Feature #7035

* compile.c (defined_expr), insns.def (defined): share single frozen
  strings.  [EXPERIMENTAL] [ruby-core:47558][Feature #7035]
* iseq.c (rb_iseq_defined_string): make expression strings.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@37025 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 41 insertions, 0 deletions

diff --git a/iseq.c b/iseq.c
index 8d8d92174d..989a8a1120 100644
--- a/iseq.c
+++ b/iseq.c
@@ -18,6 +18,8 @@
 #include "vm_core.h"
 #include "iseq.h"
 
+#define numberof(array) (int)(sizeof(array) / sizeof((array)[0]))
+
 #include "insns.inc"
 #include "insns_info.inc"
 
@@ -1747,6 +1749,45 @@ rb_iseq_parameters(const rb_iseq_t *iseq, int is_proc)
     return args;
 }
 
+VALUE
+rb_iseq_defined_string(enum defined_type type)
+{
+    static const char expr_names[][18] = {
+	"nil",
+	"instance-variable",
+	"local-variable",
+	"global-variable",
+	"class variable",
+	"constant",
+	"method",
+	"yield",
+	"super",
+	"self",
+	"true",
+	"false",
+	"assignment",
+	"expression",
+    };
+    const char *estr;
+    VALUE *defs, str;
+
+    if ((unsigned)(type - 1) >= (unsigned)numberof(expr_names)) return 0;
+    estr = expr_names[type - 1];
+    if (!estr[0]) return 0;
+    defs = GET_VM()->defined_strings;
+    if (!defs) {
+	defs = ruby_xcalloc(numberof(expr_names), sizeof(VALUE));
+	GET_VM()->defined_strings = defs;
+    }
+    str = defs[type];
+    if (!str) {
+	str = rb_str_new_cstr(estr);;
+	OBJ_FREEZE(str);
+	defs[type] = str;
+    }
+    return str;
+}
+
 /* ruby2cext */
 
 VALUE