diff options
Diffstat (limited to 'guix/build/pyproject-build-system.scm')
| -rw-r--r-- | guix/build/pyproject-build-system.scm | 393 |
1 files changed, 393 insertions, 0 deletions
diff --git a/guix/build/pyproject-build-system.scm b/guix/build/pyproject-build-system.scm new file mode 100644 index 0000000000..d247fd77a8 --- /dev/null +++ b/guix/build/pyproject-build-system.scm @@ -0,0 +1,393 @@ +;;; GNU Guix --- Functional package management for GNU +;;; Copyright © 2021 Lars-Dominik Braun <lars@6xq.net> +;;; Copyright © 2022 Marius Bakke <marius@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 build pyproject-build-system) + #:use-module ((guix build python-build-system) #:prefix python:) + #:use-module (guix build utils) + #:use-module (guix build json) + #:use-module (ice-9 match) + #:use-module (ice-9 ftw) + #:use-module (ice-9 format) + #:use-module (ice-9 rdelim) + #:use-module (ice-9 regex) + #:use-module (srfi srfi-1) + #:use-module (srfi srfi-26) + #:use-module (srfi srfi-34) + #:use-module (srfi srfi-35) + #:export (%standard-phases + add-installed-pythonpath + site-packages + python-version + pyproject-build)) + +;;; Commentary: +;;; +;;; PEP 517-compatible build system for Python packages. +;;; +;;; PEP 517 mandates the use of a TOML file called pyproject.toml at the +;;; project root, describing build and runtime dependencies, as well as the +;;; build system, which can be different from setuptools. This module uses +;;; that file to extract the build system used and call its wheel-building +;;; entry point build_wheel (see 'build). setuptools’ wheel builder is +;;; used as a fallback if either no pyproject.toml exists or it does not +;;; declare a build-system. It supports config_settings through the +;;; standard #:configure-flags argument. +;;; +;;; This wheel, which is just a ZIP file with a file structure defined +;;; by PEP 427 (https://www.python.org/dev/peps/pep-0427/), is then unpacked +;;; and its contents are moved to the appropriate locations in 'install. +;;; +;;; Then entry points, as defined by the PyPa Entry Point Specification +;;; (https://packaging.python.org/specifications/entry-points/) are read +;;; from a file called entry_points.txt in the package’s site-packages +;;; subdirectory and scripts are written to bin/. These are not part of a +;;; wheel and expected to be created by the installing utility. +;;; TODO: Add support for PEP-621 entry points. +;;; +;;; Caveats: +;;; - There is no support for in-tree build backends. +;;; +;;; Code: +;;; + +;; Re-export these variables from python-build-system as many packages +;; rely on these. +(define python-version python:python-version) +(define site-packages python:site-packages) +(define add-installed-pythonpath python:add-installed-pythonpath) + +;; Base error type. +(define-condition-type &python-build-error &error python-build-error?) + +;; Raised when 'check cannot find a valid test system in the inputs. +(define-condition-type &test-system-not-found &python-build-error + test-system-not-found?) + +;; Raised when multiple wheels are created by 'build. +(define-condition-type &cannot-extract-multiple-wheels &python-build-error + cannot-extract-multiple-wheels?) + +;; Raised, when no wheel has been built by the build system. +(define-condition-type &no-wheels-built &python-build-error no-wheels-built?) + +(define* (build #:key outputs build-backend configure-flags #:allow-other-keys) + "Build a given Python package." + + (define (pyproject.toml->build-backend file) + "Look up the build backend in a pyproject.toml file." + (call-with-input-file file + (lambda (in) + (let loop + ((line (read-line in + 'concat))) + (if (eof-object? line) #f + (let ((m (string-match "build-backend = [\"'](.+)[\"']" line))) + (if m + (match:substring m 1) + (loop (read-line in + 'concat))))))))) + + (let* ((wheel-output (assoc-ref outputs "wheel")) + (wheel-dir (if wheel-output wheel-output "dist")) + ;; There is no easy way to get data from Guile into Python via + ;; s-expressions, but we have JSON serialization already, which Python + ;; also supports out-of-the-box. + (config-settings (call-with-output-string (cut write-json + configure-flags <>))) + ;; python-setuptools’ default backend supports setup.py *and* + ;; pyproject.toml. Allow overriding this automatic detection via + ;; build-backend. + (auto-build-backend (if (file-exists? "pyproject.toml") + (pyproject.toml->build-backend + "pyproject.toml") #f)) + ;; Use build system detection here and not in importer, because a) we + ;; have alot of legacy packages and b) the importer cannot update arbitrary + ;; fields in case a package switches its build system. + (use-build-backend (or build-backend auto-build-backend + "setuptools.build_meta"))) + (format #t + "Using '~a' to build wheels, auto-detected '~a', override '~a'.~%" + use-build-backend auto-build-backend build-backend) + (mkdir-p wheel-dir) + ;; Call the PEP 517 build function, which drops a .whl into wheel-dir. + (invoke "python" + "-c" + "import sys, importlib, json\nconfig_settings = json.loads (sys.argv[3])\nbuilder = importlib.import_module(sys.argv[1])\nbuilder.build_wheel(sys.argv[2], config_settings=config_settings)" + use-build-backend + wheel-dir + config-settings))) + +(define* (check #:key inputs + outputs + tests? + test-backend + test-flags + #:allow-other-keys) + "Run the test suite of a given Python package." + (if tests? + ;; Unfortunately with PEP 517 there is no common method to specify test + ;; systems. Guess test system based on inputs instead. + (let* ((pytest (which "pytest")) + (nosetests (which "nosetests")) + (nose2 (which "nose2")) + (have-setup-py (file-exists? "setup.py")) + (use-test-backend + (or test-backend + ;; Prefer pytest + (if pytest 'pytest #f) + (if nosetests 'nose #f) + (if nose2 'nose2 #f) + ;; But fall back to setup.py, which should work for most + ;; packages. XXX: would be nice not to depend on setup.py here? + ;; fails more often than not to find any tests at all. Maybe + ;; we can run `python -m unittest`? + (if have-setup-py 'setup.py #f)))) + (format #t "Using ~a~%" use-test-backend) + (match use-test-backend + ('pytest + (apply invoke (cons pytest (or test-flags '("-vv"))))) + ('nose + (apply invoke (cons nosetests (or test-flags '("-v"))))) + ('nose2 + (apply invoke (cons nose2 (or test-flags '("-v" "--pretty-assert"))))) + ('setup.py + (apply invoke (append '("python" "setup.py") + (or test-flags '("test" "-v"))))) + ;; The developer should explicitly disable tests in this case. + (else (raise (condition (&test-system-not-found)))))) + (format #t "test suite not run~%"))) + +(define* (install #:key inputs outputs #:allow-other-keys) + "Install a wheel file according to PEP 427" + ;; See https://www.python.org/dev/peps/pep-0427/#installing-a-wheel-distribution-1-0-py32-none-any-whl + (let ((site-dir (site-packages inputs outputs)) + (python (assoc-ref inputs "python")) + (out (assoc-ref outputs "out"))) + (define (extract file) + "Extract wheel (ZIP file) into site-packages directory" + ;; Use Python’s zipfile to avoid extra dependency + (invoke "python" + "-m" + "zipfile" + "-e" + file + site-dir)) + + (define python-hashbang + (string-append "#!" python "/bin/python")) + + (define* (merge-directories source destination + #:optional (post-move #f)) + "Move all files in SOURCE into DESTINATION, merging the two directories." + (format #t "Merging directory ~a into ~a~%" source destination) + (for-each (lambda (file) + (format #t + "~a/~a -> ~a/~a~%" + source + file + destination + file) + (mkdir-p destination) + (rename-file (string-append source "/" file) + (string-append destination "/" file)) + (when post-move + (post-move file))) + (scandir source + (negate (cut member <> + '("." ".."))))) + (rmdir source)) + + (define (expand-data-directory directory) + "Move files from all .data subdirectories to their respective\ndestinations." + ;; Python’s distutils.command.install defines this mapping from source to + ;; destination mapping. + (let ((source (string-append directory "/scripts")) + (destination (string-append out "/bin"))) + (when (file-exists? source) + (merge-directories source destination + (lambda (f) + (let ((dest-path (string-append destination "/" + f))) + (chmod dest-path #o755) + (substitute* dest-path + (("#!python") + python-hashbang))))))) + ;; Data can be contained in arbitrary directory structures. Most + ;; commonly it is used for share/. + (let ((source (string-append directory "/data")) + (destination out)) + (when (file-exists? source) + (merge-directories source destination))) + (let* ((distribution (car (string-split (basename directory) #\-))) + (source (string-append directory "/headers")) + (destination (string-append out "/include/python" + (python-version python) "/" + distribution))) + (when (file-exists? source) + (merge-directories source destination)))) + + (define (list-directories base predicate) + ;; Cannot use find-files here, because it’s recursive. + (scandir base + (lambda (name) + (let ((stat (lstat (string-append base "/" name)))) + (and (not (member name + '("." ".."))) + (eq? (stat:type stat) + 'directory) + (predicate name stat)))))) + + (let* ((wheel-output (assoc-ref outputs "wheel")) + (wheel-dir (if wheel-output wheel-output "dist")) + (wheels (map (cut string-append wheel-dir "/" <>) + (scandir wheel-dir + (cut string-suffix? ".whl" <>))))) + (cond + ((> (length wheels) 1) + ;This code does not support multiple wheels + ;; yet, because their outputs would have to be + ;; merged properly. + (raise (condition (&cannot-extract-multiple-wheels)))) + ((= (length wheels) 0) + (raise (condition (&no-wheels-built))))) + (for-each extract wheels)) + (let ((datadirs (map (cut string-append site-dir "/" <>) + (list-directories site-dir + (file-name-predicate "\\.data$"))))) + (for-each (lambda (directory) + (expand-data-directory directory) + (rmdir directory)) datadirs)))) + +(define* (compile-bytecode #:key inputs outputs #:allow-other-keys) + "Compile installed byte-code in site-packages." + (let* ((site-dir (site-packages inputs outputs)) + (python (assoc-ref inputs "python")) + (major-minor (map string->number + (take (string-split (python-version python) #\.) 2))) + (<3.7? (match major-minor + ((major minor) + (or (< major 3) + (and (= major 3) + (< minor 7))))))) + (if <3.7? + ;; These versions don’t have the hash invalidation modes and do + ;; not produce reproducible bytecode files. + (format #t "Skipping bytecode compilation for Python version ~a < 3.7~%" + (python-version python)) + (invoke "python" "-m" "compileall" + "--invalidation-mode=unchecked-hash" site-dir)))) + +(define* (create-entrypoints #:key inputs outputs (configure-flags '()) #:allow-other-keys) + "Implement Entry Points Specification +(https://packaging.python.org/specifications/entry-points/) by PyPa, +which creates runnable scripts in bin/ from entry point specification +file entry_points.txt. This is necessary, because wheels do not contain +these binaries and installers are expected to create them." + + (define (entry-points.txt->entry-points file) + "Specialized parser for Python configfile-like files, in particular +entry_points.txt. Returns a list of console_script and gui_scripts +entry points." + (call-with-input-file file + (lambda (in) + (let loop ((line (read-line in)) + (inside #f) + (result '())) + (if (eof-object? line) + result + (let* ((group-match (string-match "^\\[(.+)\\]$" line)) + (group-name (if group-match + (match:substring group-match 1) + #f)) + (next-inside (if (not group-name) + inside + (or (string=? group-name + "console_scripts") + (string=? group-name "gui_scripts")))) + (item-match (string-match + "^([^ =]+)\\s*=\\s*([^:]+):(.+)$" line))) + (if (and inside item-match) + (loop (read-line in) + next-inside + (cons (list (match:substring item-match 1) + (match:substring item-match 2) + (match:substring item-match 3)) + result)) + (loop (read-line in) next-inside result)))))))) + + (define (create-script path name module function) + "Create a Python script from an entry point’s NAME, MODULE and + FUNCTION and return write it to PATH/NAME." + (let ((interpreter (which "python")) + (file-path (string-append path "/" name))) + (format #t "Creating entry point for '~a.~a' at '~a'.~%" + module function file-path) + (call-with-output-file file-path + (lambda (port) + ;; Technically the script could also include search-paths, + ;; but having a generic 'wrap phases also handles manually + ;; written entry point scripts. + (format port "#!~a +# Auto-generated entry point script. +import sys +import ~a as mod +sys.exit (mod.~a ())~%" interpreter module function))) + (chmod file-path #o755))) + + (let* ((site-dir (site-packages inputs outputs)) + (out (assoc-ref outputs "out")) + (bin-dir (string-append out "/bin")) + (entry-point-files (find-files site-dir "^entry_points.txt$"))) + (mkdir-p bin-dir) + (for-each (lambda (f) + (for-each (lambda (ep) + (apply create-script + (cons bin-dir ep))) + (entry-points.txt->entry-points f))) + entry-point-files))) + +(define* (set-SOURCE-DATE-EPOCH* #:rest _) + "Set the 'SOURCE_DATE_EPOCH' environment variable. This is used by tools +that incorporate timestamps as a way to tell them to use a fixed timestamp. +See https://reproducible-builds.org/specs/source-date-epoch/." + ;; Use a post-1980 timestamp because the Zip format used in wheels do + ;; not support timestamps before 1980. + (setenv "SOURCE_DATE_EPOCH" "315619200")) + +(define %standard-phases + ;; The build phase only builds C extensions and copies the Python sources, + ;; while the install phase copies then byte-compiles the sources to the + ;; prefix directory. The check phase is moved after the installation phase + ;; to ease testing the built package. + (modify-phases python:%standard-phases + (replace 'set-SOURCE-DATE-EPOCH set-SOURCE-DATE-EPOCH*) + (replace 'build build) + (replace 'install install) + (delete 'check) + ;; Must be before tests, so they can use installed packages’ entry points. + (add-before 'wrap 'create-entrypoints create-entrypoints) + (add-after 'wrap 'check check) + (add-before 'check 'compile-bytecode compile-bytecode))) + +(define* (pyproject-build #:key inputs (phases %standard-phases) + #:allow-other-keys #:rest args) + "Build the given Python package, applying all of PHASES in order." + (apply python:python-build #:inputs inputs #:phases phases args)) + +;;; pyproject-build-system.scm ends here |