[RFC 2/5] Implement frame apply [all | COUNT | -COUNT] [-FLAGS...] COMMAND

[Philippe Waroquiers <philippe dot waroquiers at skynet dot be>]

Also implement the command 'faas COMMAND', a shortcut for
'frame apply all -s COMMAND'
---
 gdb/stack.c | 239 +++++++++++++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 214 insertions(+), 25 deletions(-)

diff --git a/gdb/stack.c b/gdb/stack.c
index ecf1ee8379..61e86ab18b 100644
--- a/gdb/stack.c
+++ b/gdb/stack.c
@@ -777,7 +777,7 @@ do_gdb_disassembly (struct gdbarch *gdbarch,
    
    SRC_LINE: Print only source line.
    LOCATION: Print only location.
-   LOC_AND_SRC: Print location and source line.
+   SRC_AND_LOC: Print location and source line.
 
    Used in "where" output, and to emit breakpoint or step
    messages.  */
@@ -1687,6 +1687,39 @@ info_frame_command (const char *addr_exp, int from_tty)
   }
 }
 
+/* COUNT specifies the nr of outermost frames we are interested in.
+   trailing_outermost_frame returns the starting frame
+   needed to handle COUNT outermost frames.  */
+
+static struct frame_info*
+trailing_outermost_frame (int count)
+{
+  struct frame_info *current;
+  struct frame_info *trailing;
+
+  trailing = get_current_frame ();
+
+  gdb_assert (count > 0);
+
+  current = trailing;
+  while (current && count--)
+    {
+      QUIT;
+      current = get_prev_frame (current);
+    }
+
+  /* Will stop when CURRENT reaches the top of the stack.
+     TRAILING will be COUNT below it.  */
+  while (current)
+    {
+      QUIT;
+      trailing = get_prev_frame (trailing);
+      current = get_prev_frame (current);
+    }
+
+  return trailing;
+}
+
 /* Print briefly all stack frames or just the innermost COUNT_EXP
    frames.  */
 
@@ -1696,7 +1729,6 @@ backtrace_command_1 (const char *count_exp, frame_filter_flags flags,
 {
   struct frame_info *fi;
   int count;
-  int i;
   int py_start = 0, py_end = 0;
   enum ext_lang_bt_status result = EXT_LANG_BT_ERROR;
 
@@ -1756,30 +1788,13 @@ backtrace_command_1 (const char *count_exp, frame_filter_flags flags,
 
       if (count_exp != NULL && count < 0)
 	{
-	  struct frame_info *current;
-
-	  count = -count;
-
-	  current = trailing;
-	  while (current && count--)
-	    {
-	      QUIT;
-	      current = get_prev_frame (current);
-	    }
-
-	  /* Will stop when CURRENT reaches the top of the stack.
-	     TRAILING will be COUNT below it.  */
-	  while (current)
-	    {
-	      QUIT;
-	      trailing = get_prev_frame (trailing);
-	      current = get_prev_frame (current);
-	    }
-
+	  trailing = trailing_outermost_frame (-count);
 	  count = -1;
 	}
+      else
+	trailing = get_current_frame ();
 
-      for (i = 0, fi = trailing; fi && count--; i++, fi = get_prev_frame (fi))
+      for (fi = trailing; fi && count--; fi = get_prev_frame (fi))
 	{
 	  QUIT;
 
@@ -2506,9 +2521,148 @@ func_command (const char *arg, int from_tty)
     select_and_print_frame (frame);
 }
 
+/* Apply a GDB command to a all stack frames, or innermost COUNT frames.
+   With a negative COUNT, apply command on outermost -COUNT frames.
+
+   frame apply 3 info frame     Apply 'info frame' to frames 0, 1, 2
+   frame apply -3 info frame    Apply 'info frame' to outermost 3 frames.
+   frame apply all x/i $pc      Apply 'x/i $pc' cmd to all frames.
+   frame apply all -s p local_var_no_idea_in_which_frame
+                If a frame has a local variable called
+                local_var_no_idea_in_which_frame, print frame
+                and value of local_var_no_idea_in_which_frame.
+   frame apply all -sqq p local_var_no_idea_in_which_frame
+                Same as before, but only print the variable value.  */
+
+/* Apply a GDB command to COUNT stack frames, starting at trailing.
+   COUNT -1 means all frames starting at trailing.  WHICH_COMMAND is used
+   for error messages.  */
+static void
+frame_apply_command_count (const char* which_command,
+			   const char *cmd, int from_tty,
+			   struct frame_info *trailing, int count)
+{
+  int print_what_v = 2; /* Corresponding to LOCATION.  */
+  enum print_what print_what[5] =
+    {
+      LOC_AND_ADDRESS, /* Should never be used, this is verbosity 0.  */
+      SRC_LINE,
+      LOCATION,
+      LOC_AND_ADDRESS,
+      SRC_AND_LOC
+    };
+  bool cont;
+  bool silent;
+  struct frame_info *fi;
+
+  if (cmd != NULL)
+    check_for_flags_vqcs (which_command, &cmd,
+			  &print_what_v, 4,
+			  &cont, &silent);
+
+  if (cmd == NULL || *cmd == '\000')
+    error (_("Please specify a command to apply on the selected frames"));
+
+  for (fi = trailing; fi && count--; fi = get_prev_frame (fi))
+    {
+      struct frame_id frame_id = get_frame_id (fi);
+
+      QUIT;
+
+      select_frame (fi);
+      TRY
+	{
+	  std::string cmd_result = execute_command_to_string (cmd, from_tty);
+	  if (!silent || cmd_result.length() > 0)
+	    {
+	      if (print_what_v > 0)
+		print_stack_frame (fi, 1, print_what[print_what_v], 0);
+	      printf_filtered ("%s", cmd_result.c_str ());
+	    }
+	}
+      CATCH (ex, RETURN_MASK_ERROR)
+	{
+	  if (!silent)
+	    {
+	      if (print_what_v > 0)
+		print_stack_frame (fi, 1, print_what [print_what_v], 0);
+	      if (cont)
+		printf_filtered ("%s\n", ex.message);
+	      else
+		throw_exception (ex);
+	    }
+	}
+      END_CATCH;
+
+      /* execute_command_to_string might invalidate FI.  */
+      fi = frame_find_by_id (frame_id);
+      if (fi == NULL)
+	{
+	  trailing = NULL;
+	  warning (_("Unable to restore previously selected frame."));
+	  break;
+	}
+    }
+}
+
+static void
+frame_apply_all_command (const char *cmd, int from_tty)
+{
+  struct frame_info *fi;
+  struct frame_info *trailing = NULL;
+  int count;
+  int i;
+
+  if (!target_has_stack)
+    error (_("No stack."));
+
+  frame_apply_command_count ("frame apply all", cmd, from_tty,
+			     get_current_frame(), INT_MAX);
+}
+
+/* Implementation of the "frame apply" command.  */
+
+static void
+frame_apply_command (const char* cmd, int from_tty)
+{
+  int count;
+  struct frame_info *trailing;
+
+  if (!target_has_stack)
+    error (_("No stack."));
+
+  count = get_number_trailer (&cmd, 0);
+
+  if (count < 0)
+    {
+      trailing = trailing_outermost_frame (-count);
+      count = -1;
+    }
+  else
+    trailing = get_current_frame ();
+
+  frame_apply_command_count ("frame apply", cmd, from_tty,
+			     trailing, count);
+}
+
+/* Implementation of the "faas" command.  */
+
+static void
+faas_command (const char *cmd, int from_tty)
+{
+  std::string expanded = std::string ("frame apply all -s ") + std::string (cmd);
+  execute_command (expanded.c_str (), from_tty);
+}
+
+
+/* Commands with a prefix of `frame'.  */
+struct cmd_list_element *frame_cmd_list = NULL;
+
 void
 _initialize_stack (void)
 {
+  static struct cmd_list_element *frame_apply_list = NULL;
+
   add_com ("return", class_stack, return_command, _("\
 Make selected stack frame return to its caller.\n\
 Control remains in the debugger, but when you continue\n\
@@ -2531,14 +2685,49 @@ An argument says how many frames down to go."));
 Same as the `down' command, but does not print anything.\n\
 This is useful in command scripts."));
 
-  add_com ("frame", class_stack, frame_command, _("\
+  add_prefix_cmd ("frame", class_stack, frame_command, _("\
 Select and print a stack frame.\nWith no argument, \
 print the selected stack frame.  (See also \"info frame\").\n\
 An argument specifies the frame to select.\n\
-It can be a stack frame number or the address of the frame."));
+It can be a stack frame number or the address of the frame."),
+		  &frame_cmd_list, "frame ", 1, &cmdlist);
 
   add_com_alias ("f", "frame", class_stack, 1);
 
+#define FRAME_APPLY_FLAGS_HELP "\
+FLAGS letters are v(increase verbosity), q(decrease verbosity)\n\
+  c(continue), s(silent).\n\
+Verbosity (default 2) controls what to print for a frame:\n\
+  0 : no frame info is printed\n\
+  1 : source line\n\
+  2 : location\n\
+  3 : location and address\n\
+  4 : source line and location\n\
+By default, if a COMMAND raises an error, frame apply is aborted.\n\
+Flag c indicates to print the error and continue.\n\
+Flag s indicates to silently ignore a COMMAND that raises an error\n\
+or produces no output."
+
+  add_prefix_cmd ("apply", class_stack, frame_apply_command,
+		  _("Apply a command to a number of frames.\n\
+Usage: frame apply COUNT [-FLAGS...] COMMAND\n\
+With a negative COUNT argument, applies the command on outermost -COUNT frames.\n"
+FRAME_APPLY_FLAGS_HELP),
+		  &frame_apply_list, "frame apply ", 1, &frame_cmd_list);
+
+  add_cmd ("all", class_stack, frame_apply_all_command,
+	   _("\
+Apply a command to all frames.\n\
+\n\
+Usage: frame apply all [-FLAGS...] COMMAND\n"
+FRAME_APPLY_FLAGS_HELP),
+	   &frame_apply_list);
+
+  add_com ("faas", class_stack, faas_command, _("\
+Apply a command to all frames (ignoring errors and empty output)\n\
+Usage: faas COMMAND\n\
+shortcut for 'frame apply all -s COMMAND'"));
+
   add_com_suppress_notification ("select-frame", class_stack, select_frame_command, _("\
 Select a stack frame without printing anything.\n\
 An argument specifies the frame to select.\n\
-- 
2.11.0