[bug#54780] [PATCH v2 1/2] guix: build: Add absolute-inclusions.scm.

[Olivier Dion]

* guix/build/absolute-inclusions.scm: New file.
* Makefile.am (MODULES): Add it here.
---
 Makefile.am                        |  1 +
 guix/build/absolute-inclusions.scm | 51 ++++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+)
 create mode 100644 guix/build/absolute-inclusions.scm

diff --git a/Makefile.am b/Makefile.am
index fecce7c6f7..394df67016 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -181,6 +181,7 @@ MODULES =                                   \
   guix/diagnostics.scm                         \
   guix/ui.scm                                  \
   guix/status.scm                              \
+  guix/build/absolute-inclusions.scm           \
   guix/build/android-ndk-build-system.scm      \
   guix/build/ant-build-system.scm              \
   guix/build/download.scm                      \
diff --git a/guix/build/absolute-inclusions.scm 
b/guix/build/absolute-inclusions.scm
new file mode 100644
index 0000000000..06b4cd7beb
--- /dev/null
+++ b/guix/build/absolute-inclusions.scm
@@ -0,0 +1,51 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2022 Maxime Devos <maximedevos@telenet.be>
+;;; Copyright © 2022 Olivier Dion <olivier.dion@polymtl.ca>
+;;;
+;;; 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)
+  #:use-module (guix build utils)
+  #:use-module (ice-9 match)
+  #:use-module (rnrs exceptions)
+  #:export (absolute-inclusions patch-header-inclusions))
+
+(define (absolute-inclusions files header-locations)
+  (substitute* files
+    (("^[ \t]*#[ \t]*include[ \t]*<(.*)>[ \t]*" 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 header-file?
+  ;; See gcc(1) for the list of suffixes.
+  (let ((suffixes (list "h" "hh" "H" "hp" "hxx" "hpp" "HPP" "h++" "tcc")))
+    (file-name-predicate
+     (format #f "\\.(~a)$" (string-join suffixes "|" 'infix)))))
+
+(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))
+  (for-each (match-lambda
+              ((_ . output)
+               (absolute-inclusions
+                (find-files (string-append output "/include")
+                            header-file?)
+                header-locations)))
+            outputs))
-- 
2.34.0