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[v12,2/4] Add debug method interface to the extension language API

Message ID CAGyQ6gwDnVG4cV_1Tf2mKKQUJX53+TKhUz13iLPKO7_39Qcarw@mail.gmail.com
State Superseded
Headers show

Commit Message

Siva Chandra Reddy April 1, 2014, 10:53 p.m. UTC
This part adds the debug method interface to the extension language API.

2014-04-01  Siva Chandra Reddy  <sivachandra@google.com>

        * extension-priv.h (struct extension_language_ops): Add the
        debug method interface.
        * extension.c (new_debug_method_worker): New function.
        (clone_debug_method_worker): Likewise.
        (get_matching_debug_method_workers): Likewise.
        (get_debug_method_argtypes): Likewise.
        (invoke_debug_method): Likewise
        (free_debug_method_worker_vec): Likewise.
        (make_debug_method_worker_vec_cleanup): Likewise.
        * extension.h: New function declarations.
        (struct debug_method_worker): New struct.
        (VEC (debug_method_worker_ptr)): New vector type.
        (debug_method_worker_ptr): New typedef.
        (debug_method_worker_vec): Likewise.

Comments

Doug Evans April 8, 2014, 9:18 p.m. UTC | #1
Siva Chandra writes:
 > This part adds the debug method interface to the extension language API.
 > 
 > 2014-04-01  Siva Chandra Reddy  <sivachandra@google.com>
 > 
 >         * extension-priv.h (struct extension_language_ops): Add the
 >         debug method interface.
 >         * extension.c (new_debug_method_worker): New function.
 >         (clone_debug_method_worker): Likewise.
 >         (get_matching_debug_method_workers): Likewise.
 >         (get_debug_method_argtypes): Likewise.
 >         (invoke_debug_method): Likewise
 >         (free_debug_method_worker_vec): Likewise.
 >         (make_debug_method_worker_vec_cleanup): Likewise.
 >         * extension.h: New function declarations.
 >         (struct debug_method_worker): New struct.
 >         (VEC (debug_method_worker_ptr)): New vector type.
 >         (debug_method_worker_ptr): New typedef.
 >         (debug_method_worker_vec): Likewise.

LGTM

Thanks!
diff mbox

Patch

diff --git a/gdb/extension-priv.h b/gdb/extension-priv.h
index 9e63a9c..c4083f1 100644
--- a/gdb/extension-priv.h
+++ b/gdb/extension-priv.h
@@ -256,6 +256,54 @@  struct extension_language_ops
      changed or an error occurs no further languages are called.  */
   enum ext_lang_rc (*before_prompt) (const struct extension_language_defn *,
 				     const char *current_gdb_prompt);
+
+  /* Debug method support:
+     clone_debug_method_worker_data, free_debug_method_worker_data,
+     get_matching_debug_method_workers, get_debug_method_arg_types,
+     invoke_debug_method.
+     These methods are optional and may be NULL, but if one of them is
+     implemented then they all must be.  */
+
+  /* Clone DATA and return a new but identical debug method worker data
+     object for this extension language.  */
+  void * (*clone_debug_method_worker_data) (
+     const struct extension_language_defn *extlang, void *data);
+
+  /* Free the DATA object of this extension language.  */
+  void (*free_debug_method_worker_data) (
+     const struct extension_language_defn *extlang, void *data);
+
+  /* Return a vector of matching debug method workers defined in this
+     extension language.  The workers service methods with name
+     METHOD_NAME on objects of type OBJ_TYPE.  The vector is returned
+     in DM_VEC.  */
+  enum ext_lang_rc (*get_matching_debug_method_workers) (
+     const struct extension_language_defn *extlang,
+     struct type *obj_type,
+     const char *method_name,
+     debug_method_worker_vec **dm_vec);
+
+  /* Given a WORKER servicing a particular method, return the types
+     of the arguments the method takes.  The number of arguments is
+     returned in NARGS, and their types are returned in the array
+     ARGTYPES.  */
+  enum ext_lang_rc (*get_debug_method_arg_types) (
+     const struct extension_language_defn *extlang,
+     struct debug_method_worker *worker,
+     int *nargs,
+     struct type ***arg_types);
+
+  /* Invoke the debug method serviced by WORKER.  The method is invoked
+     on OBJECT with arguments in the array ARGS.  NARGS is the length of
+     this array.  The value returned by the method is returned in
+     RESULT.  */
+  enum ext_lang_rc (*invoke_debug_method) (
+     const struct extension_language_defn *extlang,
+     struct debug_method_worker *worker,
+     struct value *object,
+     struct value **args,
+     int nargs,
+     struct value **result);
 };
 
 /* State necessary to restore a signal handler to its previous value.  */
diff --git a/gdb/extension.c b/gdb/extension.c
index 1146cc7..337bfa8 100644
--- a/gdb/extension.c
+++ b/gdb/extension.c
@@ -834,6 +834,175 @@  check_quit_flag (void)
   return result;
 }
 
+/* Debug method support.  */
+
+/* Debug method API routines do not have "ext_lang" in the name because
+the name "debug_method" implies that this routine deals with extension
+languages.  Plus some of the methods take a debug_method_foo * "self/this"
+arg, not an extension_language_defn * arg.  */
+
+static void free_debug_method_worker_vec (void *vec);
+
+/* Returns a new debug_method_worker with EXTLANG and DATA.  Space for the
+   result is allocated using malloc.  Caller must free.  */
+
+struct debug_method_worker *
+new_debug_method_worker (const struct extension_language_defn *extlang,
+			 void *data)
+{
+  struct debug_method_worker *worker = XCNEW (struct debug_method_worker);
+
+  worker->extlang = extlang;
+  worker->data = data;
+
+  return worker;
+}
+
+/* Clones WORKER and returns a new but identical worker.
+   The function get_matching_debug_method_workers (see below), returns a
+   vector of matching workers.  If a particular worker is selected by GDB
+   to invoke a method, then this function can help in cloning the
+   selected worker and freeing up the vector via a cleanup (see
+   make_debug_method_worker_vec_cleanup below).
+
+   Space for the result is allocated using malloc.  Caller must free.  */
+
+struct debug_method_worker *
+clone_debug_method_worker (struct debug_method_worker *worker)
+{
+  struct debug_method_worker *new_worker;
+  const struct extension_language_defn *extlang = worker->extlang;
+
+  gdb_assert (extlang->ops->clone_debug_method_worker_data != NULL);
+
+  new_worker = new_debug_method_worker (
+     extlang,
+     extlang->ops->clone_debug_method_worker_data (extlang, worker->data));
+
+  return new_worker;
+}
+
+/* If a method with name METHOD_NAME is to be invoked on an object of type
+   TYPE, then all entension languages are searched for implementations of
+   methods with name METHOD.  All matches found are returned as a vector
+   of 'debug_method_worker_ptr' objects.  If no matching methods are
+   found, NULL is returned.  */
+
+VEC (debug_method_worker_ptr) *
+get_matching_debug_method_workers (struct type *type, const char *method_name)
+{
+  VEC (debug_method_worker_ptr) *workers = NULL;
+  int i;
+  const struct extension_language_defn *extlang;
+
+  ALL_ENABLED_EXTENSION_LANGUAGES (i, extlang)
+    {
+      VEC (debug_method_worker_ptr) *lang_workers, *new_vec;
+      enum ext_lang_rc rc;
+
+      /* If an extension language does not support debug methods, ignore
+	 it.  */
+      if (extlang->ops->get_matching_debug_method_workers == NULL)
+	continue;
+
+      rc = extlang->ops->get_matching_debug_method_workers (extlang,
+							    type, method_name,
+							    &lang_workers);
+      if (rc == EXT_LANG_RC_ERROR)
+	{
+	  free_debug_method_worker_vec (workers);
+	  error (_("Error while looking for matching debug method workers "
+		   "defined in %s."), extlang->capitalized_name);
+	}
+
+      new_vec = VEC_merge (debug_method_worker_ptr, workers, lang_workers);
+      /* Free only the vectors and not the elements as NEW_VEC still
+	 contains them.  */
+      VEC_free (debug_method_worker_ptr, workers);
+      VEC_free (debug_method_worker_ptr, lang_workers);
+      workers = new_vec;
+    }
+
+  return workers;
+}
+
+/* Return the arg types of the debug method encapsulated in WORKER.
+   An array of arg types is returned.  The length of the array is returned in
+   NARGS.  The type of the 'this' object is returned as the first element of
+   array.  */
+
+struct type **
+get_debug_method_arg_types (struct debug_method_worker *worker, int *nargs)
+{
+  enum ext_lang_rc rc;
+  struct type **type_array = NULL;
+  const struct extension_language_defn *extlang = worker->extlang;
+
+  gdb_assert (extlang->ops->get_debug_method_arg_types != NULL);
+
+  rc = extlang->ops->get_debug_method_arg_types (extlang, worker, nargs,
+						 &type_array);
+  if (rc == EXT_LANG_RC_ERROR)
+    {
+      error (_("Error while looking for arg types of a debug method worker "
+	       "defined in %s."), extlang->capitalized_name);
+    }
+
+  return type_array;
+}
+
+/* Invokes the debug method encapsulated in WORKER and returns the result.
+   The method is invoked on OBJ with arguments in the ARGS array.  NARGS is
+   the length of the this array.  */
+
+struct value *
+invoke_debug_method (struct debug_method_worker *worker, struct value *obj,
+		     struct value **args, int nargs)
+{
+  struct value *result = NULL;
+  enum ext_lang_rc rc;
+
+  gdb_assert (worker->extlang->ops->invoke_debug_method != NULL);
+
+  rc = worker->extlang->ops->invoke_debug_method (worker->extlang, worker,
+						  obj, args, nargs, &result);
+  if (rc == EXT_LANG_RC_ERROR)
+    {
+      error (_("Error while invoking a debug method defined in %s"),
+	     worker->extlang->capitalized_name);
+    }
+
+  return result;
+}
+
+/* Frees a vector of debug_method_workers VEC.  */
+
+static void
+free_debug_method_worker_vec (void *vec)
+{
+  int i;
+  struct debug_method_worker *worker;
+  VEC (debug_method_worker_ptr) *v = (VEC (debug_method_worker_ptr) *) vec;
+
+  for (i = 0; VEC_iterate (debug_method_worker_ptr, v, i, worker); i++)
+    {
+      gdb_assert (worker->extlang->ops->free_debug_method_worker_data != NULL);
+      worker->extlang->ops->free_debug_method_worker_data (worker->extlang,
+							   worker->data);
+      xfree (worker);
+    }
+
+  VEC_free (debug_method_worker_ptr, v);
+}
+
+/* Return a cleanup object to free the vector VEC of debug method workers.  */
+
+struct cleanup *
+make_debug_method_worker_vec_cleanup (VEC (debug_method_worker_ptr) *vec)
+{
+  return make_cleanup (free_debug_method_worker_vec, (void *) vec);
+}
+
 /* Called via an observer before gdb prints its prompt.
    Iterate over the extension languages giving them a chance to
    change the prompt.  The first one to change the prompt wins,
diff --git a/gdb/extension.h b/gdb/extension.h
index 61dc81b..049ce57 100644
--- a/gdb/extension.h
+++ b/gdb/extension.h
@@ -21,6 +21,7 @@ 
 #define EXTENSION_H
 
 #include "mi/mi-cmds.h" /* For PRINT_NO_VALUES, etc.  */
+#include "common/vec.h"
 
 struct breakpoint;
 struct command_line;
@@ -33,6 +34,7 @@  struct ui_file;
 struct ui_out;
 struct value;
 struct value_print_options;
+struct debug_method_worker;
 
 /* A function to load and process a script file.
    The file has been opened and is ready to be read from the beginning.
@@ -138,6 +140,23 @@  struct ext_lang_type_printers
   /* Type-printers from Python.  */
   void *py_type_printers;
 };
+
+/* A type which holds its extension language specific debug method worker
+   data.  */
+
+struct debug_method_worker
+{
+  /* The language the debug method worker is implemented in.  */
+  const struct extension_language_defn *extlang;
+
+  /* The extension language specific data for this debug method worker.  */
+  void *data;
+};
+
+typedef struct debug_method_worker *debug_method_worker_ptr;
+DEF_VEC_P (debug_method_worker_ptr);
+typedef VEC (debug_method_worker_ptr) debug_method_worker_vec;
+
 
 /* The interface for gdb's own extension(/scripting) language.  */
 extern const struct extension_language_defn extension_language_gdb;
@@ -212,4 +231,23 @@  extern const struct extension_language_defn *get_breakpoint_cond_ext_lang
 
 extern int breakpoint_ext_lang_cond_says_stop (struct breakpoint *);
 
+extern struct value *invoke_debug_method (struct debug_method_worker *,
+					  struct value *,
+					  struct value **, int nargs);
+
+extern struct debug_method_worker *clone_debug_method_worker (
+   struct debug_method_worker *);
+
+extern struct debug_method_worker *new_debug_method_worker (
+   const struct extension_language_defn *extlang, void *data);
+
+extern debug_method_worker_vec *get_matching_debug_method_workers (
+   struct type *, const char *);
+
+extern struct type **get_debug_method_arg_types (
+   struct debug_method_worker *, int *);
+
+extern struct cleanup *make_debug_method_worker_vec_cleanup (
+   debug_method_worker_vec *vec);
+
 #endif /* EXTENSION_H */