source: vbox/trunk/src/libs/xpcom18a4/xpcom/typelib/xpidl/xpidl_util.c

/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: NPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Netscape Public License
 * Version 1.1 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://www.mozilla.org/NPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is 
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or 
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the NPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the NPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

/*
 * Utility functions called by various backends.
 */ 

#include "xpidl.h"

/* XXXbe static */ char OOM[] = "ERROR: out of memory\n";

void *
xpidl_malloc(size_t nbytes)
{
    void *p = malloc(nbytes);
    if (!p) {
        fputs(OOM, stderr);
        exit(1);
    }
    return p;
}

char *
xpidl_strdup(const char *s)
{
#if defined(XP_MAC) || defined(XP_SOLARIS) /* bird: dunno why this is required, but whatever*/
    size_t len = strlen(s);
        char *ns = malloc(len + 1);
        if (ns)
                memcpy(ns, s, len + 1);
#else
    char *ns = strdup(s);
#endif
    if (!ns) {
        fputs(OOM, stderr);
        exit(1);
    }
    return ns;
}

void
xpidl_write_comment(TreeState *state, int indent)
{
    fprintf(state->file, "%*s/* ", indent, "");
    IDL_tree_to_IDL(state->tree, state->ns, state->file,
                    IDLF_OUTPUT_NO_NEWLINES |
                    IDLF_OUTPUT_NO_QUALIFY_IDENTS |
                    IDLF_OUTPUT_PROPERTIES);
    fputs(" */\n", state->file);
}

/*
 * Print an iid to into a supplied buffer; the buffer should be at least
 * UUID_LENGTH bytes.
 */
gboolean
xpidl_sprint_iid(nsID *id, char iidbuf[])
{
    int printed;

    printed = sprintf(iidbuf,
                       "%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x",
                       (PRUint32) id->m0, (PRUint32) id->m1,(PRUint32) id->m2,
                       (PRUint32) id->m3[0], (PRUint32) id->m3[1],
                       (PRUint32) id->m3[2], (PRUint32) id->m3[3],
                       (PRUint32) id->m3[4], (PRUint32) id->m3[5],
                       (PRUint32) id->m3[6], (PRUint32) id->m3[7]);

#ifdef SPRINTF_RETURNS_STRING
    return (printed && strlen((char *)printed) == 36);
#else
    return (printed == 36);
#endif
}

/* We only parse the {}-less format. */
static const char nsIDFmt2[] =
  "%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x";

/*
 * Parse a uuid string into an nsID struct.  We cannot link against libxpcom,
 * so we re-implement nsID::Parse here.
 */
gboolean
xpidl_parse_iid(nsID *id, const char *str)
{
    PRInt32 count = 0;
    PRInt32 n1, n2, n3[8];
    PRInt32 n0, i;

    XPT_ASSERT(str != NULL);
    
    if (strlen(str) != 36) {
        return FALSE;
    }
     
#ifdef DEBUG_shaver_iid
    fprintf(stderr, "parsing iid   %s\n", str);
#endif

    count = sscanf(str, nsIDFmt2,
                   &n0, &n1, &n2,
                   &n3[0],&n3[1],&n3[2],&n3[3],
                   &n3[4],&n3[5],&n3[6],&n3[7]);

    id->m0 = (PRInt32) n0;
    id->m1 = (PRInt16) n1;
    id->m2 = (PRInt16) n2;
    for (i = 0; i < 8; i++) {
      id->m3[i] = (PRInt8) n3[i];
    }

#ifdef DEBUG_shaver_iid
    if (count == 11) {
        fprintf(stderr, "IID parsed to ");
        print_IID(id, stderr);
        fputs("\n", stderr);
    }
#endif
    return (gboolean)(count == 11);
}

gboolean
verify_const_declaration(IDL_tree const_tree) {
    struct _IDL_CONST_DCL *dcl = &IDL_CONST_DCL(const_tree);
    const char *name = IDL_IDENT(dcl->ident).str;
    IDL_tree real_type;

    /* const -> list -> interface */
    if (!IDL_NODE_UP(IDL_NODE_UP(const_tree)) ||
        IDL_NODE_TYPE(IDL_NODE_UP(IDL_NODE_UP(const_tree)))
        != IDLN_INTERFACE) {
        IDL_tree_error(const_tree,
                       "const declaration \'%s\' outside interface",
                       name);
        return FALSE;
    }

    /* Could be a typedef; try to map it to the real type. */
    real_type = find_underlying_type(dcl->const_type);
    real_type = real_type ? real_type : dcl->const_type;
    if (IDL_NODE_TYPE(real_type) == IDLN_TYPE_INTEGER &&
        (IDL_TYPE_INTEGER(real_type).f_type == IDL_INTEGER_TYPE_SHORT ||
         IDL_TYPE_INTEGER(real_type).f_type == IDL_INTEGER_TYPE_LONG))
    {
        if (!IDL_TYPE_INTEGER(real_type).f_signed &&
            IDL_INTEGER(dcl->const_exp).value < 0)
        {
#ifndef G_HAVE_GINT64
            /*
             * For platforms without longlong support turned on we can get
             * confused by the high bit of the long value and think that it
             * represents a negative value in an unsigned declaration.
             * In that case we don't know if it is the programmer who is 
             * confused or the compiler. So we issue a warning instead of 
             * an error.
             */
            if (IDL_TYPE_INTEGER(real_type).f_type == IDL_INTEGER_TYPE_LONG)
            {
                XPIDL_WARNING((const_tree, IDL_WARNING1,
                              "unsigned const declaration \'%s\' "
                              "initialized with (possibly) negative constant",
                              name));
                return TRUE;
            }
#endif
            IDL_tree_error(const_tree,
                           "unsigned const declaration \'%s\' initialized with "
                           "negative constant",
                           name);
            return FALSE;
        }
    } else {
        IDL_tree_error(const_tree,
                       "const declaration \'%s\' must be of type short or long",
                       name);
        return FALSE;
    }

    return TRUE;
}



/*
 * This method consolidates error checking needed when coercing the XPIDL compiler 
 * via the -t flag to generate output for a specific version of XPConnect.
 */
static gboolean
verify_type_fits_version(IDL_tree in_tree, IDL_tree error_tree)
{
    if (major_version == 1 && minor_version == 1)
    {
        /* XPIDL Version 1.1 checks */

        /* utf8string, cstring, and astring types are not supported */
        if (IDL_tree_property_get(in_tree, "utf8string") != NULL ||
            IDL_tree_property_get(in_tree, "cstring")    != NULL ||
            IDL_tree_property_get(in_tree, "astring")    != NULL)
        {
            IDL_tree_error(error_tree,
                           "Cannot use [utf8string], [cstring] and [astring] "
                           "types when generating version 1.1 typelibs\n");
            return FALSE;
        }
    }
    return TRUE;
}

gboolean
verify_attribute_declaration(IDL_tree attr_tree)
{
    IDL_tree iface;
    IDL_tree ident;
    IDL_tree attr_type;
    gboolean scriptable_interface;

    /* We don't support attributes named IID, conflicts with static GetIID 
     * member. The conflict is due to certain compilers (VC++) choosing a
     * different vtable order, placing GetIID at the beginning regardless
     * of it's placement
     */
    if (strcmp(
        IDL_IDENT(
            IDL_LIST(IDL_ATTR_DCL(attr_tree).simple_declarations).data).str, 
        "IID") == 0) {
        IDL_tree_error(attr_tree,
                       "Attributes named IID not supported, causes vtable "
                       "ordering problems");
        return FALSE;
    }
    /* 
     * Verify that we've been called on an interface, and decide if the
     * interface was marked [scriptable].
     */
    if (IDL_NODE_UP(attr_tree) && IDL_NODE_UP(IDL_NODE_UP(attr_tree)) &&
        IDL_NODE_TYPE(iface = IDL_NODE_UP(IDL_NODE_UP(attr_tree))) 
        == IDLN_INTERFACE)
    {
        scriptable_interface =
            (IDL_tree_property_get(IDL_INTERFACE(iface).ident, "scriptable")
             != NULL);
    } else {
        IDL_tree_error(attr_tree,
                    "verify_attribute_declaration called on a non-interface?");
        return FALSE;
    }

    /*
     * Grab the first of the list of idents and hope that it'll
     * say scriptable or no.
     */
    ident = IDL_LIST(IDL_ATTR_DCL(attr_tree).simple_declarations).data;

    /*
     * If the interface isn't scriptable, or the attribute is marked noscript,
     * there's no need to check.
     */
    if (!scriptable_interface ||
        IDL_tree_property_get(ident, "noscript") != NULL)
        return TRUE;

    /*
     * If it should be scriptable, check that the type is non-native. nsid,
     * domstring, utf8string, cstring, astring are exempted.
     */
    attr_type = IDL_ATTR_DCL(attr_tree).param_type_spec;

    if (attr_type != NULL)
    {
        if (UP_IS_NATIVE(attr_type) &&
            IDL_tree_property_get(attr_type, "nsid") == NULL &&
            IDL_tree_property_get(attr_type, "domstring") == NULL &&
            IDL_tree_property_get(attr_type, "utf8string") == NULL &&
            IDL_tree_property_get(attr_type, "cstring") == NULL &&
            IDL_tree_property_get(attr_type, "astring") == NULL)
        {
            IDL_tree_error(attr_tree,
                           "attributes in [scriptable] interfaces that are "
                           "non-scriptable because they refer to native "
                           "types must be marked [noscript]\n");
            return FALSE;
        }
        /*
         * We currently don't support properties of type nsid that aren't 
         * pointers or references, unless they are marked [notxpcom} and 
         * must be read-only 
         */
         
        if ((IDL_tree_property_get(ident, "notxpcom") == NULL || !(IDL_ATTR_DCL(attr_tree).f_readonly)) &&
            IDL_tree_property_get(attr_type,"nsid") != NULL &&
            IDL_tree_property_get(attr_type,"ptr") == NULL &&
            IDL_tree_property_get(attr_type,"ref") == NULL)
        {
            IDL_tree_error(attr_tree,
                           "Feature not currently supported: "
                           "attributes with a type of nsid must be marked "
                           "either [ptr] or [ref], or "
                           "else must be marked [notxpcom] "
                           "and must be read-only\n");
            return FALSE;
        }

        /* 
         * Run additional error checks on the attribute type if targetting an 
         * older version of XPConnect.
         */

        if (!verify_type_fits_version(attr_type, attr_tree))
            return FALSE;
    }

    if (IDL_LIST(IDL_ATTR_DCL(attr_tree).simple_declarations).next != NULL)
    {
        IDL_tree_error(attr_tree,
            "multiple attributes in a single declaration is not supported\n");
        return FALSE;
    }
    return TRUE;
}

/*
 * Find the underlying type of an identifier typedef.
 * 
 * All the needed tree-walking seems pretty shaky; isn't there something in
 * libIDL to automate this?
 */
IDL_tree /* IDL_TYPE_DCL */
find_underlying_type(IDL_tree typedef_ident)
{
    IDL_tree up;

    if (typedef_ident == NULL || IDL_NODE_TYPE(typedef_ident) != IDLN_IDENT)
        return NULL;

    up = IDL_NODE_UP(typedef_ident);
    if (up == NULL || IDL_NODE_TYPE(up) != IDLN_LIST)
        return NULL;
    up = IDL_NODE_UP(up);
    if (up == NULL || IDL_NODE_TYPE(up) != IDLN_TYPE_DCL)
        return NULL;

    return IDL_TYPE_DCL(up).type_spec;
}

static IDL_tree /* IDL_PARAM_DCL */
find_named_parameter(IDL_tree method_tree, const char *param_name)
{
    IDL_tree iter;
    for (iter = IDL_OP_DCL(method_tree).parameter_dcls; iter;
         iter = IDL_LIST(iter).next)
    {
        IDL_tree param = IDL_LIST(iter).data;
        IDL_tree simple_decl = IDL_PARAM_DCL(param).simple_declarator;
        const char *current_name = IDL_IDENT(simple_decl).str;
        if (strcmp(current_name, param_name) == 0)
            return param;
    }
    return NULL;
}

typedef enum ParamAttrType {
    IID_IS,
    LENGTH_IS,
    SIZE_IS
} ParamAttrType;

/*
 * Check that parameters referred to by attributes such as size_is exist and
 * refer to parameters of the appropriate type.
 */
static gboolean
check_param_attribute(IDL_tree method_tree, IDL_tree param,
                      ParamAttrType whattocheck)
{
    const char *referred_name = NULL;
    IDL_tree simple_decl = IDL_PARAM_DCL(param).simple_declarator;
    const char *attr_name;
    const char *needed_type;

    if (whattocheck == IID_IS) {
        attr_name = "iid_is";
        needed_type = "IID";
    } else if (whattocheck == LENGTH_IS) {
        attr_name = "length_is";
        needed_type = "unsigned long (or PRUint32)";
    } else if (whattocheck == SIZE_IS) {
        attr_name = "size_is";
        needed_type = "unsigned long (or PRUint32)";
    } else {
        XPT_ASSERT("asked to check an unknown attribute type!");
        return TRUE;
    }
    
    referred_name = IDL_tree_property_get(simple_decl, attr_name);
    if (referred_name != NULL) {
        IDL_tree referred_param = find_named_parameter(method_tree,
                                                       referred_name);
        IDL_tree referred_param_type;
        if (referred_param == NULL) {
            IDL_tree_error(method_tree,
                           "attribute [%s(%s)] refers to missing "
                           "parameter \"%s\"",
                           attr_name, referred_name, referred_name);
            return FALSE;
        }
        if (referred_param == param) {
            IDL_tree_error(method_tree,
                           "attribute [%s(%s)] refers to it's own parameter",
                           attr_name, referred_name);
            return FALSE;
        }
        
        referred_param_type = IDL_PARAM_DCL(referred_param).param_type_spec;
        if (whattocheck == IID_IS) {
            /* require IID type */
            if (IDL_tree_property_get(referred_param_type, "nsid") == NULL) {
                IDL_tree_error(method_tree,
                               "target \"%s\" of [%s(%s)] attribute "
                               "must be of %s type",
                               referred_name, attr_name, referred_name,
                               needed_type);
                return FALSE;
            }
        } else if (whattocheck == LENGTH_IS || whattocheck == SIZE_IS) {
            /* require PRUint32 type */
            IDL_tree real_type;

            /* Could be a typedef; try to map it to the real type. */
            real_type = find_underlying_type(referred_param_type);
            real_type = real_type ? real_type : referred_param_type;

            if (IDL_NODE_TYPE(real_type) != IDLN_TYPE_INTEGER ||
                IDL_TYPE_INTEGER(real_type).f_signed != FALSE ||
                IDL_TYPE_INTEGER(real_type).f_type != IDL_INTEGER_TYPE_LONG)
            {
                IDL_tree_error(method_tree,
                               "target \"%s\" of [%s(%s)] attribute "
                               "must be of %s type",
                               referred_name, attr_name, referred_name,
                               needed_type);

                return FALSE;
            }
        }
    }

    return TRUE;
}


/*
 * Common method verification code, called by *op_dcl in the various backends.
 */
gboolean
verify_method_declaration(IDL_tree method_tree)
{
    struct _IDL_OP_DCL *op = &IDL_OP_DCL(method_tree);
    IDL_tree iface;
    IDL_tree iter;
    gboolean notxpcom;
    gboolean scriptable_interface;
    gboolean scriptable_method;
    gboolean seen_retval = FALSE;
    const char *method_name = IDL_IDENT(IDL_OP_DCL(method_tree).ident).str;

    /* We don't support attributes named IID, conflicts with static GetIID 
     * member. The conflict is due to certain compilers (VC++) choosing a
     * different vtable order, placing GetIID at the beginning regardless
     * of it's placement
     */
    if (strcmp(method_name, "GetIID") == 0) {
        IDL_tree_error(method_tree,
                       "Methods named GetIID not supported, causes vtable "
                       "ordering problems");
        return FALSE;
    }
    if (op->f_varargs) {
        /* We don't currently support varargs. */
        IDL_tree_error(method_tree, "varargs are not currently supported");
        return FALSE;
    }

    /* 
     * Verify that we've been called on an interface, and decide if the
     * interface was marked [scriptable].
     */
    if (IDL_NODE_UP(method_tree) && IDL_NODE_UP(IDL_NODE_UP(method_tree)) &&
        IDL_NODE_TYPE(iface = IDL_NODE_UP(IDL_NODE_UP(method_tree))) 
        == IDLN_INTERFACE)
    {
        scriptable_interface =
            (IDL_tree_property_get(IDL_INTERFACE(iface).ident, "scriptable")
             != NULL);
    } else {
        IDL_tree_error(method_tree,
                       "verify_method_declaration called on a non-interface?");
        return FALSE;
    }

    /*
     * Require that any method in an interface marked as [scriptable], that
     * *isn't* scriptable because it refers to some native type, be marked
     * [noscript] or [notxpcom].
     *
     * Also check that iid_is points to nsid, and length_is, size_is points
     * to unsigned long.
     */
    notxpcom = IDL_tree_property_get(op->ident, "notxpcom") != NULL;

    scriptable_method = scriptable_interface &&
        !notxpcom &&
        IDL_tree_property_get(op->ident, "noscript") == NULL;

    /* Loop through the parameters and check. */
    for (iter = op->parameter_dcls; iter; iter = IDL_LIST(iter).next) {
        IDL_tree param = IDL_LIST(iter).data;
        IDL_tree param_type =
            IDL_PARAM_DCL(param).param_type_spec;
        IDL_tree simple_decl =
            IDL_PARAM_DCL(param).simple_declarator;
        const char *param_name = IDL_IDENT(simple_decl).str;
        
        /*
         * Reject this method if it should be scriptable and some parameter is
         * native that isn't marked with either nsid, domstring, utf8string, 
         * cstring, astring or iid_is.
         */
        if (scriptable_method &&
            UP_IS_NATIVE(param_type) &&
            IDL_tree_property_get(param_type, "nsid") == NULL &&
            IDL_tree_property_get(simple_decl, "iid_is") == NULL &&
            IDL_tree_property_get(param_type, "domstring") == NULL &&
            IDL_tree_property_get(param_type, "utf8string") == NULL &&
            IDL_tree_property_get(param_type, "cstring") == NULL &&
            IDL_tree_property_get(param_type, "astring") == NULL)
        {
            IDL_tree_error(method_tree,
                           "methods in [scriptable] interfaces that are "
                           "non-scriptable because they refer to native "
                           "types (parameter \"%s\") must be marked "
                           "[noscript]", param_name);
            return FALSE;
        }

        /* 
         * nsid's parameters that aren't ptr's or ref's are not currently 
         * supported in xpcom or non-xpcom (marked with [notxpcom]) methods 
         * as input parameters
         */
        if (!(notxpcom && IDL_PARAM_DCL(param).attr != IDL_PARAM_IN) &&
            IDL_tree_property_get(param_type, "nsid") != NULL &&
            IDL_tree_property_get(param_type, "ptr") == NULL &&
            IDL_tree_property_get(param_type, "ref") == NULL) 
        {
            IDL_tree_error(method_tree,
                           "Feature currently not supported: "
                           "parameter \"%s\" is of type nsid and "
                           "must be marked either [ptr] or [ref] "
                           "or method \"%s\" must be marked [notxpcom] "
                           "and must not be an input parameter",
                           param_name,
                           method_name);
            return FALSE;
        }
        /*
         * Sanity checks on return values.
         */
        if (IDL_tree_property_get(simple_decl, "retval") != NULL) {
            if (IDL_LIST(iter).next != NULL) {
                IDL_tree_error(method_tree,
                               "only the last parameter can be marked [retval]");
                return FALSE;
            }
            if (op->op_type_spec) {
                IDL_tree_error(method_tree,
                               "can't have [retval] with non-void return type");
                return FALSE;
            }
            /* In case XPConnect relaxes the retval-is-last restriction. */
            if (seen_retval) {
                IDL_tree_error(method_tree,
                               "can't have more than one [retval] parameter");
                return FALSE;
            }
            seen_retval = TRUE;
        }

        /*
         * Confirm that [shared] attributes are only used with string, wstring,
         * or native (but not nsid, domstring, utf8string, cstring or astring) 
         * and can't be used with [array].
         */
        if (IDL_tree_property_get(simple_decl, "shared") != NULL) {
            IDL_tree real_type;
            real_type = find_underlying_type(param_type);
            real_type = real_type ? real_type : param_type;

            if (IDL_tree_property_get(simple_decl, "array") != NULL) {
                IDL_tree_error(method_tree,
                               "[shared] parameter \"%s\" cannot "
                               "be of array type", param_name);
                return FALSE;
            }                

            if (!(IDL_NODE_TYPE(real_type) == IDLN_TYPE_STRING ||
                  IDL_NODE_TYPE(real_type) == IDLN_TYPE_WIDE_STRING ||
                  (UP_IS_NATIVE(real_type) &&
                   !IDL_tree_property_get(real_type, "nsid") &&
                   !IDL_tree_property_get(real_type, "domstring")  &&
                   !IDL_tree_property_get(real_type, "utf8string") &&
                   !IDL_tree_property_get(real_type, "cstring")    &&
                   !IDL_tree_property_get(real_type, "astring"))))
            {
                IDL_tree_error(method_tree,
                               "[shared] parameter \"%s\" must be of type "
                               "string, wstring or native", param_name);
                return FALSE;
            }
        }

        /*
         * inout is not allowed with "domstring", "UTF8String", "CString" 
         * and "AString" types
         */
        if (IDL_PARAM_DCL(param).attr == IDL_PARAM_INOUT &&
            UP_IS_NATIVE(param_type) &&
            (IDL_tree_property_get(param_type, "domstring")  != NULL ||
             IDL_tree_property_get(param_type, "utf8string") != NULL ||
             IDL_tree_property_get(param_type, "cstring")    != NULL ||
             IDL_tree_property_get(param_type, "astring")    != NULL )) {
            IDL_tree_error(method_tree,
                           "[domstring], [utf8string], [cstring], [astring] "
                           "types cannot be used as inout parameters");
            return FALSE;
        }


        /*
         * arrays of domstring, utf8string, cstring, astring types not allowed
         */
        if (IDL_tree_property_get(simple_decl, "array") != NULL &&
            UP_IS_NATIVE(param_type) &&
            (IDL_tree_property_get(param_type, "domstring")  != NULL ||
             IDL_tree_property_get(param_type, "utf8string") != NULL ||
             IDL_tree_property_get(param_type, "cstring")    != NULL ||
             IDL_tree_property_get(param_type, "astring")    != NULL)) {
            IDL_tree_error(method_tree,
                           "[domstring], [utf8string], [cstring], [astring] "
                           "types cannot be used in array parameters");
            return FALSE;
        }                

        if (!check_param_attribute(method_tree, param, IID_IS) ||
            !check_param_attribute(method_tree, param, LENGTH_IS) ||
            !check_param_attribute(method_tree, param, SIZE_IS))
            return FALSE;

        /* 
         * Run additional error checks on the parameter type if targetting an 
         * older version of XPConnect.
         */

        if (!verify_type_fits_version(param_type, method_tree))
            return FALSE;
        
    }
    
    /* XXX q: can return type be nsid? */
    /* Native return type? */
    if (scriptable_method &&
        op->op_type_spec != NULL && UP_IS_NATIVE(op->op_type_spec) &&
        IDL_tree_property_get(op->op_type_spec, "nsid") == NULL &&
        IDL_tree_property_get(op->op_type_spec, "domstring") == NULL &&
        IDL_tree_property_get(op->op_type_spec, "utf8string") == NULL &&
        IDL_tree_property_get(op->op_type_spec, "cstring") == NULL &&
        IDL_tree_property_get(op->op_type_spec, "astring") == NULL)
    {
        IDL_tree_error(method_tree,
                       "methods in [scriptable] interfaces that are "
                       "non-scriptable because they return native "
                       "types must be marked [noscript]");
        return FALSE;
    }


    /* 
     * nsid's parameters that aren't ptr's or ref's are not currently 
     * supported in xpcom
     */
    if (!notxpcom &&
        op->op_type_spec != NULL &&
        IDL_tree_property_get(op->op_type_spec, "nsid") != NULL &&
        IDL_tree_property_get(op->op_type_spec, "ptr") == NULL &&
        IDL_tree_property_get(op->op_type_spec, "ref") == NULL) 
    {
        IDL_tree_error(method_tree,
                       "Feature currently not supported: "
                       "return value is of type nsid and "
                       "must be marked either [ptr] or [ref], "
                       "or else method \"%s\" must be marked [notxpcom] ",
                       method_name);
        return FALSE;
    }

    /* 
     * Run additional error checks on the return type if targetting an 
     * older version of XPConnect.
     */

    if (op->op_type_spec != NULL &&
        !verify_type_fits_version(op->op_type_spec, method_tree))
    {
        return FALSE;
    }

    return TRUE;
}

/*
 * Verify that a native declaration has an associated C++ expression, i.e. that
 * it's of the form native <idl-name>(<c++-name>)
 */
gboolean
check_native(TreeState *state)
{
    char *native_name;
    /* require that native declarations give a native type */
    if (IDL_NATIVE(state->tree).user_type) 
        return TRUE;
    native_name = IDL_IDENT(IDL_NATIVE(state->tree).ident).str;
    IDL_tree_error(state->tree,
                   "``native %s;'' needs C++ type: ``native %s(<C++ type>);''",
                   native_name, native_name);
    return FALSE;
}

/*
 * Print a GSList as char strings to a file.
 */
void
printlist(FILE *outfile, GSList *slist)
{
    guint i;
    guint len = g_slist_length(slist);

    for(i = 0; i < len; i++) {
        fprintf(outfile, 
                "%s\n", (char *)g_slist_nth_data(slist, i));
    }
}

void
xpidl_list_foreach(IDL_tree p, IDL_tree_func foreach, gpointer user_data)
{
    IDL_tree_func_data tfd;

    while (p) {
        struct _IDL_LIST *list = &IDL_LIST(p);
        tfd.tree = list->data;
        if (!foreach(&tfd, user_data))
            return;
        p = list->next;
    }
}

/*
 * Verify that the interface declaration is correct
 */
gboolean
verify_interface_declaration(IDL_tree interface_tree)
{
    IDL_tree iter;
    /* 
     * If we have the scriptable attribute then make sure all of our direct
     * parents have it as well.
     * NOTE: We don't recurse since all interfaces will fall through here
     */
    if (IDL_tree_property_get(IDL_INTERFACE(interface_tree).ident, 
        "scriptable")) {
        for (iter = IDL_INTERFACE(interface_tree).inheritance_spec; iter; 
            iter = IDL_LIST(iter).next) {
            if (IDL_tree_property_get(
                IDL_INTERFACE(iter).ident, "scriptable") == 0) {
                XPIDL_WARNING((interface_tree,IDL_WARNING1,
                    "%s is scriptable but inherits from the non-scriptable interface %s\n",
                    IDL_IDENT(IDL_INTERFACE(interface_tree).ident).str,
                    IDL_IDENT(IDL_INTERFACE(iter).ident).str));
            }
        }
    }
    return TRUE;
}

/*
 * Return a pointer to the start of the base filename of path
 */
char *
xpidl_basename(const char * path)
{
    char * result = g_path_get_basename(path);
    /* 
     *If this is windows then we'll handle either / or \ as a separator
     * g_basename only handles \ for windows
     */
#if defined(XP_WIN32)
# error adapt regarding g_basename() vs. g_path_get_basename()!
    const char * slash = strrchr(path, '/');
    /* If we found a slash and its after the current default OS separator */
    if (slash != NULL && (slash > result))
        result = slash + 1;
#endif
    return result;
}