X-Git-Url: https://git.distorted.org.uk/~mdw/sod/blobdiff_plain/418752c55a29e2380d6d1aef767b7cfba02cf4be..bb80145308ea388d7c6ed5336c061340e78f66e8:/src/codegen-impl.lisp

diff --git a/src/codegen-impl.lisp b/src/codegen-impl.lisp
index 3790d9d..d988b12 100644
--- a/src/codegen-impl.lisp
+++ b/src/codegen-impl.lisp
@@ -37,10 +37,19 @@
   ((in-use-p :initarg :in-use-p :initform nil
 	     :type boolean :accessor var-in-use-p)))
 
+(define-module-var *temporary-index* 0
+  "Index for temporary name generation.
+
+   This is automatically reset to zero before the output functions are
+   invoked to write a file.  This way, we can ensure that the same output
+   file is always produced from the same input.")
+
+(define-clear-the-decks reset-codegen-index
+  (setf *temporary-index* 0))
+
 (defmethod commentify-argument-name ((name temporary-name))
   nil)
 
-(export 'temporary-function)
 (defun temporary-function ()
   "Return a temporary function name."
   (make-instance 'temporary-function
@@ -66,21 +75,26 @@
 
 ;; Compound statements.
 
-(definst if (stream :export t) (condition consequent alternative)
-  (format-compound-statement (stream consequent alternative)
-    (format stream "if (~A)" condition))
-  (when alternative
-    (format-compound-statement (stream alternative)
+;; HACK: use gensyms for the `condition' slots to avoid leaking the slot
+;; names, since the symbol `condition' actually comes from the `common-lisp'
+;; package.  The `definst' machinery will symbolicate the various associated
+;; methods correctly despite this subterfuge.
+
+(definst if (stream :export t) (#1=#:cond conseq alt)
+  (format-compound-statement (stream conseq alt)
+    (format stream "if (~A)" #1#))
+  (when alt
+    (format-compound-statement (stream alt)
       (write-string "else" stream))))
 
-(definst while (stream :export t) (condition body)
+(definst while (stream :export t) (#1=#:cond body)
   (format-compound-statement (stream body)
-    (format stream "while (~A)" condition)))
+    (format stream "while (~A)" #1#)))
 
-(definst do-while (stream :export t) (body condition)
+(definst do-while (stream :export t) (body #1=#:cond)
   (format-compound-statement (stream body :space)
     (write-string "do" stream))
-  (format stream "while (~A);" condition))
+  (format stream "while (~A);" #1#))
 
 ;; Special varargs hacks.
 
@@ -95,8 +109,10 @@
 
 ;; Expressions.
 
-(definst call (stream :export t) (func args)
-  (format stream "~A(~@<~{~A~^, ~_~}~:>)" func args))
+;; HACK: use a gensym for the `func' slot to avoid leaking the slot name,
+;; since the symbol `func' is exported from our package.
+(definst call (stream :export t) (#1=#:func args)
+  (format stream "~A(~@<~{~A~^, ~_~}~:>)" #1# args))
 
 ;;;--------------------------------------------------------------------------
 ;;; Code generator objects.
@@ -125,9 +141,17 @@
 (defmethod emit-insts ((codegen basic-codegen) insts)
   (asetf (codegen-insts codegen) (revappend insts it)))
 
+(defmethod emit-decl ((codegen basic-codegen) inst)
+  (push inst (codegen-vars codegen)))
+
+(defmethod emit-decls ((codegen basic-codegen) insts)
+  (asetf (codegen-vars codegen) (revappend insts it)))
+
 (defmethod ensure-var ((codegen basic-codegen) name type &optional init)
   (let* ((vars (codegen-vars codegen))
-	 (var (find name vars :key #'inst-name :test #'equal)))
+	 (var (find name
+		    (remove-if-not (lambda (var) (typep var 'var-inst)) vars)
+		    :key #'inst-name :test #'equal)))
     (cond ((not var)
 	   (setf (codegen-vars codegen)
 		 (cons (make-var-inst name type init) vars)))
@@ -176,7 +200,7 @@
 			   (c-type-equal-p type (inst-type var)))
 		      name
 		      nil)))
-	      vars)
+	      (remove-if-not (lambda (var) (typep var 'var-inst)) vars))
 	(let* ((name (make-instance 'temporary-variable
 				    :in-use-p t
 				    :tag (prog1 temp-index