Give arguments a more reasonable location

mypy/checker.py

@@ -2067,15 +2067,22 @@ def erase_override(t: Type) -> Type:
                     if not is_subtype(
                         original.arg_types[i], erase_override(override.arg_types[i])
                     ):
+
                         arg_type_in_super = original.arg_types[i]
+
+                        if isinstance(node, FuncDef):
+                            context: Context = node.arguments[i + len(override.bound_args)]
+                        else:
+                            context = node
                         self.msg.argument_incompatible_with_supertype(
                             i + 1,
                             name,
                             type_name,
                             name_in_super,
                             arg_type_in_super,
                             supertype,
-                            node,
+                            context,
+                            secondary_context=node,
                         )
                         emitted_msg = True
 

mypy/errors.py

@@ -4,7 +4,7 @@
 import sys
 import traceback
 from collections import defaultdict
-from typing import Callable, NoReturn, Optional, TextIO, Tuple, TypeVar
+from typing import Callable, Iterable, NoReturn, Optional, TextIO, Tuple, TypeVar
 from typing_extensions import Final, Literal, TypeAlias as _TypeAlias
 
 from mypy import errorcodes as codes
@@ -78,7 +78,7 @@ class ErrorInfo:
 
     # Actual origin of the error message as tuple (path, line number, end line number)
     # If end line number is unknown, use line number.
-    origin: tuple[str, int, int]
+    origin: tuple[str, Iterable[int]]
 
     # Fine-grained incremental target where this was reported
     target: str | None = None
@@ -104,7 +104,7 @@ def __init__(
         blocker: bool,
         only_once: bool,
         allow_dups: bool,
-        origin: tuple[str, int, int] | None = None,
+        origin: tuple[str, Iterable[int]] | None = None,
         target: str | None = None,
     ) -> None:
         self.import_ctx = import_ctx
@@ -122,7 +122,7 @@ def __init__(
         self.blocker = blocker
         self.only_once = only_once
         self.allow_dups = allow_dups
-        self.origin = origin or (file, line, line)
+        self.origin = origin or (file, [line])
         self.target = target
 
 
@@ -367,7 +367,7 @@ def report(
         file: str | None = None,
         only_once: bool = False,
         allow_dups: bool = False,
-        origin_span: tuple[int, int] | None = None,
+        origin_span: Iterable[int] | None = None,
         offset: int = 0,
         end_line: int | None = None,
         end_column: int | None = None,
@@ -411,7 +411,7 @@ def report(
             message = " " * offset + message
 
         if origin_span is None:
-            origin_span = (line, line)
+            origin_span = [line]
 
         if end_line is None:
             end_line = line
@@ -434,7 +434,7 @@ def report(
             blocker,
             only_once,
             allow_dups,
-            origin=(self.file, *origin_span),
+            origin=(self.file, origin_span),
             target=self.current_target(),
         )
         self.add_error_info(info)
@@ -467,7 +467,7 @@ def _filter_error(self, file: str, info: ErrorInfo) -> bool:
         return False
 
     def add_error_info(self, info: ErrorInfo) -> None:
-        file, line, end_line = info.origin
+        file, lines = info.origin
         # process the stack of ErrorWatchers before modifying any internal state
         # in case we need to filter out the error entirely
         # NB: we need to do this both here and in _add_error_info, otherwise we
@@ -478,7 +478,7 @@ def add_error_info(self, info: ErrorInfo) -> None:
             if file in self.ignored_lines:
                 # Check each line in this context for "type: ignore" comments.
                 # line == end_line for most nodes, so we only loop once.
-                for scope_line in range(line, end_line + 1):
+                for scope_line in lines:
                     if self.is_ignored_error(scope_line, info, self.ignored_lines[file]):
                         # Annotation requests us to ignore all errors on this line.
                         self.used_ignored_lines[file][scope_line].append(

mypy/fastparse.py

@@ -1081,7 +1081,14 @@ def make_argument(
         if argument_elide_name(arg.arg):
             pos_only = True
 
-        return Argument(Var(arg.arg), arg_type, self.visit(default), kind, pos_only)
+        argument = Argument(Var(arg.arg), arg_type, self.visit(default), kind, pos_only)
+        argument.set_line(
+            arg.lineno,
+            arg.col_offset,
+            getattr(arg, "end_lineno", None),
+            getattr(arg, "end_col_offset", None),
+        )
+        return argument
 
     def fail_arg(self, msg: str, arg: ast3.arg) -> None:
         self.fail(msg, arg.lineno, arg.col_offset)

mypy/messages.py

@@ -12,6 +12,7 @@
 from __future__ import annotations
 
 import difflib
+import itertools
 import re
 from contextlib import contextmanager
 from textwrap import dedent
@@ -210,34 +211,40 @@ def report(
         origin: Context | None = None,
         offset: int = 0,
         allow_dups: bool = False,
+        secondary_context: Context | None = None,
     ) -> None:
         """Report an error or note (unless disabled).
 
         Note that context controls where error is reported, while origin controls
         where # type: ignore comments have effect.
         """
 
-        def span_from_context(ctx: Context) -> tuple[int, int]:
+        def span_from_context(ctx: Context) -> Iterable[int]:
             """This determines where a type: ignore for a given context has effect.
 
             Current logic is a bit tricky, to keep as much backwards compatibility as
             possible. We may reconsider this to always be a single line (or otherwise
             simplify it) when we drop Python 3.7.
             """
             if isinstance(ctx, (ClassDef, FuncDef)):
-                return ctx.deco_line or ctx.line, ctx.line
+                return range(ctx.deco_line or ctx.line, ctx.line + 1)
             elif not isinstance(ctx, Expression):
-                return ctx.line, ctx.line
+                return [ctx.line]
             else:
-                return ctx.line, ctx.end_line or ctx.line
+                return range(ctx.line, (ctx.end_line or ctx.line) + 1)
 
-        origin_span: tuple[int, int] | None
+        origin_span: Iterable[int] | None
         if origin is not None:
             origin_span = span_from_context(origin)
         elif context is not None:
             origin_span = span_from_context(context)
         else:
             origin_span = None
+
+        if secondary_context is not None:
+            assert origin_span is not None
+            origin_span = itertools.chain(origin_span, span_from_context(secondary_context))
+
         self.errors.report(
             context.line if context else -1,
             context.column if context else -1,
@@ -260,9 +267,18 @@ def fail(
         code: ErrorCode | None = None,
         file: str | None = None,
         allow_dups: bool = False,
+        secondary_context: Context | None = None,
     ) -> None:
         """Report an error message (unless disabled)."""
-        self.report(msg, context, "error", code=code, file=file, allow_dups=allow_dups)
+        self.report(
+            msg,
+            context,
+            "error",
+            code=code,
+            file=file,
+            allow_dups=allow_dups,
+            secondary_context=secondary_context,
+        )
 
     def note(
         self,
@@ -274,6 +290,7 @@ def note(
         allow_dups: bool = False,
         *,
         code: ErrorCode | None = None,
+        secondary_context: Context | None = None,
     ) -> None:
         """Report a note (unless disabled)."""
         self.report(
@@ -285,6 +302,7 @@ def note(
             offset=offset,
             allow_dups=allow_dups,
             code=code,
+            secondary_context=secondary_context,
         )
 
     def note_multiline(
@@ -295,11 +313,20 @@ def note_multiline(
         offset: int = 0,
         allow_dups: bool = False,
         code: ErrorCode | None = None,
+        *,
+        secondary_context: Context | None = None,
     ) -> None:
         """Report as many notes as lines in the message (unless disabled)."""
         for msg in messages.splitlines():
             self.report(
-                msg, context, "note", file=file, offset=offset, allow_dups=allow_dups, code=code
+                msg,
+                context,
+                "note",
+                file=file,
+                offset=offset,
+                allow_dups=allow_dups,
+                code=code,
+                secondary_context=secondary_context,
             )
 
     #
@@ -1153,6 +1180,7 @@ def argument_incompatible_with_supertype(
         arg_type_in_supertype: Type,
         supertype: str,
         context: Context,
+        secondary_context: Context,
     ) -> None:
         target = self.override_target(name, name_in_supertype, supertype)
         arg_type_in_supertype_f = format_type_bare(arg_type_in_supertype)
@@ -1163,17 +1191,26 @@ def argument_incompatible_with_supertype(
             ),
             context,
             code=codes.OVERRIDE,
+            secondary_context=secondary_context,
+        )
+        self.note(
+            "This violates the Liskov substitution principle",
+            context,
+            code=codes.OVERRIDE,
+            secondary_context=secondary_context,
         )
-        self.note("This violates the Liskov substitution principle", context, code=codes.OVERRIDE)
         self.note(
             "See https://mypy.readthedocs.io/en/stable/common_issues.html#incompatible-overrides",
             context,
             code=codes.OVERRIDE,
+            secondary_context=secondary_context,
         )
 
         if name == "__eq__" and type_name:
             multiline_msg = self.comparison_method_example_msg(class_name=type_name)
-            self.note_multiline(multiline_msg, context, code=codes.OVERRIDE)
+            self.note_multiline(
+                multiline_msg, context, code=codes.OVERRIDE, secondary_context=secondary_context
+            )
 
     def comparison_method_example_msg(self, class_name: str) -> str:
         return dedent(

mypy/nodes.py

@@ -704,18 +704,6 @@ def __init__(
     def max_fixed_argc(self) -> int:
         return self.max_pos
 
-    def set_line(
-        self,
-        target: Context | int,
-        column: int | None = None,
-        end_line: int | None = None,
-        end_column: int | None = None,
-    ) -> None:
-        super().set_line(target, column, end_line, end_column)
-        for arg in self.arguments:
-            # TODO: set arguments line/column to their precise locations.
-            arg.set_line(self.line, self.column, self.end_line, end_column)
-
     def is_dynamic(self) -> bool:
         return self.type is None
 

mypy/test/data.py

@@ -677,8 +677,8 @@ class DataFileCollector(pytest.Collector):
     parent: DataSuiteCollector
 
     @classmethod  # We have to fight with pytest here:
-    def from_parent(  # type: ignore[override]
-        cls, parent: DataSuiteCollector, *, name: str
+    def from_parent(
+        cls, parent: DataSuiteCollector, *, name: str  # type: ignore[override]
     ) -> DataFileCollector:
         collector = super().from_parent(parent, name=name)
         assert isinstance(collector, DataFileCollector)

test-data/unit/check-abstract.test

@@ -382,10 +382,10 @@ class A(I):
     def g(self, a: 'A') -> 'A':
         return A()
 [out]
+main:11: error: Return type "I" of "h" incompatible with return type "A" in supertype "I"
 main:11: error: Argument 1 of "h" is incompatible with supertype "I"; supertype defines the argument type as "I"
 main:11: note: This violates the Liskov substitution principle
 main:11: note: See https://mypy.readthedocs.io/en/stable/common_issues.html#incompatible-overrides
-main:11: error: Return type "I" of "h" incompatible with return type "A" in supertype "I"
 
 
 -- Accessing abstract members

test-data/unit/check-classes.test

@@ -331,6 +331,59 @@ main:7: note: This violates the Liskov substitution principle
 main:7: note: See https://mypy.readthedocs.io/en/stable/common_issues.html#incompatible-overrides
 main:9: error: Return type "object" of "h" incompatible with return type "A" in supertype "A"
 
+[case testMethodOverridingWithIncompatibleTypesOnMultipleLines]
+class A:
+    def f(self, x: int, y: str) -> None: pass
+class B(A):
+    def f(
+        self,
+        x: int,
+        y: bool,
+    ) -> None:
+        pass
+[out]
+main:7: error: Argument 2 of "f" is incompatible with supertype "A"; supertype defines the argument type as "str"
+main:7: note: This violates the Liskov substitution principle
+main:7: note: See https://mypy.readthedocs.io/en/stable/common_issues.html#incompatible-overrides
+
+[case testMultiLineMethodOverridingWithIncompatibleTypesIgnorableAtArgument]
+class A:
+    def f(self, x: int, y: str) -> None: pass
+
+class B(A):
+    def f(
+        self,
+        x: int,
+        y: bool,  # type: ignore[override]
+    ) -> None:
+        pass
+
+[case testMultiLineMethodOverridingWithIncompatibleTypesIgnorableAtDefinition]
+class A:
+    def f(self, x: int, y: str) -> None: pass
+class B(A):
+    def f(  # type: ignore[override]
+        self,
+        x: int,
+        y: bool,
+    ) -> None:
+        pass
+
+[case testMultiLineMethodOverridingWithIncompatibleTypesWrongIgnore]
+class A:
+    def f(self, x: int, y: str) -> None: pass
+class B(A):
+    def f(  # type: ignore[return-type]
+        self,
+        x: int,
+        y: bool,
+    ) -> None:
+        pass
+[out]
+main:7: error: Argument 2 of "f" is incompatible with supertype "A"; supertype defines the argument type as "str"
+main:7: note: This violates the Liskov substitution principle
+main:7: note: See https://mypy.readthedocs.io/en/stable/common_issues.html#incompatible-overrides
+
 [case testEqMethodsOverridingWithNonObjects]
 class A:
   def __eq__(self, other: A) -> bool: pass  # Fail
@@ -2626,10 +2679,10 @@ class D(A):
     def __iadd__(self, x: 'A') -> 'B': pass
 [out]
 main:6: error: Return type "A" of "__iadd__" incompatible with return type "B" in "__add__" of supertype "A"
+main:8: error: Signatures of "__iadd__" and "__add__" are incompatible
 main:8: error: Argument 1 of "__iadd__" is incompatible with "__add__" of supertype "A"; supertype defines the argument type as "A"
 main:8: note: This violates the Liskov substitution principle
 main:8: note: See https://mypy.readthedocs.io/en/stable/common_issues.html#incompatible-overrides
-main:8: error: Signatures of "__iadd__" and "__add__" are incompatible
 
 [case testGetattribute]
 

test-data/unit/check-columns.test

@@ -238,9 +238,9 @@ if int():
 class A:
     def f(self, x: int) -> None: pass
 class B(A):
-    def f(self, x: str) -> None: pass # E:5: Argument 1 of "f" is incompatible with supertype "A"; supertype defines the argument type as "int" \
-                                      # N:5: This violates the Liskov substitution principle \
-                                      # N:5: See https://mypy.readthedocs.io/en/stable/common_issues.html#incompatible-overrides
+    def f(self, x: str) -> None: pass # E:17: Argument 1 of "f" is incompatible with supertype "A"; supertype defines the argument type as "int" \
+                                      # N:17: This violates the Liskov substitution principle \
+                                      # N:17: See https://mypy.readthedocs.io/en/stable/common_issues.html#incompatible-overrides
 class C(A):
     def f(self, x: int) -> int: pass # E:5: Return type "int" of "f" incompatible with return type "None" in supertype "A"
 class D(A):