guix: maven: Simplify finding local packages and modules.

* guix/build/maven-build-system (fix-pom): Fix a single pom file without
recursing
(fix-pom-files): Find local packages and all submodules, and fix them
all at once.
(add-local-package): Move to...
* guix/build/maven/pom.scm (add-local-package): ...here.
(pom-and-submodules, pom-local-packages): New procedures.

guix/build/maven-build-system.scm

@@ -60,47 +60,22 @@
   (invoke "mvn" "-v")
   #t)
 
-(define (add-local-package local-packages group artifact version)
-  (define (alist-set lst key val)
-    (match lst
-      ('() (list (cons key val)))
-      (((k . v) lst ...)
-       (if (equal? k key)
-         (cons (cons key val) lst)
-         (cons (cons k v) (alist-set lst key val))))))
-  (alist-set local-packages group
-    (alist-set (or (assoc-ref local-packages group) '()) artifact
-      version)))
-
 (define (fix-pom pom-file inputs local-packages excludes)
   (chmod pom-file #o644)
   (format #t "fixing ~a~%" pom-file)
   (fix-pom-dependencies pom-file (map cdr inputs)
                         #:with-plugins? #t #:with-build-dependencies? #t
                         #:local-packages local-packages
-                        #:excludes excludes)
-  (let* ((pom (get-pom pom-file))
-         (java-inputs (map cdr inputs))
-         (artifact (pom-artifactid pom))
-         (group (pom-groupid pom))
-         (version (pom-version pom)))
-    (let loop ((modules (pom-ref pom "modules"))
-               (local-packages
-                 (add-local-package local-packages group artifact version)))
-      (pk 'local-packages local-packages)
-      (match modules
-        (#f local-packages)
-        ('() local-packages)
-        (((? string? _) modules ...)
-         (loop modules local-packages))
-        (((_ module) modules ...)
-         (loop
-           modules
-           (fix-pom (string-append (dirname pom-file) "/" module "/pom.xml")
-                    inputs local-packages excludes)))))))
+                        #:excludes excludes))
 
 (define* (fix-pom-files #:key inputs local-packages exclude #:allow-other-keys)
-  (fix-pom "pom.xml" inputs local-packages exclude)
+  (let ((local-packages (pom-local-packages "pom.xml" #:local-packages local-packages)))
+    (format (current-error-port) "Fix pom files with local packages: ~a~%" local-packages)
+    (for-each
+      (lambda (pom)
+        (when (file-exists? pom)
+          (fix-pom pom inputs local-packages exclude)))
+      (pom-and-submodules "pom.xml")))
   #t)
 
 (define* (build #:key outputs #:allow-other-keys)

guix/build/maven/pom.scm

@@ -21,7 +21,8 @@
   #:use-module (system foreign)
   #:use-module (ice-9 match)
   #:use-module (srfi srfi-1)
-  #:export (get-pom
+  #:export (add-local-package
+            get-pom
             pom-ref
             pom-description
             pom-name
@@ -30,8 +31,24 @@
             pom-groupid
             pom-dependencies
             group->dir
+            pom-and-submodules
+            pom-local-packages
             fix-pom-dependencies))
 
+(define (add-local-package local-packages group artifact version)
+  "Takes @var{local-packages}, a list of local packages, and adds a new one
+for @var{group}:@var{artifact} at @var{version}."
+  (define (alist-set lst key val)
+    (match lst
+      ('() (list (cons key val)))
+      (((k . v) lst ...)
+       (if (equal? k key)
+         (cons (cons key val) lst)
+         (cons (cons k v) (alist-set lst key val))))))
+  (alist-set local-packages group
+    (alist-set (or (assoc-ref local-packages group) '()) artifact
+      version)))
+
 (define (get-pom file)
   "Return the content of a @file{.pom} file."
   (let ((pom-content (call-with-input-file file xml->sxml)))
@@ -234,6 +251,40 @@ to re-declare the namespaces in the top-level element."
                    http://maven.apache.org/xsd/maven-4.0.0.xsd"))
        ,(map fix-xml sxml)))))
 
+(define (pom-and-submodules pom-file)
+  "Given @var{pom-file}, the file name of a pom, return the list of pom file
+names that correspond to itself and its submodules, recursively."
+  (define (get-modules modules)
+    (match modules
+      (#f '())
+      ('() '())
+      (((? string? _) rest ...) (get-modules rest))
+      ((('http://maven.apache.org/POM/4.0.0:module mod) rest ...)
+       (let ((pom (string-append (dirname pom-file) "/" mod "/pom.xml")))
+         (if (file-exists? pom)
+             (cons pom (get-modules rest))
+             (get-modules rest))))))
+
+  (let* ((pom (get-pom pom-file))
+         (modules (get-modules (pom-ref pom "modules"))))
+    (cons pom-file
+          (apply append (map pom-and-submodules modules)))))
+
+(define* (pom-local-packages pom-file #:key (local-packages '()))
+  "Given @var{pom-file}, a pom file name, return a list of local packages that
+this repository contains."
+  (let loop ((modules (pom-and-submodules pom-file))
+             (local-packages local-packages))
+    (match modules
+      (() local-packages)
+      ((module modules ...)
+       (let* ((pom (get-pom module))
+              (version (pom-version pom))
+              (artifactid (pom-artifactid pom))
+              (groupid (pom-groupid pom)))
+         (loop modules
+               (add-local-package local-packages groupid artifactid version)))))))
+
 (define (group->dir group)
   "Convert a group ID to a directory path."
   (string-join (string-split group #\.) "/"))