From 510404f2def62918849797e742642254700e3608 Mon Sep 17 00:00:00 2001
From: Peter Zhu <peter@peterzhu.ca>
Date: Thu, 22 Feb 2024 16:14:11 -0500
Subject: [PATCH] Stop using rb_fstring publicly

rb_fstring is a private API, so we should use rb_str_to_interned_str
instead, which is a public API.
---
 ext/-test-/string/fstring.c               | 6 ++----
 spec/ruby/optional/capi/ext/string_spec.c | 4 +---
 string.c                                  | 1 -
 3 files changed, 3 insertions(+), 8 deletions(-)

diff --git a/ext/-test-/string/fstring.c b/ext/-test-/string/fstring.c
index 7ee14a8570f7d0..d3062224d88e81 100644
--- a/ext/-test-/string/fstring.c
+++ b/ext/-test-/string/fstring.c
@@ -2,12 +2,10 @@
 #include "ruby/encoding.h"
 #include "internal/string.h"
 
-VALUE rb_fstring(VALUE str);
-
 VALUE
 bug_s_fstring(VALUE self, VALUE str)
 {
-    return rb_fstring(str);
+    return rb_str_to_interned_str(str);
 }
 
 VALUE
@@ -15,7 +13,7 @@ bug_s_fstring_fake_str(VALUE self)
 {
     static const char literal[] = "abcdefghijklmnopqrstuvwxyz";
     struct RString fake_str;
-    return rb_fstring(rb_setup_fake_str(&fake_str, literal, sizeof(literal) - 1, 0));
+    return rb_str_to_interned_str(rb_setup_fake_str(&fake_str, literal, sizeof(literal) - 1, 0));
 }
 
 VALUE
diff --git a/spec/ruby/optional/capi/ext/string_spec.c b/spec/ruby/optional/capi/ext/string_spec.c
index 2bd789fb72862a..c9c5277732ecbf 100644
--- a/spec/ruby/optional/capi/ext/string_spec.c
+++ b/spec/ruby/optional/capi/ext/string_spec.c
@@ -51,10 +51,8 @@ VALUE string_spec_rb_str_set_len_RSTRING_LEN(VALUE self, VALUE str, VALUE len) {
   return INT2FIX(RSTRING_LEN(str));
 }
 
-VALUE rb_fstring(VALUE str); /* internal.h, used in ripper */
-
 VALUE string_spec_rb_str_fstring(VALUE self, VALUE str) {
-  return rb_fstring(str);
+  return rb_str_to_interned_str(str);
 }
 
 VALUE string_spec_rb_str_buf_new(VALUE self, VALUE len, VALUE str) {
diff --git a/string.c b/string.c
index 24dd29b32e2528..8ed058eead8954 100644
--- a/string.c
+++ b/string.c
@@ -398,7 +398,6 @@ fstr_update_callback(st_data_t *key, st_data_t *value, st_data_t data, int exist
     }
 }
 
-RUBY_FUNC_EXPORTED
 VALUE
 rb_fstring(VALUE str)
 {