src/: Add commentary to the generated code.

[sod] / src / codegen-proto.lisp

diff --git a/src/codegen-proto.lisp b/src/codegen-proto.lisp
index 767f35b..186f225 100644 (file)
--- a/src/codegen-proto.lisp
+++ b/src/codegen-proto.lisp
@@ -210,6 +210,10 @@
   `(format-compound-statement* ,stream ,child ,morep
                               (lambda (,stream) ,@body)))
 
+(export 'format-banner-comment)
+(defun format-banner-comment (stream control &rest args)
+  (format stream "~@</~@<* ~@;~?~:>~_ */~:>" control args))
+
 ;; Important instruction classes.
 
 ;; HACK: Some of the slot names we'd like to use are external symbols in our
@@ -222,8 +226,12 @@
     (format stream " = ~A" init))
   (write-char #\; stream))
 
-(definst function (stream :export t) (name #1=#:type body)
+(definst function (stream :export t)
+    (name #1=#:type body &optional #2=#:banner &rest banner-args)
   (pprint-logical-block (stream nil)
+    (when #2#
+      (apply #'format-banner-comment stream #2# banner-args)
+      (pprint-newline :mandatory stream))
     (princ "static " stream)
     (pprint-c-type #1# stream name)
     (format stream "~:@_~A~:@_~:@_" body)))
@@ -250,6 +258,21 @@
 
 ;; Compound statements.
 
+(defvar *first-statement-p* t
+  "True if this is the first statement in a block.
+
+   This is used to communicate between `block-inst' and `banner-inst' so that
+   they get the formatting right between them.")
+
+(definst banner (stream :export t) (control &rest args)
+  (pprint-logical-block (stream nil)
+    (unless *first-statement-p* (pprint-newline :mandatory stream))
+    (apply #'format-banner-comment stream control args)))
+
+(export 'emit-banner)
+(defun emit-banner (codegen control &rest args)
+  (emit-inst codegen (apply #'make-banner-inst control args)))
+
 (definst block (stream :export t) (decls body)
   (write-char #\{ stream)
   (pprint-newline :mandatory stream)
@@ -266,9 +289,11 @@
            (newline)
            (write decl :stream stream))
          (when body (newline)))
-       (dolist (inst body)
-         (newline)
-         (write inst :stream stream)))))
+       (let ((*first-statement-p* t))
+         (dolist (inst body)
+           (newline)
+           (write inst :stream stream)
+           (setf *first-statement-p* nil))))))
   (pprint-newline :mandatory stream)
   (write-char #\} stream))
 
@@ -367,13 +392,15 @@
    cleanup automatically."))
 
 (export 'codegen-build-function)
-(defun codegen-build-function (codegen name type vars insts)
+(defun codegen-build-function
+    (codegen name type vars insts &optional banner &rest banner-args)
   "Build a function and add it to CODEGEN's list.
 
    Returns the function's name."
   (codegen-add-function codegen
-                       (make-function-inst name type
-                                           (make-block-inst vars insts)))
+                       (apply #'make-function-inst name type
+                              (make-block-inst vars insts)
+                              banner banner-args))
   name)
 
 (export 'codegen-pop-block)
@@ -385,15 +412,17 @@
       (make-block-inst vars insts))))
 
 (export 'codegen-pop-function)
-(defgeneric codegen-pop-function (codegen name type)
+(defgeneric codegen-pop-function
+    (codegen name type &optional banner &rest banner-args)
   (:documentation
    "Makes a function out of the completed code in CODEGEN.
 
    The NAME can be any object you like.  The TYPE should be a function type
    object which includes argument names.  The return value is the NAME.")
-  (:method (codegen name type)
+  (:method (codegen name type &optional banner &rest banner-args)
     (multiple-value-bind (vars insts) (codegen-pop codegen)
-      (codegen-build-function codegen name type vars insts))))
+      (apply #'codegen-build-function codegen name type vars insts
+            banner banner-args))))
 
 (export 'with-temporary-var)
 (defmacro with-temporary-var ((codegen var type) &body body)