* iseq.c, vm_eval.c: set th->base_block properly.

  th->base_block is information for (a) parsing, (b) compiling
  and (c) setting up the frame to execute the program passed by
  `eval' method.  For example, (1) parser need to know up-level
  variables to detect it is variable or method without paren.
  Befor (a), (b) and (c), VM set th->base_block by passed bindng
  (or previous frame information).  After execute (a), (b) and (c),
  VM should clear th->base_block.  However, if (a), (b) or (c)
  raises an exception, then th->base_block is not cleared.
  Problem is that the uncleared value th->balo_block is used for
  irrelevant iseq compilation.  It causes SEGV or critical error.
  I tried to solve this problem: to clear them before exception,
  but finally I found out that it is difficult to do it (Ruby
  program can be run in many places).
  Because of this background, I set th->base_block before
  compiling iseq and restore it after compiling.
  Basically, th->base_block is dirty hack (similar to global
  variable) and this patch is also dirty.
* bootstraptest/test_eval.rb: add a test for above.
* internal.h: remove unused decl.
* iseq.c (rb_iseq_compile_with_option): add base_block parameter.
  set th->base_block before compation and restore it after
  compilation.
* ruby.c (require_libraries): pass 0 as base_block instead of
  setting th->base_block
* tool/compile_prelude.rb (prelude_eval): apply above changes.
* vm.c, vm_eval.c: ditto.
* vm_core.h: add comments.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@36179 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 4 insertions, 7 deletions

diff --git a/vm.c b/vm.c
index 075219236a..06d2db3ddd 100644
--- a/vm.c
+++ b/vm.c
@@ -141,15 +141,14 @@ vm_set_top_stack(rb_thread_t * th, VALUE iseqval)
 }
 
 static void
-vm_set_eval_stack(rb_thread_t * th, VALUE iseqval, const NODE *cref)
+vm_set_eval_stack(rb_thread_t * th, VALUE iseqval, const NODE *cref, rb_block_t *base_block)
 {
     rb_iseq_t *iseq;
-    rb_block_t * const block = th->base_block;
     GetISeqPtr(iseqval, iseq);
 
     CHECK_STACK_OVERFLOW(th->cfp, iseq->local_size + iseq->stack_max);
-    vm_push_frame(th, iseq, VM_FRAME_MAGIC_EVAL | VM_FRAME_FLAG_FINISH, block->self,
-		  VM_ENVVAL_PREV_EP_PTR(block->ep), iseq->iseq_encoded,
+    vm_push_frame(th, iseq, VM_FRAME_MAGIC_EVAL | VM_FRAME_FLAG_FINISH, base_block->self,
+		  VM_ENVVAL_PREV_EP_PTR(base_block->ep), iseq->iseq_encoded,
 		  th->cfp->sp, iseq->local_size);
 
     if (cref) {
@@ -167,9 +166,7 @@ vm_set_main_stack(rb_thread_t *th, VALUE iseqval)
 
     GetBindingPtr(toplevel_binding, bind);
     GetEnvPtr(bind->env, env);
-    th->base_block = &env->block;
-    vm_set_eval_stack(th, iseqval, 0);
-    th->base_block = 0;
+    vm_set_eval_stack(th, iseqval, 0, &env->block);
 
     /* save binding */
     GetISeqPtr(iseqval, iseq);