path: root/ipc/ipdl/ipdl/cxx/ast.py

# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.

import copy
import functools

from ipdl.util import hash_str


class Visitor:
    def defaultVisit(self, node):
        raise Exception(
            "INTERNAL ERROR: no visitor for node type `%s'" % (node.__class__.__name__)
        )

    def visitWhitespace(self, ws):
        pass

    def visitVerbatimNode(self, verb):
        pass

    def visitGroupNode(self, group):
        for node in group.nodes:
            node.accept(self)

    def visitFile(self, f):
        for thing in f.stuff:
            thing.accept(self)

    def visitCppDirective(self, ppd):
        pass

    def visitBlock(self, block):
        for stmt in block.stmts:
            stmt.accept(self)

    def visitNamespace(self, ns):
        self.visitBlock(ns)

    def visitType(self, type):
        pass

    def visitTypeArray(self, ta):
        ta.basetype.accept(self)
        ta.nmemb.accept(self)

    def visitTypeEnum(self, enum):
        pass

    def visitTypeFunction(self, fn):
        pass

    def visitTypeUnion(self, union):
        for t, name in union.components:
            t.accept(self)

    def visitTypedef(self, tdef):
        tdef.fromtype.accept(self)

    def visitUsing(self, us):
        us.type.accept(self)

    def visitForwardDecl(self, fd):
        pass

    def visitDecl(self, decl):
        decl.type.accept(self)

    def visitParam(self, param):
        self.visitDecl(param)
        if param.default is not None:
            param.default.accept(self)

    def visitClass(self, cls):
        for inherit in cls.inherits:
            inherit.accept(self)
        self.visitBlock(cls)

    def visitInherit(self, inh):
        pass

    def visitFriendClassDecl(self, fcd):
        pass

    def visitMethodDecl(self, meth):
        for param in meth.params:
            param.accept(self)
        if meth.ret is not None:
            meth.ret.accept(self)
        if meth.typeop is not None:
            meth.typeop.accept(self)
        if meth.T is not None:
            meth.T.accept(self)

    def visitMethodDefn(self, meth):
        meth.decl.accept(self)
        self.visitBlock(meth)

    def visitFunctionDecl(self, fun):
        self.visitMethodDecl(fun)

    def visitFunctionDefn(self, fd):
        self.visitMethodDefn(fd)

    def visitConstructorDecl(self, ctor):
        self.visitMethodDecl(ctor)

    def visitConstructorDefn(self, cd):
        cd.decl.accept(self)
        for init in cd.memberinits:
            init.accept(self)
        self.visitBlock(cd)

    def visitDestructorDecl(self, dtor):
        self.visitMethodDecl(dtor)

    def visitDestructorDefn(self, dd):
        dd.decl.accept(self)
        self.visitBlock(dd)

    def visitExprLiteral(self, l):
        pass

    def visitExprVar(self, v):
        pass

    def visitExprPrefixUnop(self, e):
        e.expr.accept(self)

    def visitExprBinary(self, e):
        e.left.accept(self)
        e.right.accept(self)

    def visitExprConditional(self, c):
        c.cond.accept(self)
        c.ife.accept(self)
        c.elsee.accept(self)

    def visitExprAddrOf(self, eao):
        self.visitExprPrefixUnop(eao)

    def visitExprDeref(self, ed):
        self.visitExprPrefixUnop(ed)

    def visitExprNot(self, en):
        self.visitExprPrefixUnop(en)

    def visitExprCast(self, ec):
        ec.expr.accept(self)

    def visitExprSelect(self, es):
        es.obj.accept(self)

    def visitExprAssn(self, ea):
        ea.lhs.accept(self)
        ea.rhs.accept(self)

    def visitExprCall(self, ec):
        ec.func.accept(self)
        for arg in ec.args:
            arg.accept(self)

    def visitExprMove(self, ec):
        self.visitExprCall(ec)

    def visitExprNothing(self, ec):
        self.visitExprCall(ec)

    def visitExprSome(self, ec):
        self.visitExprCall(ec)

    def visitExprNew(self, en):
        en.ctype.accept(self)
        if en.newargs is not None:
            for arg in en.newargs:
                arg.accept(self)
        if en.args is not None:
            for arg in en.args:
                arg.accept(self)

    def visitExprDelete(self, ed):
        ed.obj.accept(self)

    def visitExprMemberInit(self, minit):
        self.visitExprCall(minit)

    def visitExprLambda(self, l):
        self.visitBlock(l)

    def visitStmtBlock(self, sb):
        self.visitBlock(sb)

    def visitStmtDecl(self, sd):
        sd.decl.accept(self)
        if sd.init is not None:
            sd.init.accept(self)

    def visitLabel(self, label):
        pass

    def visitCaseLabel(self, case):
        pass

    def visitDefaultLabel(self, dl):
        pass

    def visitStmtIf(self, si):
        si.cond.accept(self)
        si.ifb.accept(self)
        if si.elseb is not None:
            si.elseb.accept(self)

    def visitStmtFor(self, sf):
        if sf.init is not None:
            sf.init.accept(self)
        if sf.cond is not None:
            sf.cond.accept(self)
        if sf.update is not None:
            sf.update.accept(self)

    def visitStmtSwitch(self, ss):
        ss.expr.accept(self)
        self.visitBlock(ss)

    def visitStmtBreak(self, sb):
        pass

    def visitStmtExpr(self, se):
        se.expr.accept(self)

    def visitStmtReturn(self, sr):
        if sr.expr is not None:
            sr.expr.accept(self)


# ------------------------------


class Node:
    def __init__(self):
        pass

    def accept(self, visitor):
        visit = getattr(visitor, "visit" + self.__class__.__name__, None)
        if visit is None:
            return getattr(visitor, "defaultVisit")(self)
        return visit(self)


class Whitespace(Node):
    # yes, this is silly.  but we need to stick comments in the
    # generated code without resorting to more serious hacks
    def __init__(self, ws, indent=False):
        Node.__init__(self)
        self.ws = ws
        self.indent = indent


Whitespace.NL = Whitespace("\n")


class VerbatimNode(Node):
    # A block of text to be written verbatim to the output file.
    #
    # NOTE: This node is usually created by `code`. See `code.py` for details.
    # FIXME: Merge Whitespace and VerbatimNode? They're identical.
    def __init__(self, text, indent=0):
        Node.__init__(self)
        self.text = text
        self.indent = indent


class GroupNode(Node):
    # A group of nodes to be treated as a single node. These nodes have an
    # optional indentation level which should be applied when generating them.
    #
    # NOTE: This node is usually created by `code`. See `code.py` for details.
    def __init__(self, nodes, offset=0):
        Node.__init__(self)
        self.nodes = nodes
        self.offset = offset


class File(Node):
    def __init__(self, filename):
        Node.__init__(self)
        self.name = filename
        # array of stuff in the file --- stmts and preprocessor thingies
        self.stuff = []

    def addthing(self, thing):
        assert thing is not None
        assert not isinstance(thing, list)
        self.stuff.append(thing)

    def addthings(self, things):
        for t in things:
            self.addthing(t)

    # "look like" a Block so code doesn't have to care whether they're
    # in global scope or not
    def addstmt(self, stmt):
        assert stmt is not None
        assert not isinstance(stmt, list)
        self.stuff.append(stmt)

    def addstmts(self, stmts):
        for s in stmts:
            self.addstmt(s)

    def addcode(self, tmpl, **context):
        from ipdl.cxx.code import StmtCode

        self.addstmt(StmtCode(tmpl, **context))


class CppDirective(Node):
    """represents |#[directive] [rest]|, where |rest| is any string"""

    def __init__(self, directive, rest=None):
        Node.__init__(self)
        self.directive = directive
        self.rest = rest


class Block(Node):
    def __init__(self):
        Node.__init__(self)
        self.stmts = []

    def addstmt(self, stmt):
        assert stmt is not None
        assert not isinstance(stmt, tuple)
        self.stmts.append(stmt)

    def addstmts(self, stmts):
        for s in stmts:
            self.addstmt(s)

    def addcode(self, tmpl, **context):
        from ipdl.cxx.code import StmtCode

        self.addstmt(StmtCode(tmpl, **context))


# ------------------------------
# type and decl thingies


class Namespace(Block):
    def __init__(self, name):
        assert isinstance(name, str)

        Block.__init__(self)
        self.name = name


class Type(Node):
    def __init__(
        self,
        name,
        const=False,
        ptr=False,
        ptrptr=False,
        ptrconstptr=False,
        ref=False,
        rvalref=False,
        rightconst=False,
        hasimplicitcopyctor=True,
        T=None,
        inner=None,
    ):
        """
        Represents the type |name<T>::inner| with the ptr and const
        modifiers as specified.

        To avoid getting fancy with recursive types, we limit the kinds
        of pointer types that can be be constructed.

          ptr            => T*
          ptrptr         => T**
          ptrconstptr    => T* const*
          ref            => T&
          rvalref        => T&&

        Any type, naked or pointer, can be const (const T) or ref (T&)."""
        # XXX(nika): This type is complex enough at this point, perhaps we
        # should get "fancy with recursive types" to simplify it.
        assert isinstance(name, str)
        assert isinstance(const, bool)
        assert isinstance(ptr, bool)
        assert isinstance(ptrptr, bool)
        assert isinstance(ptrconstptr, bool)
        assert isinstance(ref, bool)
        assert isinstance(rvalref, bool)
        assert isinstance(rightconst, bool)
        assert not isinstance(T, str)

        Node.__init__(self)
        self.name = name
        self.const = const
        self.ptr = ptr
        self.ptrptr = ptrptr
        self.ptrconstptr = ptrconstptr
        self.ref = ref
        self.rvalref = rvalref
        self.rightconst = rightconst
        self.hasimplicitcopyctor = hasimplicitcopyctor
        self.T = T
        self.inner = inner
        # XXX could get serious here with recursive types, but shouldn't
        # need that for this codegen

    def __deepcopy__(self, memo):
        return Type(
            self.name,
            const=self.const,
            ptr=self.ptr,
            ptrptr=self.ptrptr,
            ptrconstptr=self.ptrconstptr,
            ref=self.ref,
            rvalref=self.rvalref,
            rightconst=self.rightconst,
            T=copy.deepcopy(self.T, memo),
            inner=copy.deepcopy(self.inner, memo),
        )


Type.BOOL = Type("bool")
Type.INT = Type("int")
Type.INT32 = Type("int32_t")
Type.INTPTR = Type("intptr_t")
Type.NSRESULT = Type("nsresult")
Type.UINT32 = Type("uint32_t")
Type.UINT32PTR = Type("uint32_t", ptr=True)
Type.SIZE = Type("size_t")
Type.VOID = Type("void")
Type.VOIDPTR = Type("void", ptr=True)
Type.AUTO = Type("auto")
Type.AUTORVAL = Type("auto", rvalref=True)


class TypeArray(Node):
    def __init__(self, basetype, nmemb):
        """the type |basetype DECLNAME[nmemb]|.  |nmemb| is an Expr"""
        self.basetype = basetype
        self.nmemb = nmemb


class TypeEnum(Node):
    def __init__(self, name=None):
        """name can be None"""
        Node.__init__(self)
        self.name = name
        self.idnums = []  # pairs of ('Foo', [num]) or ('Foo', None)

    def addId(self, id, num=None):
        self.idnums.append((id, num))


class TypeUnion(Node):
    def __init__(self, name=None):
        Node.__init__(self)
        self.name = name
        self.components = []  # [ Decl ]

    def addComponent(self, type, name):
        self.components.append(Decl(type, name))


class TypeFunction(Node):
    def __init__(self, params=[], ret=Type("void")):
        """Anonymous function type std::function<>"""
        self.params = params
        self.ret = ret


@functools.total_ordering
class Typedef(Node):
    def __init__(self, fromtype, totypename, templateargs=[]):
        assert isinstance(totypename, str)

        Node.__init__(self)
        self.fromtype = fromtype
        self.totypename = totypename
        self.templateargs = templateargs

    def __lt__(self, other):
        return self.totypename < other.totypename

    def __eq__(self, other):
        return self.__class__ == other.__class__ and self.totypename == other.totypename

    def __hash__(self):
        return hash_str(self.totypename)


class Using(Node):
    def __init__(self, type):
        Node.__init__(self)
        self.type = type


class ForwardDecl(Node):
    def __init__(self, pqname, cls=False, struct=False):
        # Exactly one of cls and struct must be set
        assert cls ^ struct

        self.pqname = pqname
        self.cls = cls
        self.struct = struct


class Decl(Node):
    """represents |Foo bar|, e.g. in a function signature"""

    def __init__(self, type, name):
        assert type is not None
        assert not isinstance(type, str)
        assert isinstance(name, str)

        Node.__init__(self)
        self.type = type
        self.name = name

    def __deepcopy__(self, memo):
        return Decl(copy.deepcopy(self.type, memo), self.name)


class Param(Decl):
    def __init__(self, type, name, default=None):
        Decl.__init__(self, type, name)
        self.default = default

    def __deepcopy__(self, memo):
        return Param(
            copy.deepcopy(self.type, memo), self.name, copy.deepcopy(self.default, memo)
        )


# ------------------------------
# class stuff


class Class(Block):
    def __init__(
        self,
        name,
        inherits=[],
        interface=False,
        abstract=False,
        final=False,
        specializes=None,
        struct=False,
    ):
        assert not (interface and abstract)
        assert not (abstract and final)
        assert not (interface and final)
        assert not (inherits and specializes)

        Block.__init__(self)
        self.name = name
        self.inherits = inherits  # [ Type ]
        self.interface = interface  # bool
        self.abstract = abstract  # bool
        self.final = final  # bool
        self.specializes = specializes  # Type or None
        self.struct = struct  # bool


class Inherit(Node):
    def __init__(self, type, viz="public"):
        assert isinstance(viz, str)
        Node.__init__(self)
        self.type = type
        self.viz = viz


class FriendClassDecl(Node):
    def __init__(self, friend):
        Node.__init__(self)
        self.friend = friend


# Python2 polyfill for Python3's Enum() functional API.


def make_enum(name, members_str):
    members_list = members_str.split()
    members_dict = {}
    for member_value, member in enumerate(members_list, start=1):
        members_dict[member] = member_value
    return type(name, (), members_dict)


MethodSpec = make_enum("MethodSpec", "NONE VIRTUAL PURE OVERRIDE STATIC")


class MethodDecl(Node):
    def __init__(
        self,
        name,
        params=[],
        ret=Type("void"),
        methodspec=MethodSpec.NONE,
        const=False,
        warn_unused=False,
        force_inline=False,
        typeop=None,
        T=None,
        cls=None,
    ):
        assert not (name and typeop)
        assert name is None or isinstance(name, str)
        assert not isinstance(ret, list)
        for decl in params:
            assert not isinstance(decl, str)
        assert not isinstance(T, int)
        assert isinstance(const, bool)
        assert isinstance(warn_unused, bool)
        assert isinstance(force_inline, bool)

        if typeop is not None:
            assert methodspec == MethodSpec.NONE
            ret = None

        Node.__init__(self)
        self.name = name
        self.params = params  # [ Param ]
        self.ret = ret  # Type or None
        self.methodspec = methodspec  # enum
        self.const = const  # bool
        self.warn_unused = warn_unused  # bool
        self.force_inline = force_inline or bool(T)  # bool
        self.typeop = typeop  # Type or None
        self.T = T  # Type or None
        self.cls = cls  # Class or None
        self.only_for_definition = False

    def __deepcopy__(self, memo):
        return MethodDecl(
            self.name,
            params=copy.deepcopy(self.params, memo),
            ret=copy.deepcopy(self.ret, memo),
            methodspec=self.methodspec,
            const=self.const,
            warn_unused=self.warn_unused,
            force_inline=self.force_inline,
            typeop=copy.deepcopy(self.typeop, memo),
            T=copy.deepcopy(self.T, memo),
        )


class MethodDefn(Block):
    def __init__(self, decl):
        Block.__init__(self)
        self.decl = decl


class FunctionDecl(MethodDecl):
    def __init__(
        self,
        name,
        params=[],
        ret=Type("void"),
        methodspec=MethodSpec.NONE,
        warn_unused=False,
        force_inline=False,
        T=None,
    ):
        assert methodspec == MethodSpec.NONE or methodspec == MethodSpec.STATIC
        MethodDecl.__init__(
            self,
            name,
            params=params,
            ret=ret,
            methodspec=methodspec,
            warn_unused=warn_unused,
            force_inline=force_inline,
            T=T,
        )


class FunctionDefn(MethodDefn):
    def __init__(self, decl):
        MethodDefn.__init__(self, decl)


class ConstructorDecl(MethodDecl):
    def __init__(self, name, params=[], explicit=False, force_inline=False):
        MethodDecl.__init__(
            self, name, params=params, ret=None, force_inline=force_inline
        )
        self.explicit = explicit

    def __deepcopy__(self, memo):
        return ConstructorDecl(
            self.name, copy.deepcopy(self.params, memo), self.explicit
        )


class ConstructorDefn(MethodDefn):
    def __init__(self, decl, memberinits=[]):
        MethodDefn.__init__(self, decl)
        self.memberinits = memberinits


class DestructorDecl(MethodDecl):
    def __init__(self, name, methodspec=MethodSpec.NONE, force_inline=False):
        # C++ allows pure or override destructors, but ipdl cgen does not.
        assert methodspec == MethodSpec.NONE or methodspec == MethodSpec.VIRTUAL
        MethodDecl.__init__(
            self,
            name,
            params=[],
            ret=None,
            methodspec=methodspec,
            force_inline=force_inline,
        )

    def __deepcopy__(self, memo):
        return DestructorDecl(
            self.name, methodspec=self.methodspec, force_inline=self.force_inline
        )


class DestructorDefn(MethodDefn):
    def __init__(self, decl):
        MethodDefn.__init__(self, decl)


# ------------------------------
# expressions


class ExprVar(Node):
    def __init__(self, name):
        assert isinstance(name, str)

        Node.__init__(self)
        self.name = name


ExprVar.THIS = ExprVar("this")


class ExprLiteral(Node):
    def __init__(self, value, type):
        """|type| is a Python format specifier; 'd' for example"""
        Node.__init__(self)
        self.value = value
        self.type = type

    @staticmethod
    def Int(i):
        return ExprLiteral(i, "d")

    @staticmethod
    def String(s):
        return ExprLiteral('"' + s + '"', "s")

    def __str__(self):
        return ("%" + self.type) % (self.value)


ExprLiteral.ZERO = ExprLiteral.Int(0)
ExprLiteral.ONE = ExprLiteral.Int(1)
ExprLiteral.NULL = ExprVar("nullptr")
ExprLiteral.TRUE = ExprVar("true")
ExprLiteral.FALSE = ExprVar("false")


class ExprPrefixUnop(Node):
    def __init__(self, expr, op):
        assert not isinstance(expr, tuple)
        self.expr = expr
        self.op = op


class ExprNot(ExprPrefixUnop):
    def __init__(self, expr):
        ExprPrefixUnop.__init__(self, expr, "!")


class ExprAddrOf(ExprPrefixUnop):
    def __init__(self, expr):
        ExprPrefixUnop.__init__(self, expr, "&")


class ExprDeref(ExprPrefixUnop):
    def __init__(self, expr):
        ExprPrefixUnop.__init__(self, expr, "*")


class ExprCast(Node):
    def __init__(self, expr, type, static=False, const=False):
        # Exactly one of these should be set
        assert static ^ const

        Node.__init__(self)
        self.expr = expr
        self.type = type
        self.static = static
        self.const = const


class ExprBinary(Node):
    def __init__(self, left, op, right):
        Node.__init__(self)
        self.left = left
        self.op = op
        self.right = right


class ExprConditional(Node):
    def __init__(self, cond, ife, elsee):
        Node.__init__(self)
        self.cond = cond
        self.ife = ife
        self.elsee = elsee


class ExprSelect(Node):
    def __init__(self, obj, op, field):
        assert obj and op and field
        assert not isinstance(obj, str)
        assert isinstance(op, str)

        Node.__init__(self)
        self.obj = obj
        self.op = op
        if isinstance(field, str):
            self.field = ExprVar(field)
        else:
            self.field = field


class ExprAssn(Node):
    def __init__(self, lhs, rhs, op="="):
        Node.__init__(self)
        self.lhs = lhs
        self.op = op
        self.rhs = rhs


class ExprCall(Node):
    def __init__(self, func, args=[]):
        assert hasattr(func, "accept")
        assert isinstance(args, list)
        for arg in args:
            assert arg and not isinstance(arg, str)

        Node.__init__(self)
        self.func = func
        self.args = args


class ExprMove(ExprCall):
    def __init__(self, arg):
        ExprCall.__init__(self, ExprVar("std::move"), args=[arg])


class ExprNew(Node):
    # XXX taking some poetic license ...
    def __init__(self, ctype, args=[], newargs=None):
        assert not (ctype.const or ctype.ref or ctype.rvalref)

        Node.__init__(self)
        self.ctype = ctype
        self.args = args
        self.newargs = newargs


class ExprDelete(Node):
    def __init__(self, obj):
        Node.__init__(self)
        self.obj = obj


class ExprMemberInit(ExprCall):
    def __init__(self, member, args=[]):
        ExprCall.__init__(self, member, args)


class ExprLambda(Block):
    def __init__(self, captures=[], params=[], ret=None):
        Block.__init__(self)
        assert isinstance(captures, list)
        assert isinstance(params, list)
        self.captures = captures
        self.params = params
        self.ret = ret


# ------------------------------
# statements etc.


class StmtBlock(Block):
    def __init__(self, stmts=[]):
        Block.__init__(self)
        self.addstmts(stmts)


class StmtDecl(Node):
    def __init__(self, decl, init=None, initargs=None):
        assert not (init and initargs)
        assert not isinstance(init, str)  # easy to confuse with Decl
        assert not isinstance(init, list)
        assert not isinstance(decl, tuple)

        Node.__init__(self)
        self.decl = decl
        self.init = init
        self.initargs = initargs


class Label(Node):
    def __init__(self, name):
        Node.__init__(self)
        self.name = name


Label.PUBLIC = Label("public")
Label.PROTECTED = Label("protected")
Label.PRIVATE = Label("private")


class CaseLabel(Node):
    def __init__(self, name):
        Node.__init__(self)
        self.name = name


class DefaultLabel(Node):
    def __init__(self):
        Node.__init__(self)


class StmtIf(Node):
    def __init__(self, cond):
        Node.__init__(self)
        self.cond = cond
        self.ifb = Block()
        self.elseb = None

    def addifstmt(self, stmt):
        self.ifb.addstmt(stmt)

    def addifstmts(self, stmts):
        self.ifb.addstmts(stmts)

    def addelsestmt(self, stmt):
        if self.elseb is None:
            self.elseb = Block()
        self.elseb.addstmt(stmt)

    def addelsestmts(self, stmts):
        if self.elseb is None:
            self.elseb = Block()
        self.elseb.addstmts(stmts)


class StmtFor(Block):
    def __init__(self, init=None, cond=None, update=None):
        Block.__init__(self)
        self.init = init
        self.cond = cond
        self.update = update


class StmtRangedFor(Block):
    def __init__(self, var, iteree):
        assert isinstance(var, ExprVar)
        assert iteree

        Block.__init__(self)
        self.var = var
        self.iteree = iteree


class StmtSwitch(Block):
    def __init__(self, expr):
        Block.__init__(self)
        self.expr = expr
        self.nr_cases = 0

    def addcase(self, case, block):
        """NOTE: |case| is not checked for uniqueness"""
        assert not isinstance(case, str)
        assert (
            isinstance(block, StmtBreak)
            or isinstance(block, StmtReturn)
            or isinstance(block, StmtSwitch)
            or isinstance(block, GroupNode)
            or isinstance(block, VerbatimNode)
            or (
                hasattr(block, "stmts")
                and (
                    isinstance(block.stmts[-1], StmtBreak)
                    or isinstance(block.stmts[-1], StmtReturn)
                    or isinstance(block.stmts[-1], GroupNode)
                    or isinstance(block.stmts[-1], VerbatimNode)
                )
            )
        )
        self.addstmt(case)
        self.addstmt(block)
        self.nr_cases += 1


class StmtBreak(Node):
    def __init__(self):
        Node.__init__(self)


class StmtExpr(Node):
    def __init__(self, expr):
        assert expr is not None

        Node.__init__(self)
        self.expr = expr


class StmtReturn(Node):
    def __init__(self, expr=None):
        Node.__init__(self)
        self.expr = expr


StmtReturn.TRUE = StmtReturn(ExprLiteral.TRUE)
StmtReturn.FALSE = StmtReturn(ExprLiteral.FALSE)