[PATCH v3 1/2] gdb: add a symbol* argument to get_return_value

[Lancelot SIX <lancelot.six@amd.com>]

Add an argument to the get_return_value function to indicate the symbol
of the function the debuggee is returning from.  This will be used by
the following patch.

No user visible change after this patch.

Tested on x86_64-linux.

Change-Id: Idf1279f1f7199f5022738a6679e0fa63fbd22edc
---
 gdb/infcmd.c                     |  5 +++--
 gdb/inferior.h                   |  3 ++-
 gdb/python/py-finishbreakpoint.c | 29 ++++++++++++++++++++---------
 3 files changed, 25 insertions(+), 12 deletions(-)

diff --git a/gdb/infcmd.c b/gdb/infcmd.c
index 994dd5b32a3..66667d67b21 100644
--- a/gdb/infcmd.c
+++ b/gdb/infcmd.c
@@ -1410,7 +1410,8 @@ advance_command (const char *arg, int from_tty)
    right after an inferior call has finished.  */
 
 struct value *
-get_return_value (struct value *function, struct type *value_type)
+get_return_value (struct symbol *func_symbol, struct value *function,
+		  struct type *value_type)
 {
   regcache *stop_regs = get_current_regcache ();
   struct gdbarch *gdbarch = stop_regs->arch ();
@@ -1577,7 +1578,7 @@ finish_command_fsm::should_stop (struct thread_info *tp)
 	  struct value *func;
 
 	  func = read_var_value (function, NULL, get_current_frame ());
-	  rv->value = get_return_value (func, rv->type);
+	  rv->value = get_return_value (function, func, rv->type);
 	  if (rv->value != NULL)
 	    rv->value_history_index = record_latest_value (rv->value);
 	}
diff --git a/gdb/inferior.h b/gdb/inferior.h
index ec0fb6e8b16..5fdff0f9358 100644
--- a/gdb/inferior.h
+++ b/gdb/inferior.h
@@ -219,7 +219,8 @@ extern void detach_command (const char *, int);
 
 extern void notice_new_inferior (struct thread_info *, bool, int);
 
-extern struct value *get_return_value (struct value *function,
+extern struct value *get_return_value (struct symbol *func_symbol,
+				       struct value *function,
 				       struct type *value_type);
 
 /* Prepare for execution command.  TARGET is the target that will run
diff --git a/gdb/python/py-finishbreakpoint.c b/gdb/python/py-finishbreakpoint.c
index 03bd4934506..a322918dfca 100644
--- a/gdb/python/py-finishbreakpoint.c
+++ b/gdb/python/py-finishbreakpoint.c
@@ -40,6 +40,8 @@ struct finish_breakpoint_object
 {
   /* gdb.Breakpoint base class.  */
   gdbpy_breakpoint_object py_bp;
+  /* gdb.Symbol object of the function finished by this breakpoint.  */
+  PyObject *func_symbol;
   /* gdb.Type object of the value return by the breakpointed function.
      May be NULL if no debug information was available or return type
      was VOID.  */
@@ -80,6 +82,7 @@ bpfinishpy_dealloc (PyObject *self)
   struct finish_breakpoint_object *self_bpfinish =
 	(struct finish_breakpoint_object *) self;
 
+  Py_XDECREF (self_bpfinish->func_symbol);
   Py_XDECREF (self_bpfinish->function_value);
   Py_XDECREF (self_bpfinish->return_type);
   Py_XDECREF (self_bpfinish->return_value);
@@ -104,11 +107,14 @@ bpfinishpy_pre_stop_hook (struct gdbpy_breakpoint_object *bp_obj)
 
   try
     {
+      struct symbol *func_symbol =
+	symbol_object_to_symbol (self_finishbp->func_symbol);
       struct value *function =
 	value_object_to_value (self_finishbp->function_value);
       struct type *value_type =
 	type_object_to_type (self_finishbp->return_type);
-      struct value *ret = get_return_value (function, value_type);
+      struct value *ret =
+	get_return_value (func_symbol, function, value_type);
 
       if (ret)
 	{
@@ -165,7 +171,6 @@ bpfinishpy_init (PyObject *self, PyObject *args, PyObject *kwargs)
   PyObject *internal = NULL;
   int internal_bp = 0;
   CORE_ADDR pc;
-  struct symbol *function;
 
   if (!gdb_PyArg_ParseTupleAndKeywords (args, kwargs, "|OO", keywords,
 					&frame_obj, &internal))
@@ -239,16 +244,18 @@ bpfinishpy_init (PyObject *self, PyObject *args, PyObject *kwargs)
     }
 
   /* Find the function we will return from.  */
-  self_bpfinish->return_type = NULL;
-  self_bpfinish->function_value = NULL;
+  self_bpfinish->func_symbol = nullptr;
+  self_bpfinish->return_type = nullptr;
+  self_bpfinish->function_value = nullptr;
 
   try
     {
       if (get_frame_pc_if_available (frame, &pc))
 	{
-	  function = find_pc_function (pc);
-	  if (function != NULL)
+	  struct symbol *function = find_pc_function (pc);
+	  if (function != nullptr)
 	    {
+	      self_bpfinish->func_symbol = symbol_to_symbol_object (function);
 	      struct type *ret_type =
 		check_typedef (TYPE_TARGET_TYPE (SYMBOL_TYPE (function)));
 
@@ -274,14 +281,18 @@ bpfinishpy_init (PyObject *self, PyObject *args, PyObject *kwargs)
 	 remain NULL.  */
     }
 
-  if (self_bpfinish->return_type == NULL || self_bpfinish->function_value == NULL)
+  if (self_bpfinish->func_symbol == nullptr
+      || self_bpfinish->return_type == nullptr
+      || self_bpfinish->function_value == nullptr)
     {
       /* Won't be able to compute return value.  */
+      Py_XDECREF (self_bpfinish->func_symbol);
       Py_XDECREF (self_bpfinish->return_type);
       Py_XDECREF (self_bpfinish->function_value);
 
-      self_bpfinish->return_type = NULL;
-      self_bpfinish->function_value = NULL;
+      self_bpfinish->func_symbol = nullptr;
+      self_bpfinish->return_type = nullptr;
+      self_bpfinish->function_value = nullptr;
     }
 
   bppy_pending_object = &self_bpfinish->py_bp;
-- 
2.25.1