0.8.16.6:

[sbcl.git] / src / code / macros.lisp

diff --git a/src/code/macros.lisp b/src/code/macros.lisp
index c55f1b9..baf6694 100644 (file)
--- a/src/code/macros.lisp
+++ b/src/code/macros.lisp
@@ -31,13 +31,13 @@
    some locations known to SETF, starting over with test-form. Returns NIL."
   `(do () (,test-form)
      (assert-error ',test-form ',places ,datum ,@arguments)
    some locations known to SETF, starting over with test-form. Returns NIL."
   `(do () (,test-form)
      (assert-error ',test-form ',places ,datum ,@arguments)

-     ,@(mapcar #'(lambda (place)
-                  `(setf ,place (assert-prompt ',place ,place)))
+     ,@(mapcar (lambda (place)
+                `(setf ,place (assert-prompt ',place ,place)))

               places)))
 
 (defun assert-prompt (name value)
   (cond ((y-or-n-p "The old value of ~S is ~S.~
               places)))
 
 (defun assert-prompt (name value)
   (cond ((y-or-n-p "The old value of ~S is ~S.~

-                 ~%Do you want to supply a new value? "
+                    ~%Do you want to supply a new value? "

                   name value)
         (format *query-io* "~&Type a form to be evaluated:~%")
         (flet ((read-it () (eval (read *query-io*))))
                   name value)
         (format *query-io* "~&Type a form to be evaluated:~%")
         (flet ((read-it () (eval (read *query-io*))))

@@ -54,183 +54,125 @@
 ;;; and some things (e.g., READ-CHAR) can't afford this excessive
 ;;; consing, we bend backwards a little.
 ;;;
 ;;; and some things (e.g., READ-CHAR) can't afford this excessive
 ;;; consing, we bend backwards a little.
 ;;;

-;;; FIXME: In reality, this restart cruft is needed hardly anywhere in
-;;; the system. Write NEED and NEED-TYPE to replace ASSERT and
-;;; CHECK-TYPE inside the system.
-;;;

 ;;; CHECK-TYPE-ERROR isn't defined until a later file because it uses
 ;;; the macro RESTART-CASE, which isn't defined until a later file.
 (defmacro-mundanely check-type (place type &optional type-string)
   #!+sb-doc
 ;;; CHECK-TYPE-ERROR isn't defined until a later file because it uses
 ;;; the macro RESTART-CASE, which isn't defined until a later file.
 (defmacro-mundanely check-type (place type &optional type-string)
   #!+sb-doc

-  "Signals a restartable error of type TYPE-ERROR if the value of PLACE is
+  "Signal a restartable error of type TYPE-ERROR if the value of PLACE is

   not of the specified type. If an error is signalled and the restart is
   not of the specified type. If an error is signalled and the restart is

-  used to return, the
-  return if the
-   STORE-VALUE is invoked. It will store into PLACE and start over."
+  used to return, this can only return if the STORE-VALUE restart is
+  invoked. In that case it will store into PLACE and start over."

   (let ((place-value (gensym)))
   (let ((place-value (gensym)))

-    `(do ((,place-value ,place))
+    `(do ((,place-value ,place ,place))

         ((typep ,place-value ',type))
        (setf ,place
             (check-type-error ',place ,place-value ',type ,type-string)))))
         ((typep ,place-value ',type))
        (setf ,place
             (check-type-error ',place ,place-value ',type ,type-string)))))

-
-#!+high-security-support
-(defmacro-mundanely check-type-var (place type-var &optional type-string)
-  #!+sb-doc
-  "Signals an error of type TYPE-ERROR if the contents of PLACE are not of the
-   specified type to which the TYPE-VAR evaluates. If an error is signaled,
-   this can only return if STORE-VALUE is invoked. It will store into PLACE
-   and start over."
-  (let ((place-value (gensym))
-       (type-value (gensym)))
-    `(do ((,place-value ,place)
-         (,type-value  ,type-var))
-        ((typep ,place-value ,type-value))
-       (setf ,place
-            (check-type-error ',place ,place-value ,type-value ,type-string)))))

 \f
 \f

-;;;; DEFCONSTANT
+;;;; DEFINE-SYMBOL-MACRO

 
 

-(defmacro-mundanely defconstant (name value &optional documentation)
-  #!+sb-doc
-  "For defining global constants. DEFCONSTANT says that the value is
-  constant and may be compiled into code. If the variable already has
-  a value, and this is not EQL to the init, the code is not portable
-  (undefined behavior). The third argument is an optional documentation
-  string for the variable."
+(defmacro-mundanely define-symbol-macro (name expansion)

   `(eval-when (:compile-toplevel :load-toplevel :execute)
   `(eval-when (:compile-toplevel :load-toplevel :execute)

-     (sb!c::%defconstant ',name ,value ',documentation)))
+    (sb!c::%define-symbol-macro ',name ',expansion)))

 
 

-;;; the guts of DEFCONSTANT
-(defun sb!c::%defconstant (name value doc)
+(defun sb!c::%define-symbol-macro (name expansion)

   (unless (symbolp name)
   (unless (symbolp name)

-    (error "The constant name is not a symbol: ~S" name))
-  (about-to-modify name)
-  (let ((kind (info :variable :kind name)))
-    (case kind
-      (:constant
-       ;; Note: This behavior (discouraging any non-EQL modification)
-       ;; is unpopular, but it is specified by ANSI (i.e. ANSI says a
-       ;; non-EQL change has undefined consequences). If people really
-       ;; want bindings which are constant in some sense other than
-       ;; EQL, I suggest either just using DEFVAR (which is usually
-       ;; appropriate, despite the un-mnemonic name), or defining
-       ;; something like SB-INT:DEFCONSTANT-EQX (which is occasionally
-       ;; more appropriate). -- WHN 2000-11-03
-       (unless (eql value
-                   (info :variable :constant-value name))
-        (cerror "Go ahead and change the value."
-                "The constant ~S is being redefined."
-                name)))
-      (:global
-       ;; (This is OK -- undefined variables are of this kind. So we
-       ;; don't warn or error or anything, just fall through.)
-       )
-      (t (warn "redefining ~(~A~) ~S to be a constant" kind name))))
-  (when doc
-    (setf (fdocumentation name 'variable) doc))
-
-  ;; We want to set the cross-compilation host's symbol value, not just
-  ;; the cross-compiler's (INFO :VARIABLE :CONSTANT-VALUE NAME), so
-  ;; that code like
-  ;;   (defconstant max-entries 61)
-  ;;   (deftype entry-index () `(mod ,max-entries))
-  ;; will be cross-compiled correctly.
-  #-sb-xc-host (setf (symbol-value name) value)
-  #+sb-xc-host (progn
-                (/show (symbol-package name))
-                ;; Redefining our cross-compilation host's CL symbols
-                ;; would be poor form.
-                ;;
-                ;; FIXME: Having to check this and then not treat it
-                ;; as a fatal error seems like a symptom of things
-                ;; being pretty broken. It's also a problem in and of
-                ;; itself, since it makes it too easy for cases of
-                ;; using the cross-compilation host Lisp's CL
-                ;; constant values in the target Lisp to slip by. I
-                ;; got backed into this because the cross-compiler
-                ;; translates DEFCONSTANT SB!XC:FOO into DEFCONSTANT
-                ;; CL:FOO. It would be good to unscrew the
-                ;; cross-compilation package hacks so that that
-                ;; translation doesn't happen. Perhaps:
-                ;;   * Replace SB-XC with SB-CL. SB-CL exports all the 
-                ;;     symbols which ANSI requires to be exported from CL.
-                ;;   * Make a nickname SB!CL which behaves like SB!XC.
-                ;;   * Go through the loaded-on-the-host code making
-                ;;     every target definition be in SB-CL. E.g.
-                ;;     DEFMACRO-MUNDANELY DEFCONSTANT becomes
-                ;;     DEFMACRO-MUNDANELY SB!CL:DEFCONSTANT.
-                ;;   * Make IN-TARGET-COMPILATION-MODE do 
-                ;;     UNUSE-PACKAGE CL and USE-PACKAGE SB-CL in each
-                ;;     of the target packages (then undo it on exit).
-                ;;   * Make the cross-compiler's implementation of
-                ;;     EVAL-WHEN (:COMPILE-TOPLEVEL) do UNCROSS.
-                ;;     (This may not require any change.)
-                ;;   * Hack GENESIS as necessary so that it outputs
-                ;;     SB-CL stuff as COMMON-LISP stuff.
-                ;;   * Now the code here can assert that the symbol
-                ;;     being defined isn't in the cross-compilation
-                ;;     host's CL package.
-                (unless (eql (find-symbol (symbol-name name) :cl) name)
-                  ;; KLUDGE: In the cross-compiler, we use the
-                  ;; cross-compilation host's DEFCONSTANT macro
-                  ;; instead of just (SETF SYMBOL-VALUE), in order to
-                  ;; get whatever blessing the cross-compilation host
-                  ;; may expect for a global (SETF SYMBOL-VALUE).
-                  ;; (CMU CL, at least around 2.4.19, generated full
-                  ;; WARNINGs for code -- e.g. DEFTYPE expanders --
-                  ;; which referred to symbols which had been set by
-                  ;; (SETF SYMBOL-VALUE). I doubt such warnings are
-                  ;; ANSI-compliant, but I'm not sure, so I've
-                  ;; written this in a way that CMU CL will tolerate
-                  ;; and which ought to work elsewhere too.) -- WHN
-                  ;; 2001-03-24
-                  (eval `(defconstant ,name ',value))))
-
-  (setf (info :variable :kind name) :constant)
-  (setf (info :variable :constant-value name) value)
+    (error 'simple-type-error :datum name :expected-type 'symbol
+          :format-control "Symbol macro name is not a symbol: ~S."
+          :format-arguments (list name)))
+  (with-single-package-locked-error 
+      (:symbol name "defining ~A as a symbol-macro"))
+  (ecase (info :variable :kind name)
+    ((:macro :global nil)
+     (setf (info :variable :kind name) :macro)
+     (setf (info :variable :macro-expansion name) expansion))
+    (:special
+     (error 'simple-program-error
+           :format-control "Symbol macro name already declared special: ~S."
+           :format-arguments (list name)))
+    (:constant
+     (error 'simple-program-error
+           :format-control "Symbol macro name already declared constant: ~S."
+           :format-arguments (list name))))

   name)
 \f
 ;;;; DEFINE-COMPILER-MACRO
 
   name)
 \f
 ;;;; DEFINE-COMPILER-MACRO
 

-;;; FIXME: The logic here for handling compiler macros named (SETF
-;;; FOO) was added after the fork from SBCL, is not well tested, and
-;;; may conflict with subtleties of the ANSI standard. E.g. section
-;;; "3.2.2.1 Compiler Macros" says that creating a lexical binding for
-;;; a function name shadows a compiler macro, and it's not clear that
-;;; that works with this version. It should be tested.

 (defmacro-mundanely define-compiler-macro (name lambda-list &body body)
   #!+sb-doc
   "Define a compiler-macro for NAME."
 (defmacro-mundanely define-compiler-macro (name lambda-list &body body)
   #!+sb-doc
   "Define a compiler-macro for NAME."

-  (let ((whole (gensym "WHOLE-"))
-       (environment (gensym "ENV-")))
+  (legal-fun-name-or-type-error name)
+  (when (consp name)
+    ;; It's fairly clear that the user intends the compiler macro to
+    ;; expand when he does (SETF (FOO ...) X). And that's even a
+    ;; useful and reasonable thing to want. Unfortunately,
+    ;; (SETF (FOO ...) X) macroexpands into (FUNCALL (SETF FOO) X ...),
+    ;; and it's not at all clear that it's valid to expand a FUNCALL form,
+    ;; and the ANSI standard doesn't seem to say anything else which
+    ;; would justify us expanding the compiler macro the way the user
+    ;; wants. So instead we rely on 3.2.2.1.3 "When Compiler Macros Are
+    ;; Used" which says they never have to be used, so by ignoring such
+    ;; macros we're erring on the safe side. But any user who does
+    ;; (DEFINE-COMPILER-MACRO (SETF FOO) ...) could easily be surprised
+    ;; by this way of complying with a rather screwy aspect of the ANSI
+    ;; spec, so at least we can warn him...
+    (sb!c::compiler-style-warn
+     "defining compiler macro of (SETF ...), which will not be expanded"))
+  (when (and (symbolp name) (special-operator-p name))
+    (error 'simple-program-error
+          :format-control "cannot define a compiler-macro for a special operator: ~S"
+          :format-arguments (list name)))
+  (with-unique-names (whole environment)

     (multiple-value-bind (body local-decs doc)
        (parse-defmacro lambda-list whole body name 'define-compiler-macro
                        :environment environment)
       (let ((def `(lambda (,whole ,environment)
                    ,@local-decs
     (multiple-value-bind (body local-decs doc)
        (parse-defmacro lambda-list whole body name 'define-compiler-macro
                        :environment environment)
       (let ((def `(lambda (,whole ,environment)
                    ,@local-decs

-                   (block ,(function-name-block-name name)
-                     ,body))))
-       `(sb!c::%define-compiler-macro ',name #',def ',lambda-list ,doc)))))
-(defun sb!c::%define-compiler-macro (name definition lambda-list doc)
-  ;; FIXME: Why does this have to be an interpreted function? Shouldn't
-  ;; it get compiled?
-  (aver (sb!eval:interpreted-function-p definition))
-  (setf (sb!eval:interpreted-function-name definition)
-       (format nil "DEFINE-COMPILER-MACRO ~S" name))
-  (setf (sb!eval:interpreted-function-arglist definition) lambda-list)
-  (sb!c::%%define-compiler-macro name definition doc))
-(defun sb!c::%%define-compiler-macro (name definition doc)
-  (setf (sb!xc:compiler-macro-function name) definition)
-  ;; FIXME: Add support for (SETF FDOCUMENTATION) when object is a list
-  ;; and type is COMPILER-MACRO. (Until then, we have to discard any
-  ;; compiler macro documentation for (SETF FOO).)
-  (unless (listp name)
-    (setf (fdocumentation name 'compiler-macro) doc))
-  name)
+                   ,body))
+           (debug-name (sb!c::debug-namify "DEFINE-COMPILER-MACRO " name)))
+       `(eval-when (:compile-toplevel :load-toplevel :execute)
+         (sb!c::%define-compiler-macro ',name
+                                       #',def
+                                       ',lambda-list
+                                       ,doc
+                                       ,debug-name))))))
+
+;;; FIXME: This will look remarkably similar to those who have already
+;;; seen the code for %DEFMACRO in src/code/defmacro.lisp.  Various
+;;; bits of logic should be shared (notably arglist setting).
+(macrolet
+    ((def (times set-p)
+        `(eval-when (,@times)
+          (defun sb!c::%define-compiler-macro
+              (name definition lambda-list doc debug-name)
+            ,@(unless set-p
+                '((declare (ignore lambda-list debug-name))))
+            ;; FIXME: warn about incompatible lambda list with
+            ;; respect to parent function?
+            (setf (sb!xc:compiler-macro-function name) definition)
+            ;; FIXME: Add support for (SETF FDOCUMENTATION) when
+            ;; object is a list and type is COMPILER-MACRO. (Until
+            ;; then, we have to discard any compiler macro
+            ;; documentation for (SETF FOO).)
+            (unless (listp name)
+              (setf (fdocumentation name 'compiler-macro) doc))
+            ,(when set-p
+                   `(case (widetag-of definition)
+                      (#.sb!vm:closure-header-widetag
+                       (setf (%simple-fun-arglist (%closure-fun definition))
+                             lambda-list
+                            (%simple-fun-name (%closure-fun definition))
+                            debug-name))
+                      (#.sb!vm:simple-fun-header-widetag
+                       (setf (%simple-fun-arglist definition) lambda-list
+                            (%simple-fun-name definition) debug-name))))
+            name))))
+  (progn
+    (def (:load-toplevel :execute) #-sb-xc-host t #+sb-xc-host nil)
+    #-sb-xc (def (:compile-toplevel) nil)))

 \f
 ;;;; CASE, TYPECASE, and friends
 
 \f
 ;;;; CASE, TYPECASE, and friends
 

-(eval-when (:compile-toplevel :load-toplevel :execute)
+(eval-when (#-sb-xc :compile-toplevel :load-toplevel :execute)

 
 ;;; CASE-BODY returns code for all the standard "case" macros. NAME is
 ;;; the macro name, and KEYFORM is the thing to case on. MULTI-P
 
 ;;; CASE-BODY returns code for all the standard "case" macros. NAME is
 ;;; the macro name, and KEYFORM is the thing to case on. MULTI-P

@@ -249,16 +191,22 @@
   (let ((keyform-value (gensym))
        (clauses ())
        (keys ()))
   (let ((keyform-value (gensym))
        (clauses ())
        (keys ()))

-    (dolist (case cases)
+    (do* ((cases cases (cdr cases))
+         (case (car cases) (car cases)))
+        ((null cases) nil)

       (unless (list-of-length-at-least-p case 1)
        (error "~S -- bad clause in ~S" case name))
       (destructuring-bind (keyoid &rest forms) case
       (unless (list-of-length-at-least-p case 1)
        (error "~S -- bad clause in ~S" case name))
       (destructuring-bind (keyoid &rest forms) case

-       (cond ((memq keyoid '(t otherwise))
+       (cond ((and (memq keyoid '(t otherwise))
+                   (null (cdr cases)))

               (if errorp
               (if errorp

-                  (error 'simple-program-error
-                         :format-control
-                         "No default clause is allowed in ~S: ~S"
-                         :format-arguments (list name case))
+                  (progn
+                    (style-warn "~@<Treating bare ~A in ~A as introducing a ~
+                                  normal-clause, not an otherwise-clause~@:>"
+                                keyoid name)
+                    (push keyoid keys)
+                    (push `((,test ,keyform-value ',keyoid) nil ,@forms)
+                          clauses))

                   (push `(t nil ,@forms) clauses)))
              ((and multi-p (listp keyoid))
               (setf keys (append keyoid keys))
                   (push `(t nil ,@forms) clauses)))
              ((and multi-p (listp keyoid))
               (setf keys (append keyoid keys))

@@ -364,7 +312,8 @@
 ;;;; WITH-FOO i/o-related macros
 
 (defmacro-mundanely with-open-stream ((var stream) &body forms-decls)
 ;;;; WITH-FOO i/o-related macros
 
 (defmacro-mundanely with-open-stream ((var stream) &body forms-decls)

-  (multiple-value-bind (forms decls) (parse-body forms-decls nil)
+  (multiple-value-bind (forms decls)
+      (parse-body forms-decls :doc-string-allowed nil)

     (let ((abortp (gensym)))
       `(let ((,var ,stream)
             (,abortp t))
     (let ((abortp (gensym)))
       `(let ((,var ,stream)
             (,abortp t))

@@ -383,7 +332,8 @@
 
 (defmacro-mundanely with-input-from-string ((var string &key index start end)
                                            &body forms-decls)
 
 (defmacro-mundanely with-input-from-string ((var string &key index start end)
                                            &body forms-decls)

-  (multiple-value-bind (forms decls) (parse-body forms-decls nil)
+  (multiple-value-bind (forms decls)
+      (parse-body forms-decls :doc-string-allowed nil)

     ;; The ONCE-ONLY inhibits compiler note for unreachable code when
     ;; END is true.
     (once-only ((string string))
     ;; The ONCE-ONLY inhibits compiler note for unreachable code when
     ;; END is true.
     (once-only ((string string))

@@ -408,16 +358,18 @@
           ,@(when index
               `((setf ,index (string-input-stream-current ,var)))))))))
 
           ,@(when index
               `((setf ,index (string-input-stream-current ,var)))))))))
 

-(defmacro-mundanely with-output-to-string ((var &optional string)
-                                          &body forms-decls)
-  (multiple-value-bind (forms decls) (parse-body forms-decls nil)
+(defmacro-mundanely with-output-to-string 
+    ((var &optional string &key (element-type ''character))
+     &body forms-decls)
+  (multiple-value-bind (forms decls)
+      (parse-body forms-decls :doc-string-allowed nil)

     (if string
       `(let ((,var (make-fill-pointer-output-stream ,string)))
         ,@decls
         (unwind-protect
             (progn ,@forms)
           (close ,var)))
     (if string
       `(let ((,var (make-fill-pointer-output-stream ,string)))
         ,@decls
         (unwind-protect
             (progn ,@forms)
           (close ,var)))

-      `(let ((,var (make-string-output-stream)))
+      `(let ((,var (make-string-output-stream :element-type ,element-type)))

         ,@decls
         (unwind-protect
             (progn ,@forms)
         ,@decls
         (unwind-protect
             (progn ,@forms)

@@ -428,8 +380,15 @@
 
 (defmacro-mundanely nth-value (n form)
   #!+sb-doc
 
 (defmacro-mundanely nth-value (n form)
   #!+sb-doc

-  "Evaluates FORM and returns the Nth value (zero based). This involves no
+  "Evaluate FORM and return the Nth value (zero based). This involves no

   consing when N is a trivial constant integer."
   consing when N is a trivial constant integer."

+  ;; FIXME: The above is true, if slightly misleading.  The
+  ;; MULTIPLE-VALUE-BIND idiom [ as opposed to MULTIPLE-VALUE-CALL
+  ;; (LAMBDA (&REST VALUES) (NTH N VALUES)) ] does indeed not cons at
+  ;; runtime.  However, for large N (say N = 200), COMPILE on such a
+  ;; form will take longer than can be described as adequate, as the
+  ;; optional dispatch mechanism for the M-V-B gets increasingly
+  ;; hairy.

   (if (integerp n)
       (let ((dummy-list nil)
            (keeper (gensym "KEEPER-")))
   (if (integerp n)
       (let ((dummy-list nil)
            (keeper (gensym "KEEPER-")))

@@ -452,29 +411,23 @@
   #!+sb-doc
   "DECLAIM Declaration*
   Do a declaration or declarations for the global environment."
   #!+sb-doc
   "DECLAIM Declaration*
   Do a declaration or declarations for the global environment."

-  #-sb-xc-host

   `(eval-when (:compile-toplevel :load-toplevel :execute)
   `(eval-when (:compile-toplevel :load-toplevel :execute)

-     ,@(mapcar #'(lambda (x)
-                  `(sb!xc:proclaim ',x))
-              specs))
-  ;; KLUDGE: The definition above doesn't work in the cross-compiler,
-  ;; because UNCROSS translates SB!XC:PROCLAIM into CL:PROCLAIM before
-  ;; the form gets executed. Instead, we have to explicitly do the
-  ;; proclamation at macroexpansion time. -- WHN ca. 19990810
-  ;;
-  ;; FIXME: Maybe we don't need this special treatment any more now
-  ;; that we're using DEFMACRO-MUNDANELY instead of DEFMACRO?
-  #+sb-xc-host (progn
-                (mapcar #'sb!xc:proclaim specs)
-                `(progn
-                   ,@(mapcar #'(lambda (x)
-                                 `(sb!xc:proclaim ',x))
-                             specs))))
+     ,@(mapcar (lambda (spec) `(sb!xc:proclaim ',spec))
+              specs)))

 
 

-(defmacro-mundanely print-unreadable-object ((object stream
-                                             &key type identity)
+(defmacro-mundanely print-unreadable-object ((object stream &key type identity)

                                             &body body)
                                             &body body)

+  "Output OBJECT to STREAM with \"#<\" prefix, \">\" suffix, optionally
+  with object-type prefix and object-identity suffix, and executing the
+  code in BODY to provide possible further output."

   `(%print-unreadable-object ,object ,stream ,type ,identity
                             ,(if body
   `(%print-unreadable-object ,object ,stream ,type ,identity
                             ,(if body

-                                 `#'(lambda () ,@body)
+                                 `(lambda () ,@body)

                                  nil)))
                                  nil)))

+
+(defmacro-mundanely ignore-errors (&rest forms)
+  #!+sb-doc
+  "Execute FORMS handling ERROR conditions, returning the result of the last
+  form, or (VALUES NIL the-ERROR-that-was-caught) if an ERROR was handled."
+  `(handler-case (progn ,@forms)
+     (error (condition) (values nil condition))))