0.9.1.49: callbacks on x86

  * thanks to David Lichteblau for massaging the code originally
     ported to SBCL by Thomas F. Burdick, based on the work for CMUCL
     by Helmut Eller, to the current scheme of things.

  ...now what just the sparc backend remains to be ported from sbcl-callables,
  and a new one for mips...

  ...and getting the interface straight, and rebustifying the code a bit:
  sbcl-callables includes eg. some logic to check that the types given
  are compatible -- reinstating this sounds like a good idea one things
  settle down...

src/compiler/x86/c-call.lisp

@@ -355,3 +355,59 @@
   (:generator 2
     (inst add esp-tn (fixnumize number))))
 
+#-sb-xc-host
+(defun alien-callback-accessor-form (type sp offset)
+  `(deref (sap-alien (sap+ ,sp ,offset) (* ,type))))
+
+#-sb-xc-host
+(defun alien-callback-assembler-wrapper (index return-type arg-types)
+  "Cons up a piece of code which calls call-callback with INDEX and a
+pointer to the arguments."
+  (declare (ignore arg-types))
+  (let* ((segment (make-segment))
+	 (eax eax-tn)
+	 (edx edx-tn)
+	 (ebp ebp-tn)
+	 (esp esp-tn)
+	 ([ebp-8] (make-ea :dword :base ebp :disp -8))
+	 ([ebp-4] (make-ea :dword :base ebp :disp -4)))
+    (assemble (segment)
+	      (inst push ebp)			    ; save old frame pointer
+	      (inst mov  ebp esp)		    ; establish new frame
+	      (inst mov  eax esp)		    ; 
+	      (inst sub  eax 8)		            ; place for result 
+	      (inst push eax)			    ; arg2
+	      (inst add  eax 16)		    ; arguments  
+	      (inst push eax)			    ; arg1
+	      (inst push (ash index 2))		    ; arg0
+	      (inst push (get-lisp-obj-address #'enter-alien-callback)) ; function
+	      (inst mov  eax (foreign-symbol-address-as-integer "funcall3"))
+	      (inst call eax)
+	      ;; now put the result into the right register
+	      (cond
+		((and (alien-integer-type-p return-type)
+		      (eql (alien-type-bits return-type) 64))
+		 (inst mov eax [ebp-8])
+		 (inst mov edx [ebp-4]))
+		((or (alien-integer-type-p return-type)
+		     (alien-pointer-type-p return-type)
+		     (alien-type-= #.(parse-alien-type 'system-area-pointer nil)
+				   return-type))
+		 (inst mov eax [ebp-8]))
+		((alien-single-float-type-p return-type)
+		 (inst fld  [ebp-8]))
+		((alien-double-float-type-p return-type)
+		 (inst fldd [ebp-8]))
+		((alien-void-type-p return-type))
+		(t
+		 (error "unrecognized alien type: ~A" return-type)))
+	      (inst mov esp ebp)		   ; discard frame
+	      (inst pop ebp)			   ; restore frame pointer
+	      (inst ret))
+    (finalize-segment segment)
+    ;; Now that the segment is done, convert it to a static
+    ;; vector we can point foreign code to.
+    (let ((buffer (sb!assem::segment-buffer segment)))
+      (make-static-vector (length buffer)
+			  :element-type '(unsigned-byte 8)
+			  :initial-contents buffer))))

version.lisp-expr

@@ -17,4 +17,4 @@
 ;;; checkins which aren't released. (And occasionally for internal
 ;;; versions, especially for internal versions off the main CVS
 ;;; branch, it gets hairier, e.g. "0.pre7.14.flaky4.13".)
-"0.9.1.48"
+"0.9.1.49"