[ruby/prism] Warning for ENDs in methods

(https://github.com/ruby/prism/pull/1899)

https://github.com/ruby/prism/commit/1b41c2d56c

5 files changed, 18 insertions, 1 deletions

diff --git a/lib/prism/ffi.rb b/lib/prism/ffi.rb
index c910fd3aae..847990ed9a 100644
--- a/lib/prism/ffi.rb
+++ b/lib/prism/ffi.rb
@@ -299,7 +299,7 @@ module Prism
       values << (options.fetch(:frozen_string_literal, false) ? 1 : 0)
 
       template << "C"
-      values << (options[:verbose] ? 0 : 1)
+      values << (options.fetch(:verbose, true) ? 0 : 1)
 
       template << "L"
       if (scopes = options[:scopes])
diff --git a/prism/diagnostic.c b/prism/diagnostic.c
index 7da8806b37..473960e361 100644
--- a/prism/diagnostic.c
+++ b/prism/diagnostic.c
@@ -256,6 +256,7 @@ static const char* const diagnostic_messages[PM_DIAGNOSTIC_ID_LEN] = {
     [PM_WARN_AMBIGUOUS_FIRST_ARGUMENT_PLUS]     = "Ambiguous first argument; put parentheses or a space even after `+` operator",
     [PM_WARN_AMBIGUOUS_PREFIX_STAR]             = "Ambiguous `*` has been interpreted as an argument prefix",
     [PM_WARN_AMBIGUOUS_SLASH]                   = "Ambiguous `/`; wrap regexp in parentheses or add a space after `/` operator",
+    [PM_WARN_END_IN_METHOD]                     = "END in method; use at_exit",
 };
 
 static const char*
diff --git a/prism/diagnostic.h b/prism/diagnostic.h
index 33a70229c8..68e507929f 100644
--- a/prism/diagnostic.h
+++ b/prism/diagnostic.h
@@ -250,6 +250,7 @@ typedef enum {
     PM_WARN_AMBIGUOUS_FIRST_ARGUMENT_PLUS,
     PM_WARN_AMBIGUOUS_PREFIX_STAR,
     PM_WARN_AMBIGUOUS_SLASH,
+    PM_WARN_END_IN_METHOD,
 
     /* This must be the last member. */
     PM_DIAGNOSTIC_ID_LEN,
diff --git a/prism/prism.c b/prism/prism.c
index 21eb8f07fd..bf048f1883 100644
--- a/prism/prism.c
+++ b/prism/prism.c
@@ -14891,6 +14891,10 @@ parse_expression_prefix(pm_parser_t *parser, pm_binding_power_t binding_power) {
             parser_lex(parser);
             pm_token_t keyword = parser->previous;
 
+            if (context_def_p(parser)) {
+                pm_parser_warn_token(parser, &keyword, PM_WARN_END_IN_METHOD);
+            }
+
             expect1(parser, PM_TOKEN_BRACE_LEFT, PM_ERR_END_UPCASE_BRACE);
             pm_token_t opening = parser->previous;
             pm_statements_node_t *statements = parse_statements(parser, PM_CONTEXT_POSTEXE);
diff --git a/test/prism/errors_test.rb b/test/prism/errors_test.rb
index cf7330dfb2..9362032fe3 100644
--- a/test/prism/errors_test.rb
+++ b/test/prism/errors_test.rb
@@ -1708,6 +1708,12 @@ module Prism
       ]
     end
 
+    def test_upcase_end_in_def
+      assert_warning_messages "def foo; END { }; end", [
+        "END in method; use at_exit"
+      ]
+    end
+
     private
 
     def assert_errors(expected, source, errors, compare_ripper: RUBY_ENGINE == "ruby")
@@ -1727,6 +1733,11 @@ module Prism
       assert_equal(errors, result.errors.map(&:message))
     end
 
+    def assert_warning_messages(source, warnings)
+      result = Prism.parse(source)
+      assert_equal(warnings, result.warnings.map(&:message))
+    end
+
     def expression(source)
       Prism.parse(source).value.statements.body.last
     end