Patchwork [PATCHv6] gdb: Change how frames are selected for 'frame' and 'info frame'.

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Submitter Andrew Burgess
Date Sept. 26, 2018, 11:06 p.m.
Message ID <20180926230626.GN5952@embecosm.com>
Download mbox | patch
Permalink /patch/29556/
State New
Headers show

Comments

Andrew Burgess - Sept. 26, 2018, 11:06 p.m.
Thanks for the review.

This revision makes the following changes:

  - Addresses the two small grammatical errors, and removes the random
    comment line in the testsuite.

  - Rewrites the get_new_address function in the testsuite so that is
    actually does what it says on the tin (in line with your
    suggestion).

  - Extends the header comment on parse_frame_specification.  While
    doing this I realised that due to the way this function is now
    used it can be simplified a lot.  We now only handle a single
    argument.  I'd rather not start extending the existing MI
    interface with new features at this point, and I didn't think
    keeping the more complex parse_frame_specification around "just in
    case" was good practice.

It's because of this last change that I've posted the patch for
another review.  I think the change is sensible (and the tests pass),
but I wanted another opinion.

Thanks,
Andrew

---

gdb: Change how frames are selected for 'frame' and 'info frame'.

The 'frame' command, and thanks to code reuse the 'info frame' and
'select-frame' commands, currently have an overloaded mechanism for
selecting a frame.

These commands take one or two parameters, if it's one parameter then
we first try to use the parameter as an integer to select a frame by
level (or depth in the stack).  If that fails then we treat the
parameter as an address and try to select a stack frame by
stack-address.  If we still have not selected a stack frame, or we
initially had two parameters, then GDB allows the user to view a stack
frame that is not part of the current backtrace.  Internally, a new
frame is created with the given stack and pc addresses, and this is
shown to the user.

The result of this is that a typo by the user, entering the wrong stack
frame level for example, can result in a brand new frame being viewed
rather than an error.

The purpose of this commit is to remove this overloading, while still
offering the same functionality through some new sub-commands.  By
making the default behaviour of 'frame' (and friends) be to select a
stack frame by level index, it is hoped that enough
backwards-compatibility is maintained that users will not be overly
inconvenienced.

The 'frame', 'select-frame', and 'info frame' commands now all take a
frame specification string as an argument, this string can be any of the
following:

  (1) An integer.  This is treated as a frame level.  If a frame for
  that level does not exist then the user gets an error.

  (2) A string like 'level <LEVEL>', where <LEVEL> is a frame level
  as in option (1) above.

  (3) A string like 'address <STACK-ADDRESS>', where <STACK-ADDRESS>
  is a stack-frame address.  If there is no frame for this address
  then the user gets an error.

  (4) A string like 'function <NAME>', where <NAME> is a function name,
  the inner most frame for function <NAME> is selected.  If there is no
  frame for function <NAME> then the user gets an error.

  (5) A string like 'view <STACK-ADDRESS>', this views a new frame
  with stack address <STACK-ADDRESS>.

  (6) A string like 'view <STACK-ADDRESS> <PC-ADDRESS>', this views
  a new frame with stack address <STACK-ADDRESS> and the pc <PC-ADDRESS>.

This change assumes that the most common use of the commands like
'frame' is to select a frame by frame level, it is for this reason
that this is the behaviour that is kept for backwards compatibility.
Any of the alternative behaviours, which are assumed to be less used,
now require a change in user behaviour.

The MI command '-stack-select-frame' has not been changed.  This
ensures that we maintain backwards compatibility for existing
frontends.

gdb/ChangeLog:

	(NEWS): Mention changes to frame related commands.
	* cli/cli-decode.c (add_cmd_suppress_notification): New function.
	(add_prefix_cmd_suppress_notification): New function.
	(add_com_suppress_notification): Call
	add_cmd_suppress_notification.
	* command.h (add_cmd_suppress_notification): Declare.
	(add_prefix_cmd_suppress_notification): Declare.
	* mi/mi-cmd-stack.c: Add 'safe-ctype.h' include.
	(parse_frame_specification): Moved from stack.c, with
	simplification to handle a single argument.
	(mi_cmd_stack_select_frame): Use parse_frame_specification, the
	switch to the selected frame.  Add a header comment.
	* stack.c: Remove 'safe-ctype.h' include.
	(find_frame_for_function): Add declaration.
	(find_frame_for_address): New function.
	(parse_frame_specification): Moved into mi/mi-cmd-stack.c.
	(frame_selection_by_function_completer): New function.
	(info_frame_command): Rename to...
	(info_frame_command_core): ...this, and update parameter types.
	(select_frame_command): Rename to...
	(select_frame_command_core): ...this, and update parameter types.
	(frame_command): Rename to...
	(frame_command_core): ...this, and update parameter types.
	(class frame_command_helper): New class to wrap implementations of
	frame related sub-commands.
	(frame_apply_cmd_list): New static global.
	(frame_cmd_list): Make static.
	(select_frame_cmd_list): New global for sub-commands.
	(info_frame_cmd_list): New global for sub-commands.
	(_initialize_stack): Register sub-commands for 'frame',
	'select-frame', and 'info frame'.  Update 'frame apply' commands
	to use frame_apply_cmd_list.  Move function local static
	frame_apply_list to file static frame_apply_cmd_list for
	consistency.
	* stack.h (select_frame_command): Delete declarationn.
	(select_frame_for_mi): Declare new function.

gdb/doc/ChangeLog:

	* gdb.texinfo (Frames): Rewrite the description of 'frame number'
	to highlight that the number is also the frame's level.
	(Selection): Rewrite documentation for 'frame' and 'select-frame'
	commands.
	(Frame Info): Rewrite documentation for 'info frame' command.

gdb/testsuite/ChangeLog:

	* gdb.base/frame-selection.exp: New file.
	* gdb.base/frame-selection.c: New file.
---
 gdb/ChangeLog                              |  41 +++
 gdb/NEWS                                   |   8 +
 gdb/cli/cli-decode.c                       |  44 ++-
 gdb/command.h                              |  14 +
 gdb/doc/ChangeLog                          |   8 +
 gdb/doc/gdb.texinfo                        | 111 ++++--
 gdb/mi/mi-cmd-stack.c                      |  77 ++++-
 gdb/stack.c                                | 526 +++++++++++++++++++----------
 gdb/stack.h                                |   6 +-
 gdb/testsuite/ChangeLog                    |   5 +
 gdb/testsuite/gdb.base/frame-selection.c   |  52 +++
 gdb/testsuite/gdb.base/frame-selection.exp | 188 +++++++++++
 12 files changed, 872 insertions(+), 208 deletions(-)
 create mode 100644 gdb/testsuite/gdb.base/frame-selection.c
 create mode 100644 gdb/testsuite/gdb.base/frame-selection.exp
Pedro Alves - Sept. 27, 2018, 8:58 p.m.
On 09/27/2018 12:06 AM, Andrew Burgess wrote:> Thanks for the review.
> 
> This revision makes the following changes:
> 
>   - Addresses the two small grammatical errors, and removes the random
>     comment line in the testsuite.
> 
>   - Rewrites the get_new_address function in the testsuite so that is
>     actually does what it says on the tin (in line with your
>     suggestion).
> 
>   - Extends the header comment on parse_frame_specification.  While
>     doing this I realised that due to the way this function is now
>     used it can be simplified a lot.  We now only handle a single
>     argument.  I'd rather not start extending the existing MI
>     interface with new features at this point, and I didn't think
>     keeping the more complex parse_frame_specification around "just in
>     case" was good practice.
> 
> It's because of this last change that I've posted the patch for
> another review.  I think the change is sensible (and the tests pass),
> but I wanted another opinion.

I agree.  LGTM.

Thanks,
Pedro Alves

Patch

diff --git a/gdb/NEWS b/gdb/NEWS
index a1936ca1ccb..2669fa91a12 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -21,6 +21,14 @@ 
 * GDB in batch mode now exits with status 1 if the last command to be
   executed failed.
 
+* Changes to the "frame", "select-frame", and "info frame" CLI
+  commands.  These commands all now take a frame specification which
+  is either a frame level, or one of the keywords 'level', 'address',
+  'function', or 'view' followed by a parameter.  Selecting a frame by
+  address, or viewing a frame outside the current backtrace now
+  requires the use of a keyword.  Selecting a frame by level is
+  unchanged.  The MI comment "-stack-select-frame" is unchanged.
+
 * New commands
 
 set debug compile-cplus-types
diff --git a/gdb/cli/cli-decode.c b/gdb/cli/cli-decode.c
index 83dd67efe3f..5d798e877e8 100644
--- a/gdb/cli/cli-decode.c
+++ b/gdb/cli/cli-decode.c
@@ -251,6 +251,23 @@  add_cmd (const char *name, enum command_class theclass,
   return result;
 }
 
+/* Add an element with a suppress notification to the LIST of commands.  */
+
+struct cmd_list_element *
+add_cmd_suppress_notification (const char *name, enum command_class theclass,
+			       cmd_const_cfunc_ftype *fun, const char *doc,
+			       struct cmd_list_element **list,
+			       int *suppress_notification)
+{
+  struct cmd_list_element *element;
+
+  element = add_cmd (name, theclass, fun, doc, list);
+  element->suppress_notification = suppress_notification;
+
+  return element;
+}
+
+
 /* Deprecates a command CMD.
    REPLACEMENT is the name of the command which should be used in
    place of this command, or NULL if no such command exists.
@@ -362,6 +379,25 @@  add_prefix_cmd (const char *name, enum command_class theclass,
   return c;
 }
 
+/* Like ADD_PREFIX_CMD but sets the suppress_notification pointer on the
+   new command list element.  */
+
+struct cmd_list_element *
+add_prefix_cmd_suppress_notification
+               (const char *name, enum command_class theclass,
+		cmd_const_cfunc_ftype *fun,
+		const char *doc, struct cmd_list_element **prefixlist,
+		const char *prefixname, int allow_unknown,
+		struct cmd_list_element **list,
+		int *suppress_notification)
+{
+  struct cmd_list_element *element
+    = add_prefix_cmd (name, theclass, fun, doc, prefixlist,
+		      prefixname, allow_unknown, list);
+  element->suppress_notification = suppress_notification;
+  return element;
+}
+
 /* Like add_prefix_cmd but sets the abbrev_flag on the new command.  */
 
 struct cmd_list_element *
@@ -893,12 +929,8 @@  add_com_suppress_notification (const char *name, enum command_class theclass,
 			       cmd_const_cfunc_ftype *fun, const char *doc,
 			       int *suppress_notification)
 {
-  struct cmd_list_element *element;
-
-  element = add_cmd (name, theclass, fun, doc, &cmdlist);
-  element->suppress_notification = suppress_notification;
-
-  return element;
+  return add_cmd_suppress_notification (name, theclass, fun, doc,
+					&cmdlist, suppress_notification);
 }
 
 /* Recursively walk the commandlist structures, and print out the
diff --git a/gdb/command.h b/gdb/command.h
index 3dde2475cb1..e3d55c2dcba 100644
--- a/gdb/command.h
+++ b/gdb/command.h
@@ -148,6 +148,12 @@  extern struct cmd_list_element *add_cmd (const char *, enum command_class,
 					 const char *,
 					 struct cmd_list_element **);
 
+extern struct cmd_list_element *add_cmd_suppress_notification
+			(const char *name, enum command_class theclass,
+			 cmd_const_cfunc_ftype *fun, const char *doc,
+			 struct cmd_list_element **list,
+			 int *suppress_notification);
+
 extern struct cmd_list_element *add_alias_cmd (const char *, const char *,
 					       enum command_class, int,
 					       struct cmd_list_element **);
@@ -165,6 +171,14 @@  extern struct cmd_list_element *add_prefix_cmd (const char *, enum command_class
 						const char *, int,
 						struct cmd_list_element **);
 
+extern struct cmd_list_element *add_prefix_cmd_suppress_notification
+			(const char *name, enum command_class theclass,
+			 cmd_const_cfunc_ftype *fun,
+			 const char *doc, struct cmd_list_element **prefixlist,
+			 const char *prefixname, int allow_unknown,
+			 struct cmd_list_element **list,
+			 int *suppress_notification);
+
 extern struct cmd_list_element *add_abbrev_prefix_cmd (const char *,
 						       enum command_class,
 						       cmd_const_cfunc_ftype *fun,
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index b5b6089153a..62486410981 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -7401,12 +7401,14 @@ 
 in a register called the @dfn{frame pointer register}
 (@pxref{Registers, $fp}) while execution is going on in that frame.
 
+@cindex frame level
 @cindex frame number
-@value{GDBN} assigns numbers to all existing stack frames, starting with
-zero for the innermost frame, one for the frame that called it,
-and so on upward.  These numbers do not really exist in your program;
-they are assigned by @value{GDBN} to give you a way of designating stack
-frames in @value{GDBN} commands.
+@value{GDBN} labels each existing stack frame with a @dfn{level}, a
+number that is zero for the innermost frame, one for the frame that
+called it, and so on upward.  These level numbers give you a way of
+designating stack frames in @value{GDBN} commands.  The terms
+@dfn{frame number} and @dfn{frame level} can be used interchangeably to
+describe this number.
 
 @c The -fomit-frame-pointer below perennially causes hbox overflow
 @c underflow problems.
@@ -7639,21 +7641,75 @@ 
 @table @code
 @kindex frame@r{, selecting}
 @kindex f @r{(@code{frame})}
-@item frame @var{n}
-@itemx f @var{n}
-Select frame number @var{n}.  Recall that frame zero is the innermost
+@item frame @r{[} @var{frame-selection-spec} @r{]}
+@item f @r{[} @var{frame-selection-spec} @r{]}
+The @command{frame} command allows different stack frames to be
+selected.  The @var{frame-selection-spec} can be any of the following:
+
+@table @code
+@kindex frame level
+@item @var{num}
+@item level @var{num}
+Select frame level @var{num}.  Recall that frame zero is the innermost
 (currently executing) frame, frame one is the frame that called the
-innermost one, and so on.  The highest-numbered frame is the one for
-@code{main}.
+innermost one, and so on.  The highest level frame is usually the one
+for @code{main}.
+
+As this is the most common method of navigating the frame stack, the
+string @command{level} can be omitted.  For example, the following two
+commands are equivalent:
 
-@item frame @var{stack-addr} [ @var{pc-addr} ]
-@itemx f @var{stack-addr} [ @var{pc-addr} ]
-Select the frame at address @var{stack-addr}.  This is useful mainly if the
-chaining of stack frames has been damaged by a bug, making it
-impossible for @value{GDBN} to assign numbers properly to all frames.  In
-addition, this can be useful when your program has multiple stacks and
-switches between them.  The optional @var{pc-addr} can also be given to
-specify the value of PC for the stack frame.
+@smallexample
+(@value{GDBP}) frame 3
+(@value{GDBP}) frame level 3
+@end smallexample
+
+@kindex frame address
+@item address @var{stack-address}
+Select the frame with stack address @var{stack-address}.  The
+@var{stack-address} for a frame can be seen in the output of
+@command{info frame}, for example:
+
+@smallexample
+(gdb) info frame
+Stack level 1, frame at 0x7fffffffda30:
+ rip = 0x40066d in b (amd64-entry-value.cc:59); saved rip 0x4004c5
+ tail call frame, caller of frame at 0x7fffffffda30
+ source language c++.
+ Arglist at unknown address.
+ Locals at unknown address, Previous frame's sp is 0x7fffffffda30
+@end smallexample
+
+The @var{stack-address} for this frame is @code{0x7fffffffda30} as
+indicated by the line:
+
+@smallexample
+Stack level 1, frame at 0x7fffffffda30:
+@end smallexample
+
+@kindex frame function
+@item function @var{function-name}
+Select the stack frame for function @var{function-name}.  If there are
+multiple stack frames for function @var{function-name} then the inner
+most stack frame is selected.
+
+@kindex frame view
+@item view @var{stack-address} @r{[} @var{pc-addr} @r{]}
+View a frame that is not part of @value{GDBN}'s backtrace.  The frame
+viewed has stack address @var{stack-addr}, and optionally, a program
+counter address of @var{pc-addr}.
+
+This is useful mainly if the chaining of stack frames has been
+damaged by a bug, making it impossible for @value{GDBN} to assign
+numbers properly to all frames.  In addition, this can be useful
+when your program has multiple stacks and switches between them.
+
+When viewing a frame outside the current backtrace using
+@command{frame view} then you can always return to the original
+stack using one of the previous stack frame selection instructions,
+for example @command{frame level 0}.
+
+@end table
 
 @kindex up
 @item up @var{n}
@@ -7696,11 +7752,13 @@ 
 
 @table @code
 @kindex select-frame
-@item select-frame
+@item select-frame @r{[} @var{frame-selection-spec} @r{]}
 The @code{select-frame} command is a variant of @code{frame} that does
 not display the new frame after selecting it.  This command is
 intended primarily for use in @value{GDBN} command scripts, where the
-output might be unnecessary and distracting.
+output might be unnecessary and distracting.  The
+@var{frame-selection-spec} is as for the @command{frame} command
+described in @ref{Selection, ,Selecting a Frame}.
 
 @kindex down-silently
 @kindex up-silently
@@ -7758,13 +7816,12 @@ 
 something has gone wrong that has made the stack format fail to fit
 the usual conventions.
 
-@item info frame @var{addr}
-@itemx info f @var{addr}
-Print a verbose description of the frame at address @var{addr}, without
-selecting that frame.  The selected frame remains unchanged by this
-command.  This requires the same kind of address (more than one for some
-architectures) that you specify in the @code{frame} command.
-@xref{Selection, ,Selecting a Frame}.
+@item info frame @r{[} @var{frame-selection-spec} @r{]}
+@itemx info f @r{[} @var{frame-selection-spec} @r{]}
+Print a verbose description of the frame selected by
+@var{frame-selection-spec}.  The @var{frame-selection-spec} is the
+same as for the @command{frame} command (@pxref{Selection, ,Selecting
+a Frame}).  The selected frame remains unchanged by this command.
 
 @kindex info args
 @item info args
diff --git a/gdb/mi/mi-cmd-stack.c b/gdb/mi/mi-cmd-stack.c
index 52660bdd498..0679c5739ff 100644
--- a/gdb/mi/mi-cmd-stack.c
+++ b/gdb/mi/mi-cmd-stack.c
@@ -35,6 +35,7 @@ 
 #include <ctype.h>
 #include "mi-parse.h"
 #include "common/gdb_optional.h"
+#include "safe-ctype.h"
 
 enum what_to_list { locals, arguments, all };
 
@@ -678,13 +679,87 @@  list_args_or_locals (enum what_to_list what, enum print_values values,
     }
 }
 
+/* Read a frame specification from FRAME_EXP and return the selected frame.
+   Call error() if the specification is in any way invalid (so this
+   function never returns NULL).
+
+   The frame specification is usually an integer level number, however if
+   the number does not match a valid frame level then it will be treated as
+   a frame address.  The frame address will then be used to find a matching
+   frame in the stack.  If no matching frame is found then a new frame will
+   be created.
+
+   The use of FRAME_EXP as an address is undocumented in the GDB user
+   manual, this feature is supported here purely for backward
+   compatibility.  */
+
+static struct frame_info *
+parse_frame_specification (const char *frame_exp)
+{
+  gdb_assert (frame_exp != NULL);
+
+  /* NOTE: Parse and evaluate expression, but do not use
+     functions such as parse_and_eval_long or
+     parse_and_eval_address to also extract the value.
+     Instead value_as_long and value_as_address are used.
+     This avoids problems with expressions that contain
+     side-effects.  */
+  struct value *arg = parse_and_eval (frame_exp);
+
+  /* Assume ARG is an integer, and try using that to select a frame.  */
+  struct frame_info *fid;
+  int level = value_as_long (arg);
+
+  fid = find_relative_frame (get_current_frame (), &level);
+  if (level == 0)
+    /* find_relative_frame was successful.  */
+    return fid;
+
+  /* Convert the value into a corresponding address.  */
+  CORE_ADDR addr = value_as_address (arg);
+
+  /* Assume that ADDR is an address, use that to identify a frame with a
+     matching ID.  */
+  struct frame_id id = frame_id_build_wild (addr);
+
+  /* If (s)he specifies the frame with an address, he deserves
+     what (s)he gets.  Still, give the highest one that matches.
+     (NOTE: cagney/2004-10-29: Why highest, or outer-most, I don't
+     know).  */
+  for (fid = get_current_frame ();
+       fid != NULL;
+       fid = get_prev_frame (fid))
+    {
+      if (frame_id_eq (id, get_frame_id (fid)))
+	{
+	  struct frame_info *prev_frame;
+
+	  while (1)
+	    {
+	      prev_frame = get_prev_frame (fid);
+	      if (!prev_frame
+		  || !frame_id_eq (id, get_frame_id (prev_frame)))
+		break;
+	      fid = prev_frame;
+	    }
+	  return fid;
+	}
+    }
+
+  /* We couldn't identify the frame as an existing frame, but
+     perhaps we can create one with a single argument.  */
+  return create_new_frame (addr, 0);
+}
+
+/* Implement the -stack-select-frame MI command.  */
+
 void
 mi_cmd_stack_select_frame (const char *command, char **argv, int argc)
 {
   if (argc == 0 || argc > 1)
     error (_("-stack-select-frame: Usage: FRAME_SPEC"));
 
-  select_frame_command (argv[0], 1 /* not used */ );
+  select_frame_for_mi (parse_frame_specification (argv[0]));
 }
 
 void
diff --git a/gdb/stack.c b/gdb/stack.c
index 40ff99b8fa6..fc1ccb33fa6 100644
--- a/gdb/stack.c
+++ b/gdb/stack.c
@@ -48,7 +48,6 @@ 
 #include "cli/cli-utils.h"
 #include "objfiles.h"
 
-#include "safe-ctype.h"
 #include "symfile.h"
 #include "extension.h"
 #include "observable.h"
@@ -102,6 +101,9 @@  static void set_last_displayed_sal (int valid,
 				    struct symtab *symtab,
 				    int line);
 
+static struct frame_info *find_frame_for_function (const char *);
+static struct frame_info *find_frame_for_address (CORE_ADDR);
+
 /* Zero means do things normally; we are interacting directly with the
    user.  One means print the full filename and linenumber when a
    frame is printed, and do so in a format emacs18/emacs19.22 can
@@ -1258,134 +1260,34 @@  print_frame (struct frame_info *frame, int print_level,
 }
 
 
-/* Read a frame specification in whatever the appropriate format is from
-   FRAME_EXP.  Call error() if the specification is in any way invalid (so
-   this function never returns NULL).  When SELECTED_FRAME_P is non-NULL
-   set its target to indicate that the default selected frame was used.  */
+/* Completion function for "frame function", "info frame function", and
+   "select-frame function" commands.  */
 
-static struct frame_info *
-parse_frame_specification (const char *frame_exp, int *selected_frame_p)
+void
+frame_selection_by_function_completer (struct cmd_list_element *ignore,
+				       completion_tracker &tracker,
+				       const char *text, const char *word)
 {
-  int numargs;
-  struct value *args[4];
-  CORE_ADDR addrs[ARRAY_SIZE (args)];
-
-  if (frame_exp == NULL)
-    numargs = 0;
-  else
-    {
-      numargs = 0;
-      while (1)
-	{
-	  const char *p;
-
-	  /* Skip leading white space, bail of EOL.  */
-	  frame_exp = skip_spaces (frame_exp);
-	  if (!*frame_exp)
-	    break;
-
-	  /* Parse the argument, extract it, save it.  */
-	  for (p = frame_exp;
-	       *p && !ISSPACE (*p);
-	       p++);
-	  std::string addr_string (frame_exp, p - frame_exp);
-	  frame_exp = p;
-	  
-	  /* NOTE: Parse and evaluate expression, but do not use
-	     functions such as parse_and_eval_long or
-	     parse_and_eval_address to also extract the value.
-	     Instead value_as_long and value_as_address are used.
-	     This avoids problems with expressions that contain
-	     side-effects.  */
-	  if (numargs >= ARRAY_SIZE (args))
-	    error (_("Too many args in frame specification"));
-	  args[numargs++] = parse_and_eval (addr_string.c_str ());
-	}
-    }
-
-  /* If no args, default to the selected frame.  */
-  if (numargs == 0)
-    {
-      if (selected_frame_p != NULL)
-	(*selected_frame_p) = 1;
-      return get_selected_frame (_("No stack."));
-    }
-
-  /* None of the remaining use the selected frame.  */
-  if (selected_frame_p != NULL)
-    (*selected_frame_p) = 0;
-
-  /* Assume the single arg[0] is an integer, and try using that to
-     select a frame relative to current.  */
-  if (numargs == 1)
-    {
-      struct frame_info *fid;
-      int level = value_as_long (args[0]);
-
-      fid = find_relative_frame (get_current_frame (), &level);
-      if (level == 0)
-	/* find_relative_frame was successful.  */
-	return fid;
-    }
-
-  /* Convert each value into a corresponding address.  */
-  {
-    int i;
-
-    for (i = 0; i < numargs; i++)
-      addrs[i] = value_as_address (args[i]);
-  }
-
-  /* Assume that the single arg[0] is an address, use that to identify
-     a frame with a matching ID.  Should this also accept stack/pc or
-     stack/pc/special.  */
-  if (numargs == 1)
-    {
-      struct frame_id id = frame_id_build_wild (addrs[0]);
-      struct frame_info *fid;
-
-      /* If (s)he specifies the frame with an address, he deserves
-	 what (s)he gets.  Still, give the highest one that matches.
-	 (NOTE: cagney/2004-10-29: Why highest, or outer-most, I don't
-	 know).  */
-      for (fid = get_current_frame ();
-	   fid != NULL;
-	   fid = get_prev_frame (fid))
-	{
-	  if (frame_id_eq (id, get_frame_id (fid)))
-	    {
-	      struct frame_info *prev_frame;
-
-	      while (1)
-		{
-		  prev_frame = get_prev_frame (fid);
-		  if (!prev_frame
-		      || !frame_id_eq (id, get_frame_id (prev_frame)))
-		    break;
-		  fid = prev_frame;
-		}
-	      return fid;
-	    }
-	}
-      }
-
-  /* We couldn't identify the frame as an existing frame, but
-     perhaps we can create one with a single argument.  */
-  if (numargs == 1)
-    return create_new_frame (addrs[0], 0);
-  else if (numargs == 2)
-    return create_new_frame (addrs[0], addrs[1]);
-  else
-    error (_("Too many args in frame specification"));
+  /* This is used to complete function names within a stack.  It would be
+     nice if we only offered functions that were actually in the stack.
+     However, this would mean unwinding the stack to completion, which
+     could take too long, or on a corrupted stack, possibly not end.
+     Instead, we offer all symbol names as a safer choice.  */
+  collect_symbol_completion_matches (tracker,
+				     complete_symbol_mode::EXPRESSION,
+				     symbol_name_match_type::EXPRESSION,
+				     text, word);
 }
 
-/* Print verbosely the selected frame or the frame at address
-   ADDR_EXP.  Absolutely all information in the frame is printed.  */
+/* Core of all the "info frame" sub-commands.  Print information about a
+   frame FI.  If SELECTED_FRAME_P is true then the user didn't provide a
+   frame specification, they just entered 'info frame'.  If the user did
+   provide a frame specification (for example 'info frame 0', 'info frame
+   level 1') then SELECTED_FRAME_P will be false.  */
 
 static void
-info_frame_command (const char *addr_exp, int from_tty)
+info_frame_command_core (struct frame_info *fi, bool selected_frame_p)
 {
-  struct frame_info *fi;
   struct symbol *func;
   struct symtab *s;
   struct frame_info *calling_frame_info;
@@ -1393,7 +1295,6 @@  info_frame_command (const char *addr_exp, int from_tty)
   const char *funname = 0;
   enum language funlang = language_unknown;
   const char *pc_regname;
-  int selected_frame_p;
   struct gdbarch *gdbarch;
   CORE_ADDR frame_pc;
   int frame_pc_p;
@@ -1401,7 +1302,6 @@  info_frame_command (const char *addr_exp, int from_tty)
   CORE_ADDR caller_pc = 0;
   int caller_pc_p = 0;
 
-  fi = parse_frame_specification (addr_exp, &selected_frame_p);
   gdbarch = get_frame_arch (fi);
 
   /* Name of the value returned by get_frame_pc().  Per comments, "pc"
@@ -1742,6 +1642,157 @@  trailing_outermost_frame (int count)
   return trailing;
 }
 
+/* The core of all the "select-frame" sub-commands.  Just wraps a call to
+   SELECT_FRAME.  */
+
+static void
+select_frame_command_core (struct frame_info *fi, bool ignored)
+{
+  struct frame_info *prev_frame = get_selected_frame_if_set ();
+  select_frame (fi);
+  if (get_selected_frame_if_set () != prev_frame)
+    gdb::observers::user_selected_context_changed.notify (USER_SELECTED_FRAME);
+}
+
+/* See stack.h.  */
+
+void
+select_frame_for_mi (struct frame_info *fi)
+{
+  select_frame_command_core (fi, FALSE /* Ignored.  */);
+}
+
+/* The core of all the "frame" sub-commands.  Select frame FI, and if this
+   means we change frame send out a change notification (otherwise, just
+   reprint the current frame summary).   */
+
+static void
+frame_command_core (struct frame_info *fi, bool ignored)
+{
+  struct frame_info *prev_frame = get_selected_frame_if_set ();
+
+  select_frame (fi);
+  if (get_selected_frame_if_set () != prev_frame)
+    gdb::observers::user_selected_context_changed.notify (USER_SELECTED_FRAME);
+  else
+    print_selected_thread_frame (current_uiout, USER_SELECTED_FRAME);
+}
+
+/* The three commands 'frame', 'select-frame', and 'info frame' all have a
+   common set of sub-commands that allow a specific frame to be selected.
+   All of the sub-command functions are static methods within this class
+   template which is then instantiated below.  The template parameter is a
+   callback used to implement the functionality of the base command
+   ('frame', 'select-frame', or 'info frame').
+
+   In the template parameter FI is the frame being selected.  The
+   SELECTED_FRAME_P flag is true if the frame being selected was done by
+   default, which happens when the user uses the base command with no
+   arguments.  For example the commands 'info frame', 'select-frame',
+   'frame' will all cause SELECTED_FRAME_P to be true.  In all other cases
+   SELECTED_FRAME_P is false.  */
+
+template <void (*FPTR) (struct frame_info *fi, bool selected_frame_p)>
+class frame_command_helper
+{
+public:
+
+  /* The "frame level" family of commands.  The ARG is an integer that is
+     the frame's level in the stack.  */
+  static void
+  level (const char *arg, int from_tty)
+  {
+    int level = value_as_long (parse_and_eval (arg));
+    struct frame_info *fid
+      = find_relative_frame (get_current_frame (), &level);
+    if (level != 0)
+      error (_("No frame at level %s."), arg);
+    FPTR (fid, false);
+  }
+
+  /* The "frame address" family of commands.  ARG is a stack-pointer
+     address for an existing frame.  This command does not allow new
+     frames to be created.  */
+
+  static void
+  address (const char *arg, int from_tty)
+  {
+    CORE_ADDR addr = value_as_address (parse_and_eval (arg));
+    struct frame_info *fid = find_frame_for_address (addr);
+    if (fid == NULL)
+      error (_("No frame at address %s."), arg);
+    FPTR (fid, false);
+  }
+
+  /* The "frame view" family of commands.  ARG is one or two addresses and
+     is used to view a frame that might be outside the current backtrace.
+     The addresses are stack-pointer address, and (optional) pc-address.  */
+
+  static void
+  view (const char *args, int from_tty)
+  {
+    struct frame_info *fid;
+
+    if (args == NULL)
+    error (_("Missing address argument to view a frame"));
+
+    gdb_argv argv (args);
+
+    if (argv.count () == 2)
+      {
+	CORE_ADDR addr[2];
+
+	addr [0] = value_as_address (parse_and_eval (argv[0]));
+	addr [1] = value_as_address (parse_and_eval (argv[1]));
+	fid = create_new_frame (addr[0], addr[1]);
+      }
+    else
+      {
+	CORE_ADDR addr = value_as_address (parse_and_eval (argv[0]));
+	fid = create_new_frame (addr, false);
+      }
+    FPTR (fid, false);
+  }
+
+  /* The "frame function" family of commands.  ARG is the name of a
+     function within the stack, the first function (searching from frame
+     0) with that name will be selected.  */
+
+  static void
+  function (const char *arg, int from_tty)
+  {
+    if (arg == NULL)
+      error (_("Missing function name argument"));
+    struct frame_info *fid = find_frame_for_function (arg);
+    if (fid == NULL)
+      error (_("No frame for function \"%s\"."), arg);
+    FPTR (fid, false);
+  }
+
+  /* The "frame" base command, that is, when no sub-command is specified.
+     If one argument is provided then we assume that this is a frame's
+     level as historically, this was the supported command syntax that was
+     used most often.
+
+     If no argument is provided, then the current frame is selected.  */
+
+  static void
+  base_command (const char *arg, int from_tty)
+  {
+    if (arg == NULL)
+      FPTR (get_selected_frame (_("No stack.")), true);
+    else
+      level (arg, from_tty);
+  }
+};
+
+/* Instantiate three FRAME_COMMAND_HELPER instances to implement the
+   sub-commands for 'info frame', 'frame', and 'select-frame' commands.  */
+
+static frame_command_helper <info_frame_command_core> info_frame_cmd;
+static frame_command_helper <frame_command_core> frame_cmd;
+static frame_command_helper <select_frame_command_core> select_frame_cmd;
+
 /* Print briefly all stack frames or just the innermost COUNT_EXP
    frames.  */
 
@@ -2230,39 +2281,6 @@  find_relative_frame (struct frame_info *frame, int *level_offset_ptr)
   return frame;
 }
 
-/* The "select_frame" command.  With no argument this is a NOP.
-   Select the frame at level LEVEL_EXP if it is a valid level.
-   Otherwise, treat LEVEL_EXP as an address expression and select it.
-
-   See parse_frame_specification for more info on proper frame
-   expressions.  */
-
-void
-select_frame_command (const char *level_exp, int from_tty)
-{
-  struct frame_info *prev_frame = get_selected_frame_if_set ();
-
-  select_frame (parse_frame_specification (level_exp, NULL));
-  if (get_selected_frame_if_set () != prev_frame)
-    gdb::observers::user_selected_context_changed.notify (USER_SELECTED_FRAME);
-}
-
-/* The "frame" command.  With no argument, print the selected frame
-   briefly.  With an argument, behave like select_frame and then print
-   the selected frame.  */
-
-static void
-frame_command (const char *level_exp, int from_tty)
-{
-  struct frame_info *prev_frame = get_selected_frame_if_set ();
-
-  select_frame (parse_frame_specification (level_exp, NULL));
-  if (get_selected_frame_if_set () != prev_frame)
-    gdb::observers::user_selected_context_changed.notify (USER_SELECTED_FRAME);
-  else
-    print_selected_thread_frame (current_uiout, USER_SELECTED_FRAME);
-}
-
 /* Select the frame up one or COUNT_EXP stack levels from the
    previously selected frame, and print it briefly.  */
 
@@ -2716,13 +2734,61 @@  faas_command (const char *cmd, int from_tty)
 }
 
 
+/* Find inner-mode frame with frame address ADDRESS.  Return NULL if no
+   matching frame can be found.  */
+
+static struct frame_info *
+find_frame_for_address (CORE_ADDR address)
+{
+  struct frame_id id;
+  struct frame_info *fid;
+
+  id = frame_id_build_wild (address);
+
+  /* If (s)he specifies the frame with an address, he deserves
+     what (s)he gets.  Still, give the highest one that matches.
+     (NOTE: cagney/2004-10-29: Why highest, or outer-most, I don't
+     know).  */
+  for (fid = get_current_frame ();
+       fid != NULL;
+       fid = get_prev_frame (fid))
+    {
+      if (frame_id_eq (id, get_frame_id (fid)))
+	{
+	  struct frame_info *prev_frame;
+
+	  while (1)
+	    {
+	      prev_frame = get_prev_frame (fid);
+	      if (!prev_frame
+		  || !frame_id_eq (id, get_frame_id (prev_frame)))
+		break;
+	      fid = prev_frame;
+	    }
+	  return fid;
+	}
+    }
+  return NULL;
+}
+
+
+
+/* Commands with a prefix of `frame apply'.  */
+static struct cmd_list_element *frame_apply_cmd_list = NULL;
+
 /* Commands with a prefix of `frame'.  */
-struct cmd_list_element *frame_cmd_list = NULL;
+static struct cmd_list_element *frame_cmd_list = NULL;
+
+/* Commands with a prefix of `select frame'.  */
+static struct cmd_list_element *select_frame_cmd_list = NULL;
+
+/* Commands with a prefix of `info frame'.  */
+static struct cmd_list_element *info_frame_cmd_list = NULL;
 
 void
 _initialize_stack (void)
 {
-  static struct cmd_list_element *frame_apply_list = NULL;
+  struct cmd_list_element *cmd;
 
   add_com ("return", class_stack, return_command, _("\
 Make selected stack frame return to its caller.\n\
@@ -2746,12 +2812,12 @@  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_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."),
-		  &frame_cmd_list, "frame ", 1, &cmdlist);
+  add_prefix_cmd ("frame", class_stack,
+                  &frame_cmd.base_command, _("\
+Select and print a stack frame.\n\
+With no argument, print the selected stack frame.  (See also \"info frame\").\n\
+A single numerical argument specifies the frame to select."),
+                  &frame_cmd_list, "frame ", 1, &cmdlist);
 
   add_com_alias ("f", "frame", class_stack, 1);
 
@@ -2769,7 +2835,7 @@  or produces no output."
 Usage: frame apply COUNT [FLAG]... 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);
+		  &frame_apply_cmd_list, "frame apply ", 1, &frame_cmd_list);
 
   add_cmd ("all", class_stack, frame_apply_all_command,
 	   _("\
@@ -2777,7 +2843,7 @@  Apply a command to all frames.\n\
 \n\
 Usage: frame apply all [FLAG]... COMMAND\n"
 FRAME_APPLY_FLAGS_HELP),
-	   &frame_apply_list);
+	   &frame_apply_cmd_list);
 
   add_cmd ("level", class_stack, frame_apply_level_command,
 	   _("\
@@ -2786,19 +2852,97 @@  Apply a command to a list of frames.\n\
 Usage: frame apply level LEVEL... [FLAG]... COMMAND\n\
 ID is a space-separated list of LEVELs of frames to apply COMMAND on.\n"
 FRAME_APPLY_FLAGS_HELP),
-	   &frame_apply_list);
+	   &frame_apply_cmd_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, _("\
+
+  add_prefix_cmd ("frame", class_stack,
+		  &frame_cmd.base_command, _("\
+Select and print a stack frame.\n\
+With no argument, print the selected stack frame.  (See also \"info frame\").\n\
+A single numerical argument specifies the frame to select."),
+		  &frame_cmd_list, "frame ", 1, &cmdlist);
+  add_com_alias ("f", "frame", class_stack, 1);
+
+  add_cmd ("address", class_stack, &frame_cmd.address,
+	   _("\
+Select and print a stack frame by stack address\n\
+\n\
+Usage: frame address STACK-ADDRESS"),
+	   &frame_cmd_list);
+
+  add_cmd ("view", class_stack, &frame_cmd.view,
+	   _("\
+View a stack frame that might be outside the current backtrace.\n\
+\n\
+Usage: frame view STACK-ADDRESS\n\
+       frame view STACK-ADDRESS PC-ADDRESS"),
+	   &frame_cmd_list);
+
+  cmd = add_cmd ("function", class_stack, &frame_cmd.function,
+	   _("\
+Select and print a stack frame by function name.\n\
+\n\
+Usage: frame function NAME\n\
+\n\
+The innermost frame that visited function NAME is selected."),
+	   &frame_cmd_list);
+  set_cmd_completer (cmd, frame_selection_by_function_completer);
+
+
+  add_cmd ("level", class_stack, &frame_cmd.level,
+	   _("\
+Select and print a stack frame by level.\n\
+\n\
+Usage: frame level LEVEL"),
+	   &frame_cmd_list);
+
+  cmd = add_prefix_cmd_suppress_notification ("select-frame", class_stack,
+		      &select_frame_cmd.base_command, _("\
 Select a stack frame without printing anything.\n\
-An argument specifies the frame to select.\n\
-It can be a stack frame number or the address of the frame."),
+A single numerical argument specifies the frame to select."),
+		      &select_frame_cmd_list, "select-frame ", 1, &cmdlist,
+		      &cli_suppress_notification.user_selected_context);
+
+  add_cmd_suppress_notification ("address", class_stack,
+			 &select_frame_cmd.address, _("\
+Select a stack frame by stack address.\n\
+\n\
+Usage: select-frame address STACK-ADDRESS"),
+			 &select_frame_cmd_list,
+			 &cli_suppress_notification.user_selected_context);
+
+
+  add_cmd_suppress_notification ("view", class_stack,
+		 &select_frame_cmd.view, _("\
+Select a stack frame that might be outside the current backtrace.\n\
+\n\
+Usage: select-frame view STACK-ADDRESS\n\
+       select-frame view STACK-ADDRESS PC-ADDRESS"),
+		 &select_frame_cmd_list,
 		 &cli_suppress_notification.user_selected_context);
 
+  cmd = add_cmd_suppress_notification ("function", class_stack,
+	       &select_frame_cmd.function, _("\
+Select a stack frame by function name.\n\
+\n\
+Usage: select-frame function NAME"),
+	       &select_frame_cmd_list,
+	       &cli_suppress_notification.user_selected_context);
+  set_cmd_completer (cmd, frame_selection_by_function_completer);
+
+  add_cmd_suppress_notification ("level", class_stack,
+			 &select_frame_cmd.level, _("\
+Select a stack frame by level.\n\
+\n\
+Usage: select-frame level LEVEL"),
+			 &select_frame_cmd_list,
+			 &cli_suppress_notification.user_selected_context);
+
   add_com ("backtrace", class_stack, backtrace_command, _("\
 Print backtrace of all stack frames, or innermost COUNT frames.\n\
 Usage: backtrace [QUALIFIERS]... [COUNT]\n\
@@ -2812,9 +2956,45 @@  on this backtrace."));
   add_info ("stack", backtrace_command,
 	    _("Backtrace of the stack, or innermost COUNT frames."));
   add_info_alias ("s", "stack", 1);
-  add_info ("frame", info_frame_command,
-	    _("All about selected stack frame, or frame at ADDR."));
+
+  add_prefix_cmd ("frame", class_info, &info_frame_cmd.base_command,
+		  _("All about the selected stack frame.\n\
+With no arguments, displays information about the currently selected stack\n\
+frame.  Alternatively a frame specification may be provided (See \"frame\")\n\
+the information is then printed about the specified frame."),
+		  &info_frame_cmd_list, "info frame ", 1, &infolist);
   add_info_alias ("f", "frame", 1);
+
+  add_cmd ("address", class_stack, &info_frame_cmd.address,
+	   _("\
+Print information about a stack frame selected by stack address.\n\
+\n\
+Usage: info frame address STACK-ADDRESS"),
+	   &info_frame_cmd_list);
+
+  add_cmd ("view", class_stack, &info_frame_cmd.view,
+	   _("\
+Print information about a stack frame outside the current backtrace.\n\
+\n\
+Usage: info frame view STACK-ADDRESS\n\
+       info frame view STACK-ADDRESS PC-ADDRESS"),
+	   &info_frame_cmd_list);
+
+  cmd = add_cmd ("function", class_stack, &info_frame_cmd.function,
+	   _("\
+Print information about a stack frame selected by function name.\n\
+\n\
+Usage: info frame function NAME"),
+	   &info_frame_cmd_list);
+  set_cmd_completer (cmd, frame_selection_by_function_completer);
+
+  add_cmd ("level", class_stack, &info_frame_cmd.level,
+	   _("\
+Print information about a stack frame selected by level.\n\
+\n\
+Usage: info frame level LEVEL"),
+	   &info_frame_cmd_list);
+
   add_info ("locals", info_locals_command,
 	    _("Local variables of current stack frame."));
   add_info ("args", info_args_command,
diff --git a/gdb/stack.h b/gdb/stack.h
index ca190efa9c3..3681120a776 100644
--- a/gdb/stack.h
+++ b/gdb/stack.h
@@ -20,7 +20,11 @@ 
 #ifndef STACK_H
 #define STACK_H
 
-void select_frame_command (const char *level_exp, int from_tty);
+/* Access method used by the MI -stack-select-frame command to switch to
+   frame FI.  This differs from SELECT_FRAME in that the observers for a
+   user selected context change will be triggered.  */
+
+void select_frame_for_mi (struct frame_info *fi);
 
 gdb::unique_xmalloc_ptr<char> find_frame_funname (struct frame_info *frame,
 						  enum language *funlang,
diff --git a/gdb/testsuite/gdb.base/frame-selection.c b/gdb/testsuite/gdb.base/frame-selection.c
new file mode 100644
index 00000000000..f3d81f223e0
--- /dev/null
+++ b/gdb/testsuite/gdb.base/frame-selection.c
@@ -0,0 +1,52 @@ 
+/* Copyright 2018 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+int
+frame_2 (void)
+{
+  return 0;
+}
+
+int
+frame_1 (void)
+{
+  return frame_2 ();
+}
+
+int
+recursive (int arg)
+{
+  int v;
+
+  if (arg < 2)
+    v = recursive (arg + 1);
+  else
+    v = frame_2 ();
+
+  return v;
+}
+
+int
+main (void)
+{
+  int i, j;
+
+  i = frame_1 ();
+  j = recursive (0);
+
+  return i + j;
+}
diff --git a/gdb/testsuite/gdb.base/frame-selection.exp b/gdb/testsuite/gdb.base/frame-selection.exp
new file mode 100644
index 00000000000..2dde33fef0d
--- /dev/null
+++ b/gdb/testsuite/gdb.base/frame-selection.exp
@@ -0,0 +1,188 @@ 
+# Copyright 2018 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# This tests GDB's frame selection as used by the 'frame',
+# 'select-frame', and 'info frame' commands.
+
+standard_testfile
+
+if {[prepare_for_testing "failed to prepare" $testfile $srcfile {debug}]} {
+    return -1
+}
+
+runto_main
+gdb_breakpoint frame_2
+gdb_continue_to_breakpoint frame_2
+
+gdb_test "bt" "#0  frame_2.*#1  $hex in frame_1.*#2  $hex in main.*" "backtrace at breakpoint"
+
+# Perform "info frame" to extract the frame's address.
+proc get_frame_address { {testname ""} } {
+    global hex gdb_prompt
+
+    set frame_address "unknown"
+    set testname "get_frame_address: ${testname}"
+    gdb_test_multiple "info frame" $testname {
+	-re ", frame at ($hex):\r\n.*\r\n$gdb_prompt $" {
+	    set frame_address $expect_out(1,string)
+	    pass $testname
+	}
+    }
+
+    return $frame_address
+}
+
+# Passed a list of addresses.  Return a new address that is not in the
+# list by sorting the addresses and adding 0x10 to the highest
+# address.
+proc get_new_address { {addresses {}} } {
+    # Find the highest element in the list.
+    set elem [lindex [lsort -integer -decreasing $addresses] 0]
+
+    # Return a new address as a hex formatted string.
+    return [format "%#x" [expr $elem + 0x10]]
+}
+
+
+# Check that the current frame is at stack depth LEVEL, at frame
+# address ADDRESS, and is in FUNCTION.
+proc check_frame { level address function } {
+    global hex gdb_prompt
+
+    set re [multi_line \
+		"Stack level ${level}, frame at ($address):" \
+		".* = $hex in ${function} \(\[^\r\n\]*\); saved .* = $hex" \
+		".*\r\n$gdb_prompt $" ]
+
+    set testname "check frame level ${level}"
+    gdb_test_multiple "info frame" $testname {
+	-re $re {
+	    pass $testname
+	}
+    }
+}
+
+# Select frame using level, but relying on this being the default
+# action, so "frame 0" performs "frame level 0".
+gdb_test "frame 0" "#0  frame_2.*"
+set frame_0_address [ get_frame_address "frame 0" ]
+gdb_test "frame 1" "#1  $hex in frame_1.*"
+set frame_1_address [ get_frame_address "frame 1" ]
+gdb_test "frame 2" "#2  $hex in main.*"
+set frame_2_address [ get_frame_address "frame 2" ]
+gdb_test "frame 3" "No frame at level 3\."
+
+# Find an address that matches no frame.
+set no_frame_address [ get_new_address [list $frame_0_address \
+					     $frame_1_address \
+					     $frame_2_address] ]
+
+# Select frame using 'level' specification.
+gdb_test "frame level 0" "#0  frame_2.*"
+gdb_test "frame level 1" "#1  $hex in frame_1.*"
+gdb_test "frame level 2" "#2  $hex in main.*"
+gdb_test "frame level 3" "No frame at level 3\."
+
+# Select frame by address.
+gdb_test "frame address ${frame_0_address}" "#0  frame_2.*" \
+    "select frame 0 by address"
+gdb_test "frame address ${frame_1_address}" "#1  $hex in frame_1.*" \
+    "select frame 1 by address"
+gdb_test "frame address ${frame_2_address}" "#2  $hex in main.*" \
+    "select frame 2 by address"
+gdb_test "frame address ${no_frame_address}" \
+    "No frame at address ${no_frame_address}\." \
+    "attempt to select a frame at an invalid address"
+
+# Select frame by function.
+gdb_test "frame function frame_2" "#0  frame_2.*"
+gdb_test "frame function frame_1" "#1  $hex in frame_1.*"
+gdb_test "frame function main" "#2  $hex in main.*"
+
+# Check for a distinction between a known function not in the stack
+# trace, and an unknown function.
+gdb_test "frame function recursive" "No frame for function \"recursive\"."
+gdb_test "frame function foo" "Function \"foo\" not defined."
+
+
+with_test_prefix "select-frame, no keyword" {
+    gdb_test_no_output "select-frame 0"
+    check_frame "0" "${frame_0_address}" "frame_2"
+    gdb_test_no_output "select-frame 1"
+    check_frame "1" "${frame_1_address}" "frame_1"
+    gdb_test_no_output "select-frame 2"
+    check_frame "2" "${frame_2_address}" "main"
+    gdb_test "select-frame 3" "No frame at level 3\."
+}
+
+with_test_prefix "select-frame, keyword=level" {
+    gdb_test_no_output "select-frame level 0"
+    check_frame "0" "${frame_0_address}" "frame_2"
+    gdb_test_no_output "select-frame level 1"
+    check_frame "1" "${frame_1_address}" "frame_1"
+    gdb_test_no_output "select-frame level 2"
+    check_frame "2" "${frame_2_address}" "main"
+    gdb_test "select-frame level 3" "No frame at level 3\."
+}
+
+with_test_prefix "select-frame, keyword=address" {
+    gdb_test_no_output "select-frame address ${frame_0_address}" \
+	"select frame 0 by address"
+    check_frame "0" "${frame_0_address}" "frame_2"
+    gdb_test_no_output "select-frame address ${frame_1_address}" \
+	"select frame 1 by address"
+    check_frame "1" "${frame_1_address}" "frame_1"
+    gdb_test_no_output "select-frame address ${frame_2_address}" \
+	"select frame 2 by address"
+    check_frame "2" "${frame_2_address}" "main"
+    gdb_test "select-frame address ${no_frame_address}" \
+	"No frame at address ${no_frame_address}\." \
+	"select-frame for an invalid address"
+}
+
+with_test_prefix "select-frame, keyword=function" {
+    gdb_test_no_output "select-frame function frame_2"
+    check_frame "0" "${frame_0_address}" "frame_2"
+    gdb_test_no_output "select-frame function frame_1"
+    check_frame "1" "${frame_1_address}" "frame_1"
+    gdb_test_no_output "select-frame function main"
+    check_frame "2" "${frame_2_address}" "main"
+}
+
+# Check for a distinction between a known function not in the stack
+# trace, and an unknown function.
+gdb_test "select-frame function recursive" \
+    "No frame for function \"recursive\"."
+gdb_test "select-frame function foo" \
+    "Function \"foo\" not defined."
+
+# Now continue until we hit the breakpoint again.
+with_test_prefix "second frame_2 breakpoint" {
+    gdb_continue_to_breakpoint frame_2
+    gdb_test "bt" \
+	"#0  frame_2.*#1  $hex in recursive.*#2  $hex in recursive.*#3  $hex in recursive.*#4  $hex in main.*" \
+ 	"backtrace at breakpoint with recursive frames"
+
+    # Check "frame function" when a function name occurs multiple times in
+    # the stack.  The inner most (lowest level) should always be selected.
+    gdb_test "frame function frame_2" "#0  frame_2.*"
+    gdb_test "frame function recursive" "#1  $hex in recursive.*" \
+	"select frame for function recursive, first attempt"
+    gdb_test "frame function recursive" "#1  $hex in recursive.*" \
+		"select frame for function recursive, second attempt"
+    gdb_test "frame function main" "#4  $hex in main.*"
+    gdb_test "frame function recursive" "#1  $hex in recursive.*" \
+	"select frame for function recursive, third attempt"
+}