Warn on access/modify of $SAFE, and remove effects of modifying $SAFE

This removes the security features added by $SAFE = 1, and warns for access
or modification of $SAFE from Ruby-level, as well as warning when calling
all public C functions related to $SAFE.

This modifies some internal functions that took a safe level argument
to no longer take the argument.

rb_require_safe now warns, rb_require_string has been added as a
version that takes a VALUE and does not warn.

One public C function that still takes a safe level argument and that
this doesn't warn for is rb_eval_cmd.  We may want to consider
adding an alternative method that does not take a safe level argument,
and warn for rb_eval_cmd.

1 files changed, 0 insertions, 11 deletions

diff --git a/test/ruby/test_optimization.rb b/test/ruby/test_optimization.rb
index f26b31f115..b42314b765 100644
--- a/test/ruby/test_optimization.rb
+++ b/test/ruby/test_optimization.rb
@@ -714,17 +714,6 @@ class TestRubyOptimization < Test::Unit::TestCase
     END
   end
 
-  def test_block_parameter_should_restore_safe_level
-    assert_separately [], <<-END
-      #
-      def foo &b
-        $SAFE = 1
-        b.call
-      end
-      assert_equal 1, foo{$SAFE}
-    END
-  end
-
   def test_peephole_optimization_without_trace
     assert_separately [], <<-END
       RubyVM::InstructionSequence.compile_option = {trace_instruction: false}