0.9.17.15: silence %SAP-ALIEN compiler-note for MAKE-ALIEN in default policy

[sbcl.git] / src / code / late-alieneval.lisp

diff --git a/src/code/late-alieneval.lisp b/src/code/late-alieneval.lisp
new file mode 100644 (file)
index 0000000..b9d9aab
--- /dev/null
+++ b/src/code/late-alieneval.lisp
@@ -0,0 +1,59 @@
+;;;; This file contains parts of the ALIEN implementation that
+;;;; are not part of the compiler, but depend on it.
+
+;;;; This software is part of the SBCL system. See the README file for
+;;;; more information.
+;;;;
+;;;; This software is derived from the CMU CL system, which was
+;;;; written at Carnegie Mellon University and released into the
+;;;; public domain. The software is in the public domain and is
+;;;; provided with absolutely no warranty. See the COPYING and CREDITS
+;;;; files for more information.
+
+(in-package "SB!ALIEN")
+
+(defmacro make-alien (type &optional size &environment env)
+  #!+sb-doc
+  "Allocate an alien of type TYPE and return an alien pointer to it. If SIZE
+is supplied, how it is interpreted depends on TYPE. If TYPE is an array type,
+SIZE is used as the first dimension for the allocated array. If TYPE is not an
+array, then SIZE is the number of elements to allocate. The memory is
+allocated using ``malloc'', so it can be passed to foreign functions which use
+``free''."
+  (let ((alien-type (if (alien-type-p type)
+                        type
+                        (parse-alien-type type env))))
+    (multiple-value-bind (size-expr element-type)
+        (if (alien-array-type-p alien-type)
+            (let ((dims (alien-array-type-dimensions alien-type)))
+              (cond
+                (size
+                 (unless dims
+                   (error
+                    "cannot override the size of zero-dimensional arrays"))
+                 (when (constantp size)
+                   (setf alien-type (copy-alien-array-type alien-type))
+                   (setf (alien-array-type-dimensions alien-type)
+                         (cons (constant-form-value size) (cdr dims)))))
+                (dims
+                 (setf size (car dims)))
+                (t
+                 (setf size 1)))
+              (values `(* ,size ,@(cdr dims))
+                      (alien-array-type-element-type alien-type)))
+            (values (or size 1) alien-type))
+      (let ((bits (alien-type-bits element-type))
+            (alignment (alien-type-alignment element-type)))
+        (unless bits
+          (error "The size of ~S is unknown."
+                 (unparse-alien-type element-type)))
+        (unless alignment
+          (error "The alignment of ~S is unknown."
+                 (unparse-alien-type element-type)))
+        (let ((alloc-form `(%sap-alien (%make-alien (* ,(align-offset bits alignment)
+                                                       ,size-expr))
+                                       ',(make-alien-pointer-type :to alien-type))))
+          (if (sb!c:policy env (> speed 1))
+              alloc-form
+              `(locally (declare (muffle-conditions compiler-note))
+                 ,alloc-form)))))))