* vm.c: add RubyVM::Backtrace object (btobj).

  Backtrace information contains an array consists of location
  information for each frames by string.
  RubyVM::Backtrace object is lightweight backtrace information,
  which contains complete information to generate traditional style
  backtrace (an array of strings) with faster generation.
  If someone accesses to backtrace information via
  Exception#backtrace, then convert a RubyVM::Backtrace object to
  traditonal style backtrace.
  This change causes incompatibility on marshal dumpped binary
  of Exception.  If you have any trouble on it, please tell us
  before Ruby 2.0 release.
  Note that RubyVM::Backtrace object should not expose Ruby level.
* error.c, eval.c, vm_eval.c: ditto.
* internal.h: ditto.
* eval_error.c: fix to skip "set_backtrace" method invocation in
  creating an exception object if it call a normal set_backtrace
  method (defined by core).
* test/ruby/test_settracefunc.rb: fix for above change.
* vm_method.c (rb_method_defined_by): added.  This function
  checks that the given object responds with the given method
  by the given cfunc.
* benchmark/bm_vm2_raise1.rb, benchmark/bm_vm2_raise2.rb:
  add to measure exception creation speed. raise1 create
  exception objects from shallow stack frame.  raise2 create
  exception objects from deep stack frame.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@35769 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 11 insertions, 0 deletions

diff --git a/eval_error.c b/eval_error.c
index e7eb9cf0fc..a2e95a759f 100644
--- a/eval_error.c
+++ b/eval_error.c
@@ -58,6 +58,17 @@ rb_get_backtrace(VALUE info)
 static void
 set_backtrace(VALUE info, VALUE bt)
 {
+    ID set_backtrace = rb_intern("set_backtrace");
+
+    if (rb_backtrace_p(bt)) {
+	if (rb_method_defined_by(info, set_backtrace, rb_exc_set_backtrace)) {
+	    rb_exc_set_backtrace(info, bt);
+	    return;
+	}
+	else {
+	    bt = rb_backtrace_to_str_ary(bt);
+	}
+    }
     rb_funcall(info, rb_intern("set_backtrace"), 1, bt);
 }