Re: [PATCH 2/3] Remove is_first_nonwhitespace_on_line(), instead improve get_visual_column()

[Jeff Law <law@redhat.com>]

On 06/09/2015 11:31 AM, Patrick Palka wrote:
> This patch removes the function is_first_nonwhitespace_on_line() in
> favor of augmenting the function get_visual_column() to optionally
> return the visual column corresponding to the first non-whitespace character
> on the line.  Existing usage of is_first_nonwhitespace_on_line() can
> be trivially replaced by calling get_visual_column() and comparing *out
> with *first_nws.
>
> The rationale for this change is that in many cases it is better to use
> the visual column of the first non-whitespace character rather than the
> visual column of the token.  Consider:
>
>    if (p) {
>      foo (1);
>    } else       // GUARD
>      if (q)     // BODY
>        foo (2);
>      foo (3);   // NEXT
>
> Here, with current heuristics, we do not emit a warning because we
> notice that the visual columns of each token line up ("suggesting"
> autogenerated code).  Yet it is obvious that we should warn here because
> it misleadingly looks like the foo (3); statement is guarded by the
> else.
>
> If we instead consider the visual column of the first non-whitespace
> character on the guard line, the columns will not line up thus we will
> emit the warning.  This will be done in the next patch.
>
> gcc/c-family/ChangeLog:
>
> 	* c-indentation.c (get_visual_column): Add parameter first_nws,
> 	use it.  Update comment documenting the function.
> 	(is_first_nonwhitespace_on_line): Remove.
> 	(should_warn_for_misleading_indentation): Replace usage of
> 	of is_first_nonwhitespace_on_line with get_visual_column.
Same comment/question WRT testing as the prior patch.

OK once you've confirmed bootstrap & regression testing was completed 
successfully.

jeff