Hello Florian,
pelzflorian (Florian Pelz) wrote:
Still, when would your diff break someone else’s code?
Instead of answering this tough question I decided to make another
patch (see attachment) which is guaranteed not to break another's code:
- The patch adds 'follow-symlinks?' argument to 'current-source-directory'
macro and 'absolute-dirname' procedure.
- In case of 'current-source-directory' the argument is optional and defaults
to #f. Thus new API is backward compatible with the old one.
- In case of 'absolute-dirname' the argument is mandatory, but this procedure
is internal to (guix utils) module and therefore the modification does not
change public API. The usage of 'absolute-dirname' inside this module
(only two occurrences) is corrected accordingly.
- 'local-file' macro from (guix gexp) uses 'current-source-directory' with
follow-symlinks? argument set to #t.
Regards,
Nigko
diff --git a/guix/gexp.scm b/guix/gexp.scm
index 74b4c49f90..5911ca4815 100644
--- a/guix/gexp.scm
+++ b/guix/gexp.scm
@@ -508,7 +508,7 @@ (define-syntax local-file
(string? (syntax->datum #'file))
;; FILE is a literal, so resolve it relative to the source directory.
#'(%local-file file
- (delay (absolute-file-name file
(current-source-directory)))
+ (delay (absolute-file-name file
(current-source-directory #t)))
rest ...))
((_ (assume-valid-file-name file) rest ...)
;; FILE is not a literal, so resolve it relative to the current
diff --git a/guix/utils.scm b/guix/utils.scm
index d8ce6ed886..b5fcf8cb28 100644
--- a/guix/utils.scm
+++ b/guix/utils.scm
@@ -1110,41 +1110,47 @@ (define (canonical-newline-port port)
(define (%guix-source-root-directory)
"Return the source root directory of the Guix found in %load-path."
- (dirname (absolute-dirname "guix/packages.scm")))
+ (dirname (absolute-dirname "guix/packages.scm" #f)))
(define absolute-dirname
;; Memoize to avoid repeated 'stat' storms from 'search-path'.
- (mlambda (file)
+ (mlambda (file follow-symlinks?)
"Return the absolute name of the directory containing FILE, or #f upon
-failure."
+failure. Follow symlinks if FOLLOW-SYMLINKS? is true."
(match (search-path %load-path file)
(#f #f)
((? string? file)
- ;; If there are relative names in %LOAD-PATH, FILE can be relative and
- ;; needs to be canonicalized.
- (if (string-prefix? "/" file)
- (dirname file)
- (canonicalize-path (dirname file)))))))
+ (if follow-symlinks?
+ (dirname (canonicalize-path file))
+ ;; If there are relative names in %LOAD-PATH, FILE can be relative
+ ;; and needs to be canonicalized.
+ (if (string-prefix? "/" file)
+ (dirname file)
+ (canonicalize-path (dirname file))))))))
(define-syntax current-source-directory
(lambda (s)
"Return the absolute name of the current directory, or #f if it could not
-be determined."
+be determined. Do not follow symlinks if FOLLOW-SYMLINKS? is false (the
default)."
+ (define (source-directory follow-symlinks?)
+ (match (assq 'filename (or (syntax-source s) '()))
+ (('filename . (? string? file-name))
+ ;; If %FILE-PORT-NAME-CANONICALIZATION is 'relative, then FILE-NAME
+ ;; can be relative. In that case, we try to find out at run time
+ ;; the absolute file name by looking at %LOAD-PATH; doing this at
+ ;; run time rather than expansion time is necessary to allow files
+ ;; to be moved on the file system.
+ (if (string-prefix? "/" file-name)
+ (dirname (if follow-symlinks?
+ (canonicalize-path file-name)
+ file-name))
+ #`(absolute-dirname #,file-name #,follow-symlinks?)))
+ ((or ('filename . #f) #f)
+ ;; raising an error would upset Geiser users
+ #f)))
(syntax-case s ()
- ((_)
- (match (assq 'filename (or (syntax-source s) '()))
- (('filename . (? string? file-name))
- ;; If %FILE-PORT-NAME-CANONICALIZATION is 'relative, then FILE-NAME
- ;; can be relative. In that case, we try to find out at run time
- ;; the absolute file name by looking at %LOAD-PATH; doing this at
- ;; run time rather than expansion time is necessary to allow files
- ;; to be moved on the file system.
- (if (string-prefix? "/" file-name)
- (dirname file-name)
- #`(absolute-dirname #,file-name)))
- ((or ('filename . #f) #f)
- ;; raising an error would upset Geiser users
- #f))))))
+ ((_) (source-directory #f))
+ ((_ follow-symlinks?) (source-directory #'follow-symlinks?)))))
;;;
