Handle run-program with :directory nil.

[sbcl.git] / src / code / host-c-call.lisp

diff --git a/src/code/host-c-call.lisp b/src/code/host-c-call.lisp
index d688879..7b558af 100644 (file)
--- a/src/code/host-c-call.lisp
+++ b/src/code/host-c-call.lisp
@@ -13,15 +13,18 @@
 
 (define-alien-type-class (c-string :include pointer :include-args (to))
   (external-format :default :type keyword)
-  (element-type 'character :type (member character base-char)))
+  (element-type 'character :type (member character base-char))
+  (not-null nil :type boolean))
 
 (define-alien-type-translator c-string
     (&key (external-format :default)
-          (element-type 'character))
+          (element-type 'character)
+          (not-null nil))
   (make-alien-c-string-type
    :to (parse-alien-type 'char (sb!kernel:make-null-lexenv))
    :element-type element-type
-   :external-format external-format))
+   :external-format external-format
+   :not-null not-null))
 
 (defun c-string-external-format (type)
   (let ((external-format (alien-c-string-type-external-format type)))
@@ -30,13 +33,25 @@
         external-format)))
 
 (define-alien-type-method (c-string :unparse) (type)
-  (list 'c-string
-        :external-format (alien-c-string-type-external-format type)
-        :element-type (alien-c-string-type-element-type type)))
+  (let* ((external-format (alien-c-string-type-external-format type))
+         (element-type (alien-c-string-type-element-type type))
+         (not-null (alien-c-string-type-not-null type))
+         (tail
+          (append (unless (eq :default external-format)
+                    (list :external-format external-format))
+                  (unless (eq 'character element-type)
+                    (list :element-type element-type))
+                  (when not-null
+                    (list :not-null t)))))
+    (if tail
+        (cons 'c-string tail)
+        'c-string)))
 
 (define-alien-type-method (c-string :lisp-rep) (type)
-  (declare (ignore type))
-  '(or simple-string null (alien (* char)) (simple-array (unsigned-byte 8))))
+  (let ((possibilities '(simple-string (alien (* char)) (simple-array (unsigned-byte 8)))))
+    (if (alien-c-string-type-not-null type)
+        `(or ,@possibilities)
+        `(or null ,@possibilities))))
 
 (define-alien-type-method (c-string :deport-pin-p) (type)
   (declare (ignore type))
@@ -61,9 +76,18 @@
                   #!-sb-unicode
                   (eq (first (sb!impl::ef-names external-format)) :latin-1))))))
 
+(declaim (ftype (sfunction (t) nil) null-error))
+(defun null-error (type)
+  (aver (alien-c-string-type-not-null type))
+  (error 'type-error
+         :expected-type `(alien ,(unparse-alien-type type))
+         :datum nil))
+
 (define-alien-type-method (c-string :naturalize-gen) (type alien)
   `(if (zerop (sap-int ,alien))
-       nil
+       ,(if (alien-c-string-type-not-null type)
+            `(null-error ',type)
+            nil)
        ;; Check whether we need to do a full external-format
        ;; conversion, or whether we can just do a cheap byte-by-byte
        ;; copy of the c-string data.
@@ -83,17 +107,22 @@
             `(%naturalize-c-string ,alien))))
 
 (define-alien-type-method (c-string :deport-gen) (type value)
-  (declare (ignore type))
   ;; This SAP taking is safe as DEPORT callers pin the VALUE when
   ;; necessary.
   `(etypecase ,value
-     (null (int-sap 0))
+     (null
+      ,(if (alien-c-string-type-not-null type)
+           `(null-error ',type)
+           `(int-sap 0)))
      ((alien (* char)) (alien-sap ,value))
      (vector (vector-sap ,value))))
 
 (define-alien-type-method (c-string :deport-alloc-gen) (type value)
   `(etypecase ,value
-     (null nil)
+     (null
+      ,(if (alien-c-string-type-not-null type)
+           `(null-error ',type)
+           nil))
      ((alien (* char)) ,value)
      (simple-base-string
       ,(if (c-string-needs-conversion-p type)