[GR-20446] Implement rb_str_vcatf

PullRequest: truffleruby/2814

Author: bjfish

CHANGELOG.md

@@ -16,6 +16,7 @@ Compatibility:
 * Implement `Process::Status.wait` (#2378).
 * Update `rb_str_modify` and `rb_str_modify_expand` to raise a `FrozenError` when given a frozen string (#2392).
 * Implement `rb_fiber_*` functions (#2402).
+* Implement `rb_str_vcatf`.
 
 Performance:
 

lib/cext/ABI_version.txt

@@ -1 +1 @@
-7
+8

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

@@ -501,6 +501,18 @@ static VALUE string_spec_rb_utf8_str_new_cstr(VALUE self) {
   return rb_utf8_str_new_cstr("nokogiri");
 }
 
+static VALUE call_rb_str_vcatf(VALUE mesg, const char *fmt, ...){
+  va_list ap;
+  va_start(ap, fmt);
+  VALUE result = rb_str_vcatf(mesg, fmt, ap);
+  va_end(ap);
+  return result;
+}
+
+static VALUE string_spec_rb_str_vcatf(VALUE self, VALUE mesg) {
+  return call_rb_str_vcatf(mesg, "fmt %d %d number", 42, 7);
+}
+
 void Init_string_spec(void) {
   VALUE cls = rb_define_class("CApiStringSpecs", rb_cObject);
   rb_define_method(cls, "rb_cstr2inum", string_spec_rb_cstr2inum, 2);
@@ -590,6 +602,7 @@ void Init_string_spec(void) {
   rb_define_method(cls, "rb_utf8_str_new_static", string_spec_rb_utf8_str_new_static, 0);
   rb_define_method(cls, "rb_utf8_str_new", string_spec_rb_utf8_str_new, 0);
   rb_define_method(cls, "rb_utf8_str_new_cstr", string_spec_rb_utf8_str_new_cstr, 0);
+  rb_define_method(cls, "rb_str_vcatf", string_spec_rb_str_vcatf, 1);
 }
 
 #ifdef __cplusplus

spec/ruby/optional/capi/string_spec.rb

@@ -1142,4 +1142,14 @@ def inspect
       str.encoding.should == Encoding::UTF_8
     end
   end
+
+  describe "rb_str_vcatf" do
+    it "appends the message to the string" do
+      @s.rb_str_vcatf("").should == "fmt 42 7 number"
+
+      str = "test "
+      @s.rb_str_vcatf(str)
+      str.should == "test fmt 42 7 number"
+    end
+  end
 end

src/main/c/cext/printf.c

@@ -139,3 +139,10 @@ void rb_tr_init_printf(void) {
   register_printf_specifier('P', rb_tr_fprintf_value, rb_tr_fprintf_value_arginfo);
   #endif
 }
+
+VALUE rb_str_vcatf(VALUE str, const char *fmt, va_list args) {
+  StringValue(str);
+  VALUE result = rb_vsprintf(fmt, args);
+  rb_str_concat(str, result);
+  return str;
+}