Workaround MyPy's awful flow analysis.

Author: markshannon

Tools/cases_generator/generators_common.py

@@ -470,7 +470,7 @@ def _emit_stmt(
         method = getattr(self, method_name, None)
         if method is None:
             raise NotImplementedError
-        return method(stmt, uop, storage, inst) # type: ignore
+        return method(stmt, uop, storage, inst) # type: ignore[no-any-return]
 
     def emit_SimpleStmt(
         self,
@@ -569,8 +569,8 @@ def emit_IfStmt(
         for tkn in stmt.condition:
             self.out.emit(tkn)
         if_storage = storage.copy()
+        rbrace: Token | None = stmt.if_
         try:
-            rbrace: Token | None = stmt.if_
             reachable, rbrace, if_storage = self._emit_stmt(stmt.body, uop, if_storage, inst)
             if stmt.else_ is not None:
                 assert rbrace is not None
@@ -609,6 +609,7 @@ def emit_BlockStmt(
         emit_braces: bool = True,
     ) -> tuple[bool, Token | None, Storage]:
         """ Returns (reachable?, closing '}', stack)."""
+        tkn: Token | None = None
         try:
             if emit_braces:
                 self.out.emit(stmt.open)

Tools/cases_generator/parsing.py

@@ -361,16 +361,15 @@ def label_def(self) -> LabelDef | None:
     @contextual
     def inst_def(self) -> InstDef | None:
         if hdr := self.inst_header():
-            if block := self.block():
-                return InstDef(
-                    hdr.annotations,
-                    hdr.kind,
-                    hdr.name,
-                    hdr.inputs,
-                    hdr.outputs,
-                    block,
-                )
-            raise self.make_syntax_error("Expected block")
+            block := self.block()
+            return InstDef(
+                hdr.annotations,
+                hdr.kind,
+                hdr.name,
+                hdr.inputs,
+                hdr.outputs,
+                block,
+            )
         return None
 
     @contextual