guix-devel/guix/derivations.scm

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;;; Guix --- Nix package management from Guile. -*- coding: utf-8 -*-
;;; Copyright (C) 2012 Ludovic Courtès <ludo@gnu.org>
;;;
;;; This file is part of Guix.
;;;
;;; 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.
;;;
;;; 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 Guix. If not, see <http://www.gnu.org/licenses/>.
(define-module (guix derivations)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-9)
#:use-module (srfi srfi-26)
#:use-module (rnrs io ports)
#:use-module (rnrs bytevectors)
#:use-module (ice-9 match)
#:use-module (ice-9 rdelim)
#:use-module (guix store)
#:use-module (guix utils)
#:export (derivation?
derivation-outputs
derivation-inputs
derivation-sources
derivation-system
derivation-builder-arguments
derivation-builder-environment-vars
derivation-output?
derivation-output-path
derivation-output-hash-algo
derivation-output-hash
derivation-input?
derivation-input-path
derivation-input-sub-derivations
fixed-output-derivation?
derivation-hash
read-derivation
write-derivation
derivation-path->output-path
derivation
%guile-for-build
build-expression->derivation))
;;;
;;; Nix derivations, as implemented in Nix's `derivations.cc'.
;;;
(define-record-type <derivation>
(make-derivation outputs inputs sources system builder args env-vars)
derivation?
(outputs derivation-outputs) ; list of name/<derivation-output> pairs
(inputs derivation-inputs) ; list of <derivation-input>
(sources derivation-sources) ; list of store paths
(system derivation-system) ; string
(builder derivation-builder) ; store path
(args derivation-builder-arguments) ; list of strings
(env-vars derivation-builder-environment-vars)) ; list of name/value pairs
(define-record-type <derivation-output>
(make-derivation-output path hash-algo hash)
derivation-output?
(path derivation-output-path) ; store path
(hash-algo derivation-output-hash-algo) ; symbol | #f
(hash derivation-output-hash)) ; symbol | #f
(define-record-type <derivation-input>
(make-derivation-input path sub-derivations)
derivation-input?
(path derivation-input-path) ; store path
(sub-derivations derivation-input-sub-derivations)) ; list of strings
(define (fixed-output-derivation? drv)
"Return #t if DRV is a fixed-output derivation, such as the result of a
download with a fixed hash (aka. `fetchurl')."
(match drv
(($ <derivation>
(($ <derivation-output> _ (? symbol?) (? string?))))
#t)
(_ #f)))
(define (read-derivation drv-port)
"Read the derivation from DRV-PORT and return the corresponding
<derivation> object."
(define comma (string->symbol ","))
(define (ununquote x)
(match x
(('unquote x) (ununquote x))
((x ...) (map ununquote x))
(_ x)))
(define (outputs->alist x)
(fold-right (lambda (output result)
(match output
((name path "" "")
(alist-cons name
(make-derivation-output path #f #f)
result))
((name path hash-algo hash)
;; fixed-output
(let ((algo (string->symbol hash-algo)))
(alist-cons name
(make-derivation-output path algo hash)
result)))))
'()
x))
(define (make-input-drvs x)
(fold-right (lambda (input result)
(match input
((path (sub-drvs ...))
(cons (make-derivation-input path sub-drvs)
result))))
'()
x))
(let loop ((exp (read drv-port))
(result '()))
(match exp
((? eof-object?)
(let ((result (reverse result)))
(match result
(('Derive ((outputs ...) (input-drvs ...)
(input-srcs ...)
(? string? system)
(? string? builder)
((? string? args) ...)
((var value) ...)))
(make-derivation (outputs->alist outputs)
(make-input-drvs input-drvs)
input-srcs
system builder args
(fold-right alist-cons '() var value)))
(_
(error "failed to parse derivation" drv-port result)))))
((? (cut eq? <> comma))
(loop (read drv-port) result))
(_
(loop (read drv-port)
(cons (ununquote exp) result))))))
(define (write-derivation drv port)
"Write the ATerm-like serialization of DRV to PORT. See Section 2.4 of
Eelco Dolstra's PhD dissertation for an overview of a previous version of
that form."
(define (list->string lst)
(string-append "[" (string-join lst ",") "]"))
(define (write-list lst)
(display (list->string lst) port))
(match drv
(($ <derivation> outputs inputs sources
system builder args env-vars)
(display "Derive(" port)
(write-list (map (match-lambda
((name . ($ <derivation-output> path hash-algo hash))
(format #f "(~s,~s,~s,~s)"
name path (or hash-algo "")
(or hash ""))))
outputs))
(display "," port)
(write-list (map (match-lambda
(($ <derivation-input> path sub-drvs)
(format #f "(~s,~a)" path
(list->string (map object->string sub-drvs)))))
inputs))
(display "," port)
(write-list (map object->string sources))
(format port ",~s,~s," system builder)
(write-list (map object->string args))
(display "," port)
(write-list (map (match-lambda
((name . value)
(format #f "(~s,~s)" name value)))
env-vars))
(display ")" port))))
(define* (derivation-path->output-path path #:optional (output "out"))
"Read the derivation from PATH (`/nix/store/xxx.drv'), and return the store
path of its output OUTPUT."
(let* ((drv (call-with-input-file path read-derivation))
(outputs (derivation-outputs drv)))
(and=> (assoc-ref outputs output) derivation-output-path)))
;;;
;;; Derivation primitive.
;;;
(define (compressed-hash bv size) ; `compressHash'
"Given the hash stored in BV, return a compressed version thereof that fits
in SIZE bytes."
(define new (make-bytevector size 0))
(define old-size (bytevector-length bv))
(let loop ((i 0))
(if (= i old-size)
new
(let* ((j (modulo i size))
(o (bytevector-u8-ref new j)))
(bytevector-u8-set! new j
(logxor o (bytevector-u8-ref bv i)))
(loop (+ 1 i))))))
(define derivation-hash ; `hashDerivationModulo' in derivations.cc
(memoize
(lambda (drv)
"Return the hash of DRV, modulo its fixed-output inputs, as a bytevector."
(match drv
(($ <derivation> ((_ . ($ <derivation-output> path
(? symbol? hash-algo) (? string? hash)))))
;; A fixed-output derivation.
(sha256
(string->utf8
(string-append "fixed:out:" (symbol->string hash-algo)
":" hash ":" path))))
(($ <derivation> outputs inputs sources
system builder args env-vars)
;; A regular derivation: replace the path of each input with that
;; input's hash; return the hash of serialization of the resulting
;; derivation. Note: inputs are sorted as in the order of their hex
;; hash representation because that's what the C++ `std::map' code
;; does.
(let* ((inputs (sort (map (match-lambda
(($ <derivation-input> path sub-drvs)
(let ((hash (call-with-input-file path
(compose bytevector->base16-string
derivation-hash
read-derivation))))
(make-derivation-input hash sub-drvs))))
inputs)
(lambda (i1 i2)
(string<? (derivation-input-path i1)
(derivation-input-path i2)))))
(drv (make-derivation outputs inputs sources
system builder args env-vars)))
(sha256
(string->utf8 (call-with-output-string
(cut write-derivation drv <>))))))))))
(define (store-path type hash name) ; makeStorePath
"Return the store path for NAME/HASH/TYPE."
(let* ((s (string-append type ":sha256:"
(bytevector->base16-string hash) ":"
(%store-prefix) ":" name))
(h (sha256 (string->utf8 s)))
(c (compressed-hash h 20)))
(string-append (%store-prefix) "/"
(bytevector->nix-base32-string c) "-"
name)))
(define (output-path output hash name) ; makeOutputPath
"Return an output path for OUTPUT (the name of the output as a string) of
the derivation called NAME with hash HASH."
(store-path (string-append "output:" output) hash
(if (string=? output "out")
name
(string-append name "-" output))))
(define* (derivation store name system builder args env-vars inputs
#:key (outputs '("out")) hash hash-algo hash-mode)
"Build a derivation with the given arguments. Return the resulting
store path and <derivation> object. When HASH, HASH-ALGO, and HASH-MODE
are given, a fixed-output derivation is created---i.e., one whose result is
known in advance, such as a file download."
(define (add-output-paths drv)
;; Return DRV with an actual store path for each of its output and the
;; corresponding environment variable.
(match drv
(($ <derivation> outputs inputs sources
system builder args env-vars)
(let* ((drv-hash (derivation-hash drv))
(outputs (map (match-lambda
((output-name . ($ <derivation-output>
_ algo hash))
(let ((path (output-path output-name
drv-hash name)))
(cons output-name
(make-derivation-output path algo
hash)))))
outputs)))
(make-derivation outputs inputs sources system builder args
(map (match-lambda
((name . value)
(cons name
(or (and=> (assoc-ref outputs name)
derivation-output-path)
value))))
env-vars))))))
(define (env-vars-with-empty-outputs)
;; Return a variant of ENV-VARS where each OUTPUTS is associated with an
;; empty string, even outputs that do not appear in ENV-VARS.
(let ((e (map (match-lambda
((name . val)
(if (member name outputs)
(cons name "")
(cons name val))))
env-vars)))
(fold-right (lambda (output-name env-vars)
(if (assoc output-name env-vars)
env-vars
(append env-vars `((,output-name . "")))))
e
outputs)))
(let* ((outputs (map (lambda (name)
;; Return outputs with an empty path.
(cons name
(make-derivation-output "" hash-algo hash)))
outputs))
(inputs (map (match-lambda
(((? store-path? input))
(make-derivation-input input '("out")))
(((? store-path? input) sub-drvs ...)
(make-derivation-input input sub-drvs))
((input . _)
(let ((path (add-to-store store
(basename input)
(hash-algo sha256) #t #t
input)))
(make-derivation-input path '()))))
inputs))
(env-vars (env-vars-with-empty-outputs))
(drv-masked (make-derivation outputs
(filter (compose derivation-path?
derivation-input-path)
inputs)
(filter-map (lambda (i)
(let ((p (derivation-input-path i)))
(and (not (derivation-path? p))
p)))
inputs)
system builder args env-vars))
(drv (add-output-paths drv-masked)))
(values (add-text-to-store store (string-append name ".drv")
(call-with-output-string
(cut write-derivation drv <>))
(map derivation-input-path
inputs))
drv)))
;;;
;;; Guile-based builders.
;;;
(define %guile-for-build
;; The derivation of the Guile to be used within the build environment,
;; when using `build-expression->derivation'.
(make-parameter (false-if-exception (nixpkgs-derivation "guile"))))
(define* (build-expression->derivation store name system exp inputs
#:key hash hash-algo)
"Return a derivation that executes Scheme expression EXP as a builder for
derivation NAME. INPUTS must be a list of string/derivation-path pairs. EXP
is evaluated in an environment where %OUTPUT is bound to the output path, and
where %BUILD-INPUTS is bound to an alist of string/output-path pairs made
from INPUTS."
(define guile
(string-append (derivation-path->output-path (%guile-for-build))
"/bin/guile"))
(let* ((prologue `(begin
(define %output (getenv "out"))
(define %build-inputs
',(map (match-lambda
((name . drv)
(cons name
(derivation-path->output-path drv))))
inputs))) )
(builder (add-text-to-store store
(string-append name "-guile-builder")
(string-append (object->string prologue)
(object->string exp))
(map cdr inputs))))
(derivation store name system guile `("--no-auto-compile" ,builder)
'(("HOME" . "/homeless"))
`((,(%guile-for-build))
(,builder)))))