implement break and continue, work around overly recursive pmatch expansion

* libguile/vm-i-system.c (goto/args): On a tail call to a different
  procedure, init the locals to valid scheme values. Shouldn't matter for
  well-compiled scheme, but inspecting uninitialized locals could give
  garbage, or badly-compiled code could cause a crash.

* module/language/Makefile.am (NOCOMP_SOURCES): For the moment, don't
  compile compile-ghil.scm. I need to fix this.

* module/language/ecmascript/compile-ghil.scm (load-toplevel): Sigh, and
  disable stack checking in the evaluator too. Grr.
  (comp): Implement (unnamed) break and continue.

* module/language/ecmascript/parse.scm (parse-ecmascript): Fix var
  statements in `for' -- though it still doesn't work.

4 files changed, 27 insertions, 8 deletions

diff --git a/libguile/vm-i-system.c b/libguile/vm-i-system.c
index a105c52d9..18e9a781b 100644
--- a/libguile/vm-i-system.c
+++ b/libguile/vm-i-system.c
@@ -631,6 +631,10 @@ VM_DEFINE_INSTRUCTION (40, goto_args, "goto/args", 1, -1, 1)
         CONS (external, SCM_UNDEFINED, external);
       SCM_FRAME_DATA_ADDRESS (fp)[0] = external;
 
+      /* Init locals to valid SCM values */
+      for (i = 0; i < bp->nlocs; i++)
+	LOCAL_SET (i + bp->nargs, SCM_UNDEFINED);
+
       /* Call itself */
       ip = bp->base;
       APPLY_HOOK ();
diff --git a/module/language/Makefile.am b/module/language/Makefile.am
index 6e2bd92a9..c2db20a86 100644
--- a/module/language/Makefile.am
+++ b/module/language/Makefile.am
@@ -3,13 +3,14 @@ SOURCES=ghil.scm glil.scm assembly.scm \
 	ecmascript/parse-lalr.scm \
 	ecmascript/tokenize.scm \
 	ecmascript/spec.scm \
-	ecmascript/compile-ghil.scm \
 	ecmascript/impl.scm \
 	ecmascript/base.scm \
 	ecmascript/function.scm \
 	ecmascript/array.scm
-# unfortunately, the one that we want to compile can't yet be compiled
-# -- too many local vars, or something.
-NOCOMP_SOURCES = ecmascript/parse.scm
+# unfortunately, the ones that we want to compile can't yet be compiled
+# -- too many local vars in the first case, and some non-tail-recursion
+# in pmatch in the second.
+NOCOMP_SOURCES = ecmascript/parse.scm \
+	ecmascript/compile-ghil.scm
 modpath = language
 include $(top_srcdir)/am/guilec
diff --git a/module/language/ecmascript/compile-ghil.scm b/module/language/ecmascript/compile-ghil.scm
index ffb34a54d..3826f79e3 100644
--- a/module/language/ecmascript/compile-ghil.scm
+++ b/module/language/ecmascript/compile-ghil.scm
@@ -25,6 +25,8 @@
   #:use-module (system base pmatch)
   #:export (compile-ghil))
 
+(eval-case ((load-toplevel) (debug-set! stack 0)))
+
 (define (compile-ghil exp env opts)
   (values
   (call-with-ghil-environment (make-ghil-toplevel-env) '()
@@ -434,6 +436,18 @@
                                                     '())))
                          (@implv e l *undefined*))))))
                   (make-ghil-call e l (make-ghil-ref e l (car vars)) '()))))))
+      ((break)
+       (let ((var (ghil-var-for-ref! e '%continue)))
+         (if (and (ghil-env? (ghil-var-env var))
+                  (eq? (ghil-var-env var) (ghil-env-parent e)))
+             (make-ghil-inline e l 'return (@implv e l *undefined*))
+             (error "bad break, yo"))))
+      ((continue)
+       (let ((var (ghil-var-for-ref! e '%continue)))
+         (if (and (ghil-env? (ghil-var-env var))
+                  (eq? (ghil-var-env var) (ghil-env-parent e)))
+             (make-ghil-inline e l 'goto/args (list (make-ghil-ref e l var)))
+             (error "bad continue, yo"))))
       ((block ,x)
        (comp x e))
       (else
diff --git a/module/language/ecmascript/parse.scm b/module/language/ecmascript/parse.scm
index 27070268c..4603f6235 100644
--- a/module/language/ecmascript/parse.scm
+++ b/module/language/ecmascript/parse.scm
@@ -126,10 +126,10 @@
                        (for lparen ExpressionNoIn semicolon Expression semicolon rparen Statement) -> `(for ,$3 ,$5 #f ,$8)
                        (for lparen ExpressionNoIn semicolon Expression semicolon Expression rparen Statement) -> `(for ,$3 ,$5 ,$7 ,$9)
 
-                       (for lparen var VariableDeclarationListNoIn semicolon semicolon rparen Statement) -> `(for (var ,$4) #f #f ,$8)
-                       (for lparen var VariableDeclarationListNoIn semicolon semicolon Expression rparen Statement) -> `(for (var ,$4) #f ,$7 ,$9)
-                       (for lparen var VariableDeclarationListNoIn semicolon Expression semicolon rparen Statement) -> `(for (var ,$4) ,$6 #f ,$9)
-                       (for lparen var VariableDeclarationListNoIn semicolon Expression semicolon Expression rparen Statement) -> `(for (var ,$4) ,$6 ,$8 ,$10)
+                       (for lparen var VariableDeclarationListNoIn semicolon semicolon rparen Statement) -> `(for (var ,@$4) #f #f ,$8)
+                       (for lparen var VariableDeclarationListNoIn semicolon semicolon Expression rparen Statement) -> `(for (var ,@$4) #f ,$7 ,$9)
+                       (for lparen var VariableDeclarationListNoIn semicolon Expression semicolon rparen Statement) -> `(for (var ,@$4) ,$6 #f ,$9)
+                       (for lparen var VariableDeclarationListNoIn semicolon Expression semicolon Expression rparen Statement) -> `(for (var ,@$4) ,$6 ,$8 ,$10)
 
                        (for lparen LeftHandSideExpression in Expression rparen Statement) -> `(for-in ,$3 ,$5 ,$7)
                        (for lparen var VariableDeclarationNoIn in Expression rparen Statement) -> `(for-in ,$4 ,$6 ,$8))