
+    ops->to_thread_handle_to_thread_info = delegate_thread_handle_to_thread_info;
   if (ops->to_stop == NULL)
     ops->to_stop = delegate_stop;
   if (ops->to_interrupt == NULL)
@@ -4522,6 +4557,7 @@ install_dummy_methods (struct target_ops *ops)
   ops->to_pid_to_str = default_pid_to_str;
   ops->to_extra_thread_info = tdefault_extra_thread_info;
   ops->to_thread_name = tdefault_thread_name;
+  ops->to_thread_handle_to_thread_info = tdefault_thread_handle_to_thread_info;
   ops->to_stop = tdefault_stop;
   ops->to_interrupt = tdefault_interrupt;
   ops->to_pass_ctrlc = default_target_pass_ctrlc;
@@ -4681,6 +4717,7 @@ init_debug_target (struct target_ops *ops)
   ops->to_pid_to_str = debug_pid_to_str;
   ops->to_extra_thread_info = debug_extra_thread_info;
   ops->to_thread_name = debug_thread_name;
+  ops->to_thread_handle_to_thread_info = debug_thread_handle_to_thread_info;
   ops->to_stop = debug_stop;
   ops->to_interrupt = debug_interrupt;
   ops->to_pass_ctrlc = debug_pass_ctrlc;