Subject: [bug#54780] [PATCH] gnu: lttng-ust: Fix dependencies.

From: Maxime Devos <[email-masked]>
Date: Fri, 08 Apr 2022 16:04:16 +0200

Olivier Dion via Guix-patches via schreef op do 07-04-2022 om 20:18 [-
0400]:
> Headers of liburcu are used by headers of lttng.

This can be addressed without propagation, by substitute*.  Something
like:

  (lambda* (#:key inputs #:allow-other-keys)
    (substitute* (find-files ".h")
      (("some-liburcu-header.h")
       (search-input-file inputs "include/some-liburcu-header.h"))))

Attached is some more generic and automated code I wrote a while ago.
Maybe it's good enough for lttng?

Greetings,
Maxime.
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2022 Maxime Devos <[email-masked]>
;;;
;;; This file is part of GNU Guix.
;;;
;;; GNU Guix is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; GNU Guix is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.

(define-module (guix build absolute-inclusions)
  #:export (absolute-inclusions patch-header-inclusions)
  #:use-module (guix build utils)
  #:use-module (ice-9 match)
  #:use-module (rnrs exceptions))

(define (absolute-inclusions files header-locations)
  (substitute* files
    ;; TODO: allow spaces before the < or include, maybe recognise #include
    ;; "foo" ...
    (("#include <(.*)>" original header-name)
     (guard (c ((search-error? c) original))
       ;; TODO: verify with libgcc & etc, maybe avoid increasing the closure size
       ;; by skipping glibc and linux headers ...
       (format #f "#include <~a>"
               (search-input-file header-locations
                                  (string-append "include/" header-name)))))))

(define* (patch-header-inclusions #:key inputs outputs #:allow-other-keys)
  "Patch inclusions in C headers in OUTPUTS to use absolute file names."
  (define header-locations (append outputs inputs))
  ;; TODO: are there also other header names in use?
  (define header-file? (file-name-predicate "\\.(h|hpp)$"))
  (for-each (match-lambda
              ((_ . output)
               (absolute-inclusions
                (find-files (string-append output "/include") header-file?)
                header-locations)))
            outputs))