From mboxrd@z Thu Jan  1 00:00:00 1970
Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail
From: Eli Zaretskii <eliz@gnu.org>
Newsgroups: gmane.emacs.devel
Subject: Re: master 888ff3755d4 1/3: New function internal--c-header-file-path
Date: Mon, 06 Jan 2025 22:28:48 +0200
Message-ID: <864j2b660v.fsf@gnu.org>
Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214";
	logging-data="13690"; mail-complaints-to="usenet@ciao.gmane.io"
Cc: emacs-devel@gnu.org
To: Stefan Kangas <stefankangas@gmail.com>
Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Mon Jan 06 21:30:33 2025
Return-path: <emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org>
Envelope-to: ged-emacs-devel@m.gmane-mx.org
Original-Received: from lists.gnu.org ([209.51.188.17])
	by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)
	(Exim 4.92)
	(envelope-from <emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org>)
	id 1tUtk9-0003Qx-Hr
	for ged-emacs-devel@m.gmane-mx.org; Mon, 06 Jan 2025 21:30:33 +0100
Original-Received: from localhost ([::1] helo=lists1p.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.90_1)
	(envelope-from <emacs-devel-bounces@gnu.org>)
	id 1tUtjE-00058y-UF; Mon, 06 Jan 2025 15:29:37 -0500
Original-Received: from eggs.gnu.org ([2001:470:142:3::10])
 by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)
 (Exim 4.90_1) (envelope-from <eliz@gnu.org>) id 1tUtjA-00058l-SU
 for emacs-devel@gnu.org; Mon, 06 Jan 2025 15:29:33 -0500
Original-Received: from fencepost.gnu.org ([2001:470:142:3::e])
 by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)
 (Exim 4.90_1) (envelope-from <eliz@gnu.org>)
 id 1tUtj9-00068t-MS; Mon, 06 Jan 2025 15:29:31 -0500
DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnu.org;
 s=fencepost-gnu-org; h=Subject:To:From:Date:mime-version:in-reply-to:
 references; bh=Y6e/jWjoLM5JMd9ovwa+l+VuahBlaNsrLjZmA0DGM2c=; b=sH4rPTeC29wzfi
 sfeScfgrLQJzgV4YuY0LEjFwHbiJj68TBLJhvNnYwZ0eT94BmvL8m6Q7GadNsIpEyWFZPON9FDYiQ
 pVDOHIDK0zESba6ushG29xXUU79hieWE0V9N/Jr0Q9x560OGwaBlHbyBenus2XvXRfL0zXmo78XJJ
 SEnNLM+lrY0RHy6ZIssuovoB9D+vicpoPVER+4ffDbn3gvjeaEMiAIn9f0RNFIZBOrZYLREHTYhEZ
 UFxiFd2CtWC0u5W7X36/4ABf4nc6XQ6Q9EZDnSpHPYSpDXhyGGkIHX3cGe6eeUhPIcpEGIAvN/yPx
 pHaXYFS0qWpmeoKgiatw==;
X-BeenThere: emacs-devel@gnu.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "Emacs development discussions." <emacs-devel.gnu.org>
List-Unsubscribe: <https://lists.gnu.org/mailman/options/emacs-devel>,
 <mailto:emacs-devel-request@gnu.org?subject=unsubscribe>
List-Archive: <https://lists.gnu.org/archive/html/emacs-devel>
List-Post: <mailto:emacs-devel@gnu.org>
List-Help: <mailto:emacs-devel-request@gnu.org?subject=help>
List-Subscribe: <https://lists.gnu.org/mailman/listinfo/emacs-devel>,
 <mailto:emacs-devel-request@gnu.org?subject=subscribe>
Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org
Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org
Xref: news.gmane.io gmane.emacs.devel:327750
Archived-At: <http://permalink.gmane.org/gmane.emacs.devel/327750>

Stefan,

Thanks for adding this function.  However, the method it uses to find
the include directories is incorrect and unportable.  On most systems
it will produce the default "/usr/include", which is most probably
wrong.

The way to ask GCC to show the list of directories where it looks for
header files is like this:

   (call-process "gcc" nil BUFFER nil "-v" "-E" "-")

and then look in BUFFER for text that begins with "#include <...>
search starts here:" and ends with "End of search list."  What's
in-between is the list of include directories, one directory per line,
which GCC searches for header file, in the order it searches them.