[GR-18163] Implement rb_str_format C function

PullRequest: truffleruby/4403

Author: andrykonchin

CHANGELOG.md

@@ -25,6 +25,7 @@ Compatibility:
 * Remove deprecated `Pathname#{taint,untaint}` methods (#3681, @andrykonchin).
 * Add `rb_category_warn` function (#3710, @andrykonchin).
 * Add `rb_gc_mark_locations()` (#3704, @andrykonchin).
+* Implement `rb_str_format()` (#3716, @andrykonchin).
 
 Performance:
 

lib/truffle/truffle/cext.rb

@@ -1416,6 +1416,10 @@ def rb_f_sprintf(args)
     sprintf(*args)
   end
 
+  def rb_str_format(args, format)
+    sprintf(format, *args)
+  end
+
   def rb_io_printf(out, args)
     out.printf(*args)
   end

spec/ruby/optional/capi/ext/kernel_spec.c

@@ -332,6 +332,10 @@ static VALUE kernel_spec_rb_f_sprintf(VALUE self, VALUE ary) {
   return rb_f_sprintf((int)RARRAY_LEN(ary), RARRAY_PTR(ary));
 }
 
+static VALUE kernel_spec_rb_str_format(VALUE self, VALUE count, VALUE ary, VALUE format) {
+  return rb_str_format(FIX2INT(count), RARRAY_PTR(ary), format);
+}
+
 static VALUE kernel_spec_rb_make_backtrace(VALUE self) {
   return rb_make_backtrace();
 }
@@ -421,6 +425,7 @@ void Init_kernel_spec(void) {
   rb_define_method(cls, "rb_exec_recursive", kernel_spec_rb_exec_recursive, 1);
   rb_define_method(cls, "rb_set_end_proc", kernel_spec_rb_set_end_proc, 1);
   rb_define_method(cls, "rb_f_sprintf", kernel_spec_rb_f_sprintf, 1);
+  rb_define_method(cls, "rb_str_format", kernel_spec_rb_str_format, 3);
   rb_define_method(cls, "rb_make_backtrace", kernel_spec_rb_make_backtrace, 0);
   rb_define_method(cls, "rb_funcallv", kernel_spec_rb_funcallv, 3);
 #ifdef RUBY_VERSION_IS_3_0

spec/ruby/optional/capi/kernel_spec.rb

@@ -892,4 +892,10 @@ def obj.method_missing(name, *args)
       @s.rb_check_funcall(object, :protected_method, []).should == :protected
     end
   end
+
+  describe "rb_str_format" do
+    it "returns a string according to format and arguments" do
+      @s.rb_str_format(3, [10, 2.5, "test"], "%d %f %s").should == "10 2.500000 test"
+    end
+  end
 end

src/main/c/cext/printf.c

@@ -183,3 +183,7 @@ VALUE rb_str_vcatf(VALUE str, const char *fmt, va_list args) {
   rb_str_concat(str, result);
   return str;
 }
+
+VALUE rb_str_format(int argc, const VALUE *argv, VALUE fmt) {
+  return RUBY_CEXT_INVOKE("rb_str_format", rb_ary_new4(argc, argv), fmt);
+}