Mirror of GNU Guix
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 

391 lines
14 KiB

;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2014 Ludovic Courtès <ludo@gnu.org>
;;;
;;; 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 gexp)
#:use-module ((guix store)
#:select (direct-store-path?))
#:use-module (guix monads)
#:use-module ((guix derivations)
#:select (derivation? derivation->output-path
%guile-for-build derivation))
#:use-module (guix packages)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-9)
#:use-module (srfi srfi-26)
#:use-module (ice-9 match)
#:export (gexp
gexp?
gexp->derivation
gexp->file
gexp->script))
;;; Commentary:
;;;
;;; This module implements "G-expressions", or "gexps". Gexps are like
;;; S-expressions (sexps), with two differences:
;;;
;;; 1. References (un-quotations) to derivations or packages in a gexp are
;;; replaced by the corresponding output file name;
;;;
;;; 2. Gexps embed information about the derivations they refer to.
;;;
;;; Gexps make it easy to write to files Scheme code that refers to store
;;; items, or to write Scheme code to build derivations.
;;;
;;; Code:
;; "G expressions".
(define-record-type <gexp>
(make-gexp references proc)
gexp?
(references gexp-references) ; ((DRV-OR-PKG OUTPUT) ...)
(proc gexp-proc)) ; procedure
;; Reference to one of the derivation's outputs, for gexps used in
;; derivations.
(define-record-type <output-ref>
(output-ref name)
output-ref?
(name output-ref-name))
(define raw-derivation
(store-lift derivation))
(define (lower-inputs* inputs)
"Turn any package from INPUTS into a derivation; return the corresponding
input list as a monadic value."
;; XXX: This is like 'lower-inputs' but without the "name" part in tuples.
(with-monad %store-monad
(sequence %store-monad
(map (match-lambda
(((? package? package) sub-drv ...)
(mlet %store-monad ((drv (package->derivation package)))
(return `(,drv ,@sub-drv))))
(input
(return input)))
inputs))))
(define* (gexp->derivation name exp
#:key
(system (%current-system))
hash hash-algo recursive?
(env-vars '())
(modules '())
(guile-for-build (%guile-for-build))
references-graphs
local-build?)
"Return a derivation NAME that runs EXP (a gexp) with GUILE-FOR-BUILD (a
derivation) on SYSTEM.
Make MODULES available in the evaluation context of EXP; MODULES is a list of
names of Guile modules from the current search path to be copied in the store,
compiled, and made available in the load path during the execution of
EXP---e.g., '((guix build utils) (guix build gnu-build-system)).
The other arguments are as for 'derivation'."
(define %modules modules)
(define outputs (gexp-outputs exp))
(mlet* %store-monad ((inputs (lower-inputs* (gexp-inputs exp)))
(sexp (gexp->sexp exp #:outputs outputs))
(builder (text-file (string-append name "-builder")
(object->string sexp)))
(modules (if (pair? %modules)
(imported-modules %modules
#:system system
#:guile guile-for-build)
(return #f)))
(compiled (if (pair? %modules)
(compiled-modules %modules
#:system system
#:guile guile-for-build)
(return #f)))
(guile (if guile-for-build
(return guile-for-build)
(package->derivation
(@ (gnu packages base) guile-final)
system))))
(raw-derivation name
(string-append (derivation->output-path guile)
"/bin/guile")
`("--no-auto-compile"
,@(if (pair? %modules)
`("-L" ,(derivation->output-path modules)
"-C" ,(derivation->output-path compiled))
'())
,builder)
#:outputs outputs
#:env-vars env-vars
#:system system
#:inputs `((,guile)
(,builder)
,@(if modules
`((,modules) (,compiled) ,@inputs)
inputs))
#:hash hash #:hash-algo hash-algo #:recursive? recursive?
#:references-graphs references-graphs
#:local-build? local-build?)))
(define (gexp-inputs exp)
"Return the input list for EXP."
(define (add-reference-inputs ref result)
(match ref
(((? derivation?) (? string?))
(cons ref result))
(((? package?) (? string?))
(cons ref result))
((? gexp? exp)
(append (gexp-inputs exp) result))
(((? string? file))
(if (direct-store-path? file)
(cons ref result)
result))
((refs ...)
(fold-right add-reference-inputs result refs))
(_
;; Ignore references to other kinds of objects.
result)))
(fold-right add-reference-inputs
'()
(gexp-references exp)))
(define (gexp-outputs exp)
"Return the outputs referred to by EXP as a list of strings."
(define (add-reference-output ref result)
(match ref
(($ <output-ref> name)
(cons name result))
((? gexp? exp)
(append (gexp-outputs exp) result))
(_
result)))
(fold-right add-reference-output
'()
(gexp-references exp)))
(define* (gexp->sexp exp #:key (outputs '()))
"Return (monadically) the sexp corresponding to EXP for the given OUTPUT,
and in the current monad setting (system type, etc.)"
(define (reference->sexp ref)
(with-monad %store-monad
(match ref
(((? derivation? drv) (? string? output))
(return (derivation->output-path drv output)))
(((? package? p) (? string? output))
(package-file p #:output output))
(($ <output-ref> output)
(match (member output outputs)
(#f
(error "no such output" output))
(_
(return `((@ (guile) getenv) ,output)))))
((? gexp? exp)
(gexp->sexp exp #:outputs outputs))
(((? string? str))
(return (if (direct-store-path? str) str ref)))
((refs ...)
(sequence %store-monad (map reference->sexp refs)))
(x
(return x)))))
(mlet %store-monad
((args (sequence %store-monad
(map reference->sexp (gexp-references exp)))))
(return (apply (gexp-proc exp) args))))
(define (canonicalize-reference ref)
"Return a canonical variant of REF, which adds any missing output part in
package/derivation references."
(match ref
((? package? p)
`(,p "out"))
((? derivation? d)
`(,d "out"))
(((? package?) (? string?))
ref)
(((? derivation?) (? string?))
ref)
((? string? s)
(if (direct-store-path? s) `(,s) s))
((refs ...)
(map canonicalize-reference refs))
(x x)))
(define (syntax-location-string s)
"Return a string representing the source code location of S."
(let ((props (syntax-source s)))
(if props
(let ((file (assoc-ref props 'filename))
(line (and=> (assoc-ref props 'line) 1+))
(column (assoc-ref props 'column)))
(if file
(simple-format #f "~a:~a:~a"
file line column)
(simple-format #f "~a:~a" line column)))
"<unknown location>")))
(define-syntax gexp
(lambda (s)
(define (collect-escapes exp)
;; Return all the 'ungexp' present in EXP.
(let loop ((exp exp)
(result '()))
(syntax-case exp (ungexp ungexp-splicing)
((ungexp _)
(cons exp result))
((ungexp _ _)
(cons exp result))
((ungexp-splicing _ ...)
(cons exp result))
((exp0 exp ...)
(let ((result (loop #'exp0 result)))
(fold loop result #'(exp ...))))
(_
result))))
(define (escape->ref exp)
;; Turn 'ungexp' form EXP into a "reference".
(syntax-case exp (ungexp ungexp-splicing output)
((ungexp output)
#'(output-ref "out"))
((ungexp output name)
#'(output-ref name))
((ungexp thing)
#'thing)
((ungexp drv-or-pkg out)
#'(list drv-or-pkg out))
((ungexp-splicing lst)
#'lst)))
(define (substitute-references exp substs)
;; Return a variant of EXP where all the cars of SUBSTS have been
;; replaced by the corresponding cdr.
(syntax-case exp (ungexp ungexp-splicing)
((ungexp _ ...)
(match (assoc exp substs)
((_ id)
id)
(_
#'(syntax-error "error: no 'ungexp' substitution"
#'ref))))
(((ungexp-splicing _ ...) rest ...)
(syntax-case exp ()
((exp rest ...)
(match (assoc #'exp substs)
((_ id)
(with-syntax ((id id))
#`(append id
#,(substitute-references #'(rest ...) substs))))
(_
#'(syntax-error "error: no 'ungexp-splicing' substitution"
#'ref))))))
((exp0 exp ...)
#`(cons #,(substitute-references #'exp0 substs)
#,(substitute-references #'(exp ...) substs)))
(x #''x)))
(syntax-case s (ungexp output)
((_ exp)
(let* ((escapes (delete-duplicates (collect-escapes #'exp)))
(formals (generate-temporaries escapes))
(sexp (substitute-references #'exp (zip escapes formals)))
(refs (map escape->ref escapes)))
#`(make-gexp (map canonicalize-reference (list #,@refs))
(lambda #,formals
#,sexp)))))))
;;;
;;; Convenience procedures.
;;;
(define* (gexp->script name exp
#:key (modules '())
(guile (@ (gnu packages base) guile-final)))
"Return an executable script NAME that runs EXP using GUILE with MODULES in
its search path."
(mlet %store-monad ((modules (imported-modules modules))
(compiled (compiled-modules modules)))
(gexp->derivation name
(gexp
(call-with-output-file (ungexp output)
(lambda (port)
(format port
"#!~a/bin/guile --no-auto-compile~%!#~%"
(ungexp guile))
(write
'(set! %load-path
(cons (ungexp modules) %load-path))
port)
(write
'(set! %load-compiled-path
(cons (ungexp compiled)
%load-compiled-path))
port)
(write '(ungexp exp) port)
(chmod port #o555)))))))
(define (gexp->file name exp)
"Return a derivation that builds a file NAME containing EXP."
(gexp->derivation name
(gexp
(call-with-output-file (ungexp output)
(lambda (port)
(write '(ungexp exp) port))))))
;;;
;;; Syntactic sugar.
;;;
(eval-when (expand load eval)
(define (read-ungexp chr port)
"Read an 'ungexp' or 'ungexp-splicing' form from PORT."
(define unquote-symbol
(match (peek-char port)
(#\@
(read-char port)
'ungexp-splicing)
(_
'ungexp)))
(match (read port)
((? symbol? symbol)
(let ((str (symbol->string symbol)))
(match (string-index-right str #\:)
(#f
`(,unquote-symbol ,symbol))
(colon
(let ((name (string->symbol (substring str 0 colon)))
(output (substring str (+ colon 1))))
`(,unquote-symbol ,name ,output))))))
(x
`(,unquote-symbol ,x))))
(define (read-gexp chr port)
"Read a 'gexp' form from PORT."
`(gexp ,(read port)))
;; Extend the reader
(read-hash-extend #\~ read-gexp)
(read-hash-extend #\$ read-ungexp))
;;; gexp.scm ends here