Add completer for skip numbers

  Add completer to various commands that accept skip numbers:

  - skip enable
  - skip disable
  - skip delete
  - info skip

These commands also accept ranges, but I am not too sure of how to do
that properly, so I went for the simpler goal of complete just numbers.

A future idea would be to make a re-usable and well-tested completer for
numbers and ranges.  I think it could at least be re-used for breakpoint
numbers (for example with the "enable breakpoints" command).

gdb/ChangeLog:

	* skip.c (complete_skip_number): New function.
	(_initialize_step_skip): Add completers to some skip commands.

gdb/testsuite/ChangeLog:

	* gdb.base/skip.exp: Add standard_testfile.  Add "skip delete"
	completer tests.
---
 gdb/skip.c                      | 35 +++++++++++++++++++-----
 gdb/testsuite/gdb.base/skip.exp | 48 +++++++++++++++++++++++++++++++++
 2 files changed, 76 insertions(+), 7 deletions(-)
  

On 11/10/2018 05:39 PM, Simon Marchi wrote:
> Add completer to various commands that accept skip numbers:
> 
>   - skip enable
>   - skip disable
>   - skip delete
>   - info skip
> 
> These commands also accept ranges, but I am not too sure of how to do
> that properly, so I went for the simpler goal of complete just numbers.
> 
> A future idea would be to make a re-usable and well-tested completer for
> numbers and ranges.  I think it could at least be re-used for breakpoint
> numbers (for example with the "enable breakpoints" command).

And threads.

> 
> gdb/ChangeLog:
> 
> 	* skip.c (complete_skip_number): New function.
> 	(_initialize_step_skip): Add completers to some skip commands.
> 
> gdb/testsuite/ChangeLog:
> 
> 	* gdb.base/skip.exp: Add standard_testfile.  Add "skip delete"
> 	completer tests.
> ---
>  gdb/skip.c                      | 35 +++++++++++++++++++-----
>  gdb/testsuite/gdb.base/skip.exp | 48 +++++++++++++++++++++++++++++++++
>  2 files changed, 76 insertions(+), 7 deletions(-)
> 
> diff --git a/gdb/skip.c b/gdb/skip.c
> index 13db0f6b43c6..f2a1df79e8bf 100644
> --- a/gdb/skip.c
> +++ b/gdb/skip.c
> @@ -641,6 +641,23 @@ function_name_is_marked_for_skip (const char *function_name,
>    return false;
>  }
>  
> +/* Completer for skip numbers.  */
> +
> +static void
> +complete_skip_number (cmd_list_element *cmd,
> +		      completion_tracker &completer,
> +		      const char *text, const char *word)
> +{
> +  size_t word_len = strlen (word);
> +
> +  for (const skiplist_entry &entry : skiplist_entries)
> +    {
> +      gdb::unique_xmalloc_ptr<char> name (xstrprintf ("%d", entry.number ()));
> +      if (strncmp (word, name.get (), word_len) == 0)
> +	completer.add_completion (std::move (name));
> +    }
> +}
> +
>  void
>  _initialize_step_skip (void)
>  {
> @@ -676,28 +693,31 @@ If no function name is given, skip the current function."),
>  	       &skiplist);
>    set_cmd_completer (c, location_completer);
>  
> -  add_cmd ("enable", class_breakpoint, skip_enable_command, _("\
> +  c = add_cmd ("enable", class_breakpoint, skip_enable_command, _("\
>  Enable skip entries.  You can specify numbers (e.g. \"skip enable 1 3\"), \
>  ranges (e.g. \"skip enable 4-8\"), or both (e.g. \"skip enable 1 3 4-8\").\n\n\
>  If you don't specify any numbers or ranges, we'll enable all skip entries.\n\n\
>  Usage: skip enable [NUMBER | RANGE]..."),
> -	   &skiplist);
> +	       &skiplist);
> +  set_cmd_completer (c, complete_skip_number);
>  
> -  add_cmd ("disable", class_breakpoint, skip_disable_command, _("\
> +  c = add_cmd ("disable", class_breakpoint, skip_disable_command, _("\
>  Disable skip entries.  You can specify numbers (e.g. \"skip disable 1 3\"), \
>  ranges (e.g. \"skip disable 4-8\"), or both (e.g. \"skip disable 1 3 4-8\").\n\n\
>  If you don't specify any numbers or ranges, we'll disable all skip entries.\n\n\
>  Usage: skip disable [NUMBER | RANGE]..."),
> -	   &skiplist);
> +	       &skiplist);
> +  set_cmd_completer (c, complete_skip_number);
>  
> -  add_cmd ("delete", class_breakpoint, skip_delete_command, _("\
> +  c = add_cmd ("delete", class_breakpoint, skip_delete_command, _("\
>  Delete skip entries.  You can specify numbers (e.g. \"skip delete 1 3\"), \
>  ranges (e.g. \"skip delete 4-8\"), or both (e.g. \"skip delete 1 3 4-8\").\n\n\
>  If you don't specify any numbers or ranges, we'll delete all skip entries.\n\n\
>  Usage: skip delete [NUMBER | RANGES]..."),
> -           &skiplist);
> +	       &skiplist);
> +  set_cmd_completer (c, complete_skip_number);
>  
> -  add_info ("skip", info_skip_command, _("\
> +  c = add_info ("skip", info_skip_command, _("\
>  Display the status of skips.  You can specify numbers (e.g. \"skip info 1 3\"), \
>  ranges (e.g. \"skip info 4-8\"), or both (e.g. \"skip info 1 3 4-8\").\n\n\
>  If you don't specify any numbers or ranges, we'll show all skips.\n\n\
> @@ -705,6 +725,7 @@ Usage: skip info [NUMBER | RANGES]...\n\
>  The \"Type\" column indicates one of:\n\
>  \tfile        - ignored file\n\
>  \tfunction    - ignored function"));
> +  set_cmd_completer (c, complete_skip_number);
>  
>    add_setshow_boolean_cmd ("skip", class_maintenance,
>  			   &debug_skip, _("\
> diff --git a/gdb/testsuite/gdb.base/skip.exp b/gdb/testsuite/gdb.base/skip.exp
> index 223c93d0d9b6..ee328bf35c9b 100644
> --- a/gdb/testsuite/gdb.base/skip.exp
> +++ b/gdb/testsuite/gdb.base/skip.exp
> @@ -16,6 +16,8 @@
>  # This file was written by Justin Lebar. (justin.lebar@gmail.com)
>  # And further hacked on by Doug Evans. (dje@google.com)
>  
> +standard_testfile
> +
>  if { [prepare_for_testing "failed to prepare" "skip" \
>                            {skip.c skip1.c } \
>                            {debug nowarnings}] } {
> @@ -297,3 +299,49 @@ with_test_prefix "step using -fi + -fu" {
>      gdb_test "step" ".*" "step 4"; # Skip over test_skip()
>      gdb_test "step" "test_skip_file_and_function \\(\\) at.*" "step 5"; # Return from skip1_test_skip_file_and_function()
>  }
> +
> +with_test_prefix "skip delete completion" {
> +    global binfile
> +    clean_restart "${binfile}"
> +    if ![runto_main] {
> +	fail "can't run to main"
> +	return
> +    }
> +
> +    # Create a bunch of skips, don't care what they are.
> +    for {set i 0} {$i < 12} {incr i} {
> +	gdb_test "skip" ".*" "add skip $i"
> +    }
> +
> +    gdb_test "complete skip delete " \
> +	[multi_line "skip delete 1" \
> +		    "skip delete 10" \
> +		    "skip delete 11" \
> +		    "skip delete 12" \
> +		    "skip delete 2" \
> +		    "skip delete 3" \
> +		    "skip delete 4" \
> +		    "skip delete 5" \
> +		    "skip delete 6" \
> +		    "skip delete 7" \
> +		    "skip delete 8" \
> +		    "skip delete 9"]
> +    gdb_test "complete skip delete 1" \
> +	[multi_line "skip delete 1" \
> +		    "skip delete 10" \
> +		    "skip delete 11" \
> +		    "skip delete 12"]
> +    gdb_test "complete skip delete 1 " \
> +	[multi_line "skip delete 1 1" \
> +		    "skip delete 1 10" \
> +		    "skip delete 1 11" \
> +		    "skip delete 1 12" \
> +		    "skip delete 1 2" \
> +		    "skip delete 1 3" \
> +		    "skip delete 1 4" \
> +		    "skip delete 1 5" \
> +		    "skip delete 1 6" \
> +		    "skip delete 1 7" \
> +		    "skip delete 1 8" \
> +		    "skip delete 1 9"]
> +}
Please use the lib/completion-support.exp routines
for testing this.  Those exercise both the complete command
and actual TAB completion.  Above you want to use 
test_gdb_complete_multiple.  

You should also add:

- a test that exercises unique completions like "skip delete 12",
  with test_gdb_complete_unique.

- a test that exercises no completions at all, like "skip delete 2",
  with test_gdb_complete_none.

- some test like "skip delete a1" to make sure we don't
  mistakenly complete that a1 into a1/a10/a11/a12.

As for a range completer, doesn't e.g., "skip delete 1-2<tab>" already
try to complete the "2", and "skip delete 1-" present all the numbers?
I'd think so, given that '-' is part of the default word break chars
set (default_word_break_characters).  You should add tests for that too,
IMO, since people will very naturally use it.  Even if not super smart
(e.g. 2-[TAB] ideally wouldn't present "1"), it's still useful as is.

Thanks,
Pedro Alves
  

On 2018-11-10 14:07, Pedro Alves wrote:
> On 11/10/2018 05:39 PM, Simon Marchi wrote:
>> Add completer to various commands that accept skip numbers:
>> 
>>   - skip enable
>>   - skip disable
>>   - skip delete
>>   - info skip
>> 
>> These commands also accept ranges, but I am not too sure of how to do
>> that properly, so I went for the simpler goal of complete just 
>> numbers.
>> 
>> A future idea would be to make a re-usable and well-tested completer 
>> for
>> numbers and ranges.  I think it could at least be re-used for 
>> breakpoint
>> numbers (for example with the "enable breakpoints" command).
> 
> And threads.

Right.


> Please use the lib/completion-support.exp routines
> for testing this.  Those exercise both the complete command
> and actual TAB completion.  Above you want to use
> test_gdb_complete_multiple.
> 
> You should also add:
> 
> - a test that exercises unique completions like "skip delete 12",
>   with test_gdb_complete_unique.
> 
> - a test that exercises no completions at all, like "skip delete 2",
>   with test_gdb_complete_none.
> 
> - some test like "skip delete a1" to make sure we don't
>   mistakenly complete that a1 into a1/a10/a11/a12.
> 
> As for a range completer, doesn't e.g., "skip delete 1-2<tab>" already
> try to complete the "2", and "skip delete 1-" present all the numbers?
> I'd think so, given that '-' is part of the default word break chars
> set (default_word_break_characters).  You should add tests for that 
> too,
> IMO, since people will very naturally use it.  Even if not super smart
> (e.g. 2-[TAB] ideally wouldn't present "1"), it's still useful as is.

Thanks for all the feedback, I hope I have addressed everything in v2.

Simon