xref: /illumos-gate/usr/src/lib/libdtrace/common/dt_ident.c (revision 6eeafb34dceabceff80ed689002b6dc3e060f498)

/*
 * 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) 2013 by Delphix. All rights reserved.
 * Copyright (c) 2013 Joyent, Inc. All rights reserved.
 * Copyright 2022 Oxide Computer Company
 */

#include <sys/sysmacros.h>
#include <strings.h>
#include <stdlib.h>
#include <alloca.h>
#include <assert.h>
#include <errno.h>
#include <ctype.h>
#include <sys/procfs_isa.h>
#include <limits.h>

#include <dt_ident.h>
#include <dt_parser.h>
#include <dt_provider.h>
#include <dt_strtab.h>
#include <dt_impl.h>

/*
 * Common code for cooking an identifier that uses a typed signature list (we
 * use this for associative arrays and functions).  If the argument list is
 * of the same length and types, then return the return type.  Otherwise
 * print an appropriate compiler error message and abort the compile.
 */
static void
dt_idcook_sign(dt_node_t *dnp, dt_ident_t *idp,
    int argc, dt_node_t *args, const char *prefix, const char *suffix)
{
	dt_idsig_t *isp = idp->di_data;
	int i, compat, mismatch, arglimit, iskey;

	char n1[DT_TYPE_NAMELEN];
	char n2[DT_TYPE_NAMELEN];

	iskey = idp->di_kind == DT_IDENT_ARRAY || idp->di_kind == DT_IDENT_AGG;

	if (isp->dis_varargs >= 0) {
		mismatch = argc < isp->dis_varargs;
		arglimit = isp->dis_varargs;
	} else if (isp->dis_optargs >= 0) {
		mismatch = (argc < isp->dis_optargs || argc > isp->dis_argc);
		arglimit = argc;
	} else {
		mismatch = argc != isp->dis_argc;
		arglimit = isp->dis_argc;
	}

	if (mismatch) {
		xyerror(D_PROTO_LEN, "%s%s%s prototype mismatch: %d %s%s"
		    "passed, %s%d expected\n", prefix, idp->di_name, suffix,
		    argc, iskey ? "key" : "arg", argc == 1 ? " " : "s ",
		    isp->dis_optargs >= 0 ? "at least " : "",
		    isp->dis_optargs >= 0 ? isp->dis_optargs : arglimit);
	}

	for (i = 0; i < arglimit; i++, args = args->dn_list) {
		if (isp->dis_args[i].dn_ctfp != NULL)
			compat = dt_node_is_argcompat(&isp->dis_args[i], args);
		else
			compat = 1; /* "@" matches any type */

		if (!compat) {
			xyerror(D_PROTO_ARG,
			    "%s%s%s %s #%d is incompatible with "
			    "prototype:\n\tprototype: %s\n\t%9s: %s\n",
			    prefix, idp->di_name, suffix,
			    iskey ? "key" : "argument", i + 1,
			    dt_node_type_name(&isp->dis_args[i], n1,
			    sizeof (n1)),
			    iskey ? "key" : "argument",
			    dt_node_type_name(args, n2, sizeof (n2)));
		}
	}

	dt_node_type_assign(dnp, idp->di_ctfp, idp->di_type, B_FALSE);
}

/*
 * Cook an associative array identifier.  If this is the first time we are
 * cooking this array, create its signature based on the argument list.
 * Otherwise validate the argument list against the existing signature.
 */
static void
dt_idcook_assc(dt_node_t *dnp, dt_ident_t *idp, int argc, dt_node_t *args)
{
	if (idp->di_data == NULL) {
		dt_idsig_t *isp = idp->di_data = malloc(sizeof (dt_idsig_t));
		char n[DT_TYPE_NAMELEN];
		int i;

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

		isp->dis_varargs = -1;
		isp->dis_optargs = -1;
		isp->dis_argc = argc;
		isp->dis_args = NULL;
		isp->dis_auxinfo = 0;

		if (argc != 0 && (isp->dis_args = calloc(argc,
		    sizeof (dt_node_t))) == NULL) {
			idp->di_data = NULL;
			free(isp);
			longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
		}

		/*
		 * If this identifier has not been explicitly declared earlier,
		 * set the identifier's base type to be our special type <DYN>.
		 * If this ident is an aggregation, it will remain as is.  If
		 * this ident is an associative array, it will be reassigned
		 * based on the result type of the first assignment statement.
		 */
		if (!(idp->di_flags & DT_IDFLG_DECL)) {
			idp->di_ctfp = DT_DYN_CTFP(yypcb->pcb_hdl);
			idp->di_type = DT_DYN_TYPE(yypcb->pcb_hdl);
		}

		for (i = 0; i < argc; i++, args = args->dn_list) {
			if (dt_node_is_dynamic(args) || dt_node_is_void(args)) {
				xyerror(D_KEY_TYPE, "%s expression may not be "
				    "used as %s index: key #%d\n",
				    dt_node_type_name(args, n, sizeof (n)),
				    dt_idkind_name(idp->di_kind), i + 1);
			}

			dt_node_type_propagate(args, &isp->dis_args[i]);
			isp->dis_args[i].dn_list = &isp->dis_args[i + 1];
		}

		if (argc != 0)
			isp->dis_args[argc - 1].dn_list = NULL;

		dt_node_type_assign(dnp, idp->di_ctfp, idp->di_type, B_FALSE);

	} else {
		dt_idcook_sign(dnp, idp, argc, args,
		    idp->di_kind == DT_IDENT_AGG ? "@" : "", "[ ]");
	}
}

/*
 * Cook a function call.  If this is the first time we are cooking this
 * identifier, create its type signature based on predefined prototype stored
 * in di_iarg.  We then validate the argument list against this signature.
 */
static void
dt_idcook_func(dt_node_t *dnp, dt_ident_t *idp, int argc, dt_node_t *args)
{
	if (idp->di_data == NULL) {
		dtrace_hdl_t *dtp = yypcb->pcb_hdl;
		dtrace_typeinfo_t dtt;
		dt_idsig_t *isp;
		char *s, *p1, *p2;
		int i = 0;

		assert(idp->di_iarg != NULL);
		s = strdupa(idp->di_iarg);

		if ((p2 = strrchr(s, ')')) != NULL)
			*p2 = '\0'; /* mark end of parameter list string */

		if ((p1 = strchr(s, '(')) != NULL)
			*p1++ = '\0'; /* mark end of return type string */

		if (p1 == NULL || p2 == NULL) {
			xyerror(D_UNKNOWN, "internal error: malformed entry "
			    "for built-in function %s\n", idp->di_name);
		}

		for (p2 = p1; *p2 != '\0'; p2++) {
			if (!isspace(*p2)) {
				i++;
				break;
			}
		}

		for (p2 = strchr(p2, ','); p2++ != NULL; i++)
			p2 = strchr(p2, ',');

		/*
		 * We first allocate a new ident signature structure with the
		 * appropriate number of argument entries, and then look up
		 * the return type and store its CTF data in di_ctfp/type.
		 */
		if ((isp = idp->di_data = malloc(sizeof (dt_idsig_t))) == NULL)
			longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);

		isp->dis_varargs = -1;
		isp->dis_optargs = -1;
		isp->dis_argc = i;
		isp->dis_args = NULL;
		isp->dis_auxinfo = 0;

		if (i != 0 && (isp->dis_args = calloc(i,
		    sizeof (dt_node_t))) == NULL) {
			idp->di_data = NULL;
			free(isp);
			longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
		}

		if (dt_type_lookup(s, &dtt) == -1) {
			xyerror(D_UNKNOWN, "failed to resolve type of %s (%s):"
			    " %s\n", idp->di_name, s,
			    dtrace_errmsg(dtp, dtrace_errno(dtp)));
		}

		if (idp->di_kind == DT_IDENT_AGGFUNC) {
			idp->di_ctfp = DT_DYN_CTFP(dtp);
			idp->di_type = DT_DYN_TYPE(dtp);
		} else {
			idp->di_ctfp = dtt.dtt_ctfp;
			idp->di_type = dtt.dtt_type;
		}

		/*
		 * For each comma-delimited parameter in the prototype string,
		 * we look up the corresponding type and store its CTF data in
		 * the corresponding location in dis_args[].  We also recognize
		 * the special type string "@" to indicate that the specified
		 * parameter may be a D expression of *any* type (represented
		 * as a dis_args[] element with ctfp = NULL, type == CTF_ERR).
		 * If a varargs "..." is present, we record the argument index
		 * in dis_varargs for the benefit of dt_idcook_sign(), above.
		 * If the type of an argument is enclosed in square brackets
		 * (e.g. "[int]"), the argument is considered optional:  the
		 * argument may be absent, but if it is present, it must be of
		 * the specified type.  Note that varargs may not optional,
		 * optional arguments may not follow varargs, and non-optional
		 * arguments may not follow optional arguments.
		 */
		for (i = 0; i < isp->dis_argc; i++, p1 = p2) {
			while (isspace(*p1))
				p1++; /* skip leading whitespace */

			if ((p2 = strchr(p1, ',')) == NULL)
				p2 = p1 + strlen(p1);
			else
				*p2++ = '\0';

			if (strcmp(p1, "@") == 0 || strcmp(p1, "...") == 0) {
				isp->dis_args[i].dn_ctfp = NULL;
				isp->dis_args[i].dn_type = CTF_ERR;
				isp->dis_args[i].dn_bitoff = 0;
				if (*p1 == '.')
					isp->dis_varargs = i;
				continue;
			}

			if (*p1 == '[' && p1[strlen(p1) - 1] == ']') {
				if (isp->dis_varargs != -1) {
					xyerror(D_UNKNOWN, "optional arg#%d "
					    "may not follow variable arg#%d\n",
					    i + 1, isp->dis_varargs + 1);
				}

				if (isp->dis_optargs == -1)
					isp->dis_optargs = i;

				p1[strlen(p1) - 1] = '\0';
				p1++;
			} else if (isp->dis_optargs != -1) {
				xyerror(D_UNKNOWN, "required arg#%d may not "
				    "follow optional arg#%d\n", i + 1,
				    isp->dis_optargs + 1);
			}

			if (dt_type_lookup(p1, &dtt) == -1) {
				xyerror(D_UNKNOWN, "failed to resolve type of "
				    "%s arg#%d (%s): %s\n", idp->di_name, i + 1,
				    p1, dtrace_errmsg(dtp, dtrace_errno(dtp)));
			}

			dt_node_type_assign(&isp->dis_args[i],
			    dtt.dtt_ctfp, dtt.dtt_type, B_FALSE);
		}
	}

	dt_idcook_sign(dnp, idp, argc, args, "", "( )");
}

/*
 * Cook a reference to the dynamically typed args[] array.  We verify that the
 * reference is using a single integer constant, and then construct a new ident
 * representing the appropriate type or translation specifically for this node.
 */
static void
dt_idcook_args(dt_node_t *dnp, dt_ident_t *idp, int argc, dt_node_t *ap)
{
	dtrace_hdl_t *dtp = yypcb->pcb_hdl;
	dt_probe_t *prp = yypcb->pcb_probe;

	dt_node_t tag, *nnp, *xnp;
	dt_xlator_t *dxp;
	dt_ident_t *xidp;

	char n1[DT_TYPE_NAMELEN];
	char n2[DT_TYPE_NAMELEN];

	if (argc != 1) {
		xyerror(D_PROTO_LEN, "%s[ ] prototype mismatch: %d arg%s"
		    "passed, 1 expected\n", idp->di_name, argc,
		    argc == 1 ? " " : "s ");
	}

	if (ap->dn_kind != DT_NODE_INT) {
		xyerror(D_PROTO_ARG, "%s[ ] argument #1 is incompatible with "
		    "prototype:\n\tprototype: %s\n\t argument: %s\n",
		    idp->di_name, "integer constant",
		    dt_type_name(ap->dn_ctfp, ap->dn_type, n1, sizeof (n1)));
	}

	if (yypcb->pcb_pdesc == NULL) {
		xyerror(D_ARGS_NONE, "%s[ ] may not be referenced outside "
		    "of a probe clause\n", idp->di_name);
	}

	if (prp == NULL) {
		xyerror(D_ARGS_MULTI,
		    "%s[ ] may not be referenced because probe description %s "
		    "matches an unstable set of probes\n", idp->di_name,
		    dtrace_desc2str(yypcb->pcb_pdesc, n1, sizeof (n1)));
	}

	if (ap->dn_value >= prp->pr_argc) {
		xyerror(D_ARGS_IDX, "index %lld is out of range for %s %s[ ]\n",
		    (longlong_t)ap->dn_value, dtrace_desc2str(yypcb->pcb_pdesc,
		    n1, sizeof (n1)), idp->di_name);
	}

	/*
	 * Look up the native and translated argument types for the probe.
	 * If no translation is needed, these will be the same underlying node.
	 * If translation is needed, look up the appropriate translator.  Once
	 * we have the appropriate node, create a new dt_ident_t for this node,
	 * assign it the appropriate attributes, and set the type of 'dnp'.
	 */
	xnp = prp->pr_xargv[ap->dn_value];
	nnp = prp->pr_nargv[prp->pr_mapping[ap->dn_value]];

	if (xnp->dn_type == CTF_ERR) {
		xyerror(D_ARGS_TYPE, "failed to resolve translated type for "
		    "%s[%lld]\n", idp->di_name, (longlong_t)ap->dn_value);
	}

	if (nnp->dn_type == CTF_ERR) {
		xyerror(D_ARGS_TYPE, "failed to resolve native type for "
		    "%s[%lld]\n", idp->di_name, (longlong_t)ap->dn_value);
	}

	if (dtp->dt_xlatemode == DT_XL_STATIC && (
	    nnp == xnp || dt_node_is_argcompat(nnp, xnp))) {
		dnp->dn_ident = dt_ident_create(idp->di_name, idp->di_kind,
		    idp->di_flags | DT_IDFLG_ORPHAN, idp->di_id, idp->di_attr,
		    idp->di_vers, idp->di_ops, idp->di_iarg, idp->di_gen);

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

		dt_node_type_assign(dnp,
		    prp->pr_argv[ap->dn_value].dtt_ctfp,
		    prp->pr_argv[ap->dn_value].dtt_type,
		    prp->pr_argv[ap->dn_value].dtt_flags & DTT_FL_USER ?
		    B_TRUE : B_FALSE);

	} else if ((dxp = dt_xlator_lookup(dtp,
	    nnp, xnp, DT_XLATE_FUZZY)) != NULL || (
	    dxp = dt_xlator_lookup(dtp, dt_probe_tag(prp, ap->dn_value, &tag),
	    xnp, DT_XLATE_EXACT | DT_XLATE_EXTERN)) != NULL) {

		xidp = dt_xlator_ident(dxp, xnp->dn_ctfp, xnp->dn_type);

		dnp->dn_ident = dt_ident_create(idp->di_name, xidp->di_kind,
		    xidp->di_flags | DT_IDFLG_ORPHAN, idp->di_id, idp->di_attr,
		    idp->di_vers, idp->di_ops, idp->di_iarg, idp->di_gen);

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

		if (dt_xlator_dynamic(dxp))
			dxp->dx_arg = (int)ap->dn_value;

		/*
		 * Propagate relevant members from the translator's internal
		 * dt_ident_t.  This code must be kept in sync with the state
		 * that is initialized for idents in dt_xlator_create().
		 */
		dnp->dn_ident->di_data = xidp->di_data;
		dnp->dn_ident->di_ctfp = xidp->di_ctfp;
		dnp->dn_ident->di_type = xidp->di_type;

		dt_node_type_assign(dnp, DT_DYN_CTFP(dtp), DT_DYN_TYPE(dtp),
		    B_FALSE);

	} else {
		xyerror(D_ARGS_XLATOR, "translator for %s[%lld] from %s to %s "
		    "is not defined\n", idp->di_name, (longlong_t)ap->dn_value,
		    dt_node_type_name(nnp, n1, sizeof (n1)),
		    dt_node_type_name(xnp, n2, sizeof (n2)));
	}

	assert(dnp->dn_ident->di_flags & DT_IDFLG_ORPHAN);
	assert(dnp->dn_ident->di_id == idp->di_id);
}

static void
dt_idcook_regs(dt_node_t *dnp, dt_ident_t *idp, int argc, dt_node_t *ap)
{
	dtrace_typeinfo_t dtt;
	dtrace_hdl_t *dtp = yypcb->pcb_hdl;
	char n[DT_TYPE_NAMELEN];

	if (argc != 1) {
		xyerror(D_PROTO_LEN, "%s[ ] prototype mismatch: %d arg%s"
		    "passed, 1 expected\n", idp->di_name,
		    argc, argc == 1 ? " " : "s ");
	}

	if (ap->dn_kind != DT_NODE_INT) {
		xyerror(D_PROTO_ARG, "%s[ ] argument #1 is incompatible with "
		    "prototype:\n\tprototype: %s\n\t argument: %s\n",
		    idp->di_name, "integer constant",
		    dt_type_name(ap->dn_ctfp, ap->dn_type, n, sizeof (n)));
	}

	if ((ap->dn_flags & DT_NF_SIGNED) && (int64_t)ap->dn_value < 0) {
		xyerror(D_REGS_IDX, "index %lld is out of range for array %s\n",
		    (longlong_t)ap->dn_value, idp->di_name);
	}

	if (dt_type_lookup("uint64_t", &dtt) == -1) {
		xyerror(D_UNKNOWN, "failed to resolve type of %s: %s\n",
		    idp->di_name, dtrace_errmsg(dtp, dtrace_errno(dtp)));
	}

	idp->di_ctfp = dtt.dtt_ctfp;
	idp->di_type = dtt.dtt_type;

	dt_node_type_assign(dnp, idp->di_ctfp, idp->di_type, B_FALSE);
}

/*ARGSUSED*/
static void
dt_idcook_type(dt_node_t *dnp, dt_ident_t *idp, int argc, dt_node_t *args)
{
	if (idp->di_type == CTF_ERR) {
		dtrace_hdl_t *dtp = yypcb->pcb_hdl;
		dtrace_typeinfo_t dtt;

		if (dt_type_lookup(idp->di_iarg, &dtt) == -1) {
			xyerror(D_UNKNOWN,
			    "failed to resolve type %s for identifier %s: %s\n",
			    (const char *)idp->di_iarg, idp->di_name,
			    dtrace_errmsg(dtp, dtrace_errno(dtp)));
		}

		idp->di_ctfp = dtt.dtt_ctfp;
		idp->di_type = dtt.dtt_type;
	}

	dt_node_type_assign(dnp, idp->di_ctfp, idp->di_type, B_FALSE);
}

/*ARGSUSED*/
static void
dt_idcook_thaw(dt_node_t *dnp, dt_ident_t *idp, int argc, dt_node_t *args)
{
	if (idp->di_ctfp != NULL && idp->di_type != CTF_ERR)
		dt_node_type_assign(dnp, idp->di_ctfp, idp->di_type, B_FALSE);
}

static void
dt_idcook_inline(dt_node_t *dnp, dt_ident_t *idp, int argc, dt_node_t *args)
{
	if (idp->di_kind == DT_IDENT_ARRAY)
		dt_idcook_assc(dnp, idp, argc, args);
	else
		dt_idcook_thaw(dnp, idp, argc, args);
}

static void
dt_iddtor_sign(dt_ident_t *idp)
{
	if (idp->di_data != NULL)
		free(((dt_idsig_t *)idp->di_data)->dis_args);
	free(idp->di_data);
}

static void
dt_iddtor_free(dt_ident_t *idp)
{
	free(idp->di_data);
}

static void
dt_iddtor_inline(dt_ident_t *idp)
{
	dt_idnode_t *inp = idp->di_iarg;

	if (inp != NULL) {
		dt_node_link_free(&inp->din_list);

		if (inp->din_hash != NULL)
			dt_idhash_destroy(inp->din_hash);

		free(inp->din_argv);
		free(inp);
	}

	if (idp->di_kind == DT_IDENT_ARRAY)
		dt_iddtor_sign(idp);
	else
		dt_iddtor_free(idp);
}

/*ARGSUSED*/
static void
dt_iddtor_none(dt_ident_t *idp)
{
	/* do nothing */
}

static void
dt_iddtor_probe(dt_ident_t *idp)
{
	if (idp->di_data != NULL)
		dt_probe_destroy(idp->di_data);
}

static size_t
dt_idsize_type(dt_ident_t *idp)
{
	return (ctf_type_size(idp->di_ctfp, idp->di_type));
}

/*ARGSUSED*/
static size_t
dt_idsize_none(dt_ident_t *idp)
{
	return (0);
}

const dt_idops_t dt_idops_assc = {
	dt_idcook_assc,
	dt_iddtor_sign,
	dt_idsize_none,
};

const dt_idops_t dt_idops_func = {
	dt_idcook_func,
	dt_iddtor_sign,
	dt_idsize_none,
};

const dt_idops_t dt_idops_args = {
	dt_idcook_args,
	dt_iddtor_none,
	dt_idsize_none,
};

const dt_idops_t dt_idops_regs = {
	dt_idcook_regs,
	dt_iddtor_free,
	dt_idsize_none,
};

const dt_idops_t dt_idops_type = {
	dt_idcook_type,
	dt_iddtor_free,
	dt_idsize_type,
};

const dt_idops_t dt_idops_thaw = {
	dt_idcook_thaw,
	dt_iddtor_free,
	dt_idsize_type,
};

const dt_idops_t dt_idops_inline = {
	dt_idcook_inline,
	dt_iddtor_inline,
	dt_idsize_type,
};

const dt_idops_t dt_idops_probe = {
	dt_idcook_thaw,
	dt_iddtor_probe,
	dt_idsize_none,
};

static void
dt_idhash_populate(dt_idhash_t *dhp)
{
	const dt_ident_t *idp = dhp->dh_tmpl;

	dhp->dh_tmpl = NULL; /* clear dh_tmpl first to avoid recursion */
	dt_dprintf("populating %s idhash from %p\n", dhp->dh_name, (void *)idp);

	for (; idp->di_name != NULL; idp++) {
		if (dt_idhash_insert(dhp, idp->di_name,
		    idp->di_kind, idp->di_flags, idp->di_id, idp->di_attr,
		    idp->di_vers, idp->di_ops ? idp->di_ops : &dt_idops_thaw,
		    idp->di_iarg, 0) == NULL)
			longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
	}
}

dt_idhash_t *
dt_idhash_create(const char *name, const dt_ident_t *tmpl,
    uint_t min, uint_t max)
{
	dt_idhash_t *dhp;
	size_t size;

	assert(min <= max);

	size = sizeof (dt_idhash_t) +
	    sizeof (dt_ident_t *) * (_dtrace_strbuckets - 1);

	if ((dhp = malloc(size)) == NULL)
		return (NULL);

	bzero(dhp, size);
	dhp->dh_name = name;
	dhp->dh_tmpl = tmpl;
	dhp->dh_nextid = min;
	dhp->dh_minid = min;
	dhp->dh_maxid = max;
	dhp->dh_hashsz = _dtrace_strbuckets;

	return (dhp);
}

/*
 * Destroy an entire identifier hash.  This must be done using two passes with
 * an inlined version of dt_ident_destroy() to avoid referencing freed memory.
 * In the first pass di_dtor() is called for all identifiers; then the second
 * pass frees the actual dt_ident_t's.  These must be done separately because
 * a di_dtor() may operate on data structures which contain references to other
 * identifiers inside of this hash itself (e.g. a global inline definition
 * which contains a parse tree that refers to another global variable).
 */
void
dt_idhash_destroy(dt_idhash_t *dhp)
{
	dt_ident_t *idp, *next;
	ulong_t i;

	for (i = 0; i < dhp->dh_hashsz; i++) {
		for (idp = dhp->dh_hash[i]; idp != NULL; idp = next) {
			next = idp->di_next;
			idp->di_ops->di_dtor(idp);
		}
	}

	for (i = 0; i < dhp->dh_hashsz; i++) {
		for (idp = dhp->dh_hash[i]; idp != NULL; idp = next) {
			next = idp->di_next;
			free(idp->di_name);
			free(idp);
		}
	}

	free(dhp);
}

void
dt_idhash_update(dt_idhash_t *dhp)
{
	uint_t nextid = dhp->dh_minid;
	dt_ident_t *idp;
	ulong_t i;

	for (i = 0; i < dhp->dh_hashsz; i++) {
		for (idp = dhp->dh_hash[i]; idp != NULL; idp = idp->di_next) {
			/*
			 * Right now we're hard coding which types need to be
			 * reset, but ideally this would be done dynamically.
			 */
			if (idp->di_kind == DT_IDENT_ARRAY ||
			    idp->di_kind == DT_IDENT_SCALAR ||
			    idp->di_kind == DT_IDENT_AGG)
				nextid = MAX(nextid, idp->di_id + 1);
		}
	}

	dhp->dh_nextid = nextid;
}

dt_ident_t *
dt_idhash_lookup(dt_idhash_t *dhp, const char *name)
{
	size_t len;
	ulong_t h = dt_strtab_hash(name, &len) % dhp->dh_hashsz;
	dt_ident_t *idp;

	if (dhp->dh_tmpl != NULL)
		dt_idhash_populate(dhp); /* fill hash w/ initial population */

	for (idp = dhp->dh_hash[h]; idp != NULL; idp = idp->di_next) {
		if (strcmp(idp->di_name, name) == 0)
			return (idp);
	}

	return (NULL);
}

int
dt_idhash_nextid(dt_idhash_t *dhp, uint_t *p)
{
	if (dhp->dh_nextid >= dhp->dh_maxid)
		return (-1); /* no more id's are free to allocate */

	*p = dhp->dh_nextid++;
	return (0);
}

ulong_t
dt_idhash_size(const dt_idhash_t *dhp)
{
	return (dhp->dh_nelems);
}

const char *
dt_idhash_name(const dt_idhash_t *dhp)
{
	return (dhp->dh_name);
}

dt_ident_t *
dt_idhash_insert(dt_idhash_t *dhp, const char *name, ushort_t kind,
    ushort_t flags, uint_t id, dtrace_attribute_t attr, uint_t vers,
    const dt_idops_t *ops, void *iarg, ulong_t gen)
{
	dt_ident_t *idp;
	ulong_t h;

	if (dhp->dh_tmpl != NULL)
		dt_idhash_populate(dhp); /* fill hash w/ initial population */

	idp = dt_ident_create(name, kind, flags, id,
	    attr, vers, ops, iarg, gen);

	if (idp == NULL)
		return (NULL);

	h = dt_strtab_hash(name, NULL) % dhp->dh_hashsz;
	idp->di_next = dhp->dh_hash[h];

	dhp->dh_hash[h] = idp;
	dhp->dh_nelems++;

	if (dhp->dh_defer != NULL)
		dhp->dh_defer(dhp, idp);

	return (idp);
}

void
dt_idhash_xinsert(dt_idhash_t *dhp, dt_ident_t *idp)
{
	ulong_t h;

	if (dhp->dh_tmpl != NULL)
		dt_idhash_populate(dhp); /* fill hash w/ initial population */

	h = dt_strtab_hash(idp->di_name, NULL) % dhp->dh_hashsz;
	idp->di_next = dhp->dh_hash[h];
	idp->di_flags &= ~DT_IDFLG_ORPHAN;

	dhp->dh_hash[h] = idp;
	dhp->dh_nelems++;

	if (dhp->dh_defer != NULL)
		dhp->dh_defer(dhp, idp);
}

void
dt_idhash_delete(dt_idhash_t *dhp, dt_ident_t *key)
{
	size_t len;
	ulong_t h = dt_strtab_hash(key->di_name, &len) % dhp->dh_hashsz;
	dt_ident_t **pp = &dhp->dh_hash[h];
	dt_ident_t *idp;

	for (idp = dhp->dh_hash[h]; idp != NULL; idp = idp->di_next) {
		if (idp == key)
			break;
		else
			pp = &idp->di_next;
	}

	assert(idp == key);
	*pp = idp->di_next;

	assert(dhp->dh_nelems != 0);
	dhp->dh_nelems--;

	if (!(idp->di_flags & DT_IDFLG_ORPHAN))
		dt_ident_destroy(idp);
}

static int
dt_idhash_comp(const void *lp, const void *rp)
{
	const dt_ident_t *lhs = *((const dt_ident_t **)lp);
	const dt_ident_t *rhs = *((const dt_ident_t **)rp);

	if (lhs->di_id != rhs->di_id)
		return ((int)(lhs->di_id - rhs->di_id));
	else
		return (strcmp(lhs->di_name, rhs->di_name));
}

int
dt_idhash_iter(dt_idhash_t *dhp, dt_idhash_f *func, void *data)
{
	dt_ident_t **ids;
	dt_ident_t *idp;
	ulong_t i, j, n;
	int rv;

	if (dhp->dh_tmpl != NULL)
		dt_idhash_populate(dhp); /* fill hash w/ initial population */

	n = dhp->dh_nelems;
	ids = alloca(sizeof (dt_ident_t *) * n);

	for (i = 0, j = 0; i < dhp->dh_hashsz; i++) {
		for (idp = dhp->dh_hash[i]; idp != NULL; idp = idp->di_next)
			ids[j++] = idp;
	}

	qsort(ids, dhp->dh_nelems, sizeof (dt_ident_t *), dt_idhash_comp);

	for (i = 0; i < n; i++) {
		if ((rv = func(dhp, ids[i], data)) != 0)
			return (rv);
	}

	return (0);
}

dt_ident_t *
dt_idstack_lookup(dt_idstack_t *sp, const char *name)
{
	dt_idhash_t *dhp;
	dt_ident_t *idp;

	for (dhp = dt_list_prev(&sp->dids_list);
	    dhp != NULL; dhp = dt_list_prev(dhp)) {
		if ((idp = dt_idhash_lookup(dhp, name)) != NULL)
			return (idp);
	}

	return (NULL);
}

void
dt_idstack_push(dt_idstack_t *sp, dt_idhash_t *dhp)
{
	dt_list_append(&sp->dids_list, dhp);
}

void
dt_idstack_pop(dt_idstack_t *sp, dt_idhash_t *dhp)
{
	assert(dt_list_prev(&sp->dids_list) == dhp);
	dt_list_delete(&sp->dids_list, dhp);
}

dt_ident_t *
dt_ident_create(const char *name, ushort_t kind, ushort_t flags, uint_t id,
    dtrace_attribute_t attr, uint_t vers,
    const dt_idops_t *ops, void *iarg, ulong_t gen)
{
	dt_ident_t *idp;
	char *s = NULL;

	if ((name != NULL && (s = strdup(name)) == NULL) ||
	    (idp = malloc(sizeof (dt_ident_t))) == NULL) {
		free(s);
		return (NULL);
	}

	idp->di_name = s;
	idp->di_kind = kind;
	idp->di_flags = flags;
	idp->di_id = id;
	idp->di_attr = attr;
	idp->di_vers = vers;
	idp->di_ops = ops;
	idp->di_iarg = iarg;
	idp->di_data = NULL;
	idp->di_ctfp = NULL;
	idp->di_type = CTF_ERR;
	idp->di_next = NULL;
	idp->di_gen = gen;
	idp->di_lineno = yylineno;

	return (idp);
}

/*
 * Destroy an individual identifier.  This code must be kept in sync with the
 * dt_idhash_destroy() function below, which separates out the call to di_dtor.
 */
void
dt_ident_destroy(dt_ident_t *idp)
{
	idp->di_ops->di_dtor(idp);
	free(idp->di_name);
	free(idp);
}

void
dt_ident_morph(dt_ident_t *idp, ushort_t kind,
    const dt_idops_t *ops, void *iarg)
{
	idp->di_ops->di_dtor(idp);
	idp->di_kind = kind;
	idp->di_ops = ops;
	idp->di_iarg = iarg;
	idp->di_data = NULL;
}

dtrace_attribute_t
dt_ident_cook(dt_node_t *dnp, dt_ident_t *idp, dt_node_t **pargp)
{
	dtrace_attribute_t attr;
	dt_node_t *args, *argp;
	int argc = 0;

	attr = dt_node_list_cook(pargp, DT_IDFLG_REF);
	args = pargp ? *pargp : NULL;

	for (argp = args; argp != NULL; argp = argp->dn_list)
		argc++;

	idp->di_ops->di_cook(dnp, idp, argc, args);

	if (idp->di_flags & DT_IDFLG_USER)
		dnp->dn_flags |= DT_NF_USERLAND;

	return (dt_attr_min(attr, idp->di_attr));
}

void
dt_ident_type_assign(dt_ident_t *idp, ctf_file_t *fp, ctf_id_t type)
{
	idp->di_ctfp = fp;
	idp->di_type = type;
}

dt_ident_t *
dt_ident_resolve(dt_ident_t *idp)
{
	while (idp->di_flags & DT_IDFLG_INLINE) {
		const dt_node_t *dnp = ((dt_idnode_t *)idp->di_iarg)->din_root;

		if (dnp == NULL)
			break; /* can't resolve any further yet */

		switch (dnp->dn_kind) {
		case DT_NODE_VAR:
		case DT_NODE_SYM:
		case DT_NODE_FUNC:
		case DT_NODE_AGG:
		case DT_NODE_INLINE:
		case DT_NODE_PROBE:
			idp = dnp->dn_ident;
			continue;
		}

		if (dt_node_is_dynamic(dnp))
			idp = dnp->dn_ident;
		else
			break;
	}

	return (idp);
}

size_t
dt_ident_size(dt_ident_t *idp)
{
	idp = dt_ident_resolve(idp);
	return (idp->di_ops->di_size(idp));
}

int
dt_ident_unref(const dt_ident_t *idp)
{
	return (idp->di_gen == yypcb->pcb_hdl->dt_gen &&
	    (idp->di_flags & (DT_IDFLG_REF|DT_IDFLG_MOD|DT_IDFLG_DECL)) == 0);
}

const char *
dt_idkind_name(uint_t kind)
{
	switch (kind) {
	case DT_IDENT_ARRAY:	return ("associative array");
	case DT_IDENT_SCALAR:	return ("scalar");
	case DT_IDENT_PTR:	return ("pointer");
	case DT_IDENT_FUNC:	return ("function");
	case DT_IDENT_AGG:	return ("aggregation");
	case DT_IDENT_AGGFUNC:	return ("aggregating function");
	case DT_IDENT_ACTFUNC:	return ("tracing function");
	case DT_IDENT_XLSOU:	return ("translated data");
	case DT_IDENT_XLPTR:	return ("pointer to translated data");
	case DT_IDENT_SYMBOL:	return ("external symbol reference");
	case DT_IDENT_ENUM:	return ("enumerator");
	case DT_IDENT_PRAGAT:	return ("#pragma attributes");
	case DT_IDENT_PRAGBN:	return ("#pragma binding");
	case DT_IDENT_PROBE:	return ("probe definition");
	default:		return ("<?>");
	}
}