nonguix: chromium-binary-build: Extend wrapper-plan syntax.

This commit is similar to a0079cf1bd8ef707ab9e15a0e249cbd34f157ae4 which
allowed patchelf-plan to take entries with an optional path.  Here,
wrapper-plan is extended to allow for additional syntax (not just a list of
strings) similar to patchelf-plan.  Now, entries can be a list, with the first
the string for the file to be patched and the second a list which is added to
the patchelf-plan.

This allows, for example, to patch RPATH to effectively have $ORIGIN for
binaries that need it, with an entry like `("bin/binary" (("out"
"/lib/Binary")))` common for some chromium-based packages.  See followup
commits for these changes to reduce LD_LIBRARY_PATH wrapping in some packages.

* nonguix/build-system/chromium-binary.scm (build-patchelf-plan): Handle
entries in wrapper-plan which are a list so that the cdr is added to
patchelf-plan for the car.
(chromium-binary-build): Update doc string for this change and some basics
which were not documented.

1 files changed, 13 insertions, 2 deletions

diff --git a/nonguix/build-system/chromium-binary.scm b/nonguix/build-system/chromium-binary.scm
index 874acda..fa22cd9 100644
--- a/nonguix/build-system/chromium-binary.scm
+++ b/nonguix/build-system/chromium-binary.scm
@@ -54,7 +54,12 @@
   #~(let ((patchelf-inputs
            (list #$@(map car inputs))))
       (map (lambda (file)
-             (cons file (list patchelf-inputs)))
+             ;; Either an entry in WRAPPER-PLAN is just a string which can be
+             ;; used directly, or it is a list where the second element is a
+             ;; list of additional inputs for patchelf-plan.
+             (if (list? file)
+                 (cons (car file) (list (append patchelf-inputs (cadr file))))
+                 (cons file (list patchelf-inputs))))
            #$wrapper-plan)))
 
 (define* (lower name
@@ -163,7 +168,13 @@
                        (substitutable? #t)
                        allowed-references
                        disallowed-references)
-  "Build SOURCE using binary-build-system."
+  "Build SOURCE using binary-build-system.  WRAPPER-PLAN is a list of strings for
+files which patchelf will add the INPUTS (which implicitly includes the base
+packages needed for chromium-based binaries) to RPATH and wrap with needed
+environment variables.  Optionally, an entry can be a list with the first
+entry the file to be patched and the second a list of additional inputs for
+patchelf, like PATCHELF-PLAN in binary-build-system.  PATCHELF-PLAN itself is
+ignored if WRAPPER-PLAN is not '()."
   (define builder
     (with-imported-modules imported-modules
       #~(begin