Bug #10601: Unexpected behaviour changes for Struct class

• Status: Closed
• Assignee: normalperson (Eric Wong)
• Target version: 2.2.0
• ruby -v: ruby 2.2.0dev (2014-12-14 trunk 48835) [x86_64-darwin13]
• Backport: 2.0.0: DONTNEED, 2.1: DONTNEED

[hsbt (Hiroshi SHIBATA)]

r48748 changes below code behaviour.

class Request < Struct.new(:params, :headers)
  def params=(hash)
    super
  end
 
  def []=(key, value)
    headers[key] = value
  end
end
 
Request.new.params = {}

% ruby -v test.rb
ruby 2.2.0dev (2014-12-14 trunk 48835) [x86_64-darwin13]
test.rb:7:in `[]=': undefined method `[]=' for nil:NilClass (NoMethodError)
	from <compiled>:1:in `params='
	from test.rb:3:in `params='
	from test.rb:11:in `<main>'
% ruby -v test.rb
ruby 2.1.5p273 (2014-11-13 revision 48405) [x86_64-darwin13.0]

above code is included faraday known as famous http client library.

normal

Can you investigate or revert r48748?

I think this commit is feature category if it's your expected changes.
We shouldn't apply this in 2.2.0.rc phase.

[normalperson (Eric Wong)]

I was preparing to revert and refix for 2.3, but
then I see nobu working on r48849, r48850, r48851...
I guess nobu is fixing this problem?

[nobu (Nobuyoshi Nakada)]

What do you think about this?

    iseq.c: struct accessors
    
    * iseq.c (rb_method_for_self_aref, rb_method_for_self_aset): call
      accessor functions directly, not to be affected by [] and []=
      methods.  [ruby-core:66846] [Bug #10601]
    
    * struct.c (define_aref_method, define_aset_method): ditto.
    
    * vm_insnhelper.c (rb_vm_opt_struct_aref, rb_vm_opt_struct_aset):
      direct accessors of Struct.

diff --git a/iseq.c b/iseq.c
index de30490..8d477c9 100644
--- a/iseq.c
+++ b/iseq.c
@@ -565,14 +565,14 @@ caller_location(VALUE *path)
 }
 
 VALUE
-rb_method_for_self_aref(VALUE name, VALUE arg)
+rb_method_for_self_aref(VALUE name, VALUE arg, rb_insn_func_t func)
 {
+    rb_control_frame_t *FUNC_FASTCALL(rb_vm_struct_aref_c)(rb_thread_t *, rb_control_frame_t *);
     VALUE iseqval = iseq_alloc(rb_cISeq);
     rb_iseq_t *iseq;
     VALUE path, lineno = caller_location(&path);
     VALUE parent = 0;
     VALUE misc, locals, params, exception, body, send_arg;
-    int flag = VM_CALL_FCALL | VM_CALL_ARGS_SIMPLE;
 
     GetISeqPtr(iseqval, iseq);
     iseq->self = iseqval;
@@ -589,18 +589,10 @@ rb_method_for_self_aref(VALUE name, VALUE arg)
 #define ADD(a) rb_ary_push(body, rb_obj_hide(a))
     /* def name; self[arg]; end */
     ADD(lineno);
-    ADD(rb_ary_new3(1, S(putself)));
     ADD(rb_ary_new3(2, S(putobject), arg));
 
-    /* {:mid=>:[], :flag=>264, :blockptr=>nil, :orig_argc=>1} */
-    send_arg = rb_hash_new();
-    rb_hash_aset(send_arg, S(mid), ID2SYM(idAREF));
-    rb_hash_aset(send_arg, S(flag), INT2FIX(flag));
-    rb_hash_aset(send_arg, S(blockptr), Qnil);
-    rb_hash_aset(send_arg, S(orig_argc), INT2FIX(1));
-
-    /* we do not want opt_aref for struct */
-    ADD(rb_ary_new3(2, S(opt_send_without_block), send_arg));
+    send_arg = rb_ary_new3(2, S(opt_call_c_function), (VALUE)func);
+    ADD(send_arg);
     ADD(rb_ary_new3(1, S(leave)));
 #undef S
 #undef ADD
@@ -609,19 +601,19 @@ rb_method_for_self_aref(VALUE name, VALUE arg)
     cleanup_iseq_build(iseq);
 
     rb_ary_clear(body);
+    rb_ary_clear(send_arg);
 
     return iseqval;
 }
 
 VALUE
-rb_method_for_self_aset(VALUE name, VALUE arg)
+rb_method_for_self_aset(VALUE name, VALUE arg, rb_insn_func_t func)
 {
     VALUE iseqval = iseq_alloc(rb_cISeq);
     rb_iseq_t *iseq;
     VALUE path, lineno = caller_location(&path);
     VALUE parent = 0;
     VALUE misc, locals, params, exception, body, send_arg;
-    int flag = VM_CALL_FCALL | VM_CALL_ARGS_SIMPLE;
 
     GetISeqPtr(iseqval, iseq);
     iseq->self = iseqval;
@@ -637,26 +629,16 @@ rb_method_for_self_aset(VALUE name, VALUE arg)
     locals = rb_obj_hide(rb_ary_new3(1, S(val)));
     params = rb_hash_new();
     exception = rb_ary_tmp_new(0); /* empty */
-    body = rb_ary_tmp_new(9);
+    body = rb_ary_tmp_new(6);
 
     rb_hash_aset(params, S(lead_num), INT2FIX(1));
 
     ADD(lineno);
-    ADD(rb_ary_new3(1, S(putnil)));
-    ADD(rb_ary_new3(1, S(putself)));
-    ADD(rb_ary_new3(2, S(putobject), arg));
     ADD(rb_ary_new3(3, S(getlocal), INT2FIX(2), INT2FIX(0)));
-    ADD(rb_ary_new3(2, S(setn), INT2FIX(3)));
-
-    /* {:mid=>:[]=, :flag=>264, :blockptr=>nil, :orig_argc=>2} */
-    send_arg = rb_hash_new();
-    rb_hash_aset(send_arg, S(mid), ID2SYM(idASET));
-    rb_hash_aset(send_arg, S(flag), INT2FIX(flag));
-    rb_hash_aset(send_arg, S(blockptr), Qnil);
-    rb_hash_aset(send_arg, S(orig_argc), INT2FIX(2));
+    ADD(rb_ary_new3(2, S(putobject), arg));
 
-    /* we do not want opt_aset for struct */
-    ADD(rb_ary_new3(2, S(opt_send_without_block), send_arg));
+    send_arg = rb_ary_new3(2, S(opt_call_c_function), (VALUE)func);
+    ADD(send_arg);
 
     ADD(rb_ary_new3(1, S(pop)));
     ADD(rb_ary_new3(1, S(leave)));
@@ -667,6 +649,7 @@ rb_method_for_self_aset(VALUE name, VALUE arg)
     cleanup_iseq_build(iseq);
 
     rb_ary_clear(body);
+    rb_ary_clear(send_arg);
 
     return iseqval;
 }
diff --git a/struct.c b/struct.c
index 080c0f3..c123318 100644
--- a/struct.c
+++ b/struct.c
@@ -13,8 +13,8 @@
 #include "vm_core.h"
 #include "method.h"
 
-VALUE rb_method_for_self_aref(VALUE name, VALUE arg);
-VALUE rb_method_for_self_aset(VALUE name, VALUE arg);
+VALUE rb_method_for_self_aref(VALUE name, VALUE arg, rb_insn_func_t func);
+VALUE rb_method_for_self_aset(VALUE name, VALUE arg, rb_insn_func_t func);
 
 VALUE rb_cStruct;
 static ID id_members;
@@ -175,7 +175,8 @@ new_struct(VALUE name, VALUE super)
 static void
 define_aref_method(VALUE nstr, VALUE name, VALUE off)
 {
-    VALUE iseqval = rb_method_for_self_aref(name, off);
+    rb_control_frame_t *FUNC_FASTCALL(rb_vm_opt_struct_aref)(rb_thread_t *, rb_control_frame_t *);
+    VALUE iseqval = rb_method_for_self_aref(name, off, rb_vm_opt_struct_aref);
     rb_iseq_t *iseq = DATA_PTR(iseqval);
 
     rb_add_method(nstr, SYM2ID(name), VM_METHOD_TYPE_ISEQ, iseq, NOEX_PUBLIC);
@@ -185,7 +186,8 @@ define_aref_method(VALUE nstr, VALUE name, VALUE off)
 static void
 define_aset_method(VALUE nstr, VALUE name, VALUE off)
 {
-    VALUE iseqval = rb_method_for_self_aset(name, off);
+    rb_control_frame_t *FUNC_FASTCALL(rb_vm_opt_struct_aset)(rb_thread_t *, rb_control_frame_t *);
+    VALUE iseqval = rb_method_for_self_aset(name, off, rb_vm_opt_struct_aset);
     rb_iseq_t *iseq = DATA_PTR(iseqval);
 
     rb_add_method(nstr, SYM2ID(name), VM_METHOD_TYPE_ISEQ, iseq, NOEX_PUBLIC);
diff --git a/test/ruby/test_struct.rb b/test/ruby/test_struct.rb
index 8307d79..df859f7 100644
--- a/test/ruby/test_struct.rb
+++ b/test/ruby/test_struct.rb
@@ -195,6 +195,39 @@ module TestStruct
     assert_equal(:foo, o[25])
   end
 
+  def test_overridden_aset
+    bug10601 = '[ruby-core:66846] [Bug #10601]: should not be affected by []= method'
+
+    struct = Class.new(Struct.new(*(:a..:z), :result)) do
+      def []=(*args)
+        raise args.inspect
+      end
+    end
+
+    obj = struct.new
+    assert_nothing_raised(RuntimeError, bug10601) do
+      obj.result = 42
+    end
+    assert_equal(42, obj.result, bug10601)
+  end
+
+  def test_overridden_aref
+    bug10601 = '[ruby-core:66846] [Bug #10601]: should not be affected by [] method'
+
+    struct = Class.new(Struct.new(*(:a..:z), :result)) do
+      def [](*args)
+        raise args.inspect
+      end
+    end
+
+    obj = struct.new
+    obj.result = 42
+    result = assert_nothing_raised(RuntimeError, bug10601) do
+      break obj.result
+    end
+    assert_equal(42, result, bug10601)
+  end
+
   def test_equal
     klass1 = @Struct.new(:a)
     klass2 = @Struct.new(:a, :b)
diff --git a/vm_insnhelper.c b/vm_insnhelper.c
index edb0e06..d5314c7 100644
--- a/vm_insnhelper.c
+++ b/vm_insnhelper.c
@@ -2107,3 +2107,16 @@ vm_once_clear(VALUE data)
     return Qnil;
 }
 
+rb_control_frame_t *
+FUNC_FASTCALL(rb_vm_opt_struct_aref)(rb_thread_t *th, rb_control_frame_t *reg_cfp)
+{
+    TOPN(0) = rb_struct_aref(GET_SELF(), TOPN(0));
+    return reg_cfp;
+}
+
+rb_control_frame_t *
+FUNC_FASTCALL(rb_vm_opt_struct_aset)(rb_thread_t *th, rb_control_frame_t *reg_cfp)
+{
+    rb_struct_aset(GET_SELF(), TOPN(0), TOPN(1));
+    return reg_cfp;
+}

[normalperson (Eric Wong)]

nobu: thanks, diff looks good and passes tests on my 32-bit x86 system

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Closed
• % Done changed from 0 to 100

Applied in changeset r48864.

---

iseq.c: struct accessors

• iseq.c (rb_method_for_self_aref, rb_method_for_self_aset): call
  accessor functions directly, not to be affected by [] and []=
  methods. [ruby-core:66846] [Bug #10601]
• struct.c (define_aref_method, define_aset_method): ditto.
• vm_insnhelper.c (rb_vm_opt_struct_aref, rb_vm_opt_struct_aset):
  direct accessors of Struct.

[usa (Usaku NAKAMURA)]

• Backport changed from 2.0.0: UNKNOWN, 2.1: UNKNOWN to 2.0.0: DONTNEED, 2.1: DONTNEED