Do not warn \r in shebang on windows

Author: kddnewton

src/prism.c

@@ -21772,6 +21772,9 @@ pm_strnstr(const char *big, const char *little, size_t big_length) {
     return NULL;
 }
 
+#ifdef _WIN32
+#define pm_parser_warn_shebang_carriage_return(parser, start, length) ((void) 0)
+#else
 /**
  * Potentially warn the user if the shebang that has been found to include
  * "ruby" has a carriage return at the end, as that can cause problems on some
@@ -21783,6 +21786,7 @@ pm_parser_warn_shebang_carriage_return(pm_parser_t *parser, const uint8_t *start
         pm_parser_warn(parser, start, start + length, PM_WARN_SHEBANG_CARRIAGE_RETURN);
     }
 }
+#endif
 
 /**
  * Process the shebang when initializing the parser. This function assumes that
@@ -21973,9 +21977,7 @@ pm_parser_init(pm_parser_t *parser, const uint8_t *source, size_t size, const pm
         const char *engine;
         if ((engine = pm_strnstr((const char *) parser->start, "ruby", length)) != NULL) {
             if (newline != NULL) {
-                size_t length_including_newline = length + 1;
-                pm_parser_warn_shebang_carriage_return(parser, parser->start, length_including_newline);
-
+                pm_parser_warn_shebang_carriage_return(parser, parser->start, length + 1);
                 parser->encoding_comment_start = newline + 1;
             }
 
@@ -22015,10 +22017,9 @@ pm_parser_init(pm_parser_t *parser, const uint8_t *source, size_t size, const pm
                 const char *engine;
                 if ((engine = pm_strnstr((const char *) cursor, "ruby", length)) != NULL) {
                     found_shebang = true;
-                    if (newline != NULL) {
-                        size_t length_including_newline = length + 1;
-                        pm_parser_warn_shebang_carriage_return(parser, cursor, length_including_newline);
 
+                    if (newline != NULL) {
+                        pm_parser_warn_shebang_carriage_return(parser, cursor, length + 1);
                         parser->encoding_comment_start = newline + 1;
                     }
 

test/prism/result/warnings_test.rb

@@ -321,42 +321,48 @@ def test_unreachable_statement
       assert_warning("tap { redo; foo }", "statement not reached")
     end
 
-    def test_shebang_ending_with_carriage_return
-      msg = "shebang line ending with \\r may cause problems"
-
-      assert_warning(<<~RUBY, msg, compare: false)
-        #!ruby\r
-        p(123)
-      RUBY
-
-      assert_warning(<<~RUBY, msg, compare: false)
-        #!ruby \r
-        p(123)
-      RUBY
-
-      assert_warning(<<~RUBY, msg, compare: false)
-        #!ruby -Eutf-8\r
-        p(123)
-      RUBY
-
-      # Used with the `-x` object, to ignore the script up until the first shebang that mentioned "ruby".
-      assert_warning(<<~SCRIPT, msg, compare: false)
-        #!/usr/bin/env bash
-        # Some initial shell script or other content
-        # that Ruby should ignore
-        echo "This is shell script part"
-        exit 0
-
-        #! /usr/bin/env ruby -Eutf-8\r
-        # Ruby script starts here
-        puts "Hello from Ruby!"
-      SCRIPT
-
-      refute_warning("#ruby not_a_shebang\r\n", compare: false)
-
-      # CRuby doesn't emit the warning if a malformed file only has `\r` and not `\n`.
-      # https://bugs.ruby-lang.org/issues/20700
-      refute_warning("#!ruby\r", compare: false)
+    if RbConfig::CONFIG["host_os"].match?(/bccwin|cygwin|djgpp|mingw|mswin|wince/i)
+      def test_shebang_ending_with_carriage_return
+        refute_warning("#!ruby\r\np(123)\n", compare: false)
+      end
+    else
+      def test_shebang_ending_with_carriage_return
+        msg = "shebang line ending with \\r may cause problems"
+
+        assert_warning(<<~RUBY, msg, compare: false)
+          #!ruby\r
+          p(123)
+        RUBY
+
+        assert_warning(<<~RUBY, msg, compare: false)
+          #!ruby \r
+          p(123)
+        RUBY
+
+        assert_warning(<<~RUBY, msg, compare: false)
+          #!ruby -Eutf-8\r
+          p(123)
+        RUBY
+
+        # Used with the `-x` object, to ignore the script up until the first shebang that mentioned "ruby".
+        assert_warning(<<~SCRIPT, msg, compare: false)
+          #!/usr/bin/env bash
+          # Some initial shell script or other content
+          # that Ruby should ignore
+          echo "This is shell script part"
+          exit 0
+
+          #! /usr/bin/env ruby -Eutf-8\r
+          # Ruby script starts here
+          puts "Hello from Ruby!"
+        SCRIPT
+
+        refute_warning("#ruby not_a_shebang\r\n", compare: false)
+
+        # CRuby doesn't emit the warning if a malformed file only has `\r` and not `\n`.
+        # https://bugs.ruby-lang.org/issues/20700
+        refute_warning("#!ruby\r", compare: false)
+      end
     end
 
     def test_warnings_verbosity