[PATCH 05/13] script language API for GDB

[Doug Evans <xdje42 at gmail dot com>]

This patch updates breakpoint.c to call the API functions in scripting.h.
It also updates py-breakpoint.c, the functions that implement the
script_language_ops "methods" are all named ${lang}_method_name.

The script condition test function, gdbpy_breakpoint_cond_says_stop,
has an enum result instead of just a boolean so that the caller can
know if there is a condition.  One could call the "breakpoint_has_cond"
"method" except that python "finish breakpoints" are implemented on
top of normal breakpoints and require calling "breakpoint_cond_says_stop"
even if there is no stop method.  I can imagine reworking this,
but there's no need to at the moment.

It also updates some expected output in py-breakpoint.exp.

2013-12-05  Doug Evans  <xdje42@gmail.com>

	* breakpoint.c (condition_command): Replace call to
	gdbpy_breakpoint_has_py_cond with call to breakpoint_has_script_cond.
	(bpstat_check_breakpoint_conditions): Replace call to gdbpy_should_stop
	with call to breakpoint_script_cond_says_stop.
	* python/py-breakpoint.c (gdbpy_breakpoint_cond_says_stop): Renamed
	from gdbpy_should_stop.  Change result type to enum scr_bp_stop.
	New arg slang.  Return SCR_BP_STOP_UNSET if py_bp_object is NULL.
	(gdbpy_breakpoint_has_cond): Renamed from gdbpy_breakpoint_has_py_cond.
	New arg slang.
	(local_setattro): Call breakpoint_has_script_cond.

	testsuite/
	* gdb.python/py-breakpoint.exp (test_bkpt_eval_funcs): Update expected
	output.

diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index 111660f..4064e7b 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -1052,10 +1052,11 @@ condition_command (char *arg, int from_tty)
 	   it, and if it has a definition of the "stop"
 	   method.  This method and conditions entered into GDB from
 	   the CLI are mutually exclusive.  */
-	if (b->py_bp_object
-	    && gdbpy_breakpoint_has_py_cond (b->py_bp_object))
-	  error (_("Cannot set a condition where a Python 'stop' "
-		   "method has been defined in the breakpoint."));
+	if (breakpoint_has_script_cond (b, SCRIPT_LANG_NONE))
+	  {
+	    error (_("Cannot set a condition where a scripting language"
+		     " 'stop' method has already been defined."));
+	  }
 	set_breakpoint_condition (b, p, from_tty);
 
 	if (is_breakpoint (b))
@@ -5140,9 +5141,9 @@ bpstat_check_breakpoint_conditions (bpstat bs, ptid_t ptid)
       return;
     }
 
-  /* Evaluate Python breakpoints that have a "stop" method implemented.  */
-  if (b->py_bp_object)
-    bs->stop = gdbpy_should_stop (b->py_bp_object);
+  /* Evaluate scripting language breakpoints that have a "stop" method
+     implemented.  */
+  bs->stop = breakpoint_script_cond_says_stop (b);
 
   if (is_watchpoint (b))
     {
diff --git a/gdb/python/py-breakpoint.c b/gdb/python/py-breakpoint.c
index 1085588..882ac7f 100644
--- a/gdb/python/py-breakpoint.c
+++ b/gdb/python/py-breakpoint.c
@@ -750,15 +750,22 @@ gdbpy_breakpoints (PyObject *self, PyObject *args)
    stopped at the breakpoint.  Otherwise the inferior will be
    allowed to continue.  */
 
-int
-gdbpy_should_stop (struct gdbpy_breakpoint_object *bp_obj)
+enum scr_bp_stop
+gdbpy_breakpoint_cond_says_stop (const struct script_language_defn *slang,
+				 struct breakpoint *b)
 {
-  int stop = 1;
-
+  int stop;
+  struct gdbpy_breakpoint_object *bp_obj = b->py_bp_object;
   PyObject *py_bp = (PyObject *) bp_obj;
-  struct breakpoint *b = bp_obj->bp;
-  struct gdbarch *garch = b->gdbarch ? b->gdbarch : get_current_arch ();
-  struct cleanup *cleanup = ensure_python_env (garch, current_language);
+  struct gdbarch *garch;
+  struct cleanup *cleanup;
+
+  if (bp_obj == NULL)
+    return SCR_BP_STOP_UNSET;
+
+  stop = -1;
+  garch = b->gdbarch ? b->gdbarch : get_current_arch ();
+  cleanup = ensure_python_env (garch, current_language);
 
   if (bp_obj->is_finish_bp)
     bpfinishpy_pre_stop_hook (bp_obj);
@@ -767,6 +774,7 @@ gdbpy_should_stop (struct gdbpy_breakpoint_object *bp_obj)
     {
       PyObject *result = PyObject_CallMethod (py_bp, stop_func, NULL);
 
+      stop = 1;
       if (result)
 	{
 	  int evaluate = PyObject_IsTrue (result);
@@ -790,7 +798,9 @@ gdbpy_should_stop (struct gdbpy_breakpoint_object *bp_obj)
 
   do_cleanups (cleanup);
 
-  return stop;
+  if (stop < 0)
+    return SCR_BP_STOP_UNSET;
+  return stop ? SCR_BP_STOP_YES : SCR_BP_STOP_NO;
 }
 
 /* Checks if the  "stop" method exists in this breakpoint.
@@ -798,17 +808,21 @@ gdbpy_should_stop (struct gdbpy_breakpoint_object *bp_obj)
    conditions.  */
 
 int
-gdbpy_breakpoint_has_py_cond (struct gdbpy_breakpoint_object *bp_obj)
+gdbpy_breakpoint_has_cond (const struct script_language_defn *slang,
+			   struct breakpoint *b)
 {
-  int has_func = 0;
-  PyObject *py_bp = (PyObject *) bp_obj;
-  struct gdbarch *garch = bp_obj->bp->gdbarch ? bp_obj->bp->gdbarch :
-    get_current_arch ();
-  struct cleanup *cleanup = ensure_python_env (garch, current_language);
-
-  if (py_bp != NULL)
-    has_func = PyObject_HasAttrString (py_bp, stop_func);
-
+  int has_func;
+  PyObject *py_bp;
+  struct gdbarch *garch;
+  struct cleanup *cleanup;
+
+  if (b->py_bp_object == NULL)
+    return 0;
+
+  py_bp = (PyObject *) b->py_bp_object;
+  garch = b->gdbarch ? b->gdbarch : get_current_arch ();
+  cleanup = ensure_python_env (garch, current_language);
+  has_func = PyObject_HasAttrString (py_bp, stop_func);
   do_cleanups (cleanup);
 
   return has_func;
@@ -949,7 +963,9 @@ local_setattro (PyObject *self, PyObject *name, PyObject *v)
   /* If the attribute trying to be set is the "stop" method,
      but we already have a condition set in the CLI, disallow this
      operation.  */
-  if (strcmp (attr, stop_func) == 0 && obj->bp->cond_string)
+  if (strcmp (attr, stop_func) == 0
+      && (obj->bp->cond_string != NULL
+	  || breakpoint_has_script_cond (obj->bp, SCRIPT_LANG_PYTHON)))
     {
       xfree (attr);
       PyErr_SetString (PyExc_RuntimeError,
diff --git a/gdb/testsuite/gdb.python/py-breakpoint.exp b/gdb/testsuite/gdb.python/py-breakpoint.exp
index 107b026..356ef30 100644
--- a/gdb/testsuite/gdb.python/py-breakpoint.exp
+++ b/gdb/testsuite/gdb.python/py-breakpoint.exp
@@ -372,7 +372,7 @@ proc test_bkpt_eval_funcs { } {
 	    "Set breakpoint" 0
 	set test_cond {cond $bpnum}
 	gdb_test "$test_cond \"foo==3\"" \
-	    "Cannot set a condition where a Python.*" \
+	    "Cannot set a condition where a scripting language.*" \
 	    "Check you cannot add a CLI condition to a Python breakpoint that has defined stop"
 	gdb_py_test_silent_cmd "python eval_bp2 = basic(\"$cond_bp\")" \
 	    "Set breakpoint" 0