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Date:   Mon, 21 Dec 2020 16:22:53 +0200
From:   Boris Kolpackov <boris@codesynthesis.com>
To:     Masahiro Yamada <masahiroy@kernel.org>
Cc:     linux-kbuild@vger.kernel.org, Jonathan Corbet <corbet@lwn.net>,
        Michal Marek <michal.lkml@markovi.net>,
        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] kconfig: drop filename and line number prefix from
 warning/error-if macros
Message-ID: <boris.20201221161803@codesynthesis.com>
References: <20201221094650.283511-1-masahiroy@kernel.org>
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[Copying some of my comments from another reply.]

Masahiro Yamada <masahiroy@kernel.org> writes:

> When I implemented the Kconfig macro language, I took the GNU Make
> behavior as a reference in general, but I did not follow the message
> format of $(error ...) to avoid that annoyance.
> 
> So, the following code in Kconfig:
> 
>   $(warning-if,y,This is the first line)
>   $(warning-if,y,This is the second line)
>   $(error-if,y,This is the last line)
> 
> ... will print the messages in a consistent format:
> 
>   Kconfig:1: This is the first line
>   Kconfig:2: This is the second line
>   Kconfig:3: This is the last line

IMO, there is a flaw with this approach: there is no way for the
user to know that these three lines are about the same error.

If we want this ability, then let's find a way do it properly
rather than spreading further hacks. For example, in the build
system I am working on, we have suport for multi-line diagnostics
records that to the user look like this:

Makefile:3: error: This is the first line
  This is the second line
  This is the last line


> But, in hindsight, the built-in functions should have only primitive
> functionality to print the given message without any prefix. The lesson
> I learned from GNU Make was such a prefix is easy to add, difficult to
> remove.
> 
> This commit changes the built-in functions, warning-if and error-if, to
> not print the file name or the line number.

Wouldn't automatically showing the position in the Kconfig file
where the error/warning has originated be much, much more useful
than the occasional need to print multi-line messages?