X-Git-Url: https://git.distorted.org.uk/~mdw/sod/blobdiff_plain/5536a8f3b50f256bb82849512e0270fe926b875b..12949379840101e2d65883f29c5e8f0f6de49e9c:/src/module-impl.lisp

diff --git a/src/module-impl.lisp b/src/module-impl.lisp
index cb3a8ad..fc068d3 100644
--- a/src/module-impl.lisp
+++ b/src/module-impl.lisp
@@ -25,6 +25,56 @@
 
 (cl:in-package #:sod)
 
+;; Establish a standard environment within the body of a module.  This is an
+;; attempt -- but not a wholly successful one -- to present the same
+;; environment to a module independent of the context in which we imported
+;; it.
+
+;;;--------------------------------------------------------------------------
+;;; Module variables.
+
+(eval-when (:load-toplevel :execute)
+  (macrolet ((fix (var &optional (value var))
+	       (once-only (value)
+		 `(add-module-binding ',var (lambda () ,value)))))
+
+    ;; Use `sod-user' package by default.  This seems the most useful.  Alas,
+    ;; some tenants might not keep it as tidy as we'd like, but there are
+    ;; probably useful ways to side-effect the package too.
+    (fix *package* (find-package "SOD-USER"))
+
+    ;; Stream bindings.  Hope that the values we find at load time are
+    ;; sufficiently sensible.
+    (fix *debug-io*)
+    (fix *error-output*)
+    (fix *query-io*)
+    (fix *standard-input*)
+    (fix *standard-output*)
+    (fix *terminal-io*)
+    (fix *trace-output*)
+
+    ;; Print state.
+    (fix *print-array* t)
+    (fix *print-base* 10)
+    (fix *print-case* :upcase)
+    (fix *print-circle* nil)
+    (fix *print-escape* t)
+    (fix *print-gensym* t)
+    (fix *print-length* nil)
+    (fix *print-level* nil)
+    (fix *print-lines* nil)
+    (fix *print-miser-width*)
+    (fix *print-pretty* t)
+    (fix *print-radix* nil)
+    (fix *print-readably* nil)
+    (fix *print-right-margin*)
+
+    ;; Read state.
+    (fix *read-base* 10)
+    (fix *read-eval* t)
+    (fix *read-suppress* nil)
+    (fix *readtable* (copy-readtable nil))))
+
 ;;;--------------------------------------------------------------------------
 ;;; Module basics.
 
@@ -73,9 +123,11 @@
     (let ((existing (gethash truename *module-map*)))
       (cond ((null existing))
 	    ((eq (module-state existing) t)
+	     (when (plusp (module-errors existing))
+	       (error "Module `~A' contains errors" name))
 	     (return-from build-module existing))
 	    (t
-	     (error "Module ~A already being imported at ~A"
+	     (error "Module `~A' already being imported at ~A"
 		    name (module-state existing))))))
 
   ;; Construct the new module.
@@ -101,10 +153,14 @@
   (progv
       (mapcar #'car *module-bindings-alist*)
       (module-variables module)
-    (unwind-protect (funcall thunk)
-      (setf (module-variables module)
-	    (mapcar (compose #'car #'symbol-value)
-		    *module-bindings-alist*)))))
+    (handler-bind ((error (lambda (cond)
+			    (declare (ignore cond))
+			    (incf (slot-value module 'errors))
+			    :decline)))
+      (unwind-protect (funcall thunk)
+	(setf (module-variables module)
+	      (mapcar (compose #'car #'symbol-value)
+		      *module-bindings-alist*))))))
 
 (defun call-with-temporary-module (thunk)
   "Invoke THUNK in the context of a temporary module, returning its values.
@@ -146,16 +202,6 @@
 ;;;--------------------------------------------------------------------------
 ;;; Code fragments.
 
-(export '(c-fragment c-fragment-text))
-(defclass c-fragment ()
-  ((location :initarg :location :type file-location :reader file-location)
-   (text :initarg :text :type string :reader c-fragment-text))
-  (:documentation
-   "Represents a fragment of C code to be written to an output file.
-
-   A C fragment is aware of its original location, and will bear proper
-   `#line' markers when written out."))
-
 (defun output-c-excursion (stream location func)
   "Invoke FUNC surrounding it by writing #line markers to STREAM.
 
@@ -199,7 +245,10 @@
 		 (prin1 (subseq text 0 37) stream)
 		 (write-string "..." stream))))
 	(output-c-excursion stream location
-			    (lambda (stream) (write-string text stream))))))
+			    (lambda (stream)
+			      (awhen (file-location-column location)
+				(dotimes (i it) (write-char #\space stream)))
+			      (write-string text stream))))))
 
 (defmethod make-load-form ((fragment c-fragment) &optional environment)
   (make-load-form-saving-slots fragment :environment environment))
@@ -232,10 +281,10 @@
    See `find-file' for the grubby details.")
 
 (export 'find-file)
-(defun find-file (scanner name what thunk)
+(defun find-file (home name what thunk)
   "Find a file called NAME on the module search path, and call THUNK on it.
 
-   The file is searched for relative to the SCANNER's current file, and also
+   The file is searched for relative to the HOME file or directory, and also
    in the directories mentioned in the `*module-dirs*' list.  If the file is
    found, then THUNK is invoked with two arguments: the name we used to find
    it (which might be relative to the starting directory) and the truename
@@ -249,8 +298,7 @@
    THUNK is not invoked with any additional handlers defined."
 
   (handler-case
-      (dolist (dir (cons (pathname (scanner-filename scanner)) *module-dirs*)
-	       (values nil nil))
+      (dolist (dir (cons home *module-dirs*) (values nil nil))
 	(let* ((path (merge-pathnames name dir))
 	       (probe (probe-file path)))
 	  (when probe