[syntax-error] Fix a crash when the line and column can't be retrieved (#7097)

Closes #3860

Author: Pierre-Sassoulas

doc/whatsnew/fragments/3860.bugfix

@@ -0,0 +1,4 @@
+Fixed a syntax-error crash that was not handled properly when the declared encoding of a file
+was ``utf-9``.
+
+Closes #3860

pylint/checkers/imports.py

@@ -28,6 +28,7 @@
 )
 from pylint.exceptions import EmptyReportError
 from pylint.graph import DotBackend, get_cycles
+from pylint.interfaces import HIGH
 from pylint.reporters.ureports.nodes import Paragraph, Section, VerbatimText
 from pylint.typing import MessageDefinitionTuple
 from pylint.utils import IsortDriver
@@ -800,10 +801,10 @@ def _get_imported_module(
                 return None
             self.add_message("relative-beyond-top-level", node=importnode)
         except astroid.AstroidSyntaxError as exc:
-            message = (
-                f"Cannot import {modname!r} due to syntax error {str(exc.error)!r}"
+            message = f"Cannot import {modname!r} due to '{exc.error}'"
+            self.add_message(
+                "syntax-error", line=importnode.lineno, args=message, confidence=HIGH
             )
-            self.add_message("syntax-error", line=importnode.lineno, args=message)
 
         except astroid.AstroidBuildingError:
             if not self.linter.is_message_enabled("import-error"):

pylint/lint/pylinter.py

@@ -692,11 +692,11 @@ def _check_files(
                     )
                     msg = get_fatal_error_message(file.filepath, template_path)
                     if isinstance(ex, AstroidError):
-                        symbol = "astroid-error"
-                        self.add_message(symbol, args=(file.filepath, msg))
+                        self.add_message(
+                            "astroid-error", args=(file.filepath, msg), confidence=HIGH
+                        )
                     else:
-                        symbol = "fatal"
-                        self.add_message(symbol, args=msg)
+                        self.add_message("fatal", args=msg, confidence=HIGH)
 
     def _check_file(
         self,
@@ -918,7 +918,8 @@ def get_ast(
                 "syntax-error",
                 line=getattr(ex.error, "lineno", 0),
                 col_offset=getattr(ex.error, "offset", None),
-                args=str(ex.error),
+                args=f"Parsing failed: '{ex.error}'",
+                confidence=HIGH,
             )
         except astroid.AstroidBuildingError as ex:
             self.add_message("parse-error", args=ex)

tests/functional/i/import_error.txt

@@ -1,5 +1,5 @@
 import-error:3:0:3:22::Unable to import 'totally_missing':UNDEFINED
 import-error:21:4:21:26::Unable to import 'maybe_missing_2':UNDEFINED
 no-name-in-module:33:0:33:49::No name 'syntax_error' in module 'functional.s.syntax':UNDEFINED
-syntax-error:33:0:None:None::Cannot import 'functional.s.syntax.syntax_error' due to syntax error 'invalid syntax (<unknown>, line 1)':UNDEFINED
+syntax-error:33:0:None:None::Cannot import 'functional.s.syntax.syntax_error' due to 'invalid syntax (<unknown>, line 1)':HIGH
 multiple-imports:78:0:78:15::Multiple imports on one line (foo, bar):UNDEFINED

tests/functional/s/syntax/syntax_error.txt

@@ -1 +1 @@
-syntax-error:1:5:None:None::invalid syntax (<unknown>, line 1):UNDEFINED
+syntax-error:1:5:None:None::"Parsing failed: 'invalid syntax (<unknown>, line 1)'":HIGH

tests/test_self.py

@@ -569,12 +569,9 @@ def foobar(arg):
                     expected_output=expected,
                 )
 
-    def test_stdin_syntaxerror(self) -> None:
-        expected_output = (
-            "************* Module a\n"
-            "a.py:1:4: E0001: invalid syntax (<unknown>, line 1) (syntax-error)"
-        )
-
+    def test_stdin_syntax_error(self) -> None:
+        expected_output = """************* Module a
+a.py:1:4: E0001: Parsing failed: 'invalid syntax (<unknown>, line 1)' (syntax-error)"""
         with mock.patch(
             "pylint.lint.pylinter._read_stdin", return_value="for\n"
         ) as mock_stdin: