Add (guix build syscalls).

* guix/build/syscalls.scm, tests/syscalls.scm: New files.
* Makefile.am (MODULES): Add guix/build/syscalls.scm.
  (SCM_TESTS): Add tests/syscalls.scm.
* guix/utils.scm (%libc-errno-pointer, errno): Remove; take from (guix
  build syscalls).

1 files changed, 1 insertions, 32 deletions

diff --git a/guix/utils.scm b/guix/utils.scm
index 53fc68d27b..700a191d71 100644
--- a/guix/utils.scm
+++ b/guix/utils.scm
@@ -28,6 +28,7 @@
   #:use-module (rnrs bytevectors)
   #:use-module ((rnrs io ports) #:select (put-bytevector))
   #:use-module ((guix build utils) #:select (dump-port))
+  #:use-module ((guix build syscalls) #:select (errno))
   #:use-module (ice-9 vlist)
   #:use-module (ice-9 format)
   #:autoload   (ice-9 popen)  (open-pipe*)
@@ -366,38 +367,6 @@ that goes to PORT according to COMPRESSION, a symbol such as 'xz."
          ((string-contains %host-type "linux") #(0 1 2))    ; *-linux-gnu
          (else                                 #(1 2 3))))) ; *-gnu*
 
-(define %libc-errno-pointer
-  ;; Glibc's 'errno' pointer.
-  (let ((errno-loc (dynamic-func "__errno_location" (dynamic-link))))
-    (and errno-loc
-         (let ((proc (pointer->procedure '* errno-loc '())))
-           (proc)))))
-
-(define errno
-  (if %libc-errno-pointer
-      (let ((bv (pointer->bytevector %libc-errno-pointer (sizeof int))))
-        (lambda ()
-          "Return the current errno."
-          ;; XXX: We assume that nothing changes 'errno' while we're doing all this.
-          ;; In particular, that means that no async must be running here.
-
-          ;; Use one of the fixed-size native-ref procedures because they are
-          ;; optimized down to a single VM instruction, which reduces the risk
-          ;; that we fiddle with 'errno' (needed on Guile 2.0.5, libc 2.11.)
-          (let-syntax ((ref (lambda (s)
-                              (syntax-case s ()
-                                ((_ bv)
-                                 (case (sizeof int)
-                                   ((4)
-                                    #'(bytevector-s32-native-ref bv 0))
-                                   ((8)
-                                    #'(bytevector-s64-native-ref bv 0))
-                                   (else
-                                    (error "unsupported 'int' size"
-                                           (sizeof int)))))))))
-            (ref bv))))
-      (lambda () 0)))
-
 (define fcntl-flock
   (let* ((ptr  (dynamic-func "fcntl" (dynamic-link)))
          (proc (pointer->procedure int ptr `(,int ,int *))))