20/169: build-system/go: Add subdir parameter to go-version->git-ref.

[guix-commits]

sharlatan pushed a commit to branch go-team
in repository guix.

commit 9e7d7cf56101ef70bf4c2aa2b14f2bf93e105252
Author: Christina O'Donnell <cdo@mutix.org>
AuthorDate: Sat Mar 16 10:26:05 2024 +0000

    build-system/go: Add subdir parameter to go-version->git-ref.
    
    This implements logic to handle cases where Go can have multiple modules
    at different versions within a single repository.  It distinguishes their
    releases by using tags along with their subdirectories.  See
    https://go.dev/ref/mod#vcs-version.
    
    * guix/build-system/go.scm (go-version->git-ref): Add <#:subdir> keyword
    parameter and extend condition checks.
    
    Change-Id: I68bc9e785e49877bb0b756de8458308549f4c957
    Co-authored-by: Sharlatan Hellseher <sharlatanus@gmail.com>
    Signed-off-by: Sharlatan Hellseher <sharlatanus@gmail.com>
---
 guix/build-system/go.scm | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/guix/build-system/go.scm b/guix/build-system/go.scm
index f4231df4ec..e39502991b 100644
--- a/guix/build-system/go.scm
+++ b/guix/build-system/go.scm
@@ -58,11 +58,13 @@
                 "([0-9A-Fa-f]{12})"            ;commit hash
                 "(\\+incompatible)?$")))       ;optional +incompatible tag
 
-(define (go-version->git-ref version)
+(define* (go-version->git-ref version #:key subdir)
   "Parse VERSION, a \"pseudo-version\" as defined at
 <https://golang.org/ref/mod#pseudo-versions>, and extract the commit hash from
 it, defaulting to full VERSION (stripped from the \"+incompatible\" suffix if
-present) if a pseudo-version pattern is not recognized."
+present) if a pseudo-version pattern is not recognized.  If SUBDIR is
+specified and this is not a pseudo-version, then this will prefix SUBDIR/ to
+the returned tag; when VERSION misses 'v' prefix use SUBDIR/v instead."
   ;; A module version like v1.2.3 is introduced by tagging a revision in the
   ;; underlying source repository.  Untagged revisions can be referred to
   ;; using a "pseudo-version" like v0.0.0-yyyymmddhhmmss-abcdefabcdef, where
@@ -80,7 +82,13 @@ present) if a pseudo-version pattern is not recognized."
          (match (regexp-exec %go-pseudo-version-rx version)))
     (if match
         (match:substring match 2)
-        version)))
+        (cond
+         ((and subdir (string-prefix? "v" version))
+          (string-append subdir "/" version))
+         ((and subdir (not (string-prefix? "v" version)))
+          (string-append subdir "/v" version))
+         (else
+          version)))))
 
 (define (go-pseudo-version? version)
   "True if VERSION is a Go pseudo-version, i.e., a version string made of a