Implement Write Barrier for RMatch objects

They only have two references.
ruby · Feb 10, 2023 · 4629895 · 4629895
1 parent 11e0f62
commit 4629895
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Showing 2 changed files with 23 additions and 13 deletions.
diff --git a/include/ruby/internal/rgengc.h b/include/ruby/internal/rgengc.h
@@ -129,6 +129,17 @@
 # define RGENGC_WB_PROTECTED_REGEXP 1
 #endif
 
+/**
+ * @private
+ *
+ * This  is   a  compile-time   flag  to   enable/disable  write   barrier  for
+ * struct ::RMatch.  It has to be set at the time ruby itself compiles.  Makes
+ * no sense for 3rd parties.
+ */
+#ifndef RGENGC_WB_PROTECTED_MATCH
+# define RGENGC_WB_PROTECTED_MATCH 1
+#endif
+
 /**
  * @private
  *

diff --git a/re.c b/re.c
@@ -961,11 +961,11 @@ VALUE rb_cMatch;
 static VALUE
 match_alloc(VALUE klass)
 {
-    NEWOBJ_OF(match, struct RMatch, klass, T_MATCH);
+    NEWOBJ_OF(match, struct RMatch, klass, T_MATCH | (RGENGC_WB_PROTECTED_MATCH ? FL_WB_PROTECTED : 0));
 
-    match->str = 0;
+    match->str = Qfalse;
     match->rmatch = 0;
-    match->regexp = 0;
+    match->regexp = Qfalse;
     match->rmatch = ZALLOC(struct rmatch);
 
     return (VALUE)match;
@@ -1083,8 +1083,8 @@ match_init_copy(VALUE obj, VALUE orig)
 
     if (!OBJ_INIT_COPY(obj, orig)) return obj;
 
-    RMATCH(obj)->str = RMATCH(orig)->str;
-    RMATCH(obj)->regexp = RMATCH(orig)->regexp;
+    RB_OBJ_WRITE(obj, &RMATCH(obj)->str, RMATCH(orig)->str);
+    RB_OBJ_WRITE(obj, &RMATCH(obj)->regexp, RMATCH(orig)->regexp);
 
     rm = RMATCH(obj)->rmatch;
     if (rb_reg_region_copy(&rm->regs, RMATCH_REGS(orig)))
@@ -1124,7 +1124,7 @@ match_regexp(VALUE match)
     if (NIL_P(regexp)) {
         VALUE str = rb_reg_nth_match(0, match);
         regexp = rb_reg_regcomp(rb_reg_quote(str));
-        RMATCH(match)->regexp = regexp;
+        RB_OBJ_WRITE(match, &RMATCH(match)->regexp, regexp);
     }
     return regexp;
 }
@@ -1475,8 +1475,8 @@ match_set_string(VALUE m, VALUE string, long pos, long len)
     struct RMatch *match = (struct RMatch *)m;
     struct rmatch *rmatch = match->rmatch;
 
-    match->str = string;
-    match->regexp = Qnil;
+    RB_OBJ_WRITE(match, &RMATCH(match)->str, string);
+    RB_OBJ_WRITE(match, &RMATCH(match)->regexp, Qnil);
     int err = onig_region_resize(&rmatch->regs, 1);
     if (err) rb_memerror();
     rmatch->regs.beg[0] = pos;
@@ -1737,7 +1737,7 @@ rb_reg_search_set_match(VALUE re, VALUE str, long pos, int reverse, int set_back
     memcpy(RMATCH_REGS(match), regs, sizeof(struct re_registers));
 
     if (set_backref_str) {
-        RMATCH(match)->str = rb_str_new4(str);
+        RB_OBJ_WRITE(match, &RMATCH(match)->str, rb_str_new4(str));
     }
     else {
         /* Note that a MatchData object with RMATCH(match)->str == 0 is incomplete!
@@ -1747,7 +1747,7 @@ rb_reg_search_set_match(VALUE re, VALUE str, long pos, int reverse, int set_back
         rb_obj_hide(match);
     }
 
-    RMATCH(match)->regexp = re;
+    RB_OBJ_WRITE(match, &RMATCH(match)->regexp, re);
     rb_backref_set(match);
     if (set_match) *set_match = match;
 
@@ -1831,9 +1831,8 @@ rb_reg_start_with_p(VALUE re, VALUE str)
         if (err) rb_memerror();
     }
 
-    RMATCH(match)->str = rb_str_new4(str);
-
-    RMATCH(match)->regexp = re;
+    RB_OBJ_WRITE(match, &RMATCH(match)->str, rb_str_new4(str));
+    RB_OBJ_WRITE(match, &RMATCH(match)->regexp, re);
     rb_backref_set(match);
 
     return true;