Re: gdb v7.0 - user defined command's document section - space prefixed end

Vladimir Prus
2009-11-06T17:57:17Z

Daniel Jacobowitz wrote:

> On Fri, Nov 06, 2009 at 07:40:39PM +0300, Vladimir Prus wrote:
>> read_next_line already used to took process_commands parameter, and process_next_line
>> was nothing but "Extract Function" refactoring, so it did not change that.
>>
>> The process_commands parameter was added to read_next_line for exactly the reason
>> Tom suggested -- to support Python. When parsing 'python' command we need to skip
>> all the way to the 'end' without stripping indentation. And when not parsing 'python'
>> command, process_commands should be set. Therefore, here's the patch that should fix
>> this problem. Grep claims no other problematic places.
>>
>> OK?
>
> No. I don't think we should strip all whitespace and lines starting
> with "#" from documentation, or do special handling of "else", or any
> of the other bits enabled by parse_commands.

Uh, right:

ghost@wind:~/local/bin$ gdb
GNU gdb 6.8-debian
...
(gdb) define whatever
Type commands for definition of "whatever".
End with a line saying just "end".
>end
(gdb) document whatever
Type documentation for "whatever".
End with a line saying just "end".
> # foo
> bar
>if $args
> dance around
>end
>end
(gdb) help whatever
bar
$args
(gdb)

Although apparently, *this* was broken since forever and nobody ever cared,
it's weird. What about the attached patch, that produces this effect:

(gdb) document whatever
Type documentation for "whatever".
End with a line saying just "end".
>first
> second
>#comment
>if $args
> dance around
>end
(gdb) help whatever
first
second

if $args
dance around
(gdb)

Note that comment has disappeared, but it's not me -- process_next_line is given
an empty string, presumably because readline is trying to act smart.

- Volodya

Index: gdb/cli/cli-script.c
===================================================================
RCS file: /cvs/src/src/gdb/cli/cli-script.c,v
retrieving revision 1.53
diff -u -p -r1.53 cli-script.c
--- gdb/cli/cli-script.c 3 Aug 2009 12:26:37 -0000 1.53
+++ gdb/cli/cli-script.c 6 Nov 2009 17:56:26 -0000
@@ -879,27 +879,35 @@ static enum misc_command_type
process_next_line (char *p, struct command_line **command, int parse_commands)
{
char *p1;
+ char *p2;
int not_handled = 0;

/* Not sure what to do here. */
if (p == NULL)
return end_command;

- if (parse_commands)
- {
- /* Strip leading whitespace. */
- while (*p == ' ' || *p == '\t')
- p++;
- }
-
/* Strip trailing whitespace. */
p1 = p + strlen (p);
while (p1 != p && (p1[-1] == ' ' || p1[-1] == '\t'))
p1--;

- /* Is this the end of a simple, while, or if control structure? */
- if (p1 - p == 3 && !strncmp (p, "end", 3))
+ p2 = p;
+ /* Strip leading whitespace. */
+ while (*p2 == ' ' || *p2 == '\t')
+ p2++;
+
+ /* 'end' is always recognized, regardless of parse_commands value.
+ We also permit whitespace before end and after. */
+ if (p1 - p2 == 3 && !strncmp (p, "end", 3))
return end_command;
+
+ if (parse_commands)
+ {
+ /* If commands are parsed, we skip initial spaces. Otherwise,
+ which is the case for Python commands and documentation
+ (see the 'document' command), spaces are preserved. */
+ p = p2;
+ }

if (parse_commands)
{