root/usr/src/lib/libdtrace/common/dt_decl.c
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2012, 2014 by Delphix. All rights reserved.
 * Copyright 2020 Joyent, Inc.
 */

#include <strings.h>
#include <stdlib.h>
#include <limits.h>
#include <alloca.h>
#include <assert.h>

#include <dt_decl.h>
#include <dt_parser.h>
#include <dt_module.h>
#include <dt_impl.h>

static dt_decl_t *
dt_decl_check(dt_decl_t *ddp)
{
        if (ddp->dd_kind == CTF_K_UNKNOWN)
                return (ddp); /* nothing to check if the type is not yet set */

        if (ddp->dd_name != NULL && strcmp(ddp->dd_name, "char") == 0 &&
            (ddp->dd_attr & (DT_DA_SHORT | DT_DA_LONG | DT_DA_LONGLONG))) {
                xyerror(D_DECL_CHARATTR, "invalid type declaration: short and "
                    "long may not be used with char type\n");
        }

        if (ddp->dd_name != NULL && strcmp(ddp->dd_name, "void") == 0 &&
            (ddp->dd_attr & (DT_DA_SHORT | DT_DA_LONG | DT_DA_LONGLONG |
            (DT_DA_SIGNED | DT_DA_UNSIGNED)))) {
                xyerror(D_DECL_VOIDATTR, "invalid type declaration: attributes "
                    "may not be used with void type\n");
        }

        if (ddp->dd_kind != CTF_K_INTEGER &&
            (ddp->dd_attr & (DT_DA_SIGNED | DT_DA_UNSIGNED))) {
                xyerror(D_DECL_SIGNINT, "invalid type declaration: signed and "
                    "unsigned may only be used with integer type\n");
        }

        if (ddp->dd_kind != CTF_K_INTEGER && ddp->dd_kind != CTF_K_FLOAT &&
            (ddp->dd_attr & (DT_DA_LONG | DT_DA_LONGLONG))) {
                xyerror(D_DECL_LONGINT, "invalid type declaration: long and "
                    "long long may only be used with integer or "
                    "floating-point type\n");
        }

        return (ddp);
}

dt_decl_t *
dt_decl_alloc(ushort_t kind, char *name)
{
        dt_decl_t *ddp = malloc(sizeof (dt_decl_t));

        if (ddp == NULL)
                longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);

        ddp->dd_kind = kind;
        ddp->dd_attr = 0;
        ddp->dd_ctfp = NULL;
        ddp->dd_type = CTF_ERR;
        ddp->dd_name = name;
        ddp->dd_node = NULL;
        ddp->dd_next = NULL;

        return (ddp);
}

void
dt_decl_free(dt_decl_t *ddp)
{
        dt_decl_t *ndp;

        for (; ddp != NULL; ddp = ndp) {
                ndp = ddp->dd_next;
                free(ddp->dd_name);
                dt_node_list_free(&ddp->dd_node);
                free(ddp);
        }
}

void
dt_decl_reset(void)
{
        dt_scope_t *dsp = &yypcb->pcb_dstack;
        dt_decl_t *ddp = dsp->ds_decl;

        while (ddp->dd_next != NULL) {
                dsp->ds_decl = ddp->dd_next;
                ddp->dd_next = NULL;
                dt_decl_free(ddp);
                ddp = dsp->ds_decl;
        }
}

dt_decl_t *
dt_decl_push(dt_decl_t *ddp)
{
        dt_scope_t *dsp = &yypcb->pcb_dstack;
        dt_decl_t *top = dsp->ds_decl;

        if (top != NULL &&
            top->dd_kind == CTF_K_UNKNOWN && top->dd_name == NULL) {
                top->dd_kind = CTF_K_INTEGER;
                (void) dt_decl_check(top);
        }

        assert(ddp->dd_next == NULL);
        ddp->dd_next = top;
        dsp->ds_decl = ddp;

        return (ddp);
}

dt_decl_t *
dt_decl_pop(void)
{
        dt_scope_t *dsp = &yypcb->pcb_dstack;
        dt_decl_t *ddp = dt_decl_top();

        dsp->ds_decl = NULL;
        free(dsp->ds_ident);
        dsp->ds_ident = NULL;
        dsp->ds_ctfp = NULL;
        dsp->ds_type = CTF_ERR;
        dsp->ds_class = DT_DC_DEFAULT;
        dsp->ds_enumval = -1;

        return (ddp);
}

dt_decl_t *
dt_decl_pop_param(char **idp)
{
        dt_scope_t *dsp = &yypcb->pcb_dstack;

        if (dsp->ds_class != DT_DC_DEFAULT && dsp->ds_class != DT_DC_REGISTER) {
                xyerror(D_DECL_PARMCLASS, "inappropriate storage class "
                    "for function or associative array parameter\n");
        }

        if (idp != NULL && dt_decl_top() != NULL) {
                *idp = dsp->ds_ident;
                dsp->ds_ident = NULL;
        }

        return (dt_decl_pop());
}

dt_decl_t *
dt_decl_top(void)
{
        dt_decl_t *ddp = yypcb->pcb_dstack.ds_decl;

        if (ddp == NULL)
                longjmp(yypcb->pcb_jmpbuf, EDT_NODECL);

        if (ddp->dd_kind == CTF_K_UNKNOWN && ddp->dd_name == NULL) {
                ddp->dd_kind = CTF_K_INTEGER;
                (void) dt_decl_check(ddp);
        }

        return (ddp);
}

dt_decl_t *
dt_decl_ident(char *name)
{
        dt_scope_t *dsp = &yypcb->pcb_dstack;
        dt_decl_t *ddp = dsp->ds_decl;

        if (dsp->ds_ident != NULL) {
                free(name);
                xyerror(D_DECL_IDENT, "old-style declaration or "
                    "incorrect type specified\n");
        }

        dsp->ds_ident = name;

        if (ddp == NULL)
                ddp = dt_decl_push(dt_decl_alloc(CTF_K_UNKNOWN, NULL));

        return (ddp);
}

void
dt_decl_class(dt_dclass_t class)
{
        dt_scope_t *dsp = &yypcb->pcb_dstack;

        if (dsp->ds_class != DT_DC_DEFAULT) {
                xyerror(D_DECL_CLASS, "only one storage class allowed "
                    "in a declaration\n");
        }

        dsp->ds_class = class;
}

/*
 * Set the kind and name of the current declaration.  If none is allocated,
 * make a new decl and push it on to the top of our stack.  If the name or kind
 * is already set for the current decl, then we need to fail this declaration.
 * This can occur because too many types were given (e.g. "int int"), etc.
 */
dt_decl_t *
dt_decl_spec(ushort_t kind, char *name)
{
        dt_decl_t *ddp = yypcb->pcb_dstack.ds_decl;

        if (ddp == NULL)
                return (dt_decl_push(dt_decl_alloc(kind, name)));

        /*
         * If we already have a type name specified and we see another type
         * name, this is an error if the declaration is a typedef.  If the
         * declaration is not a typedef, then the user may be trying to declare
         * a variable whose name has been returned by lex as a TNAME token:
         * call dt_decl_ident() as if the grammar's IDENT rule was matched.
         */
        if (ddp->dd_name != NULL && kind == CTF_K_TYPEDEF) {
                if (yypcb->pcb_dstack.ds_class != DT_DC_TYPEDEF)
                        return (dt_decl_ident(name));
                xyerror(D_DECL_IDRED, "identifier redeclared: %s\n", name);
        }

        if (ddp->dd_name != NULL || ddp->dd_kind != CTF_K_UNKNOWN)
                xyerror(D_DECL_COMBO, "invalid type combination\n");

        ddp->dd_kind = kind;
        ddp->dd_name = name;

        return (dt_decl_check(ddp));
}

dt_decl_t *
dt_decl_attr(ushort_t attr)
{
        dt_decl_t *ddp = yypcb->pcb_dstack.ds_decl;

        if (ddp == NULL) {
                ddp = dt_decl_push(dt_decl_alloc(CTF_K_UNKNOWN, NULL));
                ddp->dd_attr = attr;
                return (ddp);
        }

        if ((attr & DT_DA_LONG) && (ddp->dd_attr & DT_DA_LONGLONG)) {
                xyerror(D_DECL_COMBO, "the attribute 'long' may only "
                    "be used at most twice in a declaration");
        }

        if ((attr & DT_DA_SHORT) && (ddp->dd_attr & DT_DA_SHORT)) {
                xyerror(D_DECL_COMBO, "the attribute 'short' may only be "
                    "used at most once in a declaration");
        }

        if ((attr & DT_DA_SIGNED) && (ddp->dd_attr & DT_DA_SIGNED)) {
                xyerror(D_DECL_COMBO, "the attribute 'signed' may only be "
                    "used at most once in a declaration");
        }

        if ((attr & DT_DA_UNSIGNED) && (ddp->dd_attr & DT_DA_UNSIGNED)) {
                xyerror(D_DECL_COMBO, "the attribute 'unsigned' may only be "
                    "used at most once in a declaration");
        }

        if (attr == DT_DA_LONG && (ddp->dd_attr & DT_DA_LONG)) {
                ddp->dd_attr &= ~DT_DA_LONG;
                attr = DT_DA_LONGLONG;
        }

        ddp->dd_attr |= attr;
        return (dt_decl_check(ddp));
}

/*
 * Examine the list of formal parameters 'flist' and determine if the formal
 * name fnp->dn_string is defined in this list (B_TRUE) or not (B_FALSE).
 * If 'fnp' is in 'flist', do not search beyond 'fnp' itself in 'flist'.
 */
static int
dt_decl_protoform(dt_node_t *fnp, dt_node_t *flist)
{
        dt_node_t *dnp;

        for (dnp = flist; dnp != fnp && dnp != NULL; dnp = dnp->dn_list) {
                if (dnp->dn_string != NULL &&
                    strcmp(dnp->dn_string, fnp->dn_string) == 0)
                        return (B_TRUE);
        }

        return (B_FALSE);
}

/*
 * Common code for parsing array, function, and probe definition prototypes.
 * The prototype node list is specified as 'plist'.  The formal prototype
 * against which to compare the prototype is specified as 'flist'.  If plist
 * and flist are the same, we require that named parameters are unique.  If
 * plist and flist are different, we require that named parameters in plist
 * match a name that is present in flist.
 */
int
dt_decl_prototype(dt_node_t *plist,
    dt_node_t *flist, const char *kind, uint_t flags)
{
        char n[DT_TYPE_NAMELEN];
        int is_void, v = 0, i = 1;
        int form = plist != flist;
        dt_node_t *dnp;

        for (dnp = plist; dnp != NULL; dnp = dnp->dn_list, i++) {

                if (dnp->dn_type == CTF_ERR && !(flags & DT_DP_VARARGS)) {
                        dnerror(dnp, D_DECL_PROTO_VARARGS, "%s prototype may "
                            "not use a variable-length argument list\n", kind);
                }

                if (dt_node_is_dynamic(dnp) && !(flags & DT_DP_DYNAMIC)) {
                        dnerror(dnp, D_DECL_PROTO_TYPE, "%s prototype may not "
                            "use parameter of type %s: %s, parameter #%d\n",
                            kind, dt_node_type_name(dnp, n, sizeof (n)),
                            dnp->dn_string ? dnp->dn_string : "(anonymous)", i);
                }

                is_void = dt_node_is_void(dnp);
                v += is_void;

                if (is_void && !(flags & DT_DP_VOID)) {
                        dnerror(dnp, D_DECL_PROTO_TYPE, "%s prototype may not "
                            "use parameter of type %s: %s, parameter #%d\n",
                            kind, dt_node_type_name(dnp, n, sizeof (n)),
                            dnp->dn_string ? dnp->dn_string : "(anonymous)", i);
                }

                if (is_void && dnp->dn_string != NULL) {
                        dnerror(dnp, D_DECL_PROTO_NAME, "void parameter may "
                            "not have a name: %s\n", dnp->dn_string);
                }

                if (dnp->dn_string != NULL &&
                    dt_decl_protoform(dnp, flist) != form) {
                        dnerror(dnp, D_DECL_PROTO_FORM, "parameter is "
                            "%s declared in %s prototype: %s, parameter #%d\n",
                            form ? "not" : "already", kind, dnp->dn_string, i);
                }

                if (dnp->dn_string == NULL &&
                    !is_void && !(flags & DT_DP_ANON)) {
                        dnerror(dnp, D_DECL_PROTO_NAME, "parameter declaration "
                            "requires a name: parameter #%d\n", i);
                }
        }

        if (v != 0 && plist->dn_list != NULL)
                xyerror(D_DECL_PROTO_VOID, "void must be sole parameter\n");

        return (v ? 0 : i - 1); /* return zero if sole parameter is 'void' */
}

dt_decl_t *
dt_decl_array(dt_node_t *dnp)
{
        dt_decl_t *ddp = dt_decl_push(dt_decl_alloc(CTF_K_ARRAY, NULL));
        dt_scope_t *dsp = &yypcb->pcb_dstack;
        dt_decl_t *ndp = ddp;

        /*
         * After pushing the array on to the decl stack, scan ahead for multi-
         * dimensional array declarations and push the current decl to the
         * bottom to match the resulting CTF type tree and data layout.  Refer
         * to the comments in dt_decl_type() and ISO C 6.5.2.1 for more info.
         */
        while (ndp->dd_next != NULL && ndp->dd_next->dd_kind == CTF_K_ARRAY)
                ndp = ndp->dd_next; /* skip to bottom-most array declaration */

        if (ndp != ddp) {
                if (dnp != NULL && dnp->dn_kind == DT_NODE_TYPE) {
                        xyerror(D_DECL_DYNOBJ,
                            "cannot declare array of associative arrays\n");
                }
                dsp->ds_decl = ddp->dd_next;
                ddp->dd_next = ndp->dd_next;
                ndp->dd_next = ddp;
        }

        if (ddp->dd_next->dd_name != NULL &&
            strcmp(ddp->dd_next->dd_name, "void") == 0)
                xyerror(D_DECL_VOIDOBJ, "cannot declare array of void\n");

        if (dnp != NULL && dnp->dn_kind != DT_NODE_TYPE) {
                dnp = ddp->dd_node = dt_node_cook(dnp, DT_IDFLG_REF);

                if (dt_node_is_posconst(dnp) == 0) {
                        xyerror(D_DECL_ARRSUB, "positive integral constant "
                            "expression or tuple signature expected as "
                            "array declaration subscript\n");
                }

                if (dnp->dn_value > UINT_MAX)
                        xyerror(D_DECL_ARRBIG, "array dimension too big\n");

        } else if (dnp != NULL) {
                ddp->dd_node = dnp;
                (void) dt_decl_prototype(dnp, dnp, "array", DT_DP_ANON);
        }

        return (ddp);
}

/*
 * When a function is declared, we need to fudge the decl stack a bit if the
 * declaration uses the function pointer (*)() syntax.  In this case, the
 * dt_decl_func() call occurs *after* the dt_decl_ptr() call, even though the
 * resulting type is "pointer to function".  To make the pointer land on top,
 * we check to see if 'pdp' is non-NULL and a pointer.  If it is, we search
 * backward for a decl tagged with DT_DA_PAREN, and if one is found, the func
 * decl is inserted behind this node in the decl list instead of at the top.
 * In all cases, the func decl's dd_next pointer is set to the decl chain
 * for the function's return type and the function parameter list is discarded.
 */
dt_decl_t *
dt_decl_func(dt_decl_t *pdp, dt_node_t *dnp)
{
        dt_decl_t *ddp = dt_decl_alloc(CTF_K_FUNCTION, NULL);

        ddp->dd_node = dnp;

        (void) dt_decl_prototype(dnp, dnp, "function",
            DT_DP_VARARGS | DT_DP_VOID | DT_DP_ANON);

        if (pdp == NULL || pdp->dd_kind != CTF_K_POINTER)
                return (dt_decl_push(ddp));

        while (pdp->dd_next != NULL && !(pdp->dd_next->dd_attr & DT_DA_PAREN))
                pdp = pdp->dd_next;

        if (pdp->dd_next == NULL)
                return (dt_decl_push(ddp));

        ddp->dd_next = pdp->dd_next;
        pdp->dd_next = ddp;

        return (pdp);
}

dt_decl_t *
dt_decl_ptr(void)
{
        return (dt_decl_push(dt_decl_alloc(CTF_K_POINTER, NULL)));
}

dt_decl_t *
dt_decl_sou(uint_t kind, char *name)
{
        dt_decl_t *ddp = dt_decl_spec(kind, name);
        char n[DT_TYPE_NAMELEN];
        ctf_file_t *ctfp;
        ctf_id_t type;
        uint_t flag;

        if (yypcb->pcb_idepth != 0)
                ctfp = yypcb->pcb_hdl->dt_cdefs->dm_ctfp;
        else
                ctfp = yypcb->pcb_hdl->dt_ddefs->dm_ctfp;

        if (yypcb->pcb_dstack.ds_next != NULL)
                flag = CTF_ADD_NONROOT;
        else
                flag = CTF_ADD_ROOT;

        (void) snprintf(n, sizeof (n), "%s %s",
            kind == CTF_K_STRUCT ? "struct" : "union",
            name == NULL ? "(anon)" : name);

        if (name != NULL && (type = ctf_lookup_by_name(ctfp, n)) != CTF_ERR &&
            ctf_type_kind(ctfp, type) != CTF_K_FORWARD)
                xyerror(D_DECL_TYPERED, "type redeclared: %s\n", n);

        if (kind == CTF_K_STRUCT)
                type = ctf_add_struct(ctfp, flag, name);
        else
                type = ctf_add_union(ctfp, flag, name);

        if (type == CTF_ERR || ctf_update(ctfp) == CTF_ERR) {
                xyerror(D_UNKNOWN, "failed to define %s: %s\n",
                    n, ctf_errmsg(ctf_errno(ctfp)));
        }

        ddp->dd_ctfp = ctfp;
        ddp->dd_type = type;

        dt_scope_push(ctfp, type);
        return (ddp);
}

void
dt_decl_member(dt_node_t *dnp)
{
        dt_scope_t *dsp = yypcb->pcb_dstack.ds_next;
        dt_decl_t *ddp = yypcb->pcb_dstack.ds_decl;
        char *ident = yypcb->pcb_dstack.ds_ident;

        const char *idname = ident ? ident : "(anon)";
        char n[DT_TYPE_NAMELEN];

        dtrace_typeinfo_t dtt;
        ctf_encoding_t cte;
        ctf_id_t base;
        uint_t kind;
        ssize_t size;

        if (dsp == NULL)
                longjmp(yypcb->pcb_jmpbuf, EDT_NOSCOPE);

        if (ddp == NULL)
                longjmp(yypcb->pcb_jmpbuf, EDT_NODECL);

        if (dnp == NULL && ident == NULL)
                xyerror(D_DECL_MNAME, "member declaration requires a name\n");

        if (ddp->dd_kind == CTF_K_UNKNOWN && ddp->dd_name == NULL) {
                ddp->dd_kind = CTF_K_INTEGER;
                (void) dt_decl_check(ddp);
        }

        if (dt_decl_type(ddp, &dtt) != 0)
                longjmp(yypcb->pcb_jmpbuf, EDT_COMPILER);

        if (ident != NULL && strchr(ident, '`') != NULL) {
                xyerror(D_DECL_SCOPE, "D scoping operator may not be used "
                    "in a member name (%s)\n", ident);
        }

        if (dtt.dtt_ctfp == DT_DYN_CTFP(yypcb->pcb_hdl) &&
            dtt.dtt_type == DT_DYN_TYPE(yypcb->pcb_hdl)) {
                xyerror(D_DECL_DYNOBJ,
                    "cannot have dynamic member: %s\n", ident);
        }

        base = ctf_type_resolve(dtt.dtt_ctfp, dtt.dtt_type);
        kind = ctf_type_kind(dtt.dtt_ctfp, base);
        size = ctf_type_size(dtt.dtt_ctfp, base);

        if (kind == CTF_K_FORWARD || ((kind == CTF_K_STRUCT ||
            kind == CTF_K_UNION) && size == 0)) {
                xyerror(D_DECL_INCOMPLETE, "incomplete struct/union/enum %s: "
                    "%s\n", dt_type_name(dtt.dtt_ctfp, dtt.dtt_type,
                    n, sizeof (n)), ident);
        }

        if (size == 0) {
                dt_decl_t *pdp;
                dtrace_typeinfo_t pdt;
                ctf_id_t pbase;
                uint_t pkind;

                pdp = dsp->ds_decl;
                if (pdp == NULL)
                        longjmp(yypcb->pcb_jmpbuf, EDT_NODECL);
                if (dt_decl_type(pdp, &pdt) != 0)
                        longjmp(yypcb->pcb_jmpbuf, EDT_COMPILER);

                pbase = ctf_type_resolve(pdt.dtt_ctfp, pdt.dtt_type);
                pkind = ctf_type_kind(pdt.dtt_ctfp, pbase);

                /*
                 * Last member of structure may be flexible array.
                 * Please note, here we actually do allow any array
                 * in structure to have size 0, this is because
                 * the structure declaration is still incomplete.
                 */
                if (pkind != CTF_K_STRUCT || kind != CTF_K_ARRAY)
                        xyerror(D_DECL_VOIDOBJ,
                            "cannot have void member: %s\n", ident);
        }

        /*
         * If a bit-field qualifier was part of the member declaration, create
         * a new integer type of the same name and attributes as the base type
         * and size equal to the specified number of bits.  We reset 'dtt' to
         * refer to this new bit-field type and continue on to add the member.
         */
        if (dnp != NULL) {
                dnp = dt_node_cook(dnp, DT_IDFLG_REF);

                /*
                 * A bit-field member with no declarator is permitted to have
                 * size zero and indicates that no more fields are to be packed
                 * into the current storage unit.  We ignore these directives
                 * as the underlying ctf code currently does so for all fields.
                 */
                if (ident == NULL && dnp->dn_kind == DT_NODE_INT &&
                    dnp->dn_value == 0) {
                        dt_node_free(dnp);
                        goto done;
                }

                if (dt_node_is_posconst(dnp) == 0) {
                        xyerror(D_DECL_BFCONST, "positive integral constant "
                            "expression expected as bit-field size\n");
                }

                if (ctf_type_kind(dtt.dtt_ctfp, base) != CTF_K_INTEGER ||
                    ctf_type_encoding(dtt.dtt_ctfp, base, &cte) == CTF_ERR ||
                    IS_VOID(cte)) {
                        xyerror(D_DECL_BFTYPE, "invalid type for "
                            "bit-field: %s\n", idname);
                }

                if (dnp->dn_value > cte.cte_bits) {
                        xyerror(D_DECL_BFSIZE, "bit-field too big "
                            "for type: %s\n", idname);
                }

                cte.cte_offset = 0;
                cte.cte_bits = (uint_t)dnp->dn_value;

                dtt.dtt_type = ctf_add_integer(dsp->ds_ctfp,
                    CTF_ADD_NONROOT, ctf_type_name(dtt.dtt_ctfp,
                    dtt.dtt_type, n, sizeof (n)), &cte);

                if (dtt.dtt_type == CTF_ERR ||
                    ctf_update(dsp->ds_ctfp) == CTF_ERR) {
                        xyerror(D_UNKNOWN, "failed to create type for "
                            "member '%s': %s\n", idname,
                            ctf_errmsg(ctf_errno(dsp->ds_ctfp)));
                }

                dtt.dtt_ctfp = dsp->ds_ctfp;
                dt_node_free(dnp);
        }

        /*
         * If the member type is not defined in the same CTF container as the
         * one associated with the current scope (i.e. the container for the
         * struct or union itself) or its parent, copy the member type into
         * this container and reset dtt to refer to the copied type.
         */
        if (dtt.dtt_ctfp != dsp->ds_ctfp &&
            dtt.dtt_ctfp != ctf_parent_file(dsp->ds_ctfp)) {

                dtt.dtt_type = ctf_add_type(dsp->ds_ctfp,
                    dtt.dtt_ctfp, dtt.dtt_type);
                dtt.dtt_ctfp = dsp->ds_ctfp;

                if (dtt.dtt_type == CTF_ERR ||
                    ctf_update(dtt.dtt_ctfp) == CTF_ERR) {
                        xyerror(D_UNKNOWN, "failed to copy type of '%s': %s\n",
                            idname, ctf_errmsg(ctf_errno(dtt.dtt_ctfp)));
                }
        }

        if (ctf_add_member(dsp->ds_ctfp, dsp->ds_type,
            ident, dtt.dtt_type, ULONG_MAX) == CTF_ERR) {
                xyerror(D_UNKNOWN, "failed to define member '%s': %s\n",
                    idname, ctf_errmsg(ctf_errno(dsp->ds_ctfp)));
        }

done:
        free(ident);
        yypcb->pcb_dstack.ds_ident = NULL;
        dt_decl_reset();
}

/*ARGSUSED*/
static int
dt_decl_hasmembers(const char *name, int value, void *private)
{
        return (1); /* abort search and return true if a member exists */
}

dt_decl_t *
dt_decl_enum(char *name)
{
        dt_decl_t *ddp = dt_decl_spec(CTF_K_ENUM, name);
        char n[DT_TYPE_NAMELEN];
        ctf_file_t *ctfp;
        ctf_id_t type;
        uint_t flag;

        if (yypcb->pcb_idepth != 0)
                ctfp = yypcb->pcb_hdl->dt_cdefs->dm_ctfp;
        else
                ctfp = yypcb->pcb_hdl->dt_ddefs->dm_ctfp;

        if (yypcb->pcb_dstack.ds_next != NULL)
                flag = CTF_ADD_NONROOT;
        else
                flag = CTF_ADD_ROOT;

        (void) snprintf(n, sizeof (n), "enum %s", name ? name : "(anon)");

        if (name != NULL && (type = ctf_lookup_by_name(ctfp, n)) != CTF_ERR) {
                if (ctf_enum_iter(ctfp, type, dt_decl_hasmembers, NULL))
                        xyerror(D_DECL_TYPERED, "type redeclared: %s\n", n);
        } else if ((type = ctf_add_enum(ctfp, flag, name, 0)) == CTF_ERR) {
                xyerror(D_UNKNOWN, "failed to define %s: %s\n",
                    n, ctf_errmsg(ctf_errno(ctfp)));
        }

        ddp->dd_ctfp = ctfp;
        ddp->dd_type = type;

        dt_scope_push(ctfp, type);
        return (ddp);
}

void
dt_decl_enumerator(char *s, dt_node_t *dnp)
{
        dt_scope_t *dsp = yypcb->pcb_dstack.ds_next;
        dtrace_hdl_t *dtp = yypcb->pcb_hdl;

        dt_idnode_t *inp;
        dt_ident_t *idp;
        char *name;
        int value;

        name = strdupa(s);
        free(s);

        if (dsp == NULL)
                longjmp(yypcb->pcb_jmpbuf, EDT_NOSCOPE);

        assert(dsp->ds_decl->dd_kind == CTF_K_ENUM);
        value = dsp->ds_enumval + 1; /* default is previous value plus one */

        if (strchr(name, '`') != NULL) {
                xyerror(D_DECL_SCOPE, "D scoping operator may not be used in "
                    "an enumerator name (%s)\n", name);
        }

        /*
         * If the enumerator is being assigned a value, cook and check the node
         * and then free it after we get the value.  We also permit references
         * to identifiers which are previously defined enumerators in the type.
         */
        if (dnp != NULL) {
                if (dnp->dn_kind != DT_NODE_IDENT || ctf_enum_value(
                    dsp->ds_ctfp, dsp->ds_type, dnp->dn_string, &value) != 0) {
                        dnp = dt_node_cook(dnp, DT_IDFLG_REF);

                        if (dnp->dn_kind != DT_NODE_INT) {
                                xyerror(D_DECL_ENCONST, "enumerator '%s' must "
                                    "be assigned to an integral constant "
                                    "expression\n", name);
                        }

                        if ((intmax_t)dnp->dn_value > INT_MAX ||
                            (intmax_t)dnp->dn_value < INT_MIN) {
                                xyerror(D_DECL_ENOFLOW, "enumerator '%s' value "
                                    "overflows INT_MAX (%d)\n", name, INT_MAX);
                        }

                        value = (int)dnp->dn_value;
                }
                dt_node_free(dnp);
        }

        if (ctf_add_enumerator(dsp->ds_ctfp, dsp->ds_type,
            name, value) == CTF_ERR || ctf_update(dsp->ds_ctfp) == CTF_ERR) {
                xyerror(D_UNKNOWN, "failed to define enumerator '%s': %s\n",
                    name, ctf_errmsg(ctf_errno(dsp->ds_ctfp)));
        }

        dsp->ds_enumval = value; /* save most recent value */

        /*
         * If the enumerator name matches an identifier in the global scope,
         * flag this as an error.  We only do this for "D" enumerators to
         * prevent "C" header file enumerators from conflicting with the ever-
         * growing list of D built-in global variables and inlines.  If a "C"
         * enumerator conflicts with a global identifier, we add the enumerator
         * but do not insert a corresponding inline (i.e. the D variable wins).
         */
        if (dt_idstack_lookup(&yypcb->pcb_globals, name) != NULL) {
                if (dsp->ds_ctfp == dtp->dt_ddefs->dm_ctfp) {
                        xyerror(D_DECL_IDRED,
                            "identifier redeclared: %s\n", name);
                } else
                        return;
        }

        dt_dprintf("add global enumerator %s = %d\n", name, value);

        idp = dt_idhash_insert(dtp->dt_globals, name, DT_IDENT_ENUM,
            DT_IDFLG_INLINE | DT_IDFLG_REF, 0, _dtrace_defattr, 0,
            &dt_idops_inline, NULL, dtp->dt_gen);

        if (idp == NULL)
                longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);

        yyintprefix = 0;
        yyintsuffix[0] = '\0';
        yyintdecimal = 0;

        dnp = dt_node_int(value);
        dt_node_type_assign(dnp, dsp->ds_ctfp, dsp->ds_type, B_FALSE);

        if ((inp = malloc(sizeof (dt_idnode_t))) == NULL)
                longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);

        /*
         * Remove the INT node from the node allocation list and store it in
         * din_list and din_root so it persists with and is freed by the ident.
         */
        assert(yypcb->pcb_list == dnp);
        yypcb->pcb_list = dnp->dn_link;
        dnp->dn_link = NULL;

        bzero(inp, sizeof (dt_idnode_t));
        inp->din_list = dnp;
        inp->din_root = dnp;

        idp->di_iarg = inp;
        idp->di_ctfp = dsp->ds_ctfp;
        idp->di_type = dsp->ds_type;
}

/*
 * Look up the type corresponding to the specified decl stack.  The scoping of
 * the underlying type names is handled by dt_type_lookup().  We build up the
 * name from the specified string and prefixes and then lookup the type.  If
 * we fail, an errmsg is saved and the caller must abort with EDT_COMPILER.
 */
int
dt_decl_type(dt_decl_t *ddp, dtrace_typeinfo_t *tip)
{
        dtrace_hdl_t *dtp = yypcb->pcb_hdl;

        dt_module_t *dmp;
        ctf_arinfo_t r;
        ctf_id_t type;

        char n[DT_TYPE_NAMELEN];
        uint_t flag;
        char *name;
        int rv;

        tip->dtt_flags = 0;

        /*
         * Based on our current #include depth and decl stack depth, determine
         * which dynamic CTF module and scope to use when adding any new types.
         */
        dmp = yypcb->pcb_idepth ? dtp->dt_cdefs : dtp->dt_ddefs;
        flag = yypcb->pcb_dstack.ds_next ? CTF_ADD_NONROOT : CTF_ADD_ROOT;

        if (ddp->dd_attr & DT_DA_USER)
                tip->dtt_flags = DTT_FL_USER;

        /*
         * If we have already cached a CTF type for this decl, then we just
         * return the type information for the cached type.
         */
        if (ddp->dd_ctfp != NULL &&
            (dmp = dt_module_lookup_by_ctf(dtp, ddp->dd_ctfp)) != NULL) {
                tip->dtt_object = dmp->dm_name;
                tip->dtt_ctfp = ddp->dd_ctfp;
                tip->dtt_type = ddp->dd_type;
                return (0);
        }

        /*
         * Currently CTF treats all function pointers identically.  We cache a
         * representative ID of kind CTF_K_FUNCTION and just return that type.
         * If we want to support full function declarations, dd_next refers to
         * the declaration of the function return type, and the parameter list
         * should be parsed and hung off a new pointer inside of this decl.
         */
        if (ddp->dd_kind == CTF_K_FUNCTION) {
                tip->dtt_object = dtp->dt_ddefs->dm_name;
                tip->dtt_ctfp = DT_FUNC_CTFP(dtp);
                tip->dtt_type = DT_FUNC_TYPE(dtp);
                return (0);
        }

        /*
         * If the decl is a pointer, resolve the rest of the stack by calling
         * dt_decl_type() recursively and then compute a pointer to the result.
         * Similar to the code above, we return a cached id for function ptrs.
         */
        if (ddp->dd_kind == CTF_K_POINTER) {
                if (ddp->dd_next->dd_kind == CTF_K_FUNCTION) {
                        tip->dtt_object = dtp->dt_ddefs->dm_name;
                        tip->dtt_ctfp = DT_FPTR_CTFP(dtp);
                        tip->dtt_type = DT_FPTR_TYPE(dtp);
                        return (0);
                }

                if ((rv = dt_decl_type(ddp->dd_next, tip)) == 0 &&
                    (rv = dt_type_pointer(tip)) != 0) {
                        xywarn(D_UNKNOWN, "cannot find type: %s*: %s\n",
                            dt_type_name(tip->dtt_ctfp, tip->dtt_type,
                            n, sizeof (n)), ctf_errmsg(dtp->dt_ctferr));
                }

                return (rv);
        }

        /*
         * If the decl is an array, we must find the base type and then call
         * dt_decl_type() recursively and then build an array of the result.
         * The C and D multi-dimensional array syntax requires that consecutive
         * array declarations be processed from right-to-left (i.e. top-down
         * from the perspective of the declaration stack).  For example, an
         * array declaration such as int x[3][5] is stored on the stack as:
         *
         * (bottom) NULL <- ( INT "int" ) <- ( ARR [3] ) <- ( ARR [5] ) (top)
         *
         * but means that x is declared to be an array of 3 objects each of
         * which is an array of 5 integers, or in CTF representation:
         *
         * type T1:( content=int, nelems=5 ) type T2:( content=T1, nelems=3 )
         *
         * For more details, refer to K&R[5.7] and ISO C 6.5.2.1.  Rather than
         * overcomplicate the implementation of dt_decl_type(), we push array
         * declarations down into the stack in dt_decl_array(), above, so that
         * by the time dt_decl_type() is called, the decl stack looks like:
         *
         * (bottom) NULL <- ( INT "int" ) <- ( ARR [5] ) <- ( ARR [3] ) (top)
         *
         * which permits a straightforward recursive descent of the decl stack
         * to build the corresponding CTF type tree in the appropriate order.
         */
        if (ddp->dd_kind == CTF_K_ARRAY) {
                /*
                 * If the array decl has a parameter list associated with it,
                 * this is an associative array declaration: return <DYN>.
                 */
                if (ddp->dd_node != NULL &&
                    ddp->dd_node->dn_kind == DT_NODE_TYPE) {
                        tip->dtt_object = dtp->dt_ddefs->dm_name;
                        tip->dtt_ctfp = DT_DYN_CTFP(dtp);
                        tip->dtt_type = DT_DYN_TYPE(dtp);
                        return (0);
                }

                if ((rv = dt_decl_type(ddp->dd_next, tip)) != 0)
                        return (rv);

                /*
                 * If the array base type is not defined in the target
                 * container or its parent, copy the type to the target
                 * container and reset dtt_ctfp and dtt_type to the copy.
                 */
                if (tip->dtt_ctfp != dmp->dm_ctfp &&
                    tip->dtt_ctfp != ctf_parent_file(dmp->dm_ctfp)) {

                        tip->dtt_type = ctf_add_type(dmp->dm_ctfp,
                            tip->dtt_ctfp, tip->dtt_type);
                        tip->dtt_ctfp = dmp->dm_ctfp;

                        if (tip->dtt_type == CTF_ERR ||
                            ctf_update(tip->dtt_ctfp) == CTF_ERR) {
                                xywarn(D_UNKNOWN, "failed to copy type: %s\n",
                                    ctf_errmsg(ctf_errno(tip->dtt_ctfp)));
                                return (-1);
                        }
                }

                /*
                 * The array index type is irrelevant in C and D: just set it
                 * to "long" for all array types that we create on-the-fly.
                 */
                r.ctr_contents = tip->dtt_type;
                r.ctr_index = ctf_lookup_by_name(tip->dtt_ctfp, "long");
                r.ctr_nelems = ddp->dd_node ?
                    (uint_t)ddp->dd_node->dn_value : 0;

                tip->dtt_object = dmp->dm_name;
                tip->dtt_ctfp = dmp->dm_ctfp;
                tip->dtt_type = ctf_add_array(dmp->dm_ctfp, CTF_ADD_ROOT, &r);

                if (tip->dtt_type == CTF_ERR ||
                    ctf_update(tip->dtt_ctfp) == CTF_ERR) {
                        xywarn(D_UNKNOWN, "failed to create array type: %s\n",
                            ctf_errmsg(ctf_errno(tip->dtt_ctfp)));
                        return (-1);
                }

                return (0);
        }

        /*
         * Allocate space for the type name and enough space for the maximum
         * additional text ("unsigned long long \0" requires 20 more bytes).
         */
        name = alloca(ddp->dd_name ? strlen(ddp->dd_name) + 20 : 20);
        name[0] = '\0';

        switch (ddp->dd_kind) {
        case CTF_K_INTEGER:
        case CTF_K_FLOAT:
                if (ddp->dd_attr & DT_DA_SIGNED)
                        (void) strcat(name, "signed ");
                if (ddp->dd_attr & DT_DA_UNSIGNED)
                        (void) strcat(name, "unsigned ");
                if (ddp->dd_attr & DT_DA_SHORT)
                        (void) strcat(name, "short ");
                if (ddp->dd_attr & DT_DA_LONG)
                        (void) strcat(name, "long ");
                if (ddp->dd_attr & DT_DA_LONGLONG)
                        (void) strcat(name, "long long ");
                if (ddp->dd_attr == 0 && ddp->dd_name == NULL)
                        (void) strcat(name, "int");
                break;
        case CTF_K_STRUCT:
                (void) strcpy(name, "struct ");
                break;
        case CTF_K_UNION:
                (void) strcpy(name, "union ");
                break;
        case CTF_K_ENUM:
                (void) strcpy(name, "enum ");
                break;
        case CTF_K_TYPEDEF:
                break;
        default:
                xywarn(D_UNKNOWN, "internal error -- "
                    "bad decl kind %u\n", ddp->dd_kind);
                return (-1);
        }

        /*
         * Add dd_name unless a short, long, or long long is explicitly
         * suffixed by int.  We use the C/CTF canonical names for integers.
         */
        if (ddp->dd_name != NULL && (ddp->dd_kind != CTF_K_INTEGER ||
            (ddp->dd_attr & (DT_DA_SHORT | DT_DA_LONG | DT_DA_LONGLONG)) == 0))
                (void) strcat(name, ddp->dd_name);

        /*
         * Lookup the type.  If we find it, we're done.  Otherwise create a
         * forward tag for the type if it is a struct, union, or enum.  If
         * we can't find it and we can't create a tag, return failure.
         */
        if ((rv = dt_type_lookup(name, tip)) == 0)
                return (rv);

        switch (ddp->dd_kind) {
        case CTF_K_STRUCT:
        case CTF_K_UNION:
        case CTF_K_ENUM:
                type = ctf_add_forward(dmp->dm_ctfp, flag,
                    ddp->dd_name, ddp->dd_kind);
                break;
        default:
                xywarn(D_UNKNOWN, "failed to resolve type %s: %s\n", name,
                    dtrace_errmsg(dtp, dtrace_errno(dtp)));
                return (rv);
        }

        if (type == CTF_ERR || ctf_update(dmp->dm_ctfp) == CTF_ERR) {
                xywarn(D_UNKNOWN, "failed to add forward tag for %s: %s\n",
                    name, ctf_errmsg(ctf_errno(dmp->dm_ctfp)));
                return (-1);
        }

        ddp->dd_ctfp = dmp->dm_ctfp;
        ddp->dd_type = type;

        tip->dtt_object = dmp->dm_name;
        tip->dtt_ctfp = dmp->dm_ctfp;
        tip->dtt_type = type;

        return (0);
}

void
dt_scope_create(dt_scope_t *dsp)
{
        dsp->ds_decl = NULL;
        dsp->ds_next = NULL;
        dsp->ds_ident = NULL;
        dsp->ds_ctfp = NULL;
        dsp->ds_type = CTF_ERR;
        dsp->ds_class = DT_DC_DEFAULT;
        dsp->ds_enumval = -1;
}

void
dt_scope_destroy(dt_scope_t *dsp)
{
        dt_scope_t *nsp;

        for (; dsp != NULL; dsp = nsp) {
                dt_decl_free(dsp->ds_decl);
                free(dsp->ds_ident);
                nsp = dsp->ds_next;
                if (dsp != &yypcb->pcb_dstack)
                        free(dsp);
        }
}

void
dt_scope_push(ctf_file_t *ctfp, ctf_id_t type)
{
        dt_scope_t *rsp = &yypcb->pcb_dstack;
        dt_scope_t *dsp = malloc(sizeof (dt_scope_t));

        if (dsp == NULL)
                longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);

        dsp->ds_decl = rsp->ds_decl;
        dsp->ds_next = rsp->ds_next;
        dsp->ds_ident = rsp->ds_ident;
        dsp->ds_ctfp = ctfp;
        dsp->ds_type = type;
        dsp->ds_class = rsp->ds_class;
        dsp->ds_enumval = rsp->ds_enumval;

        dt_scope_create(rsp);
        rsp->ds_next = dsp;
}

dt_decl_t *
dt_scope_pop(void)
{
        dt_scope_t *rsp = &yypcb->pcb_dstack;
        dt_scope_t *dsp = rsp->ds_next;

        if (dsp == NULL)
                longjmp(yypcb->pcb_jmpbuf, EDT_NOSCOPE);

        if (dsp->ds_ctfp != NULL && ctf_update(dsp->ds_ctfp) == CTF_ERR) {
                xyerror(D_UNKNOWN, "failed to update type definitions: %s\n",
                    ctf_errmsg(ctf_errno(dsp->ds_ctfp)));
        }

        dt_decl_free(rsp->ds_decl);
        free(rsp->ds_ident);

        rsp->ds_decl = dsp->ds_decl;
        rsp->ds_next = dsp->ds_next;
        rsp->ds_ident = dsp->ds_ident;
        rsp->ds_ctfp = dsp->ds_ctfp;
        rsp->ds_type = dsp->ds_type;
        rsp->ds_class = dsp->ds_class;
        rsp->ds_enumval = dsp->ds_enumval;

        free(dsp);
        return (rsp->ds_decl);
}