72357e2170
* guix/git.scm (commit-difference): Initialize VISITED to the closure of
OLD and EXCLUDED, as written in the docstring.
* tests/git.scm ("commit-difference, excluded commits"): Adjust
accordingly.
505 lines
20 KiB
Scheme
505 lines
20 KiB
Scheme
;;; GNU Guix --- Functional package management for GNU
|
||
;;; Copyright © 2017, 2020 Mathieu Othacehe <m.othacehe@gmail.com>
|
||
;;; Copyright © 2018, 2019, 2020 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 git)
|
||
#:use-module (git)
|
||
#:use-module (git object)
|
||
#:use-module (guix i18n)
|
||
#:use-module (guix base32)
|
||
#:use-module (gcrypt hash)
|
||
#:use-module ((guix build utils) #:select (mkdir-p))
|
||
#:use-module (guix store)
|
||
#:use-module (guix utils)
|
||
#:use-module (guix records)
|
||
#:use-module (guix gexp)
|
||
#:use-module (guix sets)
|
||
#:use-module (rnrs bytevectors)
|
||
#:use-module (ice-9 match)
|
||
#:use-module (srfi srfi-1)
|
||
#:use-module (srfi srfi-11)
|
||
#:use-module (srfi srfi-34)
|
||
#:use-module (srfi srfi-35)
|
||
#:export (%repository-cache-directory
|
||
honor-system-x509-certificates!
|
||
|
||
with-repository
|
||
false-if-git-not-found
|
||
update-cached-checkout
|
||
url+commit->name
|
||
latest-repository-commit
|
||
commit-difference
|
||
commit-relation
|
||
|
||
git-checkout
|
||
git-checkout?
|
||
git-checkout-url
|
||
git-checkout-branch
|
||
git-checkout-commit
|
||
git-checkout-recursive?))
|
||
|
||
(define %repository-cache-directory
|
||
(make-parameter (string-append (cache-directory #:ensure? #f)
|
||
"/checkouts")))
|
||
|
||
(define (honor-system-x509-certificates!)
|
||
"Use the system's X.509 certificates for Git checkouts over HTTPS. Honor
|
||
the 'SSL_CERT_FILE' and 'SSL_CERT_DIR' environment variables."
|
||
;; On distros such as CentOS 7, /etc/ssl/certs contains only a couple of
|
||
;; files (instead of all the certificates) among which "ca-bundle.crt". On
|
||
;; other distros /etc/ssl/certs usually contains the whole set of
|
||
;; certificates along with "ca-certificates.crt". Try to choose the right
|
||
;; one.
|
||
(let ((file (letrec-syntax ((choose
|
||
(syntax-rules ()
|
||
((_ file rest ...)
|
||
(let ((f file))
|
||
(if (and f (file-exists? f))
|
||
f
|
||
(choose rest ...))))
|
||
((_)
|
||
#f))))
|
||
(choose (getenv "SSL_CERT_FILE")
|
||
"/etc/ssl/certs/ca-certificates.crt"
|
||
"/etc/ssl/certs/ca-bundle.crt")))
|
||
(directory (or (getenv "SSL_CERT_DIR") "/etc/ssl/certs")))
|
||
(and (or file
|
||
(and=> (stat directory #f)
|
||
(lambda (st)
|
||
(> (stat:nlink st) 2))))
|
||
(begin
|
||
(set-tls-certificate-locations! directory file)
|
||
#t))))
|
||
|
||
(define %certificates-initialized?
|
||
;; Whether 'honor-system-x509-certificates!' has already been called.
|
||
#f)
|
||
|
||
(define-syntax-rule (with-libgit2 thunk ...)
|
||
(begin
|
||
;; XXX: The right thing to do would be to call (libgit2-shutdown) here,
|
||
;; but pointer finalizers used in guile-git may be called after shutdown,
|
||
;; resulting in a segfault. Hence, let's skip shutdown call for now.
|
||
(libgit2-init!)
|
||
(unless %certificates-initialized?
|
||
(honor-system-x509-certificates!)
|
||
(set! %certificates-initialized? #t))
|
||
thunk ...))
|
||
|
||
(define* (url-cache-directory url
|
||
#:optional (cache-directory
|
||
(%repository-cache-directory))
|
||
#:key recursive?)
|
||
"Return the directory associated to URL in %repository-cache-directory."
|
||
(string-append
|
||
cache-directory "/"
|
||
(bytevector->base32-string
|
||
(sha256 (string->utf8 (if recursive?
|
||
(string-append "R:" url)
|
||
url))))))
|
||
|
||
;; Authentication appeared in Guile-Git 0.3.0, check if it is available.
|
||
(define auth-supported?
|
||
(false-if-exception (resolve-interface '(git auth))))
|
||
|
||
(define (clone* url directory)
|
||
"Clone git repository at URL into DIRECTORY. Upon failure,
|
||
make sure no empty directory is left behind."
|
||
(with-throw-handler #t
|
||
(lambda ()
|
||
(mkdir-p directory)
|
||
|
||
;; Note: Explicitly pass options to work around the invalid default
|
||
;; value in Guile-Git: <https://bugs.gnu.org/29238>.
|
||
(if (module-defined? (resolve-interface '(git))
|
||
'clone-init-options)
|
||
(let ((auth-method (and auth-supported?
|
||
(%make-auth-ssh-agent))))
|
||
(clone url directory
|
||
(if auth-supported?
|
||
(make-clone-options
|
||
#:fetch-options (make-fetch-options auth-method))
|
||
(clone-init-options))))
|
||
(clone url directory)))
|
||
(lambda _
|
||
(false-if-exception (rmdir directory)))))
|
||
|
||
(define (url+commit->name url sha1)
|
||
"Return the string \"<REPO-NAME>-<SHA1:7>\" where REPO-NAME is the name of
|
||
the git repository, extracted from URL and SHA1:7 the seven first digits
|
||
of SHA1 string."
|
||
(string-append
|
||
(string-replace-substring
|
||
(last (string-split url #\/)) ".git" "")
|
||
"-" (string-take sha1 7)))
|
||
|
||
(define (switch-to-ref repository ref)
|
||
"Switch to REPOSITORY's branch, commit or tag specified by REF. Return the
|
||
OID (roughly the commit hash) corresponding to REF."
|
||
(define obj
|
||
(let resolve ((ref ref))
|
||
(match ref
|
||
(('branch . branch)
|
||
(let ((oid (reference-target
|
||
(branch-lookup repository branch BRANCH-REMOTE))))
|
||
(object-lookup repository oid)))
|
||
(('commit . commit)
|
||
(let ((len (string-length commit)))
|
||
;; 'object-lookup-prefix' appeared in Guile-Git in Mar. 2018, so we
|
||
;; can't be sure it's available. Furthermore, 'string->oid' used to
|
||
;; read out-of-bounds when passed a string shorter than 40 chars,
|
||
;; which is why we delay calls to it below.
|
||
(if (< len 40)
|
||
(if (module-defined? (resolve-interface '(git object))
|
||
'object-lookup-prefix)
|
||
(object-lookup-prefix repository (string->oid commit) len)
|
||
(raise (condition
|
||
(&message
|
||
(message "long Git object ID is required")))))
|
||
(object-lookup repository (string->oid commit)))))
|
||
(('tag-or-commit . str)
|
||
(if (or (> (string-length str) 40)
|
||
(not (string-every char-set:hex-digit str)))
|
||
(resolve `(tag . ,str)) ;definitely a tag
|
||
(catch 'git-error
|
||
(lambda ()
|
||
(resolve `(tag . ,str)))
|
||
(lambda _
|
||
;; There's no such tag, so it must be a commit ID.
|
||
(resolve `(commit . ,str))))))
|
||
(('tag . tag)
|
||
(let ((oid (reference-name->oid repository
|
||
(string-append "refs/tags/" tag))))
|
||
;; OID may point to a "tag" object, but it can also point directly
|
||
;; to a "commit" object, as surprising as it may seem. Return that
|
||
;; object, whatever that is.
|
||
(object-lookup repository oid))))))
|
||
|
||
(reset repository obj RESET_HARD)
|
||
(object-id obj))
|
||
|
||
(define (call-with-repository directory proc)
|
||
(let ((repository #f))
|
||
(dynamic-wind
|
||
(lambda ()
|
||
(set! repository (repository-open directory)))
|
||
(lambda ()
|
||
(proc repository))
|
||
(lambda ()
|
||
(repository-close! repository)))))
|
||
|
||
(define-syntax-rule (with-repository directory repository exp ...)
|
||
"Open the repository at DIRECTORY and bind REPOSITORY to it within the
|
||
dynamic extent of EXP."
|
||
(call-with-repository directory
|
||
(lambda (repository) exp ...)))
|
||
|
||
(define (load-git-submodules)
|
||
"Attempt to load (git submodules), which was missing until Guile-Git 0.2.0.
|
||
Return true on success, false on failure."
|
||
(match (false-if-exception (resolve-interface '(git submodule)))
|
||
(#f
|
||
(set! load-git-submodules (const #f))
|
||
#f)
|
||
(iface
|
||
(module-use! (resolve-module '(guix git)) iface)
|
||
(set! load-git-submodules (const #t))
|
||
#t)))
|
||
|
||
(define* (update-submodules repository
|
||
#:key (log-port (current-error-port)))
|
||
"Update the submodules of REPOSITORY, a Git repository object."
|
||
;; Guile-Git < 0.2.0 did not have (git submodule).
|
||
(if (load-git-submodules)
|
||
(for-each (lambda (name)
|
||
(let ((submodule (submodule-lookup repository name)))
|
||
(format log-port (G_ "updating submodule '~a'...~%")
|
||
name)
|
||
(submodule-update submodule)
|
||
|
||
;; Recurse in SUBMODULE.
|
||
(let ((directory (string-append
|
||
(repository-working-directory repository)
|
||
"/" (submodule-path submodule))))
|
||
(with-repository directory repository
|
||
(update-submodules repository
|
||
#:log-port log-port)))))
|
||
(repository-submodules repository))
|
||
(format (current-error-port)
|
||
(G_ "Support for submodules is missing; \
|
||
please upgrade Guile-Git.~%"))))
|
||
|
||
(define-syntax-rule (false-if-git-not-found exp)
|
||
"Evaluate EXP, returning #false if a GIT_ENOTFOUND error is raised."
|
||
(catch 'git-error
|
||
(lambda ()
|
||
exp)
|
||
(lambda (key error . rest)
|
||
(if (= GIT_ENOTFOUND (git-error-code error))
|
||
#f
|
||
(apply throw key error rest)))))
|
||
|
||
(define (reference-available? repository ref)
|
||
"Return true if REF, a reference such as '(commit . \"cabba9e\"), is
|
||
definitely available in REPOSITORY, false otherwise."
|
||
(match ref
|
||
(('commit . commit)
|
||
(false-if-git-not-found
|
||
(->bool (commit-lookup repository (string->oid commit)))))
|
||
(_
|
||
#f)))
|
||
|
||
(define* (update-cached-checkout url
|
||
#:key
|
||
(ref '(branch . "master"))
|
||
recursive?
|
||
starting-commit
|
||
(log-port (%make-void-port "w"))
|
||
(cache-directory
|
||
(url-cache-directory
|
||
url (%repository-cache-directory)
|
||
#:recursive? recursive?)))
|
||
"Update the cached checkout of URL to REF in CACHE-DIRECTORY. Return three
|
||
values: the cache directory name, and the SHA1 commit (a string) corresponding
|
||
to REF, and the relation of the new commit relative to STARTING-COMMIT (if
|
||
provided) as returned by 'commit-relation'.
|
||
|
||
REF is pair whose key is [branch | commit | tag | tag-or-commit ] and value
|
||
the associated data: [<branch name> | <sha1> | <tag name> | <string>].
|
||
|
||
When RECURSIVE? is true, check out submodules as well, if any."
|
||
(define canonical-ref
|
||
;; We used to require callers to specify "origin/" for each branch, which
|
||
;; made little sense since the cache should be transparent to them. So
|
||
;; here we append "origin/" if it's missing and otherwise keep it.
|
||
(match ref
|
||
(('branch . branch)
|
||
`(branch . ,(if (string-prefix? "origin/" branch)
|
||
branch
|
||
(string-append "origin/" branch))))
|
||
(_ ref)))
|
||
|
||
(with-libgit2
|
||
(let* ((cache-exists? (openable-repository? cache-directory))
|
||
(repository (if cache-exists?
|
||
(repository-open cache-directory)
|
||
(clone* url cache-directory))))
|
||
;; Only fetch remote if it has not been cloned just before.
|
||
(when (and cache-exists?
|
||
(not (reference-available? repository ref)))
|
||
(if auth-supported?
|
||
(let ((auth-method (and auth-supported?
|
||
(%make-auth-ssh-agent))))
|
||
(remote-fetch (remote-lookup repository "origin")
|
||
#:fetch-options (make-fetch-options auth-method)))
|
||
(remote-fetch (remote-lookup repository "origin"))))
|
||
(when recursive?
|
||
(update-submodules repository #:log-port log-port))
|
||
|
||
;; Note: call 'commit-relation' from here because it's more efficient
|
||
;; than letting users re-open the checkout later on.
|
||
(let* ((oid (switch-to-ref repository canonical-ref))
|
||
(new (and starting-commit
|
||
(commit-lookup repository oid)))
|
||
(old (and starting-commit
|
||
(false-if-git-not-found
|
||
(commit-lookup repository
|
||
(string->oid starting-commit)))))
|
||
(relation (and starting-commit
|
||
(if old
|
||
(commit-relation old new)
|
||
'unrelated))))
|
||
|
||
;; Reclaim file descriptors and memory mappings associated with
|
||
;; REPOSITORY as soon as possible.
|
||
(when (module-defined? (resolve-interface '(git repository))
|
||
'repository-close!)
|
||
(repository-close! repository))
|
||
|
||
(values cache-directory (oid->string oid) relation)))))
|
||
|
||
(define* (latest-repository-commit store url
|
||
#:key
|
||
recursive?
|
||
(log-port (%make-void-port "w"))
|
||
(cache-directory
|
||
(%repository-cache-directory))
|
||
(ref '(branch . "master")))
|
||
"Return two values: the content of the git repository at URL copied into a
|
||
store directory and the sha1 of the top level commit in this directory. The
|
||
reference to be checkout, once the repository is fetched, is specified by REF.
|
||
REF is pair whose key is [branch | commit | tag] and value the associated
|
||
data, respectively [<branch name> | <sha1> | <tag name>].
|
||
|
||
When RECURSIVE? is true, check out submodules as well, if any.
|
||
|
||
Git repositories are kept in the cache directory specified by
|
||
%repository-cache-directory parameter.
|
||
|
||
Log progress and checkout info to LOG-PORT."
|
||
(define (dot-git? file stat)
|
||
(and (string=? (basename file) ".git")
|
||
(or (eq? 'directory (stat:type stat))
|
||
|
||
;; Submodule checkouts end up with a '.git' regular file that
|
||
;; contains metadata about where their actual '.git' directory
|
||
;; lives.
|
||
(and recursive?
|
||
(eq? 'regular (stat:type stat))))))
|
||
|
||
(format log-port "updating checkout of '~a'...~%" url)
|
||
(let*-values
|
||
(((checkout commit _)
|
||
(update-cached-checkout url
|
||
#:recursive? recursive?
|
||
#:ref ref
|
||
#:cache-directory
|
||
(url-cache-directory url cache-directory
|
||
#:recursive?
|
||
recursive?)
|
||
#:log-port log-port))
|
||
((name)
|
||
(url+commit->name url commit)))
|
||
(format log-port "retrieved commit ~a~%" commit)
|
||
(values (add-to-store store name #t "sha256" checkout
|
||
#:select? (negate dot-git?))
|
||
commit)))
|
||
|
||
(define (print-git-error port key args default-printer)
|
||
(match args
|
||
(((? git-error? error) . _)
|
||
(format port (G_ "Git error: ~a~%")
|
||
(git-error-message error)))))
|
||
|
||
(set-exception-printer! 'git-error print-git-error)
|
||
|
||
|
||
;;;
|
||
;;; Commit difference.
|
||
;;;
|
||
|
||
(define* (commit-closure commit #:optional (visited (setq)))
|
||
"Return the closure of COMMIT as a set. Skip commits contained in VISITED,
|
||
a set, and adjoin VISITED to the result."
|
||
(let loop ((commits (list commit))
|
||
(visited visited))
|
||
(match commits
|
||
(()
|
||
visited)
|
||
((head . tail)
|
||
(if (set-contains? visited head)
|
||
(loop tail visited)
|
||
(loop (append (commit-parents head) tail)
|
||
(set-insert head visited)))))))
|
||
|
||
(define* (commit-difference new old #:optional (excluded '()))
|
||
"Return the list of commits between NEW and OLD, where OLD is assumed to be
|
||
an ancestor of NEW. Exclude all the commits listed in EXCLUDED along with
|
||
their ancestors.
|
||
|
||
Essentially, this computes the set difference between the closure of NEW and
|
||
that of OLD."
|
||
(let loop ((commits (list new))
|
||
(result '())
|
||
(visited (fold commit-closure
|
||
(setq)
|
||
(cons old excluded))))
|
||
(match commits
|
||
(()
|
||
(reverse result))
|
||
((head . tail)
|
||
(if (set-contains? visited head)
|
||
(loop tail result visited)
|
||
(loop (append (commit-parents head) tail)
|
||
(cons head result)
|
||
(set-insert head visited)))))))
|
||
|
||
(define (commit-relation old new)
|
||
"Return a symbol denoting the relation between OLD and NEW, two commit
|
||
objects: 'ancestor (meaning that OLD is an ancestor of NEW), 'descendant, or
|
||
'unrelated, or 'self (OLD and NEW are the same commit)."
|
||
(if (eq? old new)
|
||
'self
|
||
(let ((newest (commit-closure new)))
|
||
(if (set-contains? newest old)
|
||
'ancestor
|
||
(let* ((seen (list->setq (commit-parents new)))
|
||
(oldest (commit-closure old seen)))
|
||
(if (set-contains? oldest new)
|
||
'descendant
|
||
'unrelated))))))
|
||
|
||
|
||
;;;
|
||
;;; Checkouts.
|
||
;;;
|
||
|
||
;; Representation of the "latest" checkout of a branch or a specific commit.
|
||
(define-record-type* <git-checkout>
|
||
git-checkout make-git-checkout
|
||
git-checkout?
|
||
(url git-checkout-url)
|
||
(branch git-checkout-branch (default "master"))
|
||
(commit git-checkout-commit (default #f)) ;#f | tag | commit
|
||
(recursive? git-checkout-recursive? (default #f)))
|
||
|
||
(define* (latest-repository-commit* url #:key ref recursive? log-port)
|
||
;; Monadic variant of 'latest-repository-commit'.
|
||
(lambda (store)
|
||
;; The caller--e.g., (guix scripts build)--may not handle 'git-error' so
|
||
;; translate it into '&message' conditions that we know will be properly
|
||
;; handled.
|
||
(catch 'git-error
|
||
(lambda ()
|
||
(values (latest-repository-commit store url
|
||
#:ref ref
|
||
#:recursive? recursive?
|
||
#:log-port log-port)
|
||
store))
|
||
(lambda (key error . _)
|
||
(raise (condition
|
||
(&message
|
||
(message
|
||
(match ref
|
||
(('commit . commit)
|
||
(format #f (G_ "cannot fetch commit ~a from ~a: ~a")
|
||
commit url (git-error-message error)))
|
||
(('branch . branch)
|
||
(format #f (G_ "cannot fetch branch '~a' from ~a: ~a")
|
||
branch url (git-error-message error)))
|
||
(_
|
||
(format #f (G_ "Git failure while fetching ~a: ~a")
|
||
url (git-error-message error))))))))))))
|
||
|
||
(define-gexp-compiler (git-checkout-compiler (checkout <git-checkout>)
|
||
system target)
|
||
;; "Compile" CHECKOUT by updating the local checkout and adding it to the
|
||
;; store.
|
||
(match checkout
|
||
(($ <git-checkout> url branch commit recursive?)
|
||
(latest-repository-commit* url
|
||
#:ref (if commit
|
||
`(tag-or-commit . ,commit)
|
||
`(branch . ,branch))
|
||
#:recursive? recursive?
|
||
#:log-port (current-error-port)))))
|
||
|
||
;; Local Variables:
|
||
;; eval: (put 'with-repository 'scheme-indent-function 2)
|
||
;; End:
|