diff options
| -rw-r--r-- | guix/build/ruby-build-system.scm | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/guix/build/ruby-build-system.scm b/guix/build/ruby-build-system.scm index e3a8111514..a28c47db9d 100644 --- a/guix/build/ruby-build-system.scm +++ b/guix/build/ruby-build-system.scm @@ -173,6 +173,109 @@ GEM-FLAGS are passed to the 'gem' invokation, if present." "Makefile"))))) #t)))) +(define* (wrap-ruby-program prog #:key (gem-clear-paths #t) #:rest vars) + "Make a wrapper for PROG. VARS should look like this: + + '(VARIABLE DELIMITER POSITION LIST-OF-DIRECTORIES) + +where DELIMITER is optional. ':' will be used if DELIMITER is not given. + +For example, this command: + + (wrap-ruby-program \"foo\" + '(\"PATH\" \":\" = (\"/gnu/.../bar/bin\")) + '(\"CERT_PATH\" suffix (\"/gnu/.../baz/certs\" + \"/qux/certs\"))) + +will copy 'foo' to '.real/fool' and create the file 'foo' with the following +contents: + + #!location/of/bin/ruby + ENV['PATH'] = \"/gnu/.../bar/bin\" + ENV['CERT_PATH'] = (ENV.key?('CERT_PATH') ? (ENV['CERT_PATH'] + ':') : '') + '/gnu/.../baz/certs:/qux/certs' + load location/of/.real/foo + +This is useful for scripts that expect particular programs to be in $PATH, for +programs that expect particular gems to be in the GEM_PATH. + +This is preferable to wrap-program, which uses a bash script, as this prevents +ruby scripts from being executed with @command{ruby -S ...}. + +If PROG has previously been wrapped by 'wrap-ruby-program', the wrapper is +extended with definitions for VARS." + (define wrapped-file + (string-append (dirname prog) "/.real/" (basename prog))) + + (define already-wrapped? + (file-exists? wrapped-file)) + + (define (last-line port) + ;; Return the last line read from PORT and leave PORT's cursor right + ;; before it. + (let loop ((previous-line-offset 0) + (previous-line "") + (position (seek port 0 SEEK_CUR))) + (match (read-line port 'concat) + ((? eof-object?) + (seek port previous-line-offset SEEK_SET) + previous-line) + ((? string? line) + (loop position line (+ (string-length line) position)))))) + + (define (export-variable lst) + ;; Return a string that exports an environment variable. + (match lst + ((var sep '= rest) + (format #f "ENV['~a'] = '~a'" + var (string-join rest sep))) + ((var sep 'prefix rest) + (format #f "ENV['~a'] = '~a' + (ENV.key?('~a') ? ('~a' + ENV['~a']) : '')" + var (string-join rest sep) var sep var)) + ((var sep 'suffix rest) + (format #f "ENV['~a'] = (ENV.key?('~a') ? (ENV['~a'] + '~a') : '') + '~a'" + var var var sep (string-join rest sep))) + ((var '= rest) + (format #f "ENV['~a'] = '~a'" + var (string-join rest ":"))) + ((var 'prefix rest) + (format #f "ENV['~a'] = '~a' + (ENV.key?('~a') ? (':' + ENV['~a']) : '')" + var (string-join rest ":") var var)) + ((var 'suffix rest) + (format #f "ENV['~a'] = (ENV.key?('~a') ? (ENV['~a'] + ':') : '') + '~a'" + var var var (string-join rest ":"))))) + + (if already-wrapped? + + ;; PROG is already a wrapper: add the new "export VAR=VALUE" lines just + ;; before the last line. + (let* ((port (open-file prog "r+")) + (last (last-line port))) + (for-each (lambda (var) + (display (export-variable var) port) + (newline port)) + vars) + (display last port) + (close-port port)) + + ;; PROG is not wrapped yet: create a shell script that sets VARS. + (let ((prog-tmp (string-append wrapped-file "-tmp"))) + (mkdir-p (dirname prog-tmp)) + (link prog wrapped-file) + + (call-with-output-file prog-tmp + (lambda (port) + (format port + "#!~a~%~a~%~a~%load '~a'~%" + (which "ruby") + (string-join (map export-variable vars) "\n") + ;; This ensures that if the GEM_PATH has been changed, + ;; then that change will be noticed. + (if gem-clear-paths "Gem.clear_paths" "") + (canonicalize-path wrapped-file)))) + + (chmod prog-tmp #o755) + (rename-file prog-tmp prog)))) + (define (log-file-deletion file) (display (string-append "deleting '" file "' for reproducibility\n"))) |