Remove null states

Ref. #700
AdaCore · May 8, 2023 · 534cee6 · 534cee6
1 parent fc1ca64
commit 534cee6
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Showing 6 changed files with 8 additions and 34 deletions.
diff --git a/parser/language/parser.py b/parser/language/parser.py
@@ -489,7 +489,6 @@
     ),
     declaration=Or(grammar.renaming_declaration, grammar.variable_declaration),
     description_aspect=ast.Description("Desc", "=>", grammar.string_literal),
-    null_state_body=ast.NullStateBody("null", "state"),
     assignment_statement=ast.Assignment(
         grammar.unqualified_identifier, ":=", grammar.extended_expression
     ),
@@ -534,7 +533,7 @@
     ),
     transition=ast.Transition(
         "goto",
-        Or(ast.NullID("null"), grammar.unqualified_identifier),
+        grammar.unqualified_identifier,
         Opt("with", grammar.description_aspect),
     ),
     state_body=ast.StateBody(
@@ -553,7 +552,7 @@
         grammar.unqualified_identifier,
         Opt("with", grammar.description_aspect),
         "is",
-        Or(grammar.null_state_body, grammar.state_body),
+        grammar.state_body,
     ),
     session_declaration=ast.SessionDecl(
         "generic",

diff --git a/parser/language/rflx_ast.py b/parser/language/rflx_ast.py
@@ -166,15 +166,6 @@ class RenamingDecl(LocalDecl):
     expression = Field(type=Expr)
 
 
-@abstract
-class BaseStateBody(RFLXNode):
-    """Base class for session state body."""
-
-
-class NullStateBody(BaseStateBody):
-    pass
-
-
 @abstract
 class Statement(RFLXNode):
     """Base class for statements."""
@@ -270,7 +261,7 @@ class ConditionalTransition(Transition):
     condition = Field(type=Expr)
 
 
-class StateBody(BaseStateBody):
+class StateBody(RFLXNode):
     """Body of a session state."""
 
     declarations = Field(type=LocalDecl.list)
@@ -286,7 +277,7 @@ class State(RFLXNode):
 
     identifier = Field(type=UnqualifiedID)
     description = Field(type=Description)
-    body = Field(type=BaseStateBody)
+    body = Field(type=StateBody)
 
 
 class SessionDecl(Declaration):

diff --git a/parser/tests/data/session/tls_handshake_session.rflx b/parser/tests/data/session/tls_handshake_session.rflx
@@ -1486,10 +1486,8 @@ package TLS_Handshake_Session is
          Application_Control_Channel'Write (GreenTLS::Application_Control_Message'(Tag => GreenTLS::APPLICATION_ALERT, Length => Data'Size, Data => Data)
             where Data = GreenTLS::Alert_Message'(Description => Error));
       transition
-         goto TERMINATED
+         goto null
       end ERROR_SEND_LOCAL;
-
-      state TERMINATED is null state;
    end Client;
 
 end TLS_Handshake_Session;
diff --git a/parser/tests/data/session/tls_record_session.rflx b/parser/tests/data/session/tls_record_session.rflx
@@ -463,10 +463,8 @@ package TLS_Record_Session is
          Client_Key_Update_Message'Reset;
          Server_Key_Update_Message'Reset;
       transition
-         goto TERMINATED
+         goto null
       end TERMINATING;
-
-      state TERMINATED is null state;
    end Client;
 
 end TLS_Record_Session;
diff --git a/parser/tests/grammar_test.py b/parser/tests/grammar_test.py
@@ -3269,12 +3269,10 @@ def test_state(string: str, expected: Dict[str, str]) -> None:
                   begin
                      Z := False;
                   transition
-                     goto B
+                     goto null
                         if Z = False
                      goto A
                   end A;
-
-                  state B is null state;
                end Session
          """,
             {
@@ -3375,7 +3373,7 @@ def test_state(string: str, expected: Dict[str, str]) -> None:
                                         },
                                     },
                                     "description": None,
-                                    "target": {"_kind": "UnqualifiedID", "_value": "B"},
+                                    "target": {"_kind": "UnqualifiedID", "_value": "null"},
                                 }
                             ],
                             "declarations": [
@@ -3417,12 +3415,6 @@ def test_state(string: str, expected: Dict[str, str]) -> None:
                         "description": None,
                         "identifier": {"_kind": "UnqualifiedID", "_value": "A"},
                     },
-                    {
-                        "_kind": "State",
-                        "body": {"_kind": "NullStateBody", "_value": "null state"},
-                        "description": None,
-                        "identifier": {"_kind": "UnqualifiedID", "_value": "B"},
-                    },
                 ],
             },
         ),

diff --git a/parser/tests/parser_test.py b/parser/tests/parser_test.py
@@ -381,10 +381,6 @@ def test_suffix_precedence() -> None:
             "begin transition goto {keyword} end {keyword}",
             librflxlang.GrammarRule.state_body_rule,
         ),
-        (
-            "state {keyword} is null state",
-            librflxlang.GrammarRule.state_rule,
-        ),
         (
             "generic session {keyword} is begin end {keyword}",
             librflxlang.GrammarRule.session_declaration_rule,