X-Git-Url: https://git.distorted.org.uk/~mdw/sod/blobdiff_plain/aa14a4cddcb96b681d5c19a2ec8bad382f43b264..944bf9362ff51217b1617f85126d26e821b8aa91:/src/codegen-impl.lisp

diff --git a/src/codegen-impl.lisp b/src/codegen-impl.lisp
index 25413f8..ccc66a1 100644
--- a/src/codegen-impl.lisp
+++ b/src/codegen-impl.lisp
@@ -7,7 +7,7 @@
 
 ;;;----- Licensing notice ---------------------------------------------------
 ;;;
-;;; This file is part of the Sensble Object Design, an object system for C.
+;;; This file is part of the Sensible Object Design, an object system for C.
 ;;;
 ;;; SOD is free software; you can redistribute it and/or modify
 ;;; it under the terms of the GNU General Public License as published by
@@ -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
@@ -62,55 +71,6 @@
       (format-temporary-name var stream)))
 
 ;;;--------------------------------------------------------------------------
-;;; Instruction types.
-
-;; Compound statements.
-
-(export '(if-inst make-if-inst
-	  while-inst make-while-inst
-	  do-inst make-do-inst
-	  inst-condition inst-consequent inst-alternative inst-body))
-
-(definst if (stream) (condition consequent alternative)
-  (format-compound-statement (stream consequent alternative)
-    (format stream "if (~A)" condition))
-  (when alternative
-    (format-compound-statement (stream alternative)
-      (write-string "else" stream))))
-
-(definst while (stream) (condition body)
-  (format-compound-statement (stream body)
-    (format stream "while (~A)" condition)))
-
-(definst do-while (stream) (body condition)
-  (format-compound-statement (stream body :space)
-    (write-string "do" stream))
-  (format stream "while (~A);" condition))
-
-;; Special varargs hacks.
-
-(export '(va-start-inst make-va-start-inst
-	  va-copy-inst make-va-copy-inst
-	  va-end-inst make-va-end-inst
-	  inst-ap inst-arg inst-to inst-from))
-
-(definst va-start (stream) (ap arg)
-  (format stream "va_start(~@<~A, ~_~A~:>);" ap arg))
-
-(definst va-copy (stream) (to from)
-  (format stream "va_copy(~@<~A, ~_~A~:>);" to from))
-
-(definst va-end (stream) (ap)
-  (format stream "va_end(~A);" ap))
-
-;; Expressions.
-
-(export '(call-inst make-call-inst inst-func inst-args))
-
-(definst call (stream) (func args)
-  (format stream "~A(~@<~{~A~^, ~_~}~:>)" func args))
-
-;;;--------------------------------------------------------------------------
 ;;; Code generator objects.
 
 (defclass basic-codegen ()
@@ -121,11 +81,11 @@
   (:documentation
    "Base class for code generator state.
 
-   This contains the bare essentials for supporting the EMIT-INST and
-   ENSURE-VAR protocols; see the documentation for those generic functions
+   This contains the bare essentials for supporting the `emit-inst' and
+   `ensure-var' protocols; see the documentation for those generic functions
    for more details.
 
-   This class isn't abstract.  A full CODEGEN object uses instances of this
+   This class isn't abstract.  A full `codegen' object uses instances of this
    to keep track of pending functions which haven't been completed yet.
 
    Just in case that wasn't clear enough: this is nothing to do with the
@@ -137,26 +97,34 @@
 (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)))
 	  ((not (c-type-equal-p type (inst-type var)))
-	   (error "(Internal) Redefining type for variable ~A." name)))
+	   (error "(Internal) Redefining type for variable ~A" name)))
     name))
 
 (export 'codegen)
 (defclass codegen (basic-codegen)
-  ((functions :initform nil :type list :accessor codegen-functions)
+  ((functions :initform nil :type list :reader codegen-functions)
    (stack :initform nil :type list :accessor codegen-stack))
   (:documentation
    "A full-fat code generator which can generate and track functions.
 
    This is the real deal.  Subclasses may which to attach additional state
    for convenience's sake, but this class is self-contained.  It supports the
-   CODEGEN-PUSH, CODEGEN-POP and CODEGEN-POP-FUNCTION protocols."))
+   `codegen-push', `codegen-pop' and `codegen-pop-function' protocols."))
 
 (defmethod codegen-push ((codegen codegen))
   (with-slots (vars insts temp-index stack) codegen
@@ -188,12 +156,12 @@
 			   (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
 					   (incf temp-index)))))
-	  (push (make-var-inst name type nil) vars)
+	  (push (make-var-inst name type) vars)
 	  name))))
 
 ;;;----- That's all, folks --------------------------------------------------