Commit ce5a75d9 authored by Chuck Lever's avatar Chuck Lever
Browse files

xdrgen: XDR width for union types 



Not yet complete.

The tool doesn't do any math yet. Thus, even though the maximum XDR
width of a union is the width of the union enumerator plus the width
of its largest arm, we're using the sum of all the elements of the
union for the moment.

This means that buffer size requirements are overestimated, and that
the generated maxsize macro cannot yet be used for determining data
element alignment in the XDR buffer.

Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
parent 447dc1ef

tools/net/sunrpc/xdrgen/xdr_ast.py

+26 −0
Original line number Diff line number Diff line
@@ -450,9 +450,35 @@ class _XdrUnion(_XdrAst): 
    cases: List[_XdrCaseSpec]

    default: _XdrDeclaration



    def max_width(self) -> int:

        """Return width of type in XDR_UNITS"""

        max_width = 0

        for case in self.cases:

            if case.arm.max_width() > max_width:

                max_width = case.arm.max_width()

        if self.default:

            if self.default.arm.max_width() > max_width:

                max_width = self.default.arm.max_width()

        return 1 + max_width



    def symbolic_width(self) -> List:

        """Return list containing XDR width of type's components"""

        max_width = 0

        for case in self.cases:

            if case.arm.max_width() > max_width:

                max_width = case.arm.max_width()

                width = case.arm.symbolic_width()

        if self.default:

            if self.default.arm.max_width() > max_width:

                max_width = self.default.arm.max_width()

                width = self.default.arm.symbolic_width()

        return symbolic_widths[self.discriminant.name] + width



    def __post_init__(self):

        structs.add(self.name)

        pass_by_reference.add(self.name)

        max_widths[self.name] = self.max_width()

        symbolic_widths[self.name] = self.symbolic_width()





@dataclass