Report errors when trying to using optional ranges

Signed-off-by: Christian Vetter <[email protected]>

flatdata-generator/flatdata/generator/tree/builder.py

@@ -10,7 +10,7 @@
 from flatdata.generator.tree.errors import (
     InvalidEnumWidthError, InvalidRangeName, InvalidRangeReference,
     InvalidConstReference, InvalidConstValueReference, DuplicateInvalidValueReference,
-    InvalidStructInExplicitReference)
+    InvalidStructInExplicitReference, OptionalRange)
 from flatdata.generator.tree.nodes.explicit_reference import ExplicitReference
 from flatdata.generator.tree.nodes.archive import Archive
 from flatdata.generator.tree.nodes.node import Node
@@ -181,6 +181,9 @@ def _check_ranges(root):
         for sibling in field.parent.fields:
             if sibling.name == name:
                 raise InvalidRangeName(name)
+        # Also check that the range is not optional
+        if field.invalid_value:
+            raise OptionalRange(name)
 
     # Now check that structs with ranges are only used in vectors
     for reference in root.iterate(StructureReference):

flatdata-generator/flatdata/generator/tree/errors.py

@@ -148,4 +148,10 @@ class InvalidRangeReference(FlatdataSyntaxError):
     def __init__(self, name):
         super().__init__(
             "Structs with @range can only be used in vectors: {name}"
+            .format(name=name))
+
+class OptionalRange(FlatdataSyntaxError):
+    def __init__(self, name):
+        super().__init__(
+            "@range cannot be combined with @optional, store empty ranges instead: {name}"
             .format(name=name))

flatdata-generator/tests/tree/test_syntax_tree_builder.py

@@ -10,7 +10,7 @@
 sys.path.insert(0, "..")
 from flatdata.generator.tree.errors import MissingSymbol, InvalidRangeName, InvalidRangeReference, \
     InvalidConstReference, InvalidConstValueReference, DuplicateInvalidValueReference, \
-    InvalidStructInExplicitReference
+    InvalidStructInExplicitReference, OptionalRange
 from flatdata.generator.tree.builder import build_ast
 from flatdata.generator.tree.nodes.trivial import Namespace, Structure, Field, Constant, Enumeration, EnumerationValue
 from flatdata.generator.tree.nodes.archive import Archive
@@ -21,8 +21,6 @@
     FieldReference, ArchiveReference, BuiltinStructureReference, ConstantValueReference, \
     EnumerationReference, InvalidValueReference
 
-
-
 def test_validating_archive_with_no_structure_defined_raises_missing_symbol_error():
     def __test(resource_type):
         with assert_raises(MissingSymbol):
@@ -103,6 +101,17 @@ def test_range_cannot_be_used_in_struct_resource():
             }
             """)
 
+def test_optional_range():
+    with assert_raises(OptionalRange):
+        build_ast("""namespace foo{
+            const u32 NO_EDGES_REF = 200;
+            struct Node {
+                @range(edges_range)
+                @optional( NO_EDGES_REF )
+                first_edge_ref : u32;
+            }
+            }""")
+
 def test_ranges_can_be_used_in_normally():
     build_ast("""namespace foo{
         struct A {