[ruby/prism] Add whitespace warnings

ruby/prism@01d137a0cb
ruby · Mar 12, 2024 · 157733b · 157733b
1 parent 5c84850
commit 157733b
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Showing 3 changed files with 37 additions and 7 deletions.
diff --git a/prism/config.yml b/prism/config.yml
@@ -247,6 +247,7 @@ warnings:
   - KEYWORD_EOL
   - LITERAL_IN_CONDITION_DEFAULT
   - LITERAL_IN_CONDITION_VERBOSE
+  - UNEXPECTED_CARRIAGE_RETURN
 tokens:
   - name: EOF
     value: 1

diff --git a/prism/prism.c b/prism/prism.c
@@ -9291,6 +9291,7 @@ parser_lex(pm_parser_t *parser) {
                         if (match_eol_offset(parser, 1)) {
                             chomping = false;
                         } else {
+                            pm_parser_warn(parser, parser->current.end, parser->current.end + 1, PM_WARN_UNEXPECTED_CARRIAGE_RETURN);
                             parser->current.end++;
                             space_seen = true;
                         }
@@ -10348,16 +10349,43 @@ parser_lex(pm_parser_t *parser) {
                         // other options. We'll skip past it and return the next
                         // token after adding an appropriate error message.
                         if (!width) {
-                            pm_diagnostic_id_t diag_id;
                             if (*parser->current.start >= 0x80) {
-                                diag_id = PM_ERR_INVALID_MULTIBYTE_CHARACTER;
-                            } else if (char_is_ascii_printable(*parser->current.start) || (*parser->current.start == '\\')) {
-                                diag_id = PM_ERR_INVALID_PRINTABLE_CHARACTER;
+                                PM_PARSER_ERR_TOKEN_FORMAT(parser, parser->current, PM_ERR_INVALID_MULTIBYTE_CHARACTER, *parser->current.start);
+                            } else if (*parser->current.start == '\\') {
+                                switch (peek_at(parser, parser->current.start + 1)) {
+                                    case ' ':
+                                        parser->current.end++;
+                                        PM_PARSER_ERR_TOKEN_FORMAT(parser, parser->current, PM_ERR_UNEXPECTED_TOKEN_IGNORE, "escaped space");
+                                        break;
+                                    case '\f':
+                                        parser->current.end++;
+                                        PM_PARSER_ERR_TOKEN_FORMAT(parser, parser->current, PM_ERR_UNEXPECTED_TOKEN_IGNORE, "escaped form feed");
+                                        break;
+                                    case '\t':
+                                        parser->current.end++;
+                                        PM_PARSER_ERR_TOKEN_FORMAT(parser, parser->current, PM_ERR_UNEXPECTED_TOKEN_IGNORE, "escaped horizontal tab");
+                                        break;
+                                    case '\v':
+                                        parser->current.end++;
+                                        PM_PARSER_ERR_TOKEN_FORMAT(parser, parser->current, PM_ERR_UNEXPECTED_TOKEN_IGNORE, "escaped vertical tab");
+                                        break;
+                                    case '\r':
+                                        if (peek_at(parser, parser->current.start + 2) != '\n') {
+                                            parser->current.end++;
+                                            PM_PARSER_ERR_TOKEN_FORMAT(parser, parser->current, PM_ERR_UNEXPECTED_TOKEN_IGNORE, "escaped carriage return");
+                                            break;
+                                        }
+                                        /* fallthrough */
+                                    default:
+                                        PM_PARSER_ERR_TOKEN_FORMAT(parser, parser->current, PM_ERR_UNEXPECTED_TOKEN_IGNORE, "backslash");
+                                        break;
+                                }
+                            } else if (char_is_ascii_printable(*parser->current.start)) {
+                                PM_PARSER_ERR_TOKEN_FORMAT(parser, parser->current, PM_ERR_INVALID_PRINTABLE_CHARACTER, *parser->current.start);
                             } else {
-                                diag_id = PM_ERR_INVALID_CHARACTER;
+                                PM_PARSER_ERR_TOKEN_FORMAT(parser, parser->current, PM_ERR_INVALID_CHARACTER, *parser->current.start);
                             }
 
-                            PM_PARSER_ERR_TOKEN_FORMAT(parser, parser->current, diag_id, *parser->current.start);
                             goto lex_next_token;
                         }
 

diff --git a/prism/templates/src/diagnostic.c.erb b/prism/templates/src/diagnostic.c.erb
@@ -326,7 +326,8 @@ static const pm_diagnostic_data_t diagnostic_messages[PM_DIAGNOSTIC_ID_MAX] = {
     [PM_WARN_INVALID_CHARACTER]                 = { "invalid character syntax; use %s%s%s", PM_WARNING_LEVEL_DEFAULT },
     [PM_WARN_KEYWORD_EOL]                       = { "`%.*s` at the end of line without an expression", PM_WARNING_LEVEL_VERBOSE },
     [PM_WARN_LITERAL_IN_CONDITION_DEFAULT]      = { "%sliteral in %s", PM_WARNING_LEVEL_DEFAULT },
-    [PM_WARN_LITERAL_IN_CONDITION_VERBOSE]      = { "%sliteral in %s", PM_WARNING_LEVEL_VERBOSE }
+    [PM_WARN_LITERAL_IN_CONDITION_VERBOSE]      = { "%sliteral in %s", PM_WARNING_LEVEL_VERBOSE },
+    [PM_WARN_UNEXPECTED_CARRIAGE_RETURN]        = { "encountered \\r in middle of line, treated as a mere space", PM_WARNING_LEVEL_DEFAULT }
 };
 
 /**