string.c: rb_fstring_cstr

* string.c (rb_fstring_cstr): new function to make a fstring from
  a string literal.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@51009 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,4 +1,7 @@
-Wed Jun 24 12:47:14 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+Wed Jun 24 12:49:11 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* string.c (rb_fstring_cstr): new function to make a fstring from
+	  a string literal.
 
 	* internal.h (rb_fstring_lit): new macro to make a fstring from a
 	  string literal.

internal.h

@@ -1091,6 +1091,15 @@ VALUE rb_fstring(VALUE);
 VALUE rb_fstring_new(const char *ptr, long len);
 #define rb_fstring_lit(str) rb_fstring_new((str), rb_strlen_lit(str))
 #define rb_fstring_literal(str) rb_fstring_lit(str)
+VALUE rb_fstring_cstr(const char *str);
+#if defined(__GNUC__) && !defined(__PCC__)
+#define rb_fstring_cstr(str) __extension__ (	\
+{						\
+    (__builtin_constant_p(str)) ?		\
+	rb_fstring_new((str), (long)strlen(str)) : \
+	rb_fstring_cstr(str); \
+})
+#endif
 int rb_str_buf_cat_escaped_char(VALUE result, unsigned int c, int unicode_p);
 int rb_str_symname_p(VALUE);
 VALUE rb_str_quote_unprintable(VALUE);

string.c

@@ -46,6 +46,7 @@
 #undef rb_str_buf_cat2
 #undef rb_str_cat2
 #undef rb_str_cat_cstr
+#undef rb_fstring_cstr
 
 static VALUE rb_str_clear(VALUE str);
 
@@ -303,6 +304,12 @@ rb_fstring_new(const char *ptr, long len)
     return rb_fstring(setup_fake_str(&fake_str, ptr, len, ENCINDEX_US_ASCII));
 }
 
+VALUE
+rb_fstring_cstr(const char *ptr)
+{
+    return rb_fstring_new(ptr, strlen(ptr));
+}
+
 static int
 fstring_set_class_i(st_data_t key, st_data_t val, st_data_t arg)
 {