From c458cd97996d6ff6fd1eda7d6523915d7c2cdc75 Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Thu, 5 Mar 2015 11:21:25 -0700
Subject: [PATCH] remove over-eager namespace cleanup in the compiler/expander

The compiler/expander attempted to clear out references in a namespace
used only during macro expansion, but it's possible for references to
be retained (via unusual macros), so get rid of the broken attempt to
help the GC.
---
 racket/src/racket/src/env.c     | 26 --------------------------
 racket/src/racket/src/module.c  | 13 +------------
 racket/src/racket/src/schpriv.h |  2 --
 3 files changed, 1 insertion(+), 40 deletions(-)

diff --git a/racket/src/racket/src/env.c b/racket/src/racket/src/env.c
index 37f09a115b..e3418877ad 100644
--- a/racket/src/racket/src/env.c
+++ b/racket/src/racket/src/env.c
@@ -1240,32 +1240,6 @@ Scheme_Bucket_Table *scheme_clone_toplevel(Scheme_Bucket_Table *ht, Scheme_Env *
   return r;
 }
 
-void scheme_clean_dead_env(Scheme_Env *env)
-{
-  Scheme_Object *modchain, *next;
-
-  if (env->exp_env) {
-    env->exp_env->template_env = NULL;
-    scheme_clean_dead_env(env->exp_env);
-    env->exp_env = NULL;
-  }
-  if (env->template_env) {
-    env->template_env->exp_env = NULL;
-    scheme_clean_dead_env(env->template_env);
-    env->template_env = NULL;
-  }
-
-  env->modvars = NULL;
-  
-  modchain = env->modchain;
-  env->modchain = NULL;
-  while (modchain && !SCHEME_VECTORP(modchain)) {
-    next = SCHEME_VEC_ELS(modchain)[1];
-    SCHEME_VEC_ELS(modchain)[1] = scheme_void;
-    modchain = next;
-  }
-}
-
 Scheme_Object *scheme_get_home_weak_link(Scheme_Env *e)
 {
   if (!e->weak_self_link) {
diff --git a/racket/src/racket/src/module.c b/racket/src/racket/src/module.c
index 670518200d..685a4fc2d0 100644
--- a/racket/src/racket/src/module.c
+++ b/racket/src/racket/src/module.c
@@ -8192,7 +8192,7 @@ static void flush_definitions(Scheme_Env *genv)
 static Scheme_Object *do_module_begin(Scheme_Object *orig_form, Scheme_Comp_Env *env, 
 				      Scheme_Compile_Expand_Info *rec, int drec)
 {
-  int num_phases, *_num_phases, i, exicount, *all_simple_renames, can_clean, has_submodules;
+  int num_phases, *_num_phases, i, exicount, *all_simple_renames, has_submodules;
   Scheme_Hash_Tree *all_defs;
   Scheme_Hash_Table *tables, *all_defs_out, *all_provided, *all_reprovided, *modidx_cache;
   Scheme_Module_Export_Info **exp_infos, *exp_info;
@@ -8379,18 +8379,10 @@ static Scheme_Object *do_module_begin(Scheme_Object *orig_form, Scheme_Comp_Env
     genv = genv->exp_env;
   }
 
-  if (rec[drec].comp || (rec[drec].depth != -2))
-    can_clean = 1;
-  else
-    can_clean = 0;
-
   has_submodules = (!SCHEME_NULLP(bxs->saved_submodules)
                     || (env->genv->module->submodule_path
                         && !SCHEME_NULLP(env->genv->module->submodule_path)));
 
-  if (can_clean && !has_submodules)
-    scheme_clean_dead_env(env->genv);
-
   if (!rec[drec].comp) {
     Scheme_Module_Phase_Exports *rt = env->genv->module->me->rt;
     int excount = rt->num_provides;
@@ -8564,9 +8556,6 @@ static Scheme_Object *do_module_begin(Scheme_Object *orig_form, Scheme_Comp_Env
     if (!rec[drec].comp) {
       (void)fixup_expanded(expanded_l, expanded_modules, 0, MODULE_MODFORM_KIND);
     }
-
-    if (can_clean)
-      scheme_clean_dead_env(env->genv);
   }
 
   /* Return module or expanded code: */
diff --git a/racket/src/racket/src/schpriv.h b/racket/src/racket/src/schpriv.h
index 21680d0d5a..d59ee5b666 100644
--- a/racket/src/racket/src/schpriv.h
+++ b/racket/src/racket/src/schpriv.h
@@ -3563,8 +3563,6 @@ Scheme_Bucket_Table *scheme_clone_toplevel(Scheme_Bucket_Table *ht, Scheme_Env *
 
 Scheme_Env *scheme_copy_module_env(Scheme_Env *menv, Scheme_Env *ns, Scheme_Object *modchain, int clone);
 
-void scheme_clean_dead_env(Scheme_Env *env);
-
 Scheme_Module *scheme_extract_compiled_module(Scheme_Object *o);
 
 int scheme_is_kernel_modname(Scheme_Object *modname);