xref: /illumos-gate/usr/src/lib/libdtrace/common/dt_decl.c (revision 74e12c43fe52f2c30f36e65a4d0fb0e8dfd7068a)

/*
 * 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)
		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);
}