ResumableParser: use throw rather than raise for handled EOS

ext/json/ext/parser/extconf.rb

@@ -2,6 +2,8 @@
 require 'mkmf'
 
 $defs << "-DJSON_DEBUG" if ENV.fetch("JSON_DEBUG", "0") != "0"
+$defs << "-DJSON_WORKAROUND_RB_CATCH_BUG" if RUBY_ENGINE == 'truffleruby'
+
 have_func("rb_enc_interned_str", "ruby/encoding.h") # RUBY_VERSION >= 3.0
 have_func("rb_str_to_interned_str", "ruby.h") # RUBY_VERSION >= 3.0
 have_func("rb_hash_new_capa", "ruby.h") # RUBY_VERSION >= 3.2

ext/json/ext/parser/parser.c

@@ -5,7 +5,7 @@
 static VALUE mJSON, eNestingError, eParserError, Encoding_UTF_8;
 static VALUE CNaN, CInfinity, CMinusInfinity;
 
-static ID i_new, i_try_convert, i_uminus, i_encode, i_at_line, i_at_column, i_at_eos;
+static ID i_new, i_try_convert, i_uminus, i_encode, i_at_line, i_at_column;
 
 static VALUE sym_max_nesting, sym_allow_nan, sym_allow_trailing_comma, sym_allow_comments,
              sym_allow_control_characters, sym_allow_invalid_escape, sym_symbolize_names,
@@ -669,18 +669,52 @@ static VALUE parse_error_new(JSON_ParserState *state, VALUE message, long line,
     VALUE exc = rb_exc_new_str(eParserError, message);
     rb_ivar_set(exc, i_at_line, LONG2NUM(line));
     rb_ivar_set(exc, i_at_column, LONG2NUM(column));
-    if (eos && state->parser) {
-        rb_ivar_set(exc, i_at_eos, state->parser);
-    }
     return exc;
 }
 
+#ifdef JSON_WORKAROUND_RB_CATCH_BUG
+#define JSON_CATCH_FUNC_ARGLIST(yielded_arg, func_args) VALUE func_args
+
+NORETURN(static) void parser_throw_eos(VALUE parser)
+{
+    VALUE exc = rb_exc_new_str(eParserError, rb_utf8_str_new_cstr("EOS"));
+    rb_ivar_set(exc, rb_intern("@resumable_parser_eos"), parser);
+    rb_exc_raise(exc);
+}
+
+static VALUE parser_catch_eos(VALUE parser, VALUE (*func)(VALUE args), VALUE func_args)
+{
+    int status;
+    VALUE result = rb_protect(func, func_args, &status);
+    if (status) {
+        VALUE error_source = rb_ivar_get(rb_errinfo(), rb_intern("@resumable_parser_eos"));
+        if (error_source == parser) {
+            rb_set_errinfo(Qnil);
+            return parser;
+        }
+        rb_jump_tag(status);
+    }
+    return result;
+}
+#else
+#define JSON_CATCH_FUNC_ARGLIST RB_BLOCK_CALL_FUNC_ARGLIST
+#define parser_throw_eos(parser) rb_throw_obj(parser, parser)
+#define parser_catch_eos(parser, func, func_args) rb_catch_obj(parser, func, func_args)
+#endif
+
 NORETURN(static) void raise_parse_error(const char *format, JSON_ParserState *state, bool eos)
 {
-    VALUE message = build_parse_error_message(format, state);
-    if (state->parser) { // line and columns can't be accurate in resumable
-        rb_exc_raise(parse_error_new(state, message, 0, 0, eos));
+    if (state->parser) { 
+        if (eos) {
+            // the error will be swallowed by ResumableParser#parse, so no
+            // point building a message or backtrace.
+            parser_throw_eos(state->parser);
+        } else {
+            // line and columns can't be accurate in resumable
+            rb_exc_raise(parse_error_new(state, build_parse_error_message(format, state), 0, 0, eos));
+        }
     } else {
+        VALUE message = build_parse_error_message(format, state);
         long line, column;
         cursor_position(state, &line, &column);
         rb_str_catf(message, " at line %ld column %ld", line, column);
@@ -2379,14 +2413,22 @@ static VALUE cResumableParser_feed(VALUE self, VALUE str)
 struct json_parse_any_args {
     JSON_ParserState *state;
     JSON_ParserConfig *config;
+    VALUE parser;
 };
 
-static VALUE json_parse_any_resumable_safe(VALUE _args)
+static VALUE json_parse_any_resumable_safe0(JSON_CATCH_FUNC_ARGLIST(yielded_arg, _args))
 {
     struct json_parse_any_args *args = (struct json_parse_any_args *)_args;
     return (VALUE)json_parse_any(args->state, args->config, true);
 }
 
+static VALUE json_parse_any_resumable_safe(VALUE _args)
+{
+    struct json_parse_any_args *args = (struct json_parse_any_args *)_args;
+    VALUE result = parser_catch_eos(args->parser, json_parse_any_resumable_safe0, _args);
+    return result == args->parser ? Qfalse : result;
+}
+
 static JSON_ResumableParser *ResumableParser_acquire(VALUE self, bool lock)
 {
     JSON_ResumableParser *parser = cResumableParser_get(self);
@@ -2455,25 +2497,20 @@ static VALUE cResumableParser_parse(VALUE self)
     struct json_parse_any_args args = {
         .state = &parser->state,
         .config = &parser->config,
+        .parser = self,
     };
     int status;
     const char *initial_cursor = parser->state.cursor;
     parser->complete = rb_protect(json_parse_any_resumable_safe, (VALUE)&args, &status);
+
     if (status) {
-        VALUE error_source = rb_ivar_get(rb_errinfo(), i_at_eos);
-        if (error_source == self) {
-            parser->complete = false; // is an EOS error raised by ourself
-            rb_set_errinfo(Qnil);
-            status = 0;
-        } else {
-            parser->complete = true; // a parse error is considered complete
-        }
+        parser->complete = true; // a parse error is considered complete
     }
 
     parser->parsed_bytes += parser->state.cursor - initial_cursor;
     parser->incomplete_bytes = parser->complete ? 0 : parser->state.end - parser->state.cursor;
-
     parser->in_use = false;
+
     if (status) {
         rb_jump_tag(status); // reraise
     }
@@ -2765,7 +2802,6 @@ void Init_parser(void)
     i_encode = rb_intern("encode");
     i_at_line = rb_intern("@line");
     i_at_column = rb_intern("@column");
-    i_at_eos = rb_intern("@eos");
 
     binary_encindex = rb_ascii8bit_encindex();
     utf8_encindex = rb_utf8_encindex();