(address . guix-patches@gnu.org)
20230917152149.8587-2-soeren@soeren-tempel.net
From: Sören Tempel <soeren@soeren-tempel.net>
This commit allows using Guix on a foreign distro which uses musl libc,
for example, Alpine Linux. Usage of musl libc is detected via a new
musl-libc? variable using the Guile %host-type.
Using the new musl-libc? variable, we can now implement musl-specific
quirks. The two compatibility problems I encountered in this regard are
that musl dose not export a readdir64 and statfs64 symbol. On musl,
these two functions are implemented as CPP macros that expand to
readdir/statfs. To workaround that, a case-distinction was added.
The existing linux? variable has been modified to return true if the
%host-system contains "linux-" in order to ensure it is true for both
linux-gnu as well as linux-musl host systems.
The patch has been tested on Alpine Linux and is already used for the
downstream Guix package shipped in Alpine Linux's package repository.
* guix/build/syscalls.scm (musl-libc?): New variable.
* guix/build/syscalls.scm (linux?): Truth value on any linux system.
* guix/build/syscalls.scm (readdir-procedure): Support musl libc.
* guix/build/syscalls.scm (statfs): Support musl libc.
Signed-off-by: Sören Tempel <soeren@soeren-tempel.net>
---
guix/build/syscalls.scm | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
Toggle diff (32 lines)
diff --git a/guix/build/syscalls.scm b/guix/build/syscalls.scm
index c9c0bf594d..b845b8aab9 100644
--- a/guix/build/syscalls.scm
+++ b/guix/build/syscalls.scm
@@ -836,7 +836,8 @@ (define-record-type <file-system>
(define-syntax fsword ;fsword_t
(identifier-syntax long))
-(define linux? (string-contains %host-type "linux-gnu"))
+(define musl-libc? (string-contains %host-type "linux-musl"))
+(define linux? (string-contains %host-type "linux-"))
(define-syntax define-statfs-flags
(syntax-rules (linux hurd)
@@ -905,7 +906,7 @@ (define-c-struct %statfs ;<bits/statfs.h>
(spare (array fsword 4)))
(define statfs
- (let ((proc (syscall->procedure int "statfs64" '(* *))))
+ (let ((proc (syscall->procedure int (if musl-libc? "statfs" "statfs64") '(* *))))
(lambda (file)
"Return a <file-system> data structure describing the file system
mounted at FILE."
@@ -1232,7 +1233,7 @@ (define closedir*
(define (readdir-procedure name-field-offset sizeof-dirent-header
read-dirent-header)
- (let ((proc (syscall->procedure '* "readdir64" '(*))))
+ (let ((proc (syscall->procedure '* (if musl-libc? "readdir" "readdir64") '(*))))
(lambda* (directory #:optional (pointer->string pointer->string/utf-8))
(let ((ptr (proc directory)))
(and (not (null-pointer? ptr))