From 6a1101f23ea403a8825c2f361508eeb85878b011 Mon Sep 17 00:00:00 2001
From: ko1 <ko1@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Fri, 21 Jun 2013 11:22:18 +0000
Subject: [PATCH] * include/ruby/ruby.h: support write barrier protection for
 T_STRUCT.   Introduce the following C APIs:   * RSTRUCT_RAWPTR(st) returns
 pointer (do WB on your risk).     The type of returned pointer is (const
 VALUE *).   * RSTRUCT_GET(st, idx) returns idx-th value of struct.   *
 RSTRUCT_SET(st, idx, v) set idx-th value by v with WB.   And   *
 RSTRUCT_PTR(st) returns pointer with shady operation.     The type of
 returned pointer is (VALUE *). * struct.c, re.c, gc.c, marshal.c: rewrite
 with above APIs.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41534 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 ChangeLog           |  14 +++++
 gc.c                |   4 +-
 include/ruby/ruby.h |  19 ++++---
 marshal.c           |   2 +-
 range.c             |  17 +++---
 struct.c            | 126 +++++++++++++++++++++-----------------------
 6 files changed, 102 insertions(+), 80 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 92a464ee60..27c74879eb 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,17 @@
+Fri Jun 21 20:15:49 2013  Koichi Sasada  <ko1@atdot.net>
+
+	* include/ruby/ruby.h: support write barrier protection for T_STRUCT.
+	  Introduce the following C APIs:
+	    * RSTRUCT_RAWPTR(st) returns pointer (do WB on your risk).
+	      The type of returned pointer is (const VALUE *).
+	    * RSTRUCT_GET(st, idx) returns idx-th value of struct.
+	    * RSTRUCT_SET(st, idx, v) set idx-th value by v with WB.
+	  And 
+	    * RSTRUCT_PTR(st) returns pointer with shady operation.
+	      The type of returned pointer is (VALUE *).
+
+	* struct.c, re.c, gc.c, marshal.c: rewrite with above APIs.
+
 Fri Jun 21 19:38:37 2013  Tanaka Akira  <akr@fsij.org>
 
 	* bignum.c (BDIGMAX): Use BIGRAD.
diff --git a/gc.c b/gc.c
index bd0cc0272b..6527a814f1 100644
--- a/gc.c
+++ b/gc.c
@@ -1283,7 +1283,7 @@ obj_free(rb_objspace_t *objspace, VALUE obj)
       case T_STRUCT:
 	if ((RBASIC(obj)->flags & RSTRUCT_EMBED_LEN_MASK) == 0 &&
 	    RANY(obj)->as.rstruct.as.heap.ptr) {
-	    xfree(RANY(obj)->as.rstruct.as.heap.ptr);
+	    xfree((void *)RANY(obj)->as.rstruct.as.heap.ptr);
 	}
 	break;
 
@@ -3386,7 +3386,7 @@ gc_mark_children(rb_objspace_t *objspace, VALUE ptr)
       case T_STRUCT:
 	{
 	    long len = RSTRUCT_LEN(obj);
-	    VALUE *ptr = RSTRUCT_PTR(obj);
+	    const VALUE *ptr = RSTRUCT_RAWPTR(obj);
 
 	    while (len--) {
 		gc_mark(objspace, *ptr++);
diff --git a/include/ruby/ruby.h b/include/ruby/ruby.h
index 32e7e196e7..f812e3146b 100644
--- a/include/ruby/ruby.h
+++ b/include/ruby/ruby.h
@@ -709,6 +709,9 @@ VALUE rb_obj_setup(VALUE obj, VALUE klass, VALUE type);
 #ifndef RGENGC_WB_PROTECTED_HASH
 #define RGENGC_WB_PROTECTED_HASH 1
 #endif
+#ifndef RGENGC_WB_PROTECTED_STRUCT
+#define RGENGC_WB_PROTECTED_STRUCT 1
+#endif
 #ifndef RGENGC_WB_PROTECTED_STRING
 #define RGENGC_WB_PROTECTED_STRING 1
 #endif
@@ -1109,9 +1112,9 @@ struct RStruct {
     union {
 	struct {
 	    long len;
-	    VALUE *ptr;
+	    const VALUE *ptr;
 	} heap;
-	VALUE ary[RSTRUCT_EMBED_LEN_MAX];
+	const VALUE ary[RSTRUCT_EMBED_LEN_MAX];
     } as;
 };
 #define RSTRUCT_EMBED_LEN_MASK (FL_USER2|FL_USER1)
@@ -1121,11 +1124,15 @@ struct RStruct {
      (long)((RBASIC(st)->flags >> RSTRUCT_EMBED_LEN_SHIFT) & \
             (RSTRUCT_EMBED_LEN_MASK >> RSTRUCT_EMBED_LEN_SHIFT)) : \
      RSTRUCT(st)->as.heap.len)
-#define RSTRUCT_PTR(st) \
-    ((RBASIC(st)->flags & RSTRUCT_EMBED_LEN_MASK) ? \
-     RSTRUCT(st)->as.ary : \
-     RSTRUCT(st)->as.heap.ptr)
 #define RSTRUCT_LENINT(st) rb_long2int(RSTRUCT_LEN(st))
+#define RSTRUCT_RAWPTR(st) \
+  ((RBASIC(st)->flags & RSTRUCT_EMBED_LEN_MASK) ? \
+   RSTRUCT(st)->as.ary : \
+   RSTRUCT(st)->as.heap.ptr)
+#define RSTRUCT_PTR(st) ((VALUE *)RSTRUCT_RAWPTR(RGENGC_WB_PROTECTED_STRUCT ? OBJ_WB_GIVEUP((VALUE)st) : (VALUE)st))
+
+#define RSTRUCT_SET(st, idx, v) OBJ_WRITE(st, (VALUE *)&RSTRUCT_RAWPTR(st)[idx], v)
+#define RSTRUCT_GET(st, idx)    (RSTRUCT_RAWPTR(st)[idx])
 
 #define RBIGNUM_EMBED_LEN_MAX ((int)((sizeof(VALUE)*3)/sizeof(BDIGIT)))
 struct RBignum {
diff --git a/marshal.c b/marshal.c
index 9df02f310d..0884b7592c 100644
--- a/marshal.c
+++ b/marshal.c
@@ -821,7 +821,7 @@ w_object(VALUE obj, struct dump_arg *arg, int limit)
 		mem = rb_struct_members(obj);
 		for (i=0; i<len; i++) {
 		    w_symbol(SYM2ID(RARRAY_AREF(mem, i)), arg);
-		    w_object(RSTRUCT_PTR(obj)[i], arg, limit);
+		    w_object(RSTRUCT_GET(obj, i), arg, limit);
 		}
 	    }
 	    break;
diff --git a/range.c b/range.c
index 6d6a52873e..280c333dc2 100644
--- a/range.c
+++ b/range.c
@@ -27,7 +27,12 @@ static ID id_cmp, id_succ, id_beg, id_end, id_excl, id_integer_p, id_div;
 #define RANGE_EXCL(r) (RSTRUCT(r)->as.ary[2])
 
 #define EXCL(r) RTEST(RANGE_EXCL(r))
-#define SET_EXCL(r,v) (RSTRUCT(r)->as.ary[2] = (v) ? Qtrue : Qfalse)
+static inline VALUE
+SET_EXCL(VALUE r, VALUE v)
+{
+    RSTRUCT_SET(r, 2, v);
+    return v ? Qtrue : Qfalse;
+}
 
 static VALUE
 range_failed(void)
@@ -59,8 +64,8 @@ range_init(VALUE range, VALUE beg, VALUE end, int exclude_end)
     }
 
     SET_EXCL(range, exclude_end);
-    RSTRUCT(range)->as.ary[0] = beg;
-    RSTRUCT(range)->as.ary[1] = end;
+    RSTRUCT_SET(range, 0, beg);
+    RSTRUCT_SET(range, 1, end);
 }
 
 VALUE
@@ -1228,9 +1233,9 @@ range_loader(VALUE range, VALUE obj)
         rb_raise(rb_eTypeError, "not a dumped range object");
     }
 
-    RSTRUCT(range)->as.ary[0] = rb_ivar_get(obj, id_beg);
-    RSTRUCT(range)->as.ary[1] = rb_ivar_get(obj, id_end);
-    RSTRUCT(range)->as.ary[2] = rb_ivar_get(obj, id_excl);
+    RSTRUCT_SET(range, 0, rb_ivar_get(obj, id_beg));
+    RSTRUCT_SET(range, 1, rb_ivar_get(obj, id_end));
+    RSTRUCT_SET(range, 2, rb_ivar_get(obj, id_excl));
     return range;
 }
 
diff --git a/struct.c b/struct.c
index 4356f0013f..dbfd406f72 100644
--- a/struct.c
+++ b/struct.c
@@ -89,17 +89,15 @@ rb_struct_members_m(VALUE obj)
 VALUE
 rb_struct_getmember(VALUE obj, ID id)
 {
-    VALUE members, slot, *ptr, *ptr_members;
+    VALUE members, slot;
     long i, len;
 
-    ptr = RSTRUCT_PTR(obj);
     members = rb_struct_members(obj);
-    ptr_members = RARRAY_PTR(members);
     slot = ID2SYM(id);
     len = RARRAY_LEN(members);
     for (i=0; i<len; i++) {
-	if (ptr_members[i] == slot) {
-	    return ptr[i];
+	if (RARRAY_AREF(members, i) == slot) {
+	    return RSTRUCT_GET(obj, i);
 	}
     }
     rb_name_error(id, "%s is not struct member", rb_id2name(id));
@@ -113,16 +111,16 @@ rb_struct_ref(VALUE obj)
     return rb_struct_getmember(obj, rb_frame_this_func());
 }
 
-static VALUE rb_struct_ref0(VALUE obj) {return RSTRUCT_PTR(obj)[0];}
-static VALUE rb_struct_ref1(VALUE obj) {return RSTRUCT_PTR(obj)[1];}
-static VALUE rb_struct_ref2(VALUE obj) {return RSTRUCT_PTR(obj)[2];}
-static VALUE rb_struct_ref3(VALUE obj) {return RSTRUCT_PTR(obj)[3];}
-static VALUE rb_struct_ref4(VALUE obj) {return RSTRUCT_PTR(obj)[4];}
-static VALUE rb_struct_ref5(VALUE obj) {return RSTRUCT_PTR(obj)[5];}
-static VALUE rb_struct_ref6(VALUE obj) {return RSTRUCT_PTR(obj)[6];}
-static VALUE rb_struct_ref7(VALUE obj) {return RSTRUCT_PTR(obj)[7];}
-static VALUE rb_struct_ref8(VALUE obj) {return RSTRUCT_PTR(obj)[8];}
-static VALUE rb_struct_ref9(VALUE obj) {return RSTRUCT_PTR(obj)[9];}
+static VALUE rb_struct_ref0(VALUE obj) {return RSTRUCT_GET(obj, 0);}
+static VALUE rb_struct_ref1(VALUE obj) {return RSTRUCT_GET(obj, 1);}
+static VALUE rb_struct_ref2(VALUE obj) {return RSTRUCT_GET(obj, 2);}
+static VALUE rb_struct_ref3(VALUE obj) {return RSTRUCT_GET(obj, 3);}
+static VALUE rb_struct_ref4(VALUE obj) {return RSTRUCT_GET(obj, 4);}
+static VALUE rb_struct_ref5(VALUE obj) {return RSTRUCT_GET(obj, 5);}
+static VALUE rb_struct_ref6(VALUE obj) {return RSTRUCT_GET(obj, 6);}
+static VALUE rb_struct_ref7(VALUE obj) {return RSTRUCT_GET(obj, 7);}
+static VALUE rb_struct_ref8(VALUE obj) {return RSTRUCT_GET(obj, 8);}
+static VALUE rb_struct_ref9(VALUE obj) {return RSTRUCT_GET(obj, 9);}
 
 #define N_REF_FUNC numberof(ref_func)
 
@@ -149,18 +147,16 @@ rb_struct_modify(VALUE s)
 static VALUE
 rb_struct_set(VALUE obj, VALUE val)
 {
-    VALUE members, slot, *ptr, *ptr_members;
+    VALUE members, slot;
     long i, len;
 
     members = rb_struct_members(obj);
-    ptr_members = RARRAY_PTR(members);
     len = RARRAY_LEN(members);
     rb_struct_modify(obj);
-    ptr = RSTRUCT_PTR(obj);
     for (i=0; i<len; i++) {
-	slot = ptr_members[i];
+	slot = RARRAY_AREF(members, i);
 	if (rb_id_attrset(SYM2ID(slot)) == rb_frame_this_func()) {
-	    return ptr[i] = val;
+	    return RSTRUCT_SET(obj, i, val);
 	}
     }
     rb_name_error(rb_frame_this_func(), "`%s' is not a struct member",
@@ -390,16 +386,18 @@ static VALUE
 rb_struct_initialize_m(int argc, VALUE *argv, VALUE self)
 {
     VALUE klass = rb_obj_class(self);
-    long n;
+    long i, n;
 
     rb_struct_modify(self);
     n = num_members(klass);
     if (n < argc) {
 	rb_raise(rb_eArgError, "struct size differs");
     }
-    MEMCPY(RSTRUCT_PTR(self), argv, VALUE, argc);
+    for (i=0; i<argc; i++) {
+	RSTRUCT_SET(self, i, argv[i]);
+    }
     if (n > argc) {
-	rb_mem_clear(RSTRUCT_PTR(self)+argc, n-argc);
+	rb_mem_clear((VALUE *)RSTRUCT_RAWPTR(self)+argc, n-argc);
     }
     return Qnil;
 }
@@ -414,18 +412,18 @@ static VALUE
 struct_alloc(VALUE klass)
 {
     long n;
-    NEWOBJ_OF(st, struct RStruct, klass, T_STRUCT);
+    NEWOBJ_OF(st, struct RStruct, klass, T_STRUCT | (RGENGC_WB_PROTECTED_STRUCT ? FL_WB_PROTECTED : 0));
 
     n = num_members(klass);
 
     if (0 < n && n <= RSTRUCT_EMBED_LEN_MAX) {
         RBASIC(st)->flags &= ~RSTRUCT_EMBED_LEN_MASK;
         RBASIC(st)->flags |= n << RSTRUCT_EMBED_LEN_SHIFT;
-	rb_mem_clear(st->as.ary, n);
+	rb_mem_clear((VALUE *)st->as.ary, n);
     }
     else {
 	st->as.heap.ptr = ALLOC_N(VALUE, n);
-	rb_mem_clear(st->as.heap.ptr, n);
+	rb_mem_clear((VALUE *)st->as.heap.ptr, n);
 	st->as.heap.len = n;
     }
 
@@ -488,7 +486,7 @@ rb_struct_each(VALUE s)
 
     RETURN_SIZED_ENUMERATOR(s, 0, 0, rb_struct_size);
     for (i=0; i<RSTRUCT_LEN(s); i++) {
-	rb_yield(RSTRUCT_PTR(s)[i]);
+	rb_yield(RSTRUCT_GET(s, i));
     }
     return s;
 }
@@ -522,7 +520,7 @@ rb_struct_each_pair(VALUE s)
     members = rb_struct_members(s);
     for (i=0; i<RSTRUCT_LEN(s); i++) {
 	VALUE key = rb_ary_entry(members, i);
-	VALUE value = RSTRUCT_PTR(s)[i];
+	VALUE value = RSTRUCT_GET(s, i);
 	rb_yield(rb_assoc_new(key, value));
     }
     return s;
@@ -533,7 +531,6 @@ inspect_struct(VALUE s, VALUE dummy, int recur)
 {
     VALUE cname = rb_class_name(rb_obj_class(s));
     VALUE members, str = rb_str_new2("#<struct ");
-    VALUE *ptr, *ptr_members;
     long i, len;
     char first = RSTRING_PTR(cname)[0];
 
@@ -545,9 +542,8 @@ inspect_struct(VALUE s, VALUE dummy, int recur)
     }
 
     members = rb_struct_members(s);
-    ptr_members = RARRAY_PTR(members);
-    ptr = RSTRUCT_PTR(s);
     len = RSTRUCT_LEN(s);
+
     for (i=0; i<len; i++) {
 	VALUE slot;
 	ID id;
@@ -558,7 +554,7 @@ inspect_struct(VALUE s, VALUE dummy, int recur)
 	else if (first != '#') {
 	    rb_str_cat2(str, " ");
 	}
-	slot = ptr_members[i];
+	slot = RARRAY_AREF(members, i);
 	id = SYM2ID(slot);
 	if (rb_is_local_id(id) || rb_is_const_id(id)) {
 	    rb_str_append(str, rb_id2str(id));
@@ -567,7 +563,7 @@ inspect_struct(VALUE s, VALUE dummy, int recur)
 	    rb_str_append(str, rb_inspect(slot));
 	}
 	rb_str_cat2(str, "=");
-	rb_str_append(str, rb_inspect(ptr[i]));
+	rb_str_append(str, rb_inspect(RSTRUCT_GET(s, i)));
     }
     rb_str_cat2(str, ">");
     OBJ_INFECT(str, s);
@@ -604,7 +600,7 @@ rb_struct_inspect(VALUE s)
 static VALUE
 rb_struct_to_a(VALUE s)
 {
-    return rb_ary_new4(RSTRUCT_LEN(s), RSTRUCT_PTR(s));
+    return rb_ary_new4(RSTRUCT_LEN(s), RSTRUCT_RAWPTR(s));
 }
 
 /*
@@ -626,7 +622,7 @@ rb_struct_to_h(VALUE s)
     long i;
 
     for (i=0; i<RSTRUCT_LEN(s); i++) {
-	rb_hash_aset(h, rb_ary_entry(members, i), RSTRUCT_PTR(s)[i]);
+	rb_hash_aset(h, rb_ary_entry(members, i), RSTRUCT_GET(s, i));
     }
     return h;
 }
@@ -635,11 +631,16 @@ rb_struct_to_h(VALUE s)
 VALUE
 rb_struct_init_copy(VALUE copy, VALUE s)
 {
+    long i, len;
+
     if (!OBJ_INIT_COPY(copy, s)) return copy;
     if (RSTRUCT_LEN(copy) != RSTRUCT_LEN(s)) {
 	rb_raise(rb_eTypeError, "struct size mismatch");
     }
-    MEMCPY(RSTRUCT_PTR(copy), RSTRUCT_PTR(s), VALUE, RSTRUCT_LEN(copy));
+
+    for (i=0, len=RSTRUCT_LEN(copy); i<len; i++) {
+	RSTRUCT_SET(copy, i, RSTRUCT_GET(s, i));
+    }
 
     return copy;
 }
@@ -647,16 +648,12 @@ rb_struct_init_copy(VALUE copy, VALUE s)
 static VALUE
 rb_struct_aref_id(VALUE s, ID id)
 {
-    VALUE *ptr, members, *ptr_members;
-    long i, len;
+    VALUE members = rb_struct_members(s);
+    long i, len = RARRAY_LEN(members);
 
-    ptr = RSTRUCT_PTR(s);
-    members = rb_struct_members(s);
-    ptr_members = RARRAY_PTR(members);
-    len = RARRAY_LEN(members);
     for (i=0; i<len; i++) {
-	if (SYM2ID(ptr_members[i]) == id) {
-	    return ptr[i];
+	if (SYM2ID(RARRAY_AREF(members, i)) == id) {
+	    return RSTRUCT_GET(s, i);
 	}
     }
     rb_name_error(id, "no member '%s' in struct", rb_id2name(id));
@@ -706,27 +703,24 @@ rb_struct_aref(VALUE s, VALUE idx)
     if (RSTRUCT_LEN(s) <= i)
         rb_raise(rb_eIndexError, "offset %ld too large for struct(size:%ld)",
 		 i, RSTRUCT_LEN(s));
-    return RSTRUCT_PTR(s)[i];
+    return RSTRUCT_GET(s, i);
 }
 
 static VALUE
 rb_struct_aset_id(VALUE s, ID id, VALUE val)
 {
-    VALUE members, *ptr, *ptr_members;
-    long i, len;
+    VALUE members = rb_struct_members(s);
+    long i, len = RARRAY_LEN(members);
 
-    members = rb_struct_members(s);
-    len = RARRAY_LEN(members);
-    rb_struct_modify(s);
     if (RSTRUCT_LEN(s) != len) {
 	rb_raise(rb_eTypeError, "struct size differs (%ld required %ld given)",
 		 len, RSTRUCT_LEN(s));
     }
-    ptr = RSTRUCT_PTR(s);
-    ptr_members = RARRAY_PTR(members);
+
     for (i=0; i<len; i++) {
-	if (SYM2ID(ptr_members[i]) == id) {
-	    ptr[i] = val;
+	if (SYM2ID(RARRAY_AREF(members, i)) == id) {
+	    rb_struct_modify(s);
+	    RSTRUCT_SET(s, i, val);
 	    return val;
 	}
     }
@@ -782,7 +776,8 @@ rb_struct_aset(VALUE s, VALUE idx, VALUE val)
 		 i, RSTRUCT_LEN(s));
     }
     rb_struct_modify(s);
-    return RSTRUCT_PTR(s)[i] = val;
+    RSTRUCT_SET(s, i, val);
+    return val;
 }
 
 static VALUE
@@ -835,8 +830,8 @@ rb_struct_select(int argc, VALUE *argv, VALUE s)
     RETURN_SIZED_ENUMERATOR(s, 0, 0, rb_struct_size);
     result = rb_ary_new();
     for (i = 0; i < RSTRUCT_LEN(s); i++) {
-	if (RTEST(rb_yield(RSTRUCT_PTR(s)[i]))) {
-	    rb_ary_push(result, RSTRUCT_PTR(s)[i]);
+	if (RTEST(rb_yield(RSTRUCT_GET(s, i)))) {
+	    rb_ary_push(result, RSTRUCT_GET(s, i));
 	}
     }
 
@@ -846,12 +841,12 @@ rb_struct_select(int argc, VALUE *argv, VALUE s)
 static VALUE
 recursive_equal(VALUE s, VALUE s2, int recur)
 {
-    VALUE *ptr, *ptr2;
+    const VALUE *ptr, *ptr2;
     long i, len;
 
     if (recur) return Qtrue; /* Subtle! */
-    ptr = RSTRUCT_PTR(s);
-    ptr2 = RSTRUCT_PTR(s2);
+    ptr = RSTRUCT_RAWPTR(s);
+    ptr2 = RSTRUCT_RAWPTR(s2);
     len = RSTRUCT_LEN(s);
     for (i=0; i<len; i++) {
 	if (!rb_equal(ptr[i], ptr2[i])) return Qfalse;
@@ -892,11 +887,12 @@ recursive_hash(VALUE s, VALUE dummy, int recur)
 {
     long i, len;
     st_index_t h;
-    VALUE n, *ptr;
+    VALUE n;
+    const VALUE *ptr;
 
     h = rb_hash_start(rb_hash(rb_obj_class(s)));
     if (!recur) {
-	ptr = RSTRUCT_PTR(s);
+	ptr = RSTRUCT_RAWPTR(s);
 	len = RSTRUCT_LEN(s);
 	for (i = 0; i < len; i++) {
 	    n = rb_hash(ptr[i]);
@@ -923,12 +919,12 @@ rb_struct_hash(VALUE s)
 static VALUE
 recursive_eql(VALUE s, VALUE s2, int recur)
 {
-    VALUE *ptr, *ptr2;
+    const VALUE *ptr, *ptr2;
     long i, len;
 
     if (recur) return Qtrue; /* Subtle! */
-    ptr = RSTRUCT_PTR(s);
-    ptr2 = RSTRUCT_PTR(s2);
+    ptr = RSTRUCT_RAWPTR(s);
+    ptr2 = RSTRUCT_RAWPTR(s2);
     len = RSTRUCT_LEN(s);
     for (i=0; i<len; i++) {
 	if (!rb_eql(ptr[i], ptr2[i])) return Qfalse;