adjust transfer of compiled in one namespace and run in another

Formerly, compiling a definition in one namespace and evaluating it in
another would cause the definition to take place in the original
namespace --- unless the compiled code is marshaled to a byte string
and back. Adjust the "linking" process to redirect the variable
definition and any references to the new namespace. (This is a change
relative to the compiler with the old macro expander.)

Also, repair a compiled `require` form along similar lines. (This is
*not* a change relative to the compiler with the old macro expander;
the mismatch is part of the motivation for changing `define`
handling.)

pkgs/racket-test-core/tests/racket/namespac.rktl

@@ -321,6 +321,53 @@
   (test cons eval 'cons ns)
   (test 2 eval 'extra ns))
 
+;; ----------------------------------------
+;; Check that compilation in one namespace can
+;; be transferred to another namespace
+
+(let ()
+  ;; transfer a `require`
+  (define c
+    (parameterize ([current-namespace (make-base-namespace)])
+      (compile '(require racket/base))))
+  (parameterize ([current-namespace (make-base-empty-namespace)])
+    (test (void) 'eval (eval c))
+    (test add1 eval 'add1)))
+
+(let ()
+  ;; transfer a definition, reference is visible, original
+  ;; namespace is unchanged
+  (define-values (c get)
+    (parameterize ([current-namespace (make-base-namespace)])
+      (define c (compile '(define one 1)))
+      (values
+       c
+       (eval '(lambda () one)))))
+  (parameterize ([current-namespace (make-base-empty-namespace)])
+    (test (void) 'eval (eval c))
+    (test 1 eval 'one)
+    (err/rt-test (get) exn:fail:contract:variable?)))
+
+(let ()
+  ;; transfer a definition of a macro-introduced variable, and
+  ;; check access via a syntax object that is compiled at the same time:
+  (define-values (c get)
+    (parameterize ([current-namespace (make-base-namespace)])
+      (eval '(define-syntax-rule (m id)
+              (begin
+                (define one 1)
+                (define id (quote-syntax one))
+                one)))
+      (define c (compile '(m id)))
+      (values
+       c
+       (eval '(lambda () one)))))
+  (parameterize ([current-namespace (make-base-empty-namespace)])
+    (test 1 'eval (eval c))
+    (err/rt-test (eval 'one) exn:fail:syntax?)
+    (test 1 eval (eval 'id))
+    (err/rt-test (get) exn:fail:contract:variable?)))
+
 ;; ----------------------------------------
 
 (report-errs)

racket/src/racket/src/env.c

@@ -1575,8 +1575,12 @@ void scheme_shadow(Scheme_Env *env, Scheme_Object *n, Scheme_Object *val, int as
   } else
     id = NULL;
 
-  if (!id)
-    return;
+  if (!id) {
+    if (env->module)
+      return;
+    id = scheme_datum_to_syntax(n, scheme_false, scheme_false, 0, 0);
+    id = scheme_stx_add_module_context(id, env->stx_context);
+  }
 
   if (env->binding_names_need_shift) {
     id = scheme_stx_shift(id, scheme_make_integer(env->phase - env->mod_phase),

racket/src/racket/src/eval.c

@@ -1004,8 +1004,10 @@ static Scheme_Object *link_toplevel(Scheme_Object **exprs, int which, Scheme_Env
 
     home = scheme_get_bucket_home(b);
     
-    if (!env || !home || !home->module)
+    if (!env || !home)
       return (Scheme_Object *)b;
+    else if (!home->module)
+      return (Scheme_Object *)scheme_global_bucket((Scheme_Object *)b->key, env);
     else
       return link_module_variable(home->module->modname,
 				  (Scheme_Object *)b->key,

racket/src/racket/src/module.c

@@ -12472,13 +12472,13 @@ do_require_execute(Scheme_Env *env, Scheme_Object *form)
 {
   Scheme_Object *modidx;
 
+  /* Use the current top-level context: */
+  form = scheme_stx_add_module_context(form, env->stx_context);
+
   /* Check for collisions again, in case there's a difference between
      compile and run times: */
   modidx = check_require_form(env, form);
 
-  /* Use the current top-level context: */
-  form = scheme_stx_push_module_context(form, env->stx_context);
-
   parse_requires(form, env->phase, modidx, env, NULL,
                  env->stx_context,
                  NULL, NULL,
@@ -12518,8 +12518,9 @@ static Scheme_Object *do_require(Scheme_Object *form, Scheme_Comp_Env *env,
   (void)check_require_form(env->genv, form);
 
   if (rec && rec[drec].comp) {
-    form = scheme_revert_use_site_scopes(form, env);
-    
+    /* Remove all context specific to the compile-time environment: */
+    form = scheme_stx_remove_module_context(form, env->genv->stx_context);
+
     /* Dummy lets us access a top-level environment: */
     dummy = scheme_make_environment_dummy(env);
     

racket/src/racket/src/schpriv.h

@@ -1195,6 +1195,7 @@ Scheme_Object *scheme_make_module_context(Scheme_Object *insp,
 Scheme_Object *scheme_module_context_at_phase(Scheme_Object *mc, Scheme_Object *phase);
 
 Scheme_Object *scheme_stx_add_module_context(Scheme_Object *stx, Scheme_Object *mc);
+Scheme_Object *scheme_stx_remove_module_context(Scheme_Object *stx, Scheme_Object *mc);
 Scheme_Object *scheme_stx_add_module_frame_context(Scheme_Object *stx, Scheme_Object *mc);
 Scheme_Object *scheme_stx_adjust_module_use_site_context(Scheme_Object *stx, Scheme_Object *mc, int mode);
 Scheme_Object *scheme_stx_introduce_to_module_context(Scheme_Object *stx, Scheme_Object *mc);

racket/src/racket/src/syntax.c

@@ -4320,6 +4320,11 @@ Scheme_Object *scheme_stx_add_module_context(Scheme_Object *stx, Scheme_Object *
   return adjust_module_context_except(stx, mc, NULL, SCHEME_STX_ADD);
 }
 
+Scheme_Object *scheme_stx_remove_module_context(Scheme_Object *stx, Scheme_Object *mc)
+{
+  return adjust_module_context_except(stx, mc, NULL, SCHEME_STX_REMOVE);
+}
+
 Scheme_Object *scheme_stx_push_module_context(Scheme_Object *stx, Scheme_Object *mc)
 {
   Scheme_Object *intro_multi_scope = SCHEME_VEC_ELS(mc)[4];