From 35d154345be08159c28cfb66e3a2b8248073159b Mon Sep 17 00:00:00 2001
From: Danny Yoo <dyoo@hashcollision.org>
Date: Sun, 3 Mar 2013 15:28:02 -0700
Subject: [PATCH] Right in the middle of getting global references to work.

---
 whalesong/compiler/compiler.rkt    | 19 +++++++++++++++----
 whalesong/compiler/il-structs.rkt  | 16 +++++++++++++++-
 whalesong/compiler/optimize-il.rkt |  4 +++-
 3 files changed, 33 insertions(+), 6 deletions(-)

diff --git a/whalesong/compiler/compiler.rkt b/whalesong/compiler/compiler.rkt
index 2ee2d31..d1282e6 100644
--- a/whalesong/compiler/compiler.rkt
+++ b/whalesong/compiler/compiler.rkt
@@ -448,9 +448,16 @@
                                   (make-EnvPrefixReference (ToplevelRef-depth exp)
                                                            (ToplevelRef-pos exp)
                                                            #t))])]
+                         [(GlobalBucket? prefix-element)
+                          (append-instruction-sequences
+                           (if (ToplevelRef-check-defined? exp)
+                               (make-Perform (make-CheckGlobalBound! (GlobalBucket-name prefix-element)))
+                               empty-instruction-sequence)
+                           (make-AssignImmediate
+                            target
+                            (make-GlobalsReference (GlobalBucket-name prefix-element))))]
                          [(or (eq? prefix-element #f)
-                              (symbol? prefix-element)
-                              (GlobalBucket? prefix-element))
+                              (symbol? prefix-element))
                           (append-instruction-sequences
                            (if (ToplevelRef-check-defined? exp)
                                (make-Perform (make-CheckToplevelBound!
@@ -487,9 +494,13 @@
                                               (ToplevelSet-pos exp)
                                               #t)
                      next-linkage/expects-single)]
+           [(GlobalBucket? prefix-element)
+            (compile (ToplevelSet-value exp)
+                     cenv
+                     (make-GlobalsReference (GlobalBucket-name prefix-element))
+                     next-linkage/expects-single)]
            [(or (eq? prefix-element #f)
-                (symbol? prefix-element)
-                (GlobalBucket? prefix-element))
+                (symbol? prefix-element))
             (compile (ToplevelSet-value exp)
                      cenv
                      (make-EnvPrefixReference (ToplevelSet-depth exp)
diff --git a/whalesong/compiler/il-structs.rkt b/whalesong/compiler/il-structs.rkt
index b0c4b78..94c2095 100644
--- a/whalesong/compiler/il-structs.rkt
+++ b/whalesong/compiler/il-structs.rkt
@@ -38,6 +38,7 @@
                       ModulePredicate
                       PrimitiveKernelValue
                       VariableReference
+                      GlobalsReference
                       ))
 
 
@@ -45,7 +46,8 @@
 (define-type Target (U AtomicRegisterSymbol 
                        EnvLexicalReference
                        EnvPrefixReference
-                       PrimitivesReference                   
+                       PrimitivesReference
+                       GlobalsReference
                        ControlFrameTemporary
                        ModulePrefixTarget
                        ))
@@ -152,6 +154,10 @@
 (define-struct: PrimitivesReference ([name : Symbol])
   #:transparent)
 
+(define-struct: GlobalsReference ([name : Symbol])
+  #:transparent)
+
+
 ;; Produces the entry point of the module.
 (define-struct: ModuleEntry ([name : ModuleLocator])
   #:transparent)
@@ -313,6 +319,7 @@
 
                                   ModuleVariable
                                   PrimitivesReference
+                                  GlobalsReference
                                   
                                   MakeBoxedEnvironmentValue
 
@@ -398,6 +405,12 @@
                                      [pos : Natural])
   #:transparent)
 
+;; Check that the global can be defined.
+;; If not, raise an error and stop evaluation.
+(define-struct: CheckGlobalBound! ([name : Symbol])
+  #:transparent)
+
+
 ;; Check the closure procedure value in 'proc and make sure it's a closure
 ;; that can accept the right arguments (stored as a number in the argcount register.).
 (define-struct: CheckClosureAndArity! ()
@@ -511,6 +524,7 @@
 
 (define-type PrimitiveCommand (U                                
                                CheckToplevelBound!
+                               CheckGlobalBound!
                                CheckClosureAndArity!
                                CheckPrimitiveArity!
 
diff --git a/whalesong/compiler/optimize-il.rkt b/whalesong/compiler/optimize-il.rkt
index bb1fd77..2276350 100644
--- a/whalesong/compiler/optimize-il.rkt
+++ b/whalesong/compiler/optimize-il.rkt
@@ -147,7 +147,9 @@
        
        [(PrimitivesReference? op)
         op]
-       ))
+       
+       [(GlobalsReference? op)
+        op]))
 
 
     (: rewrite-primcmd (PrimitiveCommand -> PrimitiveCommand))