Resync yarp (#8498)

* [YARP] Reject numbered parameters in block parameters

* [YARP] Do not allow BEGIN except the toplevel

---------

Co-authored-by: Haldun Bayhantopcu <haldun@github.com>

test/yarp/errors_test.rb

@@ -1302,6 +1302,20 @@ def test_alnum_delimiters
       assert_error_messages "%sXfooX", error_messages
     end
 
+    def test_begin_at_toplevel
+      source = "def foo; BEGIN {}; end"
+      assert_errors expression(source), source, [
+        ["BEGIN is permitted only at toplevel", 9..14],
+      ]
+    end
+
+    def test_numbered_parameters_in_block_arguments
+      source = "foo { |_1| }"
+      assert_errors expression(source), source, [
+        ["Token reserved for a numbered parameter", 7..9],
+      ]
+    end
+
     def test_conditional_predicate_closed
       source = "if 0 0; end\nunless 0 0; end"
       assert_errors expression(source), source, [

yarp/diagnostic.c

@@ -77,6 +77,7 @@ static const char* const diagnostic_messages[YP_DIAGNOSTIC_ID_LEN] = {
     [YP_ERR_BEGIN_TERM]                         = "Expected an `end` to close the `begin` statement",
     [YP_ERR_BEGIN_UPCASE_BRACE]                 = "Expected a `{` after `BEGIN`",
     [YP_ERR_BEGIN_UPCASE_TERM]                  = "Expected a `}` to close the `BEGIN` statement",
+    [YP_ERR_BEGIN_UPCASE_TOPLEVEL]              = "BEGIN is permitted only at toplevel",
     [YP_ERR_BLOCK_PARAM_LOCAL_VARIABLE]         = "Expected a local variable name in the block parameters",
     [YP_ERR_BLOCK_PARAM_PIPE_TERM]              = "Expected the block parameters to end with `|`",
     [YP_ERR_BLOCK_TERM_BRACE]                   = "Expected a block beginning with `{` to end with `}`",

yarp/diagnostic.h

@@ -42,6 +42,7 @@ typedef enum {
     YP_ERR_BEGIN_TERM,
     YP_ERR_BEGIN_UPCASE_BRACE,
     YP_ERR_BEGIN_UPCASE_TERM,
+    YP_ERR_BEGIN_UPCASE_TOPLEVEL,
     YP_ERR_BLOCK_PARAM_LOCAL_VARIABLE,
     YP_ERR_BLOCK_PARAM_PIPE_TERM,
     YP_ERR_BLOCK_TERM_BRACE,

yarp/yarp.c

@@ -4818,10 +4818,20 @@ yp_parser_local_add_owned(yp_parser_t *parser, const uint8_t *start, size_t leng
     if (constant_id != 0) yp_parser_local_add(parser, constant_id);
 }
 
+static inline bool
+token_is_numbered_parameter(const uint8_t *start, const uint8_t *end) {
+    return (end - start == 2) && (start[0] == '_') && (start[1] != '0') && (yp_char_is_decimal_digit(start[1]));
+}
+
 // Add a parameter name to the current scope and check whether the name of the
 // parameter is unique or not.
 static void
 yp_parser_parameter_name_check(yp_parser_t *parser, yp_token_t *name) {
+    // We want to check whether the parameter name is a numbered parameter or not.
+    if (token_is_numbered_parameter(name->start, name->end)) {
+        yp_diagnostic_list_append(&parser->error_list, name->start, name->end, YP_ERR_PARAMETER_NUMBERED_RESERVED);
+    }
+
     // We want to ignore any parameter name that starts with an underscore.
     if ((*name->start == '_')) return;
 
@@ -4902,11 +4912,6 @@ char_is_global_name_punctuation(const uint8_t b) {
     return (yp_global_name_punctuation_hash[(i - 0x20) / 32] >> (i % 32)) & 1;
 }
 
-static inline bool
-token_is_numbered_parameter(const uint8_t *start, const uint8_t *end) {
-    return (end - start == 2) && (start[0] == '_') && (start[1] != '0') && (yp_char_is_decimal_digit(start[1]));
-}
-
 static inline bool
 token_is_setter_name(yp_token_t *token) {
     return (
@@ -12155,6 +12160,10 @@ parse_expression_prefix(yp_parser_t *parser, yp_binding_power_t binding_power) {
             yp_statements_node_t *statements = parse_statements(parser, YP_CONTEXT_PREEXE);
 
             expect1(parser, YP_TOKEN_BRACE_RIGHT, YP_ERR_BEGIN_UPCASE_TERM);
+            yp_context_t context = parser->current_context->context;
+            if ((context != YP_CONTEXT_MAIN) && (context != YP_CONTEXT_PREEXE)) {
+                yp_diagnostic_list_append(&parser->error_list, keyword.start, keyword.end, YP_ERR_BEGIN_UPCASE_TOPLEVEL);
+            }
             return (yp_node_t *) yp_pre_execution_node_create(parser, &keyword, &opening, statements, &parser->previous);
         }
         case YP_TOKEN_KEYWORD_BREAK: