Merge pull request #142 from robotpy/fix/issue-141-constexpr-friend

Fix reordered friend declaration parsing

Author: virtuald

cxxheaderparser/parser.py

@@ -2573,6 +2573,7 @@ def _parse_type(
 
         pqname: typing.Optional[PQName] = None
         pqname_optional = False
+        friend_tok: typing.Optional[LexToken] = None
 
         _pqname_start_tokens = self._pqname_start_tokens
         _attribute_start = self._attribute_start_tokens
@@ -2597,6 +2598,8 @@ def _parse_type(
                 break
             elif tok_type == "const":
                 const = True
+            elif tok_type == "friend" and pqname is None:
+                friend_tok = tok
             elif tok_type in self._type_kwd_both:
                 if tok_type == "extern":
                     # TODO: store linkage
@@ -2635,7 +2638,7 @@ def _parse_type(
         self.lex.return_token(tok)
 
         # Always return the modifiers
-        mods = ParsedTypeModifiers(vars, both, meths, explicit_value)
+        mods = ParsedTypeModifiers(vars, both, meths, explicit_value, friend_tok)
         return parsed_type, mods
 
     def _parse_decl(
@@ -2871,6 +2874,12 @@ def _parse_declarations(
         parsed_type, mods = self._parse_type(tok, operator_ok=True)
         attributes.extend(self._take_pending_attributes())
 
+        if mods.friend is not None:
+            if is_friend or is_typedef or not isinstance(self.state, ClassBlockState):
+                raise self._parse_error(mods.friend)
+            is_friend = True
+            mods = mods._replace(friend=None)
+
         # Check to see if this might be a class/enum declaration
         if (
             parsed_type is not None

cxxheaderparser/parserstate.py

@@ -16,8 +16,12 @@ class ParsedTypeModifiers(typing.NamedTuple):
     #: parens (omitting the parens themselves). ``None`` if absent or if
     #: ``explicit`` was used as a bare keyword.
     explicit_value: typing.Optional[Value] = None
+    #: ``friend`` if encountered while parsing declaration specifiers.
+    friend: typing.Optional[LexToken] = None
 
-    def validate(self, *, var_ok: bool, meth_ok: bool, msg: str) -> None:
+    def validate(
+        self, *, var_ok: bool, meth_ok: bool, msg: str, friend_ok: bool = False
+    ) -> None:
         # Almost there! Do any checks the caller asked for
         if not var_ok and self.vars:
             for tok in self.vars.values():
@@ -31,6 +35,9 @@ def validate(self, *, var_ok: bool, meth_ok: bool, msg: str) -> None:
             for tok in self.both.values():
                 raise CxxParseError(f"{msg}: unexpected '{tok.value}'")
 
+        if not friend_ok and self.friend is not None:
+            raise CxxParseError(f"{msg}: unexpected '{self.friend.value}'")
+
 
 #: custom user data for this state type
 T = typing.TypeVar("T")

tests/test_friends.py

@@ -1,6 +1,7 @@
 # Note: testcases generated via `python -m cxxheaderparser.gentest`
 
 from cxxheaderparser.types import (
+    AutoSpecifier,
     ClassDecl,
     Field,
     ForwardDecl,
@@ -381,3 +382,42 @@ class Garlic {
             ]
         )
     )
+
+
+def test_constexpr_friend_decl_order() -> None:
+    content = """
+      struct friend_constexpr_test {
+        constexpr friend auto foo() {
+        }
+      };
+    """
+    data = parse_string(content, cleandoc=True)
+
+    assert data == ParsedData(
+        namespace=NamespaceScope(
+            classes=[
+                ClassScope(
+                    class_decl=ClassDecl(
+                        typename=PQName(
+                            segments=[NameSpecifier(name="friend_constexpr_test")],
+                            classkey="struct",
+                        )
+                    ),
+                    friends=[
+                        FriendDecl(
+                            fn=Method(
+                                return_type=Type(
+                                    typename=PQName(segments=[AutoSpecifier()])
+                                ),
+                                name=PQName(segments=[NameSpecifier(name="foo")]),
+                                parameters=[],
+                                constexpr=True,
+                                has_body=True,
+                                access="public",
+                            )
+                        )
+                    ],
+                )
+            ]
+        )
+    )