less verbose code by sharing attribute definitions

The idea behind this commit is that handles_sp and leaf are two
concepts that are not mutually independent.  By making one explicitly
depend another, we can reduces the number of lines of codes written,
thus making things concise.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65426 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 19 insertions, 5 deletions

diff --git a/tool/ruby_vm/models/bare_instructions.rb b/tool/ruby_vm/models/bare_instructions.rb
index 7d9ed6da5a..2767f383e6 100755
--- a/tool/ruby_vm/models/bare_instructions.rb
+++ b/tool/ruby_vm/models/bare_instructions.rb
@@ -144,6 +144,7 @@ class RubyVM::BareInstructions
   end
 
   def predefine_attributes
+    # Beware: order matters here because some attribute depends another.
     generate_attribute 'const char*', 'name', "insn_name(#{bin})"
     generate_attribute 'enum ruby_vminsn_type', 'bin', bin
     generate_attribute 'rb_num_t', 'open', opes.size
@@ -151,11 +152,24 @@ class RubyVM::BareInstructions
     generate_attribute 'rb_num_t', 'retn', rets.size
     generate_attribute 'rb_num_t', 'width', width
     generate_attribute 'rb_snum_t', 'sp_inc', rets.size - pops.size
-    generate_attribute 'bool', 'handles_sp', false
-    generate_attribute 'bool', 'leaf', opes.all? {|o|
-      # Insn with ISEQ should yield it; can never be a leaf.
-      o[:type] != 'ISEQ'
-    }
+    generate_attribute 'bool', 'handles_sp', default_definition_of_handles_sp
+    generate_attribute 'bool', 'leaf', default_definition_of_leaf
+  end
+
+  def default_definition_of_handles_sp
+    # Insn with ISEQ should yield it; can handle sp.
+    return opes.any? {|o| o[:type] == 'ISEQ' }
+  end
+
+  def default_definition_of_leaf
+    # Insn that handles SP can never be a leaf.
+    if not has_attribute? 'handles_sp' then
+      return ! default_definition_of_handles_sp
+    elsif handles_sp? then
+      return "! #{call_attribute 'handles_sp'}"
+    else
+      return true
+    end
   end
 
   def typesplit a