syscalls: Move code around [NFC].

* guix/build/syscalls.scm: Move packed structure handling to the top.
master
Ludovic Courtès 2016-04-25 14:57:26 +02:00
parent f489ce3c93
commit 73f38d5ff3
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GPG Key ID: 090B11993D9AEBB5
1 changed files with 116 additions and 101 deletions

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@ -101,6 +101,112 @@
;;;
;;; Code:
;;;
;;; Packed structures.
;;;
(define-syntax sizeof*
;; XXX: This duplicates 'compile-time-value'.
(syntax-rules (int128)
((_ int128)
16)
((_ type)
(let-syntax ((v (lambda (s)
(let ((val (sizeof type)))
(syntax-case s ()
(_ val))))))
v))))
(define-syntax alignof*
;; XXX: This duplicates 'compile-time-value'.
(syntax-rules (int128)
((_ int128)
16)
((_ type)
(let-syntax ((v (lambda (s)
(let ((val (alignof type)))
(syntax-case s ()
(_ val))))))
v))))
(define-syntax align ;as found in (system foreign)
(syntax-rules (~)
"Add to OFFSET whatever it takes to get proper alignment for TYPE."
((_ offset (type ~ endianness))
(align offset type))
((_ offset type)
(1+ (logior (1- offset) (1- (alignof* type)))))))
(define-syntax type-size
(syntax-rules (~)
((_ (type ~ order))
(sizeof* type))
((_ type)
(sizeof* type))))
(define-syntax write-type
(syntax-rules (~)
((_ bv offset (type ~ order) value)
(bytevector-uint-set! bv offset value
(endianness order) (sizeof* type)))
((_ bv offset type value)
(bytevector-uint-set! bv offset value
(native-endianness) (sizeof* type)))))
(define-syntax write-types
(syntax-rules ()
((_ bv offset () ())
#t)
((_ bv offset (type0 types ...) (field0 fields ...))
(begin
(write-type bv (align offset type0) type0 field0)
(write-types bv
(+ (align offset type0) (type-size type0))
(types ...) (fields ...))))))
(define-syntax read-type
(syntax-rules (~ quote *)
((_ bv offset '*)
(make-pointer (bytevector-uint-ref bv offset
(native-endianness)
(sizeof* '*))))
((_ bv offset (type ~ order))
(bytevector-uint-ref bv offset
(endianness order) (sizeof* type)))
((_ bv offset type)
(bytevector-uint-ref bv offset
(native-endianness) (sizeof* type)))))
(define-syntax read-types
(syntax-rules ()
((_ return bv offset () (values ...))
(return values ...))
((_ return bv offset (type0 types ...) (values ...))
(read-types return
bv
(+ (align offset type0) (type-size type0))
(types ...)
(values ... (read-type bv
(align offset type0)
type0))))))
(define-syntax define-c-struct
(syntax-rules ()
"Define READ as a deserializer and WRITE! as a serializer for the C
structure with the given TYPES. READ uses WRAP-FIELDS to return its value."
((_ name wrap-fields read write! (fields types) ...)
(begin
(define (write! bv offset fields ...)
(write-types bv offset (types ...) (fields ...)))
(define (read bv offset)
(read-types wrap-fields bv offset (types ...) ()))))))
;;;
;;; FFI.
;;;
(define %libc-errno-pointer
;; Glibc's 'errno' pointer.
(let ((errno-loc (dynamic-func "__errno_location" (dynamic-link))))
@ -159,6 +265,11 @@ the returned procedure is called."
(error (format #f "~a: syscall->procedure failed: ~s"
name args))))))
;;;
;;; File systems.
;;;
(define (augment-mtab source target type options)
"Augment /etc/mtab with information about the given mount point."
(let ((port (open-file "/etc/mtab" "a")))
@ -322,6 +433,11 @@ string TMPL and return its file name. TMPL must end with 'XXXXXX'."
(list err)))
(pointer->string result)))))
;;;
;;; Containers.
;;;
;; Linux clone flags, from linux/sched.h
(define CLONE_CHILD_CLEARTID #x00200000)
(define CLONE_CHILD_SETTID #x01000000)
@ -395,107 +511,6 @@ system to PUT-OLD."
(list new-root put-old (strerror err))
(list err)))))))
;;;
;;; Packed structures.
;;;
(define-syntax sizeof*
;; XXX: This duplicates 'compile-time-value'.
(syntax-rules (int128)
((_ int128)
16)
((_ type)
(let-syntax ((v (lambda (s)
(let ((val (sizeof type)))
(syntax-case s ()
(_ val))))))
v))))
(define-syntax alignof*
;; XXX: This duplicates 'compile-time-value'.
(syntax-rules (int128)
((_ int128)
16)
((_ type)
(let-syntax ((v (lambda (s)
(let ((val (alignof type)))
(syntax-case s ()
(_ val))))))
v))))
(define-syntax align ;as found in (system foreign)
(syntax-rules (~)
"Add to OFFSET whatever it takes to get proper alignment for TYPE."
((_ offset (type ~ endianness))
(align offset type))
((_ offset type)
(1+ (logior (1- offset) (1- (alignof* type)))))))
(define-syntax type-size
(syntax-rules (~)
((_ (type ~ order))
(sizeof* type))
((_ type)
(sizeof* type))))
(define-syntax write-type
(syntax-rules (~)
((_ bv offset (type ~ order) value)
(bytevector-uint-set! bv offset value
(endianness order) (sizeof* type)))
((_ bv offset type value)
(bytevector-uint-set! bv offset value
(native-endianness) (sizeof* type)))))
(define-syntax write-types
(syntax-rules ()
((_ bv offset () ())
#t)
((_ bv offset (type0 types ...) (field0 fields ...))
(begin
(write-type bv (align offset type0) type0 field0)
(write-types bv
(+ (align offset type0) (type-size type0))
(types ...) (fields ...))))))
(define-syntax read-type
(syntax-rules (~ quote *)
((_ bv offset '*)
(make-pointer (bytevector-uint-ref bv offset
(native-endianness)
(sizeof* '*))))
((_ bv offset (type ~ order))
(bytevector-uint-ref bv offset
(endianness order) (sizeof* type)))
((_ bv offset type)
(bytevector-uint-ref bv offset
(native-endianness) (sizeof* type)))))
(define-syntax read-types
(syntax-rules ()
((_ return bv offset () (values ...))
(return values ...))
((_ return bv offset (type0 types ...) (values ...))
(read-types return
bv
(+ (align offset type0) (type-size type0))
(types ...)
(values ... (read-type bv
(align offset type0)
type0))))))
(define-syntax define-c-struct
(syntax-rules ()
"Define READ as a deserializer and WRITE! as a serializer for the C
structure with the given TYPES. READ uses WRAP-FIELDS to return its value."
((_ name wrap-fields read write! (fields types) ...)
(begin
(define (write! bv offset fields ...)
(write-types bv offset (types ...) (fields ...)))
(define (read bv offset)
(read-types wrap-fields bv offset (types ...) ()))))))
;;;
;;; Network interfaces.