build-system: Add haskell-build-system.

* guix/build-system/haskell.scm: New file.
* guix/build/haskell-build-system.scm: New file.
* doc/guix.texi: Add section on 'haskell-build-system'.

1 files changed, 220 insertions, 0 deletions

diff --git a/guix/build/haskell-build-system.scm b/guix/build/haskell-build-system.scm
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+++ b/guix/build/haskell-build-system.scm
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+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2015 Federico Beffa <beffa@fbengineering.ch>
+;;;
+;;; 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 haskell-build-system)
+  #:use-module ((guix build gnu-build-system) #:prefix gnu:)
+  #:use-module (guix build utils)
+  #:use-module (srfi srfi-1)
+  #:use-module (srfi srfi-26)
+  #:use-module (ice-9 rdelim)
+  #:use-module (ice-9 regex)
+  #:use-module (ice-9 match)
+  #:export (%standard-phases
+            haskell-build))
+
+;; Commentary:
+;;
+;; Builder-side code of the standard Haskell package build procedure.
+;;
+;; The Haskell compiler, to find libraries, relies on a library database with
+;; a binary cache. For GHC the cache has to be named 'package.cache'. If every
+;; library would generate the cache at build time, then they would clash in
+;; profiles. For this reason we do not generate the cache when we generate
+;; libraries substitutes. Instead:
+;;
+;; - At build time we use the 'setup-compiler' phase to generate a temporary
+;;   library database and its cache.
+;;
+;; - We generate the cache when a profile is created.
+;;
+;; Code:
+
+;; Directory where we create the temporary libraries database with its cache
+;; as required by the compiler.
+(define %tmp-db-dir
+  (string-append (or (getenv "TMP") "/tmp")
+                 "/package.conf.d"))
+
+(define (run-setuphs command params)
+  (let ((setup-file (cond
+                     ((file-exists? "Setup.hs")
+                      "Setup.hs")
+                     ((file-exists? "Setup.lhs")
+                      "Setup.lhs")
+                     (else
+                      #f))))
+    (if setup-file
+        (begin
+          (format #t "running \"runhaskell Setup.hs\" with command ~s \
+and parameters ~s~%"
+                  command params)
+          (zero? (apply system* "runhaskell" setup-file command params)))
+        (error "no Setup.hs nor Setup.lhs found"))))
+
+(define* (configure #:key outputs inputs tests? (configure-flags '())
+                    #:allow-other-keys)
+  "Configure a given Haskell package."
+  (let* ((out (assoc-ref outputs "out"))
+         (input-dirs (match inputs
+                       (((_ . dir) ...)
+                        dir)
+                       (_ '())))
+         (params (append `(,(string-append "--prefix=" out))
+                         `(,(string-append
+                             "--docdir=" out "/share/doc/"
+                             (package-name-version out)))
+                         `(,(string-append "--package-db=" %tmp-db-dir))
+                         '("--global")
+                         `(,(string-append
+                             "--extra-include-dirs="
+                             (list->search-path-as-string
+                              (search-path-as-list '("include") input-dirs)
+                              ":")))
+                         `(,(string-append
+                             "--extra-lib-dirs="
+                             (list->search-path-as-string
+                              (search-path-as-list '("lib") input-dirs)
+                              ":")))
+                         (if tests?
+                             '("--enable-tests")
+                             '())
+                         configure-flags)))
+    (run-setuphs "configure" params)))
+
+(define* (build #:rest empty)
+  "Build a given Haskell package."
+  (run-setuphs "build" '()))
+
+(define* (install #:rest empty)
+  "Install a given Haskell package."
+  (run-setuphs "copy" '()))
+
+(define (package-name-version store-dir)
+  "Given a store directory STORE-DIR return 'name-version' of the package."
+  (let* ((base (basename store-dir)))
+    (string-drop base
+                 (+ 1 (string-index base #\-)))))
+
+(define (grep rx port)
+  "Given a regular-expression RX including a group, read from PORT until the
+first match and return the content of the group."
+  (let ((line (read-line port)))
+    (if (eof-object? line)
+        #f
+        (let ((rx-result (regexp-exec rx line)))
+          (if rx-result
+              (match:substring rx-result 1)
+              (grep rx port))))))
+
+(define* (setup-compiler #:key system inputs outputs #:allow-other-keys)
+  "Setup the compiler environment."
+  (let* ((haskell (assoc-ref inputs "haskell"))
+         (name-version (package-name-version haskell)))
+    (cond
+     ((string-match "ghc" name-version)
+      (make-ghc-package-database system inputs outputs))
+     (else
+      (format #t
+              "Compiler ~a not supported~%" name-version)))))
+
+(define (make-ghc-package-database system inputs outputs)
+  "Generate the GHC package database."
+  (let* ((haskell  (assoc-ref inputs "haskell"))
+         (input-dirs (match inputs
+                       (((_ . dir) ...)
+                        dir)
+                       (_ '())))
+         (conf-dirs (search-path-as-list
+                     `(,(string-append "lib/" system "-"
+                                       (package-name-version haskell)
+                                       "/package.conf.d"))
+                     input-dirs))
+         (conf-files (append-map (cut find-files <> "\\.conf$") conf-dirs)))
+    (mkdir-p %tmp-db-dir)
+    (for-each (lambda (file)
+                (copy-file file
+                           (string-append %tmp-db-dir "/" (basename file))))
+              conf-files)
+    (zero? (system* "ghc-pkg"
+                    (string-append "--package-db=" %tmp-db-dir)
+                    "recache"))))
+
+(define* (register #:key name system inputs outputs #:allow-other-keys)
+  "Generate the compiler registration file for a given Haskell package.  Don't
+generate the cache as it would clash in user profiles."
+  (let* ((out (assoc-ref outputs "out"))
+         (haskell  (assoc-ref inputs "haskell"))
+         (lib (string-append out "/lib"))
+         (config-dir (string-append lib "/" system
+                                    "-" (package-name-version haskell)
+                                    "/package.conf.d"))
+         (id-rx (make-regexp "^id: *(.*)$"))
+         (lib-rx (make-regexp "lib.*\\.(a|so)"))
+         (config-file (string-append config-dir "/" name ".conf"))
+         (params
+          (list (string-append "--gen-pkg-config=" config-file))))
+    (unless (null? (find-files lib lib-rx))
+      (mkdir-p config-dir)
+      (run-setuphs "register" params)
+      (let ((config-file-name+id
+             (call-with-ascii-input-file config-file (cut grep id-rx <>))))
+        (rename-file config-file
+                     (string-append config-dir "/" config-file-name+id
+                                    ".conf"))))
+    #t))
+
+(define* (check #:key tests? test-target #:allow-other-keys)
+  "Run the test suite of a given Haskell package."
+  (if tests?
+      (run-setuphs test-target '())
+      (begin
+        (format #t "test suite not run~%")
+        #t)))
+
+(define* (haddock #:key outputs haddock? haddock-flags #:allow-other-keys)
+  "Run the test suite of a given Haskell package."
+  (if haddock?
+      (let* ((out (assoc-ref outputs "out"))
+             (doc-src (string-append (getcwd) "/dist/doc"))
+             (doc-dest (string-append out "/share/doc/"
+                                      (package-name-version out))))
+        (if (run-setuphs "haddock" haddock-flags)
+            (begin
+              (copy-recursively doc-src doc-dest)
+              #t)
+            #f))
+      #t))
+
+(define %standard-phases
+  (modify-phases gnu:%standard-phases
+    (add-before configure setup-compiler setup-compiler)
+    (add-after install haddock haddock)
+    (add-after install register register)
+    (replace install install)
+    (replace check check)
+    (replace build build)
+    (replace configure configure)))
+
+(define* (haskell-build #:key inputs (phases %standard-phases)
+                        #:allow-other-keys #:rest args)
+  "Build the given Haskell package, applying all of PHASES in order."
+  (apply gnu:gnu-build
+         #:inputs inputs #:phases phases
+         args))
+
+;;; haskell-build-system.scm ends here