Re: [PATCH 2/2] userdiff: improve Fortran xfuncname regex

[Elijah Newren <newren@gmail.com>]

On Wed, Aug 12, 2020 at 3:34 PM Philippe Blain via GitGitGadget
<gitgitgadget@gmail.com> wrote:
>
> From: Philippe Blain <levraiphilippeblain@gmail.com>
>
> The third part of the Fortran xfuncname regex wants to match the
> beginning of a subroutine or function, so it allows for all characters
> except `'`, `"` or whitespace before the keyword 'function' or
> 'subroutine'. This is meant to match the 'recursive', 'elemental' or
> 'pure' keywords, as well as function return types, and to prevent
> matches inside strings.
>
> However, the negated set does not contain the `!` comment character,
> so a line with an end-of-line comment containing the keyword 'function' or
> 'subroutine' followed by another word is mistakenly chosen as a hunk header.
>
> Improve the regex by adding `!` to the negated set.
>
> Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
> ---
>  t/t4018/fortran-comment-keyword | 1 -
>  userdiff.c                      | 2 +-
>  2 files changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/t/t4018/fortran-comment-keyword b/t/t4018/fortran-comment-keyword
> index c5dbdb4c61..e9206a5379 100644
> --- a/t/t4018/fortran-comment-keyword
> +++ b/t/t4018/fortran-comment-keyword
> @@ -8,7 +8,6 @@
>        real funcB  ! grid function b
>
>        real ChangeMe
> -      integer broken
>
>        end subroutine RIGHT
>

This change seems orthogonal to the explanation in the commit message.
What is its purpose, and does it belong in this commit or a different
one?

> diff --git a/userdiff.c b/userdiff.c
> index 707d82435a..fde02f225b 100644
> --- a/userdiff.c
> +++ b/userdiff.c
> @@ -53,7 +53,7 @@ IPATTERN("fortran",
>          /* Program, module, block data */
>          "^[ \t]*((END[ \t]+)?(PROGRAM|MODULE|BLOCK[ \t]+DATA"
>                 /* Subroutines and functions */
> -               "|([^'\" \t]+[ \t]+)*(SUBROUTINE|FUNCTION))[ \t]+[A-Z].*)$",
> +               "|([^!'\" \t]+[ \t]+)*(SUBROUTINE|FUNCTION))[ \t]+[A-Z].*)$",
>          /* -- */
>          "[a-zA-Z][a-zA-Z0-9_]*"
>          "|\\.([Ee][Qq]|[Nn][Ee]|[Gg][TtEe]|[Ll][TtEe]|[Tt][Rr][Uu][Ee]|[Ff][Aa][Ll][Ss][Ee]|[Aa][Nn][Dd]|[Oo][Rr]|[Nn]?[Ee][Qq][Vv]|[Nn][Oo][Tt])\\."
> --
> gitgitgadget