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Diffstat (limited to 'guix/build/kconfig.scm')
-rw-r--r-- | guix/build/kconfig.scm | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/guix/build/kconfig.scm b/guix/build/kconfig.scm new file mode 100644 index 0000000000..0c9ef6baff --- /dev/null +++ b/guix/build/kconfig.scm @@ -0,0 +1,181 @@ +;;; GNU Guix --- Functional package management for GNU +;;; Copyright © 2020 Stefan <stefan-guix@vodafonemail.de> +;;; +;;; 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 kconfig) + #:use-module (ice-9 rdelim) + #:use-module (ice-9 regex) + #:use-module (srfi srfi-1) + #:use-module (srfi srfi-26) + #:export (modify-defconfig + verify-config)) + +;; Commentary: +;; +;; Builder-side code to modify configurations for the Kconfig build system as +;; used by Linux and U-Boot. +;; +;; Code: + +(define (pair->config-string pair) + "Convert a PAIR back to a config-string." + (let* ((key (first pair)) + (value (cdr pair))) + (if (string? key) + (if (string? value) + (string-append key "=" value) + (string-append "# " key " is not set")) + value))) + +(define (config-string->pair config-string) + "Parse a configuration string like \"CONFIG_EXAMPLE=m\" into a key-value pair. +An error is thrown for invalid configurations. + +\"CONFIG_A=y\" -> '(\"CONFIG_A\" . \"y\") +\"CONFIG_B=\\\"\\\"\" -> '(\"CONFIG_B\" . \"\\\"\\\"\") +\"CONFIG_C=\" -> '(\"CONFIG_C\" . \"\") +\"# CONFIG_E is not set\" -> '(\"CONFIG_E\" . #f) +\"CONFIG_D\" -> '(\"CONFIG_D\" . #f) +\"# Any comment\" -> '(#f . \"# Any comment\") +\"\" -> '(#f . \"\") +\"# CONFIG_E=y\" -> (error \"Invalid configuration\") +\"CONFIG_E is not set\" -> (error \"Invalid configuration\") +\"Anything else\" -> (error \"Invalid configuration\")" + (define config-regexp + (make-regexp + ;; (match:substring (string-match "=(.*)" "=") 1) returns "", but the + ;; pattern "=(.+)?" makes it return #f instead. From a "CONFIG_A=" we like + ;; to get "", which later emits "CONFIG_A=" again. + (string-append "^ *(#[\\t ]*)?(CONFIG_[a-zA-Z0-9_]+)([\\t ]*=" + "[\\t ]*(.*)|([\\t ]+is[\\t ]+not[\\t ]+set))?$"))) + + (define config-comment-regexp + (make-regexp "^([\\t ]*(#.*)?)$")) + + (let ((match (regexp-exec config-regexp (string-trim-right config-string)))) + (if match + (let* ((comment (match:substring match 1)) + (key (match:substring match 2)) + (unset (match:substring match 5)) + (value (and (not comment) + (not unset) + (match:substring match 4)))) + (if (eq? (not comment) (not unset)) + ;; The key is uncommented and set or commented and unset. + (cons key value) + ;; The key is set or unset ambigiously. + (error (format #f "invalid configuration, did you mean \"~a\"?" + (pair->config-string (cons key #f))) + config-string))) + ;; This is not a valid or ambigious config-string, but maybe a + ;; comment. + (if (regexp-exec config-comment-regexp config-string) + (cons #f config-string) ;keep valid comments + (error "Invalid configuration" config-string))))) + +(define (defconfig->alist defconfig) + "Convert the content of a DEFCONFIG (or .config) file into an alist." + (with-input-from-file defconfig + (lambda () + (let loop ((alist '()) + (line (read-line))) + (if (eof-object? line) + ;; Building the alist is done, now check for duplicates. + ;; Note: the filter invocation is used to remove comments. + (let loop ((keys (map first (filter first alist))) + (duplicates '())) + (if (null? keys) + ;; The search for duplicates is done. + ;; Return the alist or throw an error on duplicates. + (if (null? duplicates) + (reverse alist) + (error + (format #f "duplicate configurations in ~a" defconfig) + (reverse duplicates))) + ;; Continue the search for duplicates. + (loop (cdr keys) + (if (member (first keys) (cdr keys)) + (cons (first keys) duplicates) + duplicates)))) + ;; Build the alist. + (loop (cons (config-string->pair line) alist) + (read-line))))))) + +(define (modify-defconfig defconfig configs) + "This function can modify a given DEFCONFIG (or .config) file by adding, +changing or removing the list of strings in CONFIGS. This allows customization +of Kconfig based projects like the kernel Linux or the bootloader 'Das U-Boot'. + +These are examples for CONFIGS to add, change or remove configurations to/from +DEFCONFIG: + +'(\"CONFIG_A=\\\"a\\\"\" + \"CONFIG_B=0\" + \"CONFIG_C=y\" + \"CONFIG_D=m\" + \"CONFIG_E=\" + \"# CONFIG_G is not set\" + ;; For convenience this abbrevation can be used for not set configurations. + \"CONFIG_F\") + +Instead of a list, CONFIGS can be a string with one configuration per line." + ;; Normalize CONFIGS to a list of configuration pairs. + (let* ((config-pairs (map config-string->pair + (append-map (cut string-split <> #\newline) + (if (string? configs) + (list configs) + configs)))) + ;; Generate a blocklist from all valid keys in config-pairs. + (blocklist (delete #f (map first config-pairs))) + ;; Generate an alist from the defconfig without the keys in blocklist. + (filtered-defconfig-pairs (remove (lambda (pair) + (member (first pair) blocklist)) + (defconfig->alist defconfig)))) + (with-output-to-file defconfig + (lambda () + (for-each (lambda (pair) + (display (pair->config-string pair)) + (newline)) + (append filtered-defconfig-pairs config-pairs)))))) + +(define (verify-config config defconfig) + "Verify that the CONFIG file contains all configurations from the DEFCONFIG +file. When the verification fails, raise an error with the mismatching keys +and their values." + (let* ((config-pairs (defconfig->alist config)) + (defconfig-pairs (defconfig->alist defconfig)) + (mismatching-pairs + (remove (lambda (pair) + ;; Remove all configurations, whose values are #f and + ;; whose keys are not in config-pairs, as not in + ;; config-pairs means unset, ... + (and (not (cdr pair)) + (not (assoc-ref config-pairs (first pair))))) + ;; ... from the defconfig-pairs different to config-pairs. + (lset-difference equal? + ;; Remove comments by filtering with first. + (filter first defconfig-pairs) + config-pairs)))) + (unless (null? mismatching-pairs) + (error (format #f "Mismatching configurations in ~a and ~a" + config defconfig) + (map (lambda (mismatching-pair) + (let* ((key (first mismatching-pair)) + (defconfig-value (cdr mismatching-pair)) + (config-value (assoc-ref config-pairs key))) + (cons key (list (list config-value defconfig-value))))) + mismatching-pairs))))) |