/*
 * 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) 2011, 2016 by Delphix. All rights reserved.
 * Copyright (c) 2013, Joyent Inc. All rights reserved.
 * Copyright 2015 Gary Mills
 */

/*
 * DTrace D Language Compiler
 *
 * The code in this source file implements the main engine for the D language
 * compiler.  The driver routine for the compiler is dt_compile(), below.  The
 * compiler operates on either stdio FILEs or in-memory strings as its input
 * and can produce either dtrace_prog_t structures from a D program or a single
 * dtrace_difo_t structure from a D expression.  Multiple entry points are
 * provided as wrappers around dt_compile() for the various input/output pairs.
 * The compiler itself is implemented across the following source files:
 *
 * dt_lex.l - lex scanner
 * dt_grammar.y - yacc grammar
 * dt_parser.c - parse tree creation and semantic checking
 * dt_decl.c - declaration stack processing
 * dt_xlator.c - D translator lookup and creation
 * dt_ident.c - identifier and symbol table routines
 * dt_pragma.c - #pragma processing and D pragmas
 * dt_printf.c - D printf() and printa() argument checking and processing
 * dt_cc.c - compiler driver and dtrace_prog_t construction
 * dt_cg.c - DIF code generator
 * dt_as.c - DIF assembler
 * dt_dof.c - dtrace_prog_t -> DOF conversion
 *
 * Several other source files provide collections of utility routines used by
 * these major files.  The compiler itself is implemented in multiple passes:
 *
 * (1) The input program is scanned and parsed by dt_lex.l and dt_grammar.y
 *     and parse tree nodes are constructed using the routines in dt_parser.c.
 *     This node construction pass is described further in dt_parser.c.
 *
 * (2) The parse tree is "cooked" by assigning each clause a context (see the
 *     routine dt_setcontext(), below) based on its probe description and then
 *     recursively descending the tree performing semantic checking.  The cook
 *     routines are also implemented in dt_parser.c and described there.
 *
 * (3) For actions that are DIF expression statements, the DIF code generator
 *     and assembler are invoked to create a finished DIFO for the statement.
 *
 * (4) The dtrace_prog_t data structures for the program clauses and actions
 *     are built, containing pointers to any DIFOs created in step (3).
 *
 * (5) The caller invokes a routine in dt_dof.c to convert the finished program
 *     into DOF format for use in anonymous tracing or enabling in the kernel.
 *
 * In the implementation, steps 2-4 are intertwined in that they are performed
 * in order for each clause as part of a loop that executes over the clauses.
 *
 * The D compiler currently implements nearly no optimization.  The compiler
 * implements integer constant folding as part of pass (1), and a set of very
 * simple peephole optimizations as part of pass (3).  As with any C compiler,
 * a large number of optimizations are possible on both the intermediate data
 * structures and the generated DIF code.  These possibilities should be
 * investigated in the context of whether they will have any substantive effect
 * on the overall DTrace probe effect before they are undertaken.
 */

#include <sys/types.h>
#include <sys/wait.h>
#include <sys/sysmacros.h>

#include <assert.h>
#include <strings.h>
#include <signal.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <ucontext.h>
#include <limits.h>
#include <ctype.h>
#include <dirent.h>
#include <dt_module.h>
#include <dt_program.h>
#include <dt_provider.h>
#include <dt_printf.h>
#include <dt_pid.h>
#include <dt_grammar.h>
#include <dt_ident.h>
#include <dt_string.h>
#include <dt_impl.h>

static const dtrace_diftype_t dt_void_rtype = {
        DIF_TYPE_CTF, CTF_K_INTEGER, 0, 0, 0
};

static const dtrace_diftype_t dt_int_rtype = {
        DIF_TYPE_CTF, CTF_K_INTEGER, 0, 0, sizeof (uint64_t)
};

static void *dt_compile(dtrace_hdl_t *, int, dtrace_probespec_t, void *,
    uint_t, int, char *const[], FILE *, const char *);

/*ARGSUSED*/
static int
dt_idreset(dt_idhash_t *dhp, dt_ident_t *idp, void *ignored)
{
        idp->di_flags &= ~(DT_IDFLG_REF | DT_IDFLG_MOD |
            DT_IDFLG_DIFR | DT_IDFLG_DIFW);
        return (0);
}

/*ARGSUSED*/
static int
dt_idpragma(dt_idhash_t *dhp, dt_ident_t *idp, void *ignored)
{
        yylineno = idp->di_lineno;
        xyerror(D_PRAGMA_UNUSED, "unused #pragma %s\n", (char *)idp->di_iarg);
        return (0);
}

static dtrace_stmtdesc_t *
dt_stmt_create(dtrace_hdl_t *dtp, dtrace_ecbdesc_t *edp,
    dtrace_attribute_t descattr, dtrace_attribute_t stmtattr)
{
        dtrace_stmtdesc_t *sdp = dtrace_stmt_create(dtp, edp);

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

        assert(yypcb->pcb_stmt == NULL);
        yypcb->pcb_stmt = sdp;

        sdp->dtsd_descattr = descattr;
        sdp->dtsd_stmtattr = stmtattr;

        return (sdp);
}

static dtrace_actdesc_t *
dt_stmt_action(dtrace_hdl_t *dtp, dtrace_stmtdesc_t *sdp)
{
        dtrace_actdesc_t *new;

        if ((new = dtrace_stmt_action(dtp, sdp)) == NULL)
                longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);

        return (new);
}

/*
 * Utility function to determine if a given action description is destructive.
 * The dtdo_destructive bit is set for us by the DIF assembler (see dt_as.c).
 */
static int
dt_action_destructive(const dtrace_actdesc_t *ap)
{
        return (DTRACEACT_ISDESTRUCTIVE(ap->dtad_kind) || (ap->dtad_kind ==
            DTRACEACT_DIFEXPR && ap->dtad_difo->dtdo_destructive));
}

static void
dt_stmt_append(dtrace_stmtdesc_t *sdp, const dt_node_t *dnp)
{
        dtrace_ecbdesc_t *edp = sdp->dtsd_ecbdesc;
        dtrace_actdesc_t *ap, *tap;
        int commit = 0;
        int speculate = 0;
        int datarec = 0;

        /*
         * Make sure that the new statement jibes with the rest of the ECB.
         */
        for (ap = edp->dted_action; ap != NULL; ap = ap->dtad_next) {
                if (ap->dtad_kind == DTRACEACT_COMMIT) {
                        if (commit) {
                                dnerror(dnp, D_COMM_COMM, "commit( ) may "
                                    "not follow commit( )\n");
                        }

                        if (datarec) {
                                dnerror(dnp, D_COMM_DREC, "commit( ) may "
                                    "not follow data-recording action(s)\n");
                        }

                        for (tap = ap; tap != NULL; tap = tap->dtad_next) {
                                if (!DTRACEACT_ISAGG(tap->dtad_kind))
                                        continue;

                                dnerror(dnp, D_AGG_COMM, "aggregating actions "
                                    "may not follow commit( )\n");
                        }

                        commit = 1;
                        continue;
                }

                if (ap->dtad_kind == DTRACEACT_SPECULATE) {
                        if (speculate) {
                                dnerror(dnp, D_SPEC_SPEC, "speculate( ) may "
                                    "not follow speculate( )\n");
                        }

                        if (commit) {
                                dnerror(dnp, D_SPEC_COMM, "speculate( ) may "
                                    "not follow commit( )\n");
                        }

                        if (datarec) {
                                dnerror(dnp, D_SPEC_DREC, "speculate( ) may "
                                    "not follow data-recording action(s)\n");
                        }

                        speculate = 1;
                        continue;
                }

                if (DTRACEACT_ISAGG(ap->dtad_kind)) {
                        if (speculate) {
                                dnerror(dnp, D_AGG_SPEC, "aggregating actions "
                                    "may not follow speculate( )\n");
                        }

                        datarec = 1;
                        continue;
                }

                if (speculate) {
                        if (dt_action_destructive(ap)) {
                                dnerror(dnp, D_ACT_SPEC, "destructive actions "
                                    "may not follow speculate( )\n");
                        }

                        if (ap->dtad_kind == DTRACEACT_EXIT) {
                                dnerror(dnp, D_EXIT_SPEC, "exit( ) may not "
                                    "follow speculate( )\n");
                        }
                }

                /*
                 * Exclude all non data-recording actions.
                 */
                if (dt_action_destructive(ap) ||
                    ap->dtad_kind == DTRACEACT_DISCARD)
                        continue;

                if (ap->dtad_kind == DTRACEACT_DIFEXPR &&
                    ap->dtad_difo->dtdo_rtype.dtdt_kind == DIF_TYPE_CTF &&
                    ap->dtad_difo->dtdo_rtype.dtdt_size == 0)
                        continue;

                if (commit) {
                        dnerror(dnp, D_DREC_COMM, "data-recording actions "
                            "may not follow commit( )\n");
                }

                if (!speculate)
                        datarec = 1;
        }

        if (dtrace_stmt_add(yypcb->pcb_hdl, yypcb->pcb_prog, sdp) != 0)
                longjmp(yypcb->pcb_jmpbuf, dtrace_errno(yypcb->pcb_hdl));

        if (yypcb->pcb_stmt == sdp)
                yypcb->pcb_stmt = NULL;
}

/*
 * For the first element of an aggregation tuple or for printa(), we create a
 * simple DIF program that simply returns the immediate value that is the ID
 * of the aggregation itself.  This could be optimized in the future by
 * creating a new in-kernel dtad_kind that just returns an integer.
 */
static void
dt_action_difconst(dtrace_actdesc_t *ap, uint_t id, dtrace_actkind_t kind)
{
        dtrace_hdl_t *dtp = yypcb->pcb_hdl;
        dtrace_difo_t *dp = dt_zalloc(dtp, sizeof (dtrace_difo_t));

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

        dp->dtdo_buf = dt_alloc(dtp, sizeof (dif_instr_t) * 2);
        dp->dtdo_inttab = dt_alloc(dtp, sizeof (uint64_t));

        if (dp->dtdo_buf == NULL || dp->dtdo_inttab == NULL) {
                dt_difo_free(dtp, dp);
                longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
        }

        dp->dtdo_buf[0] = DIF_INSTR_SETX(0, 1); /* setx DIF_INTEGER[0], %r1 */
        dp->dtdo_buf[1] = DIF_INSTR_RET(1);     /* ret  %r1 */
        dp->dtdo_len = 2;
        dp->dtdo_inttab[0] = id;
        dp->dtdo_intlen = 1;
        dp->dtdo_rtype = dt_int_rtype;

        ap->dtad_difo = dp;
        ap->dtad_kind = kind;
}

static void
dt_action_clear(dtrace_hdl_t *dtp, dt_node_t *dnp, dtrace_stmtdesc_t *sdp)
{
        dt_ident_t *aid;
        dtrace_actdesc_t *ap;
        dt_node_t *anp;

        char n[DT_TYPE_NAMELEN];
        int argc = 0;

        for (anp = dnp->dn_args; anp != NULL; anp = anp->dn_list)
                argc++; /* count up arguments for error messages below */

        if (argc != 1) {
                dnerror(dnp, D_CLEAR_PROTO,
                    "%s( ) prototype mismatch: %d args passed, 1 expected\n",
                    dnp->dn_ident->di_name, argc);
        }

        anp = dnp->dn_args;
        assert(anp != NULL);

        if (anp->dn_kind != DT_NODE_AGG) {
                dnerror(dnp, D_CLEAR_AGGARG,
                    "%s( ) argument #1 is incompatible with prototype:\n"
                    "\tprototype: aggregation\n\t argument: %s\n",
                    dnp->dn_ident->di_name,
                    dt_node_type_name(anp, n, sizeof (n)));
        }

        aid = anp->dn_ident;

        if (aid->di_gen == dtp->dt_gen && !(aid->di_flags & DT_IDFLG_MOD)) {
                dnerror(dnp, D_CLEAR_AGGBAD,
                    "undefined aggregation: @%s\n", aid->di_name);
        }

        ap = dt_stmt_action(dtp, sdp);
        dt_action_difconst(ap, anp->dn_ident->di_id, DTRACEACT_LIBACT);
        ap->dtad_arg = DT_ACT_CLEAR;
}

static void
dt_action_normalize(dtrace_hdl_t *dtp, dt_node_t *dnp, dtrace_stmtdesc_t *sdp)
{
        dt_ident_t *aid;
        dtrace_actdesc_t *ap;
        dt_node_t *anp, *normal;
        int denormal = (strcmp(dnp->dn_ident->di_name, "denormalize") == 0);

        char n[DT_TYPE_NAMELEN];
        int argc = 0;

        for (anp = dnp->dn_args; anp != NULL; anp = anp->dn_list)
                argc++; /* count up arguments for error messages below */

        if ((denormal && argc != 1) || (!denormal && argc != 2)) {
                dnerror(dnp, D_NORMALIZE_PROTO,
                    "%s( ) prototype mismatch: %d args passed, %d expected\n",
                    dnp->dn_ident->di_name, argc, denormal ? 1 : 2);
        }

        anp = dnp->dn_args;
        assert(anp != NULL);

        if (anp->dn_kind != DT_NODE_AGG) {
                dnerror(dnp, D_NORMALIZE_AGGARG,
                    "%s( ) argument #1 is incompatible with prototype:\n"
                    "\tprototype: aggregation\n\t argument: %s\n",
                    dnp->dn_ident->di_name,
                    dt_node_type_name(anp, n, sizeof (n)));
        }

        if ((normal = anp->dn_list) != NULL && !dt_node_is_scalar(normal)) {
                dnerror(dnp, D_NORMALIZE_SCALAR,
                    "%s( ) argument #2 must be of scalar type\n",
                    dnp->dn_ident->di_name);
        }

        aid = anp->dn_ident;

        if (aid->di_gen == dtp->dt_gen && !(aid->di_flags & DT_IDFLG_MOD)) {
                dnerror(dnp, D_NORMALIZE_AGGBAD,
                    "undefined aggregation: @%s\n", aid->di_name);
        }

        ap = dt_stmt_action(dtp, sdp);
        dt_action_difconst(ap, anp->dn_ident->di_id, DTRACEACT_LIBACT);

        if (denormal) {
                ap->dtad_arg = DT_ACT_DENORMALIZE;
                return;
        }

        ap->dtad_arg = DT_ACT_NORMALIZE;

        assert(normal != NULL);
        ap = dt_stmt_action(dtp, sdp);
        dt_cg(yypcb, normal);

        ap->dtad_difo = dt_as(yypcb);
        ap->dtad_kind = DTRACEACT_LIBACT;
        ap->dtad_arg = DT_ACT_NORMALIZE;
}

static void
dt_action_trunc(dtrace_hdl_t *dtp, dt_node_t *dnp, dtrace_stmtdesc_t *sdp)
{
        dt_ident_t *aid;
        dtrace_actdesc_t *ap;
        dt_node_t *anp, *trunc;

        char n[DT_TYPE_NAMELEN];
        int argc = 0;

        for (anp = dnp->dn_args; anp != NULL; anp = anp->dn_list)
                argc++; /* count up arguments for error messages below */

        if (argc > 2 || argc < 1) {
                dnerror(dnp, D_TRUNC_PROTO,
                    "%s( ) prototype mismatch: %d args passed, %s expected\n",
                    dnp->dn_ident->di_name, argc,
                    argc < 1 ? "at least 1" : "no more than 2");
        }

        anp = dnp->dn_args;
        assert(anp != NULL);
        trunc = anp->dn_list;

        if (anp->dn_kind != DT_NODE_AGG) {
                dnerror(dnp, D_TRUNC_AGGARG,
                    "%s( ) argument #1 is incompatible with prototype:\n"
                    "\tprototype: aggregation\n\t argument: %s\n",
                    dnp->dn_ident->di_name,
                    dt_node_type_name(anp, n, sizeof (n)));
        }

        if (argc == 2) {
                assert(trunc != NULL);
                if (!dt_node_is_scalar(trunc)) {
                        dnerror(dnp, D_TRUNC_SCALAR,
                            "%s( ) argument #2 must be of scalar type\n",
                            dnp->dn_ident->di_name);
                }
        }

        aid = anp->dn_ident;

        if (aid->di_gen == dtp->dt_gen && !(aid->di_flags & DT_IDFLG_MOD)) {
                dnerror(dnp, D_TRUNC_AGGBAD,
                    "undefined aggregation: @%s\n", aid->di_name);
        }

        ap = dt_stmt_action(dtp, sdp);
        dt_action_difconst(ap, anp->dn_ident->di_id, DTRACEACT_LIBACT);
        ap->dtad_arg = DT_ACT_TRUNC;

        ap = dt_stmt_action(dtp, sdp);

        if (argc == 1) {
                dt_action_difconst(ap, 0, DTRACEACT_LIBACT);
        } else {
                assert(trunc != NULL);
                dt_cg(yypcb, trunc);
                ap->dtad_difo = dt_as(yypcb);
                ap->dtad_kind = DTRACEACT_LIBACT;
        }

        ap->dtad_arg = DT_ACT_TRUNC;
}

static void
dt_action_printa(dtrace_hdl_t *dtp, dt_node_t *dnp, dtrace_stmtdesc_t *sdp)
{
        dt_ident_t *aid, *fid;
        dtrace_actdesc_t *ap;
        const char *format;
        dt_node_t *anp, *proto = NULL;

        char n[DT_TYPE_NAMELEN];
        int argc = 0, argr = 0;

        for (anp = dnp->dn_args; anp != NULL; anp = anp->dn_list)
                argc++; /* count up arguments for error messages below */

        if (dnp->dn_args != NULL) {
                switch (dnp->dn_args->dn_kind) {
                case DT_NODE_STRING:
                        format = dnp->dn_args->dn_string;
                        anp = dnp->dn_args->dn_list;
                        argr = 2;
                        break;
                case DT_NODE_AGG:
                        format = NULL;
                        anp = dnp->dn_args;
                        argr = 1;
                        break;
                default:
                        format = NULL;
                        anp = dnp->dn_args;
                        argr = 1;
                }
        }

        if (argc < argr) {
                dnerror(dnp, D_PRINTA_PROTO,
                    "%s( ) prototype mismatch: %d args passed, %d expected\n",
                    dnp->dn_ident->di_name, argc, argr);
        }

        assert(anp != NULL);

        while (anp != NULL) {
                if (anp->dn_kind != DT_NODE_AGG) {
                        dnerror(dnp, D_PRINTA_AGGARG,
                            "%s( ) argument #%d is incompatible with "
                            "prototype:\n\tprototype: aggregation\n"
                            "\t argument: %s\n", dnp->dn_ident->di_name, argr,
                            dt_node_type_name(anp, n, sizeof (n)));
                }

                aid = anp->dn_ident;
                fid = aid->di_iarg;

                if (aid->di_gen == dtp->dt_gen &&
                    !(aid->di_flags & DT_IDFLG_MOD)) {
                        dnerror(dnp, D_PRINTA_AGGBAD,
                            "undefined aggregation: @%s\n", aid->di_name);
                }

                /*
                 * If we have multiple aggregations, we must be sure that
                 * their key signatures match.
                 */
                if (proto != NULL) {
                        dt_printa_validate(proto, anp);
                } else {
                        proto = anp;
                }

                if (format != NULL) {
                        yylineno = dnp->dn_line;

                        sdp->dtsd_fmtdata =
                            dt_printf_create(yypcb->pcb_hdl, format);
                        dt_printf_validate(sdp->dtsd_fmtdata,
                            DT_PRINTF_AGGREGATION, dnp->dn_ident, 1,
                            fid->di_id, ((dt_idsig_t *)aid->di_data)->dis_args);
                        format = NULL;
                }

                ap = dt_stmt_action(dtp, sdp);
                dt_action_difconst(ap, anp->dn_ident->di_id, DTRACEACT_PRINTA);

                anp = anp->dn_list;
                argr++;
        }
}

static void
dt_action_printflike(dtrace_hdl_t *dtp, dt_node_t *dnp, dtrace_stmtdesc_t *sdp,
    dtrace_actkind_t kind)
{
        dt_node_t *anp, *arg1;
        dtrace_actdesc_t *ap = NULL;
        char n[DT_TYPE_NAMELEN], *str;

        assert(DTRACEACT_ISPRINTFLIKE(kind));

        if (dnp->dn_args->dn_kind != DT_NODE_STRING) {
                dnerror(dnp, D_PRINTF_ARG_FMT,
                    "%s( ) argument #1 is incompatible with prototype:\n"
                    "\tprototype: string constant\n\t argument: %s\n",
                    dnp->dn_ident->di_name,
                    dt_node_type_name(dnp->dn_args, n, sizeof (n)));
        }

        arg1 = dnp->dn_args->dn_list;
        yylineno = dnp->dn_line;
        str = dnp->dn_args->dn_string;


        /*
         * If this is an freopen(), we use an empty string to denote that
         * stdout should be restored.  For other printf()-like actions, an
         * empty format string is illegal:  an empty format string would
         * result in malformed DOF, and the compiler thus flags an empty
         * format string as a compile-time error.  To avoid propagating the
         * freopen() special case throughout the system, we simply transpose
         * an empty string into a sentinel string (DT_FREOPEN_RESTORE) that
         * denotes that stdout should be restored.
         */
        if (kind == DTRACEACT_FREOPEN) {
                if (strcmp(str, DT_FREOPEN_RESTORE) == 0) {
                        /*
                         * Our sentinel is always an invalid argument to
                         * freopen(), but if it's been manually specified, we
                         * must fail now instead of when the freopen() is
                         * actually evaluated.
                         */
                        dnerror(dnp, D_FREOPEN_INVALID,
                            "%s( ) argument #1 cannot be \"%s\"\n",
                            dnp->dn_ident->di_name, DT_FREOPEN_RESTORE);
                }

                if (str[0] == '\0')
                        str = DT_FREOPEN_RESTORE;
        }

        sdp->dtsd_fmtdata = dt_printf_create(dtp, str);

        dt_printf_validate(sdp->dtsd_fmtdata, DT_PRINTF_EXACTLEN,
            dnp->dn_ident, 1, DTRACEACT_AGGREGATION, arg1);

        if (arg1 == NULL) {
                dif_instr_t *dbuf;
                dtrace_difo_t *dp;

                if ((dbuf = dt_alloc(dtp, sizeof (dif_instr_t))) == NULL ||
                    (dp = dt_zalloc(dtp, sizeof (dtrace_difo_t))) == NULL) {
                        dt_free(dtp, dbuf);
                        longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
                }

                dbuf[0] = DIF_INSTR_RET(DIF_REG_R0); /* ret %r0 */

                dp->dtdo_buf = dbuf;
                dp->dtdo_len = 1;
                dp->dtdo_rtype = dt_int_rtype;

                ap = dt_stmt_action(dtp, sdp);
                ap->dtad_difo = dp;
                ap->dtad_kind = kind;
                return;
        }

        for (anp = arg1; anp != NULL; anp = anp->dn_list) {
                ap = dt_stmt_action(dtp, sdp);
                dt_cg(yypcb, anp);
                ap->dtad_difo = dt_as(yypcb);
                ap->dtad_kind = kind;
        }
}

static void
dt_action_trace(dtrace_hdl_t *dtp, dt_node_t *dnp, dtrace_stmtdesc_t *sdp)
{
        int ctflib;

        dtrace_actdesc_t *ap = dt_stmt_action(dtp, sdp);
        boolean_t istrace = (dnp->dn_ident->di_id == DT_ACT_TRACE);
        const char *act = istrace ?  "trace" : "print";

        if (dt_node_is_void(dnp->dn_args)) {
                dnerror(dnp->dn_args, istrace ? D_TRACE_VOID : D_PRINT_VOID,
                    "%s( ) may not be applied to a void expression\n", act);
        }

        if (dt_node_resolve(dnp->dn_args, DT_IDENT_XLPTR) != NULL) {
                dnerror(dnp->dn_args, istrace ? D_TRACE_DYN : D_PRINT_DYN,
                    "%s( ) may not be applied to a translated pointer\n", act);
        }

        if (dnp->dn_args->dn_kind == DT_NODE_AGG) {
                dnerror(dnp->dn_args, istrace ? D_TRACE_AGG : D_PRINT_AGG,
                    "%s( ) may not be applied to an aggregation%s\n", act,
                    istrace ? "" : " -- did you mean printa()?");
        }

        dt_cg(yypcb, dnp->dn_args);

        /*
         * The print() action behaves identically to trace(), except that it
         * stores the CTF type of the argument (if present) within the DOF for
         * the DIFEXPR action.  To do this, we set the 'dtsd_strdata' to point
         * to the fully-qualified CTF type ID for the result of the DIF
         * action.  We use the ID instead of the name to handles complex types
         * like arrays and function pointers that can't be resolved by
         * ctf_type_lookup().  This is later processed by dtrace_dof_create()
         * and turned into a reference into the string table so that we can
         * get the type information when we process the data after the fact.  In
         * the case where we are referring to userland CTF data, we also need to
         * to identify which ctf container in question we care about and encode
         * that within the name.
         */
        if (dnp->dn_ident->di_id == DT_ACT_PRINT) {
                dt_node_t *dret;
                size_t n;
                dt_module_t *dmp;

                dret = yypcb->pcb_dret;
                dmp = dt_module_lookup_by_ctf(dtp, dret->dn_ctfp);

                if (dmp->dm_pid != 0) {
                        ctflib = dt_module_getlibid(dtp, dmp, dret->dn_ctfp);
                        assert(ctflib >= 0);
                        n = snprintf(NULL, 0, "%s`%d`%d", dmp->dm_name,
                            ctflib, dret->dn_type) + 1;
                } else {
                        n = snprintf(NULL, 0, "%s`%d", dmp->dm_name,
                            dret->dn_type) + 1;
                }
                sdp->dtsd_strdata = dt_alloc(dtp, n);
                if (sdp->dtsd_strdata == NULL)
                        longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
                if (dmp->dm_pid != 0) {
                        (void) snprintf(sdp->dtsd_strdata, n, "%s`%d`%d",
                            dmp->dm_name, ctflib, dret->dn_type);
                } else {
                        (void) snprintf(sdp->dtsd_strdata, n, "%s`%d",
                            dmp->dm_name, dret->dn_type);
                }
        }

        ap->dtad_difo = dt_as(yypcb);
        ap->dtad_kind = DTRACEACT_DIFEXPR;
}

static void
dt_action_tracemem(dtrace_hdl_t *dtp, dt_node_t *dnp, dtrace_stmtdesc_t *sdp)
{
        dtrace_actdesc_t *ap = dt_stmt_action(dtp, sdp);

        dt_node_t *addr = dnp->dn_args;
        dt_node_t *max = dnp->dn_args->dn_list;
        dt_node_t *size;

        char n[DT_TYPE_NAMELEN];

        if (dt_node_is_integer(addr) == 0 && dt_node_is_pointer(addr) == 0) {
                dnerror(addr, D_TRACEMEM_ADDR,
                    "tracemem( ) argument #1 is incompatible with "
                    "prototype:\n\tprototype: pointer or integer\n"
                    "\t argument: %s\n",
                    dt_node_type_name(addr, n, sizeof (n)));
        }

        if (dt_node_is_posconst(max) == 0) {
                dnerror(max, D_TRACEMEM_SIZE, "tracemem( ) argument #2 must "
                    "be a non-zero positive integral constant expression\n");
        }

        if ((size = max->dn_list) != NULL) {
                if (size->dn_list != NULL) {
                        dnerror(size, D_TRACEMEM_ARGS, "tracemem ( ) prototype "
                            "mismatch: expected at most 3 args\n");
                }

                if (!dt_node_is_scalar(size)) {
                        dnerror(size, D_TRACEMEM_DYNSIZE, "tracemem ( ) "
                            "dynamic size (argument #3) must be of "
                            "scalar type\n");
                }

                dt_cg(yypcb, size);
                ap->dtad_difo = dt_as(yypcb);
                ap->dtad_difo->dtdo_rtype = dt_int_rtype;
                ap->dtad_kind = DTRACEACT_TRACEMEM_DYNSIZE;

                ap = dt_stmt_action(dtp, sdp);
        }

        dt_cg(yypcb, addr);
        ap->dtad_difo = dt_as(yypcb);
        ap->dtad_kind = DTRACEACT_TRACEMEM;

        ap->dtad_difo->dtdo_rtype.dtdt_flags |= DIF_TF_BYREF;
        ap->dtad_difo->dtdo_rtype.dtdt_size = max->dn_value;
}

static void
dt_action_stack_args(dtrace_hdl_t *dtp, dtrace_actdesc_t *ap, dt_node_t *arg0)
{
        ap->dtad_kind = DTRACEACT_STACK;

        if (dtp->dt_options[DTRACEOPT_STACKFRAMES] != DTRACEOPT_UNSET) {
                ap->dtad_arg = dtp->dt_options[DTRACEOPT_STACKFRAMES];
        } else {
                ap->dtad_arg = 0;
        }

        if (arg0 != NULL) {
                if (arg0->dn_list != NULL) {
                        dnerror(arg0, D_STACK_PROTO, "stack( ) prototype "
                            "mismatch: too many arguments\n");
                }

                if (dt_node_is_posconst(arg0) == 0) {
                        dnerror(arg0, D_STACK_SIZE, "stack( ) size must be a "
                            "non-zero positive integral constant expression\n");
                }

                ap->dtad_arg = arg0->dn_value;
        }
}

static void
dt_action_stack(dtrace_hdl_t *dtp, dt_node_t *dnp, dtrace_stmtdesc_t *sdp)
{
        dtrace_actdesc_t *ap = dt_stmt_action(dtp, sdp);
        dt_action_stack_args(dtp, ap, dnp->dn_args);
}

static void
dt_action_ustack_args(dtrace_hdl_t *dtp, dtrace_actdesc_t *ap, dt_node_t *dnp)
{
        uint32_t nframes = 0;
        uint32_t strsize = 0;   /* default string table size */
        dt_node_t *arg0 = dnp->dn_args;
        dt_node_t *arg1 = arg0 != NULL ? arg0->dn_list : NULL;

        assert(dnp->dn_ident->di_id == DT_ACT_JSTACK ||
            dnp->dn_ident->di_id == DT_ACT_USTACK);

        if (dnp->dn_ident->di_id == DT_ACT_JSTACK) {
                if (dtp->dt_options[DTRACEOPT_JSTACKFRAMES] != DTRACEOPT_UNSET)
                        nframes = dtp->dt_options[DTRACEOPT_JSTACKFRAMES];

                if (dtp->dt_options[DTRACEOPT_JSTACKSTRSIZE] != DTRACEOPT_UNSET)
                        strsize = dtp->dt_options[DTRACEOPT_JSTACKSTRSIZE];

                ap->dtad_kind = DTRACEACT_JSTACK;
        } else {
                assert(dnp->dn_ident->di_id == DT_ACT_USTACK);

                if (dtp->dt_options[DTRACEOPT_USTACKFRAMES] != DTRACEOPT_UNSET)
                        nframes = dtp->dt_options[DTRACEOPT_USTACKFRAMES];

                ap->dtad_kind = DTRACEACT_USTACK;
        }

        if (arg0 != NULL) {
                if (!dt_node_is_posconst(arg0)) {
                        dnerror(arg0, D_USTACK_FRAMES, "ustack( ) argument #1 "
                            "must be a non-zero positive integer constant\n");
                }
                nframes = (uint32_t)arg0->dn_value;
        }

        if (arg1 != NULL) {
                if (arg1->dn_kind != DT_NODE_INT ||
                    ((arg1->dn_flags & DT_NF_SIGNED) &&
                    (int64_t)arg1->dn_value < 0)) {
                        dnerror(arg1, D_USTACK_STRSIZE, "ustack( ) argument #2 "
                            "must be a positive integer constant\n");
                }

                if (arg1->dn_list != NULL) {
                        dnerror(arg1, D_USTACK_PROTO, "ustack( ) prototype "
                            "mismatch: too many arguments\n");
                }

                strsize = (uint32_t)arg1->dn_value;
        }

        ap->dtad_arg = DTRACE_USTACK_ARG(nframes, strsize);
}

static void
dt_action_ustack(dtrace_hdl_t *dtp, dt_node_t *dnp, dtrace_stmtdesc_t *sdp)
{
        dtrace_actdesc_t *ap = dt_stmt_action(dtp, sdp);
        dt_action_ustack_args(dtp, ap, dnp);
}

static void
dt_action_setopt(dtrace_hdl_t *dtp, dt_node_t *dnp, dtrace_stmtdesc_t *sdp)
{
        dtrace_actdesc_t *ap;
        dt_node_t *arg0, *arg1;

        /*
         * The prototype guarantees that we are called with either one or
         * two arguments, and that any arguments that are present are strings.
         */
        arg0 = dnp->dn_args;
        arg1 = arg0->dn_list;

        ap = dt_stmt_action(dtp, sdp);
        dt_cg(yypcb, arg0);
        ap->dtad_difo = dt_as(yypcb);
        ap->dtad_kind = DTRACEACT_LIBACT;
        ap->dtad_arg = DT_ACT_SETOPT;

        ap = dt_stmt_action(dtp, sdp);

        if (arg1 == NULL) {
                dt_action_difconst(ap, 0, DTRACEACT_LIBACT);
        } else {
                dt_cg(yypcb, arg1);
                ap->dtad_difo = dt_as(yypcb);
                ap->dtad_kind = DTRACEACT_LIBACT;
        }

        ap->dtad_arg = DT_ACT_SETOPT;
}

/*ARGSUSED*/
static void
dt_action_symmod_args(dtrace_hdl_t *dtp, dtrace_actdesc_t *ap,
    dt_node_t *dnp, dtrace_actkind_t kind)
{
        assert(kind == DTRACEACT_SYM || kind == DTRACEACT_MOD ||
            kind == DTRACEACT_USYM || kind == DTRACEACT_UMOD ||
            kind == DTRACEACT_UADDR);

        dt_cg(yypcb, dnp);
        ap->dtad_difo = dt_as(yypcb);
        ap->dtad_kind = kind;
        ap->dtad_difo->dtdo_rtype.dtdt_size = sizeof (uint64_t);
}

static void
dt_action_symmod(dtrace_hdl_t *dtp, dt_node_t *dnp, dtrace_stmtdesc_t *sdp,
    dtrace_actkind_t kind)
{
        dtrace_actdesc_t *ap = dt_stmt_action(dtp, sdp);
        dt_action_symmod_args(dtp, ap, dnp->dn_args, kind);
}

/*ARGSUSED*/
static void
dt_action_ftruncate(dtrace_hdl_t *dtp, dt_node_t *dnp, dtrace_stmtdesc_t *sdp)
{
        dtrace_actdesc_t *ap = dt_stmt_action(dtp, sdp);

        /*
         * Library actions need a DIFO that serves as an argument.  As
         * ftruncate() doesn't take an argument, we generate the constant 0
         * in a DIFO; this constant will be ignored when the ftruncate() is
         * processed.
         */
        dt_action_difconst(ap, 0, DTRACEACT_LIBACT);
        ap->dtad_arg = DT_ACT_FTRUNCATE;
}

/*ARGSUSED*/
static void
dt_action_stop(dtrace_hdl_t *dtp, dt_node_t *dnp, dtrace_stmtdesc_t *sdp)
{
        dtrace_actdesc_t *ap = dt_stmt_action(dtp, sdp);

        ap->dtad_kind = DTRACEACT_STOP;
        ap->dtad_arg = 0;
}

/*ARGSUSED*/
static void
dt_action_breakpoint(dtrace_hdl_t *dtp, dt_node_t *dnp, dtrace_stmtdesc_t *sdp)
{
        dtrace_actdesc_t *ap = dt_stmt_action(dtp, sdp);

        ap->dtad_kind = DTRACEACT_BREAKPOINT;
        ap->dtad_arg = 0;
}

/*ARGSUSED*/
static void
dt_action_panic(dtrace_hdl_t *dtp, dt_node_t *dnp, dtrace_stmtdesc_t *sdp)
{
        dtrace_actdesc_t *ap = dt_stmt_action(dtp, sdp);

        ap->dtad_kind = DTRACEACT_PANIC;
        ap->dtad_arg = 0;
}

static void
dt_action_chill(dtrace_hdl_t *dtp, dt_node_t *dnp, dtrace_stmtdesc_t *sdp)
{
        dtrace_actdesc_t *ap = dt_stmt_action(dtp, sdp);

        dt_cg(yypcb, dnp->dn_args);
        ap->dtad_difo = dt_as(yypcb);
        ap->dtad_kind = DTRACEACT_CHILL;
}

static void
dt_action_raise(dtrace_hdl_t *dtp, dt_node_t *dnp, dtrace_stmtdesc_t *sdp)
{
        dtrace_actdesc_t *ap = dt_stmt_action(dtp, sdp);

        dt_cg(yypcb, dnp->dn_args);
        ap->dtad_difo = dt_as(yypcb);
        ap->dtad_kind = DTRACEACT_RAISE;
}

static void
dt_action_exit(dtrace_hdl_t *dtp, dt_node_t *dnp, dtrace_stmtdesc_t *sdp)
{
        dtrace_actdesc_t *ap = dt_stmt_action(dtp, sdp);

        dt_cg(yypcb, dnp->dn_args);
        ap->dtad_difo = dt_as(yypcb);
        ap->dtad_kind = DTRACEACT_EXIT;
        ap->dtad_difo->dtdo_rtype.dtdt_size = sizeof (int);
}

static void
dt_action_speculate(dtrace_hdl_t *dtp, dt_node_t *dnp, dtrace_stmtdesc_t *sdp)
{
        dtrace_actdesc_t *ap = dt_stmt_action(dtp, sdp);

        dt_cg(yypcb, dnp->dn_args);
        ap->dtad_difo = dt_as(yypcb);
        ap->dtad_kind = DTRACEACT_SPECULATE;
}

static void
dt_action_commit(dtrace_hdl_t *dtp, dt_node_t *dnp, dtrace_stmtdesc_t *sdp)
{
        dtrace_actdesc_t *ap = dt_stmt_action(dtp, sdp);

        dt_cg(yypcb, dnp->dn_args);
        ap->dtad_difo = dt_as(yypcb);
        ap->dtad_kind = DTRACEACT_COMMIT;
}

static void
dt_action_discard(dtrace_hdl_t *dtp, dt_node_t *dnp, dtrace_stmtdesc_t *sdp)
{
        dtrace_actdesc_t *ap = dt_stmt_action(dtp, sdp);

        dt_cg(yypcb, dnp->dn_args);
        ap->dtad_difo = dt_as(yypcb);
        ap->dtad_kind = DTRACEACT_DISCARD;
}

static void
dt_compile_fun(dtrace_hdl_t *dtp, dt_node_t *dnp, dtrace_stmtdesc_t *sdp)
{
        switch (dnp->dn_expr->dn_ident->di_id) {
        case DT_ACT_BREAKPOINT:
                dt_action_breakpoint(dtp, dnp->dn_expr, sdp);
                break;
        case DT_ACT_CHILL:
                dt_action_chill(dtp, dnp->dn_expr, sdp);
                break;
        case DT_ACT_CLEAR:
                dt_action_clear(dtp, dnp->dn_expr, sdp);
                break;
        case DT_ACT_COMMIT:
                dt_action_commit(dtp, dnp->dn_expr, sdp);
                break;
        case DT_ACT_DENORMALIZE:
                dt_action_normalize(dtp, dnp->dn_expr, sdp);
                break;
        case DT_ACT_DISCARD:
                dt_action_discard(dtp, dnp->dn_expr, sdp);
                break;
        case DT_ACT_EXIT:
                dt_action_exit(dtp, dnp->dn_expr, sdp);
                break;
        case DT_ACT_FREOPEN:
                dt_action_printflike(dtp, dnp->dn_expr, sdp, DTRACEACT_FREOPEN);
                break;
        case DT_ACT_FTRUNCATE:
                dt_action_ftruncate(dtp, dnp->dn_expr, sdp);
                break;
        case DT_ACT_MOD:
                dt_action_symmod(dtp, dnp->dn_expr, sdp, DTRACEACT_MOD);
                break;
        case DT_ACT_NORMALIZE:
                dt_action_normalize(dtp, dnp->dn_expr, sdp);
                break;
        case DT_ACT_PANIC:
                dt_action_panic(dtp, dnp->dn_expr, sdp);
                break;
        case DT_ACT_PRINT:
                dt_action_trace(dtp, dnp->dn_expr, sdp);
                break;
        case DT_ACT_PRINTA:
                dt_action_printa(dtp, dnp->dn_expr, sdp);
                break;
        case DT_ACT_PRINTF:
                dt_action_printflike(dtp, dnp->dn_expr, sdp, DTRACEACT_PRINTF);
                break;
        case DT_ACT_RAISE:
                dt_action_raise(dtp, dnp->dn_expr, sdp);
                break;
        case DT_ACT_SETOPT:
                dt_action_setopt(dtp, dnp->dn_expr, sdp);
                break;
        case DT_ACT_SPECULATE:
                dt_action_speculate(dtp, dnp->dn_expr, sdp);
                break;
        case DT_ACT_STACK:
                dt_action_stack(dtp, dnp->dn_expr, sdp);
                break;
        case DT_ACT_STOP:
                dt_action_stop(dtp, dnp->dn_expr, sdp);
                break;
        case DT_ACT_SYM:
                dt_action_symmod(dtp, dnp->dn_expr, sdp, DTRACEACT_SYM);
                break;
        case DT_ACT_SYSTEM:
                dt_action_printflike(dtp, dnp->dn_expr, sdp, DTRACEACT_SYSTEM);
                break;
        case DT_ACT_TRACE:
                dt_action_trace(dtp, dnp->dn_expr, sdp);
                break;
        case DT_ACT_TRACEMEM:
                dt_action_tracemem(dtp, dnp->dn_expr, sdp);
                break;
        case DT_ACT_TRUNC:
                dt_action_trunc(dtp, dnp->dn_expr, sdp);
                break;
        case DT_ACT_UADDR:
                dt_action_symmod(dtp, dnp->dn_expr, sdp, DTRACEACT_UADDR);
                break;
        case DT_ACT_UMOD:
                dt_action_symmod(dtp, dnp->dn_expr, sdp, DTRACEACT_UMOD);
                break;
        case DT_ACT_USYM:
                dt_action_symmod(dtp, dnp->dn_expr, sdp, DTRACEACT_USYM);
                break;
        case DT_ACT_USTACK:
        case DT_ACT_JSTACK:
                dt_action_ustack(dtp, dnp->dn_expr, sdp);
                break;
        default:
                dnerror(dnp->dn_expr, D_UNKNOWN, "tracing function %s( ) is "
                    "not yet supported\n", dnp->dn_expr->dn_ident->di_name);
        }
}

static void
dt_compile_exp(dtrace_hdl_t *dtp, dt_node_t *dnp, dtrace_stmtdesc_t *sdp)
{
        dtrace_actdesc_t *ap = dt_stmt_action(dtp, sdp);

        dt_cg(yypcb, dnp->dn_expr);
        ap->dtad_difo = dt_as(yypcb);
        ap->dtad_difo->dtdo_rtype = dt_void_rtype;
        ap->dtad_kind = DTRACEACT_DIFEXPR;
}

static void
dt_compile_agg(dtrace_hdl_t *dtp, dt_node_t *dnp, dtrace_stmtdesc_t *sdp)
{
        dt_ident_t *aid, *fid;
        dt_node_t *anp, *incr = NULL;
        dtrace_actdesc_t *ap;
        uint_t n = 1, argmax;
        uint64_t arg = 0;

        /*
         * If the aggregation has no aggregating function applied to it, then
         * this statement has no effect.  Flag this as a programming error.
         */
        if (dnp->dn_aggfun == NULL) {
                dnerror(dnp, D_AGG_NULL, "expression has null effect: @%s\n",
                    dnp->dn_ident->di_name);
        }

        aid = dnp->dn_ident;
        fid = dnp->dn_aggfun->dn_ident;

        if (dnp->dn_aggfun->dn_args != NULL &&
            dt_node_is_scalar(dnp->dn_aggfun->dn_args) == 0) {
                dnerror(dnp->dn_aggfun, D_AGG_SCALAR, "%s( ) argument #1 must "
                    "be of scalar type\n", fid->di_name);
        }

        /*
         * The ID of the aggregation itself is implicitly recorded as the first
         * member of each aggregation tuple so we can distinguish them later.
         */
        ap = dt_stmt_action(dtp, sdp);
        dt_action_difconst(ap, aid->di_id, DTRACEACT_DIFEXPR);

        for (anp = dnp->dn_aggtup; anp != NULL; anp = anp->dn_list) {
                ap = dt_stmt_action(dtp, sdp);
                n++;

                if (anp->dn_kind == DT_NODE_FUNC) {
                        if (anp->dn_ident->di_id == DT_ACT_STACK) {
                                dt_action_stack_args(dtp, ap, anp->dn_args);
                                continue;
                        }

                        if (anp->dn_ident->di_id == DT_ACT_USTACK ||
                            anp->dn_ident->di_id == DT_ACT_JSTACK) {
                                dt_action_ustack_args(dtp, ap, anp);
                                continue;
                        }

                        switch (anp->dn_ident->di_id) {
                        case DT_ACT_UADDR:
                                dt_action_symmod_args(dtp, ap,
                                    anp->dn_args, DTRACEACT_UADDR);
                                continue;

                        case DT_ACT_USYM:
                                dt_action_symmod_args(dtp, ap,
                                    anp->dn_args, DTRACEACT_USYM);
                                continue;

                        case DT_ACT_UMOD:
                                dt_action_symmod_args(dtp, ap,
                                    anp->dn_args, DTRACEACT_UMOD);
                                continue;

                        case DT_ACT_SYM:
                                dt_action_symmod_args(dtp, ap,
                                    anp->dn_args, DTRACEACT_SYM);
                                continue;

                        case DT_ACT_MOD:
                                dt_action_symmod_args(dtp, ap,
                                    anp->dn_args, DTRACEACT_MOD);
                                continue;

                        default:
                                break;
                        }
                }

                dt_cg(yypcb, anp);
                ap->dtad_difo = dt_as(yypcb);
                ap->dtad_kind = DTRACEACT_DIFEXPR;
        }

        if (fid->di_id == DTRACEAGG_LQUANTIZE) {
                /*
                 * For linear quantization, we have between two and four
                 * arguments in addition to the expression:
                 *
                 *    arg1 => Base value
                 *    arg2 => Limit value
                 *    arg3 => Quantization level step size (defaults to 1)
                 *    arg4 => Quantization increment value (defaults to 1)
                 */
                dt_node_t *arg1 = dnp->dn_aggfun->dn_args->dn_list;
                dt_node_t *arg2 = arg1->dn_list;
                dt_node_t *arg3 = arg2->dn_list;
                dt_idsig_t *isp;
                uint64_t nlevels, step = 1, oarg;
                int64_t baseval, limitval;

                if (arg1->dn_kind != DT_NODE_INT) {
                        dnerror(arg1, D_LQUANT_BASETYPE, "lquantize( ) "
                            "argument #1 must be an integer constant\n");
                }

                baseval = (int64_t)arg1->dn_value;

                if (baseval < INT32_MIN || baseval > INT32_MAX) {
                        dnerror(arg1, D_LQUANT_BASEVAL, "lquantize( ) "
                            "argument #1 must be a 32-bit quantity\n");
                }

                if (arg2->dn_kind != DT_NODE_INT) {
                        dnerror(arg2, D_LQUANT_LIMTYPE, "lquantize( ) "
                            "argument #2 must be an integer constant\n");
                }

                limitval = (int64_t)arg2->dn_value;

                if (limitval < INT32_MIN || limitval > INT32_MAX) {
                        dnerror(arg2, D_LQUANT_LIMVAL, "lquantize( ) "
                            "argument #2 must be a 32-bit quantity\n");
                }

                if (limitval < baseval) {
                        dnerror(dnp, D_LQUANT_MISMATCH,
                            "lquantize( ) base (argument #1) must be less "
                            "than limit (argument #2)\n");
                }

                if (arg3 != NULL) {
                        if (!dt_node_is_posconst(arg3)) {
                                dnerror(arg3, D_LQUANT_STEPTYPE, "lquantize( ) "
                                    "argument #3 must be a non-zero positive "
                                    "integer constant\n");
                        }

                        if ((step = arg3->dn_value) > UINT16_MAX) {
                                dnerror(arg3, D_LQUANT_STEPVAL, "lquantize( ) "
                                    "argument #3 must be a 16-bit quantity\n");
                        }
                }

                nlevels = (limitval - baseval) / step;

                if (nlevels == 0) {
                        dnerror(dnp, D_LQUANT_STEPLARGE,
                            "lquantize( ) step (argument #3) too large: must "
                            "have at least one quantization level\n");
                }

                if (nlevels > UINT16_MAX) {
                        dnerror(dnp, D_LQUANT_STEPSMALL, "lquantize( ) step "
                            "(argument #3) too small: number of quantization "
                            "levels must be a 16-bit quantity\n");
                }

                arg = (step << DTRACE_LQUANTIZE_STEPSHIFT) |
                    (nlevels << DTRACE_LQUANTIZE_LEVELSHIFT) |
                    ((baseval << DTRACE_LQUANTIZE_BASESHIFT) &
                    DTRACE_LQUANTIZE_BASEMASK);

                assert(arg != 0);

                isp = (dt_idsig_t *)aid->di_data;

                if (isp->dis_auxinfo == 0) {
                        /*
                         * This is the first time we've seen an lquantize()
                         * for this aggregation; we'll store our argument
                         * as the auxiliary signature information.
                         */
                        isp->dis_auxinfo = arg;
                } else if ((oarg = isp->dis_auxinfo) != arg) {
                        /*
                         * If we have seen this lquantize() before and the
                         * argument doesn't match the original argument, pick
                         * the original argument apart to concisely report the
                         * mismatch.
                         */
                        int obaseval = DTRACE_LQUANTIZE_BASE(oarg);
                        int onlevels = DTRACE_LQUANTIZE_LEVELS(oarg);
                        int ostep = DTRACE_LQUANTIZE_STEP(oarg);

                        if (obaseval != baseval) {
                                dnerror(dnp, D_LQUANT_MATCHBASE, "lquantize( ) "
                                    "base (argument #1) doesn't match previous "
                                    "declaration: expected %d, found %d\n",
                                    obaseval, (int)baseval);
                        }

                        if (onlevels * ostep != nlevels * step) {
                                dnerror(dnp, D_LQUANT_MATCHLIM, "lquantize( ) "
                                    "limit (argument #2) doesn't match previous"
                                    " declaration: expected %d, found %d\n",
                                    obaseval + onlevels * ostep,
                                    (int)baseval + (int)nlevels * (int)step);
                        }

                        if (ostep != step) {
                                dnerror(dnp, D_LQUANT_MATCHSTEP, "lquantize( ) "
                                    "step (argument #3) doesn't match previous "
                                    "declaration: expected %d, found %d\n",
                                    ostep, (int)step);
                        }

                        /*
                         * We shouldn't be able to get here -- one of the
                         * parameters must be mismatched if the arguments
                         * didn't match.
                         */
                        assert(0);
                }

                incr = arg3 != NULL ? arg3->dn_list : NULL;
                argmax = 5;
        }

        if (fid->di_id == DTRACEAGG_LLQUANTIZE) {
                /*
                 * For log/linear quantizations, we have between one and five
                 * arguments in addition to the expression:
                 *
                 *    arg1 => Factor
                 *    arg2 => Low magnitude
                 *    arg3 => High magnitude
                 *    arg4 => Number of steps per magnitude
                 *    arg5 => Quantization increment value (defaults to 1)
                 */
                dt_node_t *llarg = dnp->dn_aggfun->dn_args->dn_list;
                uint64_t oarg, order, v;
                dt_idsig_t *isp;
                int i;

                struct {
                        char *str;              /* string identifier */
                        int badtype;            /* error on bad type */
                        int badval;             /* error on bad value */
                        int mismatch;           /* error on bad match */
                        int shift;              /* shift value */
                        uint16_t value;         /* value itself */
                } args[] = {
                        { "factor", D_LLQUANT_FACTORTYPE,
                            D_LLQUANT_FACTORVAL, D_LLQUANT_FACTORMATCH,
                            DTRACE_LLQUANTIZE_FACTORSHIFT },
                        { "low magnitude", D_LLQUANT_LOWTYPE,
                            D_LLQUANT_LOWVAL, D_LLQUANT_LOWMATCH,
                            DTRACE_LLQUANTIZE_LOWSHIFT },
                        { "high magnitude", D_LLQUANT_HIGHTYPE,
                            D_LLQUANT_HIGHVAL, D_LLQUANT_HIGHMATCH,
                            DTRACE_LLQUANTIZE_HIGHSHIFT },
                        { "linear steps per magnitude", D_LLQUANT_NSTEPTYPE,
                            D_LLQUANT_NSTEPVAL, D_LLQUANT_NSTEPMATCH,
                            DTRACE_LLQUANTIZE_NSTEPSHIFT },
                        { NULL }
                };

                assert(arg == 0);

                for (i = 0; args[i].str != NULL; i++) {
                        if (llarg->dn_kind != DT_NODE_INT) {
                                dnerror(llarg, args[i].badtype, "llquantize( ) "
                                    "argument #%d (%s) must be an "
                                    "integer constant\n", i + 1, args[i].str);
                        }

                        if ((uint64_t)llarg->dn_value > UINT16_MAX) {
                                dnerror(llarg, args[i].badval, "llquantize( ) "
                                    "argument #%d (%s) must be an unsigned "
                                    "16-bit quantity\n", i + 1, args[i].str);
                        }

                        args[i].value = (uint16_t)llarg->dn_value;

                        assert(!(arg & (UINT16_MAX << args[i].shift)));
                        arg |= ((uint64_t)args[i].value << args[i].shift);
                        llarg = llarg->dn_list;
                }

                assert(arg != 0);

                if (args[0].value < 2) {
                        dnerror(dnp, D_LLQUANT_FACTORSMALL, "llquantize( ) "
                            "factor (argument #1) must be two or more\n");
                }

                if (args[1].value >= args[2].value) {
                        dnerror(dnp, D_LLQUANT_MAGRANGE, "llquantize( ) "
                            "high magnitude (argument #3) must be greater "
                            "than low magnitude (argument #2)\n");
                }

                if (args[3].value < args[0].value) {
                        dnerror(dnp, D_LLQUANT_FACTORNSTEPS, "llquantize( ) "
                            "factor (argument #1) must be less than or "
                            "equal to the number of linear steps per "
                            "magnitude (argument #4)\n");
                }

                for (v = args[0].value; v < args[3].value; v *= args[0].value)
                        continue;

                if ((args[3].value % args[0].value) || (v % args[3].value)) {
                        dnerror(dnp, D_LLQUANT_FACTOREVEN, "llquantize( ) "
                            "factor (argument #1) must evenly divide the "
                            "number of steps per magnitude (argument #4), "
                            "and the number of steps per magnitude must evenly "
                            "divide a power of the factor\n");
                }

                for (i = 0, order = 1; i < args[2].value; i++) {
                        if (order * args[0].value > order) {
                                order *= args[0].value;
                                continue;
                        }

                        dnerror(dnp, D_LLQUANT_MAGTOOBIG, "llquantize( ) "
                            "factor (%d) raised to power of high magnitude "
                            "(%d) overflows 64-bits\n", args[0].value,
                            args[2].value);
                }

                isp = (dt_idsig_t *)aid->di_data;

                if (isp->dis_auxinfo == 0) {
                        /*
                         * This is the first time we've seen an llquantize()
                         * for this aggregation; we'll store our argument
                         * as the auxiliary signature information.
                         */
                        isp->dis_auxinfo = arg;
                } else if ((oarg = isp->dis_auxinfo) != arg) {
                        /*
                         * If we have seen this llquantize() before and the
                         * argument doesn't match the original argument, pick
                         * the original argument apart to concisely report the
                         * mismatch.
                         */
                        int expected = 0, found = 0;

                        for (i = 0; expected == found; i++) {
                                assert(args[i].str != NULL);

                                expected = (oarg >> args[i].shift) & UINT16_MAX;
                                found = (arg >> args[i].shift) & UINT16_MAX;
                        }

                        dnerror(dnp, args[i - 1].mismatch, "llquantize( ) "
                            "%s (argument #%d) doesn't match previous "
                            "declaration: expected %d, found %d\n",
                            args[i - 1].str, i, expected, found);
                }

                incr = llarg;
                argmax = 6;
        }

        if (fid->di_id == DTRACEAGG_QUANTIZE) {
                incr = dnp->dn_aggfun->dn_args->dn_list;
                argmax = 2;
        }

        if (incr != NULL) {
                if (!dt_node_is_scalar(incr)) {
                        dnerror(dnp, D_PROTO_ARG, "%s( ) increment value "
                            "(argument #%d) must be of scalar type\n",
                            fid->di_name, argmax);
                }

                if ((anp = incr->dn_list) != NULL) {
                        int argc = argmax;

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

                        dnerror(incr, D_PROTO_LEN, "%s( ) prototype "
                            "mismatch: %d args passed, at most %d expected",
                            fid->di_name, argc, argmax);
                }

                ap = dt_stmt_action(dtp, sdp);
                n++;

                dt_cg(yypcb, incr);
                ap->dtad_difo = dt_as(yypcb);
                ap->dtad_difo->dtdo_rtype = dt_void_rtype;
                ap->dtad_kind = DTRACEACT_DIFEXPR;
        }

        assert(sdp->dtsd_aggdata == NULL);
        sdp->dtsd_aggdata = aid;

        ap = dt_stmt_action(dtp, sdp);
        assert(fid->di_kind == DT_IDENT_AGGFUNC);
        assert(DTRACEACT_ISAGG(fid->di_id));
        ap->dtad_kind = fid->di_id;
        ap->dtad_ntuple = n;
        ap->dtad_arg = arg;

        if (dnp->dn_aggfun->dn_args != NULL) {
                dt_cg(yypcb, dnp->dn_aggfun->dn_args);
                ap->dtad_difo = dt_as(yypcb);
        }
}

static void
dt_compile_one_clause(dtrace_hdl_t *dtp, dt_node_t *cnp, dt_node_t *pnp)
{
        dtrace_ecbdesc_t *edp;
        dtrace_stmtdesc_t *sdp;
        dt_node_t *dnp;

        yylineno = pnp->dn_line;
        dt_setcontext(dtp, pnp->dn_desc);
        (void) dt_node_cook(cnp, DT_IDFLG_REF);

        if (DT_TREEDUMP_PASS(dtp, 2))
                dt_node_printr(cnp, stderr, 0);

        if ((edp = dt_ecbdesc_create(dtp, pnp->dn_desc)) == NULL)
                longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);

        assert(yypcb->pcb_ecbdesc == NULL);
        yypcb->pcb_ecbdesc = edp;

        if (cnp->dn_pred != NULL) {
                dt_cg(yypcb, cnp->dn_pred);
                edp->dted_pred.dtpdd_difo = dt_as(yypcb);
        }

        if (cnp->dn_acts == NULL) {
                dt_stmt_append(dt_stmt_create(dtp, edp,
                    cnp->dn_ctxattr, _dtrace_defattr), cnp);
        }

        for (dnp = cnp->dn_acts; dnp != NULL; dnp = dnp->dn_list) {
                assert(yypcb->pcb_stmt == NULL);
                sdp = dt_stmt_create(dtp, edp, cnp->dn_ctxattr, cnp->dn_attr);

                switch (dnp->dn_kind) {
                case DT_NODE_DEXPR:
                        if (dnp->dn_expr->dn_kind == DT_NODE_AGG)
                                dt_compile_agg(dtp, dnp->dn_expr, sdp);
                        else
                                dt_compile_exp(dtp, dnp, sdp);
                        break;
                case DT_NODE_DFUNC:
                        dt_compile_fun(dtp, dnp, sdp);
                        break;
                case DT_NODE_AGG:
                        dt_compile_agg(dtp, dnp, sdp);
                        break;
                default:
                        dnerror(dnp, D_UNKNOWN, "internal error -- node kind "
                            "%u is not a valid statement\n", dnp->dn_kind);
                }

                assert(yypcb->pcb_stmt == sdp);
                dt_stmt_append(sdp, dnp);
        }

        assert(yypcb->pcb_ecbdesc == edp);
        dt_ecbdesc_release(dtp, edp);
        dt_endcontext(dtp);
        yypcb->pcb_ecbdesc = NULL;
}

static void
dt_compile_clause(dtrace_hdl_t *dtp, dt_node_t *cnp)
{
        dt_node_t *pnp;

        for (pnp = cnp->dn_pdescs; pnp != NULL; pnp = pnp->dn_list)
                dt_compile_one_clause(dtp, cnp, pnp);
}

static void
dt_compile_xlator(dt_node_t *dnp)
{
        dt_xlator_t *dxp = dnp->dn_xlator;
        dt_node_t *mnp;

        for (mnp = dnp->dn_members; mnp != NULL; mnp = mnp->dn_list) {
                assert(dxp->dx_membdif[mnp->dn_membid] == NULL);
                dt_cg(yypcb, mnp);
                dxp->dx_membdif[mnp->dn_membid] = dt_as(yypcb);
        }
}

void
dt_setcontext(dtrace_hdl_t *dtp, dtrace_probedesc_t *pdp)
{
        const dtrace_pattr_t *pap;
        dt_probe_t *prp;
        dt_provider_t *pvp;
        dt_ident_t *idp;
        char attrstr[8];
        int err;

        /*
         * Both kernel and pid based providers are allowed to have names
         * ending with what could be interpreted as a number. We assume it's
         * a pid and that we may need to dynamically create probes for
         * that process if:
         *
         * (1) The provider doesn't exist, or,
         * (2) The provider exists and has DTRACE_PRIV_PROC privilege.
         *
         * On an error, dt_pid_create_probes() will set the error message
         * and tag -- we just have to longjmp() out of here.
         */
        if (isdigit(pdp->dtpd_provider[strlen(pdp->dtpd_provider) - 1]) &&
            ((pvp = dt_provider_lookup(dtp, pdp->dtpd_provider)) == NULL ||
            pvp->pv_desc.dtvd_priv.dtpp_flags & DTRACE_PRIV_PROC) &&
            dt_pid_create_probes(pdp, dtp, yypcb) != 0) {
                longjmp(yypcb->pcb_jmpbuf, EDT_COMPILER);
        }

        /*
         * Call dt_probe_info() to get the probe arguments and attributes.  If
         * a representative probe is found, set 'pap' to the probe provider's
         * attributes.  Otherwise set 'pap' to default Unstable attributes.
         */
        if ((prp = dt_probe_info(dtp, pdp, &yypcb->pcb_pinfo)) == NULL) {
                pap = &_dtrace_prvdesc;
                err = dtrace_errno(dtp);
                bzero(&yypcb->pcb_pinfo, sizeof (dtrace_probeinfo_t));
                yypcb->pcb_pinfo.dtp_attr = pap->dtpa_provider;
                yypcb->pcb_pinfo.dtp_arga = pap->dtpa_args;
        } else {
                pap = &prp->pr_pvp->pv_desc.dtvd_attr;
                err = 0;
        }

        if (err == EDT_NOPROBE && !(yypcb->pcb_cflags & DTRACE_C_ZDEFS)) {
                xyerror(D_PDESC_ZERO, "probe description %s:%s:%s:%s does not "
                    "match any probes\n", pdp->dtpd_provider, pdp->dtpd_mod,
                    pdp->dtpd_func, pdp->dtpd_name);
        }

        if (err != EDT_NOPROBE && err != EDT_UNSTABLE && err != 0)
                xyerror(D_PDESC_INVAL, "%s\n", dtrace_errmsg(dtp, err));

        dt_dprintf("set context to %s:%s:%s:%s [%u] prp=%p attr=%s argc=%d\n",
            pdp->dtpd_provider, pdp->dtpd_mod, pdp->dtpd_func, pdp->dtpd_name,
            pdp->dtpd_id, (void *)prp, dt_attr_str(yypcb->pcb_pinfo.dtp_attr,
            attrstr, sizeof (attrstr)), yypcb->pcb_pinfo.dtp_argc);

        /*
         * Reset the stability attributes of D global variables that vary
         * based on the attributes of the provider and context itself.
         */
        if ((idp = dt_idhash_lookup(dtp->dt_globals, "probeprov")) != NULL)
                idp->di_attr = pap->dtpa_provider;
        if ((idp = dt_idhash_lookup(dtp->dt_globals, "probemod")) != NULL)
                idp->di_attr = pap->dtpa_mod;
        if ((idp = dt_idhash_lookup(dtp->dt_globals, "probefunc")) != NULL)
                idp->di_attr = pap->dtpa_func;
        if ((idp = dt_idhash_lookup(dtp->dt_globals, "probename")) != NULL)
                idp->di_attr = pap->dtpa_name;
        if ((idp = dt_idhash_lookup(dtp->dt_globals, "args")) != NULL)
                idp->di_attr = pap->dtpa_args;

        yypcb->pcb_pdesc = pdp;
        yypcb->pcb_probe = prp;
}

/*
 * Reset context-dependent variables and state at the end of cooking a D probe
 * definition clause.  This ensures that external declarations between clauses
 * do not reference any stale context-dependent data from the previous clause.
 */
void
dt_endcontext(dtrace_hdl_t *dtp)
{
        static const char *const cvars[] = {
                "probeprov", "probemod", "probefunc", "probename", "args", NULL
        };

        dt_ident_t *idp;
        int i;

        for (i = 0; cvars[i] != NULL; i++) {
                if ((idp = dt_idhash_lookup(dtp->dt_globals, cvars[i])) != NULL)
                        idp->di_attr = _dtrace_defattr;
        }

        yypcb->pcb_pdesc = NULL;
        yypcb->pcb_probe = NULL;
}

static int
dt_reduceid(dt_idhash_t *dhp, dt_ident_t *idp, dtrace_hdl_t *dtp)
{
        if (idp->di_vers != 0 && idp->di_vers > dtp->dt_vmax)
                dt_idhash_delete(dhp, idp);

        return (0);
}

/*
 * When dtrace_setopt() is called for "version", it calls dt_reduce() to remove
 * any identifiers or translators that have been previously defined as bound to
 * a version greater than the specified version.  Therefore, in our current
 * version implementation, establishing a binding is a one-way transformation.
 * In addition, no versioning is currently provided for types as our .d library
 * files do not define any types and we reserve prefixes DTRACE_ and dtrace_
 * for our exclusive use.  If required, type versioning will require more work.
 */
int
dt_reduce(dtrace_hdl_t *dtp, dt_version_t v)
{
        char s[DT_VERSION_STRMAX];
        dt_xlator_t *dxp, *nxp;

        if (v > dtp->dt_vmax)
                return (dt_set_errno(dtp, EDT_VERSREDUCED));
        else if (v == dtp->dt_vmax)
                return (0); /* no reduction necessary */

        dt_dprintf("reducing api version to %s\n",
            dt_version_num2str(v, s, sizeof (s)));

        dtp->dt_vmax = v;

        for (dxp = dt_list_next(&dtp->dt_xlators); dxp != NULL; dxp = nxp) {
                nxp = dt_list_next(dxp);
                if ((dxp->dx_souid.di_vers != 0 && dxp->dx_souid.di_vers > v) ||
                    (dxp->dx_ptrid.di_vers != 0 && dxp->dx_ptrid.di_vers > v))
                        dt_list_delete(&dtp->dt_xlators, dxp);
        }

        (void) dt_idhash_iter(dtp->dt_macros, (dt_idhash_f *)dt_reduceid, dtp);
        (void) dt_idhash_iter(dtp->dt_aggs, (dt_idhash_f *)dt_reduceid, dtp);
        (void) dt_idhash_iter(dtp->dt_globals, (dt_idhash_f *)dt_reduceid, dtp);
        (void) dt_idhash_iter(dtp->dt_tls, (dt_idhash_f *)dt_reduceid, dtp);

        return (0);
}

/*
 * Fork and exec the cpp(1) preprocessor to run over the specified input file,
 * and return a FILE handle for the cpp output.  We use the /dev/fd filesystem
 * here to simplify the code by leveraging file descriptor inheritance.
 */
static FILE *
dt_preproc(dtrace_hdl_t *dtp, FILE *ifp)
{
        int argc = dtp->dt_cpp_argc;
        char **argv = malloc(sizeof (char *) * (argc + 5));
        FILE *ofp = tmpfile();

        char ipath[20], opath[20]; /* big enough for /dev/fd/ + INT_MAX + \0 */
        char verdef[32]; /* big enough for -D__SUNW_D_VERSION=0x%08x + \0 */

        struct sigaction act, oact;
        sigset_t mask, omask;

        int wstat, estat;
        pid_t pid;
        off64_t off;
        int c;

        if (argv == NULL || ofp == NULL) {
                (void) dt_set_errno(dtp, errno);
                goto err;
        }

        /*
         * If the input is a seekable file, see if it is an interpreter file.
         * If we see #!, seek past the first line because cpp will choke on it.
         * We start cpp just prior to the \n at the end of this line so that
         * it still sees the newline, ensuring that #line values are correct.
         */
        if (isatty(fileno(ifp)) == 0 && (off = ftello64(ifp)) != -1) {
                if ((c = fgetc(ifp)) == '#' && (c = fgetc(ifp)) == '!') {
                        for (off += 2; c != '\n'; off++) {
                                if ((c = fgetc(ifp)) == EOF)
                                        break;
                        }
                        if (c == '\n')
                                off--; /* start cpp just prior to \n */
                }
                (void) fflush(ifp);
                (void) fseeko64(ifp, off, SEEK_SET);
        }

        (void) snprintf(ipath, sizeof (ipath), "/dev/fd/%d", fileno(ifp));
        (void) snprintf(opath, sizeof (opath), "/dev/fd/%d", fileno(ofp));

        bcopy(dtp->dt_cpp_argv, argv, sizeof (char *) * argc);

        (void) snprintf(verdef, sizeof (verdef),
            "-D__SUNW_D_VERSION=0x%08x", dtp->dt_vmax);
        argv[argc++] = verdef;

        switch (dtp->dt_stdcmode) {
        case DT_STDC_XA:
        case DT_STDC_XT:
                argv[argc++] = "-D__STDC__=0";
                break;
        case DT_STDC_XC:
                argv[argc++] = "-D__STDC__=1";
                break;
        }

        argv[argc++] = ipath;
        argv[argc++] = opath;
        argv[argc] = NULL;

        /*
         * libdtrace must be able to be embedded in other programs that may
         * include application-specific signal handlers.  Therefore, if we
         * need to fork to run cpp(1), we must avoid generating a SIGCHLD
         * that could confuse the containing application.  To do this,
         * we block SIGCHLD and reset its disposition to SIG_DFL.
         * We restore our signal state once we are done.
         */
        (void) sigemptyset(&mask);
        (void) sigaddset(&mask, SIGCHLD);
        (void) sigprocmask(SIG_BLOCK, &mask, &omask);

        bzero(&act, sizeof (act));
        act.sa_handler = SIG_DFL;
        (void) sigaction(SIGCHLD, &act, &oact);

        if ((pid = fork1()) == -1) {
                (void) sigaction(SIGCHLD, &oact, NULL);
                (void) sigprocmask(SIG_SETMASK, &omask, NULL);
                (void) dt_set_errno(dtp, EDT_CPPFORK);
                goto err;
        }

        if (pid == 0) {
                (void) execvp(dtp->dt_cpp_path, argv);
                _exit(errno == ENOENT ? 127 : 126);
        }

        do {
                dt_dprintf("waiting for %s (PID %d)\n", dtp->dt_cpp_path,
                    (int)pid);
        } while (waitpid(pid, &wstat, 0) == -1 && errno == EINTR);

        (void) sigaction(SIGCHLD, &oact, NULL);
        (void) sigprocmask(SIG_SETMASK, &omask, NULL);

        dt_dprintf("%s returned exit status 0x%x\n", dtp->dt_cpp_path, wstat);
        estat = WIFEXITED(wstat) ? WEXITSTATUS(wstat) : -1;

        if (estat != 0) {
                switch (estat) {
                case 126:
                        (void) dt_set_errno(dtp, EDT_CPPEXEC);
                        break;
                case 127:
                        (void) dt_set_errno(dtp, EDT_CPPENT);
                        break;
                default:
                        (void) dt_set_errno(dtp, EDT_CPPERR);
                }
                goto err;
        }

        free(argv);
        (void) fflush(ofp);
        (void) fseek(ofp, 0, SEEK_SET);
        return (ofp);

err:
        free(argv);
        (void) fclose(ofp);
        return (NULL);
}

static void
dt_lib_depend_error(dtrace_hdl_t *dtp, const char *format, ...)
{
        va_list ap;

        va_start(ap, format);
        dt_set_errmsg(dtp, NULL, NULL, NULL, 0, format, ap);
        va_end(ap);
}

int
dt_lib_depend_add(dtrace_hdl_t *dtp, dt_list_t *dlp, const char *arg)
{
        dt_lib_depend_t *dld;
        const char *end;

        assert(arg != NULL);

        if ((end = strrchr(arg, '/')) == NULL)
                return (dt_set_errno(dtp, EINVAL));

        if ((dld = dt_zalloc(dtp, sizeof (dt_lib_depend_t))) == NULL)
                return (-1);

        if ((dld->dtld_libpath = dt_alloc(dtp, MAXPATHLEN)) == NULL) {
                dt_free(dtp, dld);
                return (-1);
        }

        (void) strlcpy(dld->dtld_libpath, arg, end - arg + 2);
        if ((dld->dtld_library = strdup(arg)) == NULL) {
                dt_free(dtp, dld->dtld_libpath);
                dt_free(dtp, dld);
                return (dt_set_errno(dtp, EDT_NOMEM));
        }

        dt_list_append(dlp, dld);
        return (0);
}

dt_lib_depend_t *
dt_lib_depend_lookup(dt_list_t *dld, const char *arg)
{
        dt_lib_depend_t *dldn;

        for (dldn = dt_list_next(dld); dldn != NULL;
            dldn = dt_list_next(dldn)) {
                if (strcmp(dldn->dtld_library, arg) == 0)
                        return (dldn);
        }

        return (NULL);
}

/*
 * Go through all the library files, and, if any library dependencies exist for
 * that file, add it to that node's list of dependents. The result of this
 * will be a graph which can then be topologically sorted to produce a
 * compilation order.
 */
static int
dt_lib_build_graph(dtrace_hdl_t *dtp)
{
        dt_lib_depend_t *dld, *dpld;

        for (dld = dt_list_next(&dtp->dt_lib_dep); dld != NULL;
            dld = dt_list_next(dld)) {
                char *library = dld->dtld_library;

                for (dpld = dt_list_next(&dld->dtld_dependencies); dpld != NULL;
                    dpld = dt_list_next(dpld)) {
                        dt_lib_depend_t *dlda;

                        if ((dlda = dt_lib_depend_lookup(&dtp->dt_lib_dep,
                            dpld->dtld_library)) == NULL) {
                                dt_lib_depend_error(dtp,
                                    "Invalid library dependency in %s: %s\n",
                                    dld->dtld_library, dpld->dtld_library);

                                return (dt_set_errno(dtp, EDT_COMPILER));
                        }

                        if ((dt_lib_depend_add(dtp, &dlda->dtld_dependents,
                            library)) != 0) {
                                return (-1); /* preserve dt_errno */
                        }
                }
        }
        return (0);
}

static int
dt_topo_sort(dtrace_hdl_t *dtp, dt_lib_depend_t *dld, int *count)
{
        dt_lib_depend_t *dpld, *dlda, *new;

        dld->dtld_start = ++(*count);

        for (dpld = dt_list_next(&dld->dtld_dependents); dpld != NULL;
            dpld = dt_list_next(dpld)) {
                dlda = dt_lib_depend_lookup(&dtp->dt_lib_dep,
                    dpld->dtld_library);
                assert(dlda != NULL);

                if (dlda->dtld_start == 0 &&
                    dt_topo_sort(dtp, dlda, count) == -1)
                        return (-1);
        }

        if ((new = dt_zalloc(dtp, sizeof (dt_lib_depend_t))) == NULL)
                return (-1);

        if ((new->dtld_library = strdup(dld->dtld_library)) == NULL) {
                dt_free(dtp, new);
                return (dt_set_errno(dtp, EDT_NOMEM));
        }

        new->dtld_start = dld->dtld_start;
        new->dtld_finish = dld->dtld_finish = ++(*count);
        dt_list_prepend(&dtp->dt_lib_dep_sorted, new);

        dt_dprintf("library %s sorted (%d/%d)\n", new->dtld_library,
            new->dtld_start, new->dtld_finish);

        return (0);
}

static int
dt_lib_depend_sort(dtrace_hdl_t *dtp)
{
        dt_lib_depend_t *dld, *dpld, *dlda;
        int count = 0;

        if (dt_lib_build_graph(dtp) == -1)
                return (-1); /* preserve dt_errno */

        /*
         * Perform a topological sort of the graph that hangs off
         * dtp->dt_lib_dep. The result of this process will be a
         * dependency ordered list located at dtp->dt_lib_dep_sorted.
         */
        for (dld = dt_list_next(&dtp->dt_lib_dep); dld != NULL;
            dld = dt_list_next(dld)) {
                if (dld->dtld_start == 0 &&
                    dt_topo_sort(dtp, dld, &count) == -1)
                        return (-1); /* preserve dt_errno */;
        }

        /*
         * Check the graph for cycles. If an ancestor's finishing time is
         * less than any of its dependent's finishing times then a back edge
         * exists in the graph and this is a cycle.
         */
        for (dld = dt_list_next(&dtp->dt_lib_dep); dld != NULL;
            dld = dt_list_next(dld)) {
                for (dpld = dt_list_next(&dld->dtld_dependents); dpld != NULL;
                    dpld = dt_list_next(dpld)) {
                        dlda = dt_lib_depend_lookup(&dtp->dt_lib_dep_sorted,
                            dpld->dtld_library);
                        assert(dlda != NULL);

                        if (dlda->dtld_finish > dld->dtld_finish) {
                                dt_lib_depend_error(dtp,
                                    "Cyclic dependency detected: %s => %s\n",
                                    dld->dtld_library, dpld->dtld_library);

                                return (dt_set_errno(dtp, EDT_COMPILER));
                        }
                }
        }

        return (0);
}

static void
dt_lib_depend_free(dtrace_hdl_t *dtp)
{
        dt_lib_depend_t *dld, *dlda;

        while ((dld = dt_list_next(&dtp->dt_lib_dep)) != NULL) {
                while ((dlda = dt_list_next(&dld->dtld_dependencies)) != NULL) {
                        dt_list_delete(&dld->dtld_dependencies, dlda);
                        dt_free(dtp, dlda->dtld_library);
                        dt_free(dtp, dlda->dtld_libpath);
                        dt_free(dtp, dlda);
                }
                while ((dlda = dt_list_next(&dld->dtld_dependents)) != NULL) {
                        dt_list_delete(&dld->dtld_dependents, dlda);
                        dt_free(dtp, dlda->dtld_library);
                        dt_free(dtp, dlda->dtld_libpath);
                        dt_free(dtp, dlda);
                }
                dt_list_delete(&dtp->dt_lib_dep, dld);
                dt_free(dtp, dld->dtld_library);
                dt_free(dtp, dld->dtld_libpath);
                dt_free(dtp, dld);
        }

        while ((dld = dt_list_next(&dtp->dt_lib_dep_sorted)) != NULL) {
                dt_list_delete(&dtp->dt_lib_dep_sorted, dld);
                dt_free(dtp, dld->dtld_library);
                dt_free(dtp, dld);
        }
}

/*
 * Open all the .d library files found in the specified directory and
 * compile each one of them.  We silently ignore any missing directories and
 * other files found therein.  We only fail (and thereby fail dt_load_libs()) if
 * we fail to compile a library and the error is something other than #pragma D
 * depends_on.  Dependency errors are silently ignored to permit a library
 * directory to contain libraries which may not be accessible depending on our
 * privileges.
 */
static int
dt_load_libs_dir(dtrace_hdl_t *dtp, const char *path)
{
        struct dirent *dp;
        const char *p, *end;
        DIR *dirp;

        char fname[PATH_MAX];
        FILE *fp;
        void *rv;
        dt_lib_depend_t *dld;

        if ((dirp = opendir(path)) == NULL) {
                dt_dprintf("skipping lib dir %s: %s\n", path, strerror(errno));
                return (0);
        }

        /* First, parse each file for library dependencies. */
        while ((dp = readdir(dirp)) != NULL) {
                if ((p = strrchr(dp->d_name, '.')) == NULL || strcmp(p, ".d"))
                        continue; /* skip any filename not ending in .d */

                (void) snprintf(fname, sizeof (fname),
                    "%s/%s", path, dp->d_name);

                if ((fp = fopen(fname, "rF")) == NULL) {
                        dt_dprintf("skipping library %s: %s\n",
                            fname, strerror(errno));
                        continue;
                }

                /*
                 * Skip files whose name match an already processed library
                 */
                for (dld = dt_list_next(&dtp->dt_lib_dep); dld != NULL;
                    dld = dt_list_next(dld)) {
                        end = strrchr(dld->dtld_library, '/');
                        /* dt_lib_depend_add ensures this */
                        assert(end != NULL);
                        if (strcmp(end + 1, dp->d_name) == 0)
                                break;
                }

                if (dld != NULL) {
                        dt_dprintf("skipping library %s, already processed "
                            "library with the same name: %s", dp->d_name,
                            dld->dtld_library);
                        (void) fclose(fp);
                        continue;
                }

                dtp->dt_filetag = fname;
                if (dt_lib_depend_add(dtp, &dtp->dt_lib_dep, fname) != 0) {
                        (void) fclose(fp);
                        return (-1); /* preserve dt_errno */
                }

                rv = dt_compile(dtp, DT_CTX_DPROG,
                    DTRACE_PROBESPEC_NAME, NULL,
                    DTRACE_C_EMPTY | DTRACE_C_CTL, 0, NULL, fp, NULL);

                if (rv != NULL && dtp->dt_errno &&
                    (dtp->dt_errno != EDT_COMPILER ||
                    dtp->dt_errtag != dt_errtag(D_PRAGMA_DEPEND))) {
                        (void) fclose(fp);
                        return (-1); /* preserve dt_errno */
                }

                if (dtp->dt_errno)
                        dt_dprintf("error parsing library %s: %s\n",
                            fname, dtrace_errmsg(dtp, dtrace_errno(dtp)));

                (void) fclose(fp);
                dtp->dt_filetag = NULL;
        }

        (void) closedir(dirp);

        return (0);
}

/*
 * Perform a topological sorting of all the libraries found across the entire
 * dt_lib_path.  Once sorted, compile each one in topological order to cache its
 * inlines and translators, etc.  We silently ignore any missing directories and
 * other files found therein. We only fail (and thereby fail dt_load_libs()) if
 * we fail to compile a library and the error is something other than #pragma D
 * depends_on.  Dependency errors are silently ignored to permit a library
 * directory to contain libraries which may not be accessible depending on our
 * privileges.
 */
static int
dt_load_libs_sort(dtrace_hdl_t *dtp)
{
        dtrace_prog_t *pgp;
        FILE *fp;
        dt_lib_depend_t *dld;

        /*
         * Finish building the graph containing the library dependencies
         * and perform a topological sort to generate an ordered list
         * for compilation.
         */
        if (dt_lib_depend_sort(dtp) == -1)
                goto err;

        for (dld = dt_list_next(&dtp->dt_lib_dep_sorted); dld != NULL;
            dld = dt_list_next(dld)) {

                if ((fp = fopen(dld->dtld_library, "r")) == NULL) {
                        dt_dprintf("skipping library %s: %s\n",
                            dld->dtld_library, strerror(errno));
                        continue;
                }

                dtp->dt_filetag = dld->dtld_library;
                pgp = dtrace_program_fcompile(dtp, fp, DTRACE_C_EMPTY, 0, NULL);
                (void) fclose(fp);
                dtp->dt_filetag = NULL;

                if (pgp == NULL && (dtp->dt_errno != EDT_COMPILER ||
                    dtp->dt_errtag != dt_errtag(D_PRAGMA_DEPEND)))
                        goto err;

                if (pgp == NULL) {
                        dt_dprintf("skipping library %s: %s\n",
                            dld->dtld_library,
                            dtrace_errmsg(dtp, dtrace_errno(dtp)));
                } else {
                        dld->dtld_loaded = B_TRUE;
                        dt_program_destroy(dtp, pgp);
                }
        }

        dt_lib_depend_free(dtp);
        return (0);

err:
        dt_lib_depend_free(dtp);
        return (-1); /* preserve dt_errno */
}

/*
 * Load the contents of any appropriate DTrace .d library files.  These files
 * contain inlines and translators that will be cached by the compiler.  We
 * defer this activity until the first compile to permit libdtrace clients to
 * add their own library directories and so that we can properly report errors.
 */
static int
dt_load_libs(dtrace_hdl_t *dtp)
{
        dt_dirpath_t *dirp;

        if (dtp->dt_cflags & DTRACE_C_NOLIBS)
                return (0); /* libraries already processed */

        dtp->dt_cflags |= DTRACE_C_NOLIBS;

        /*
         * /usr/lib/dtrace is always at the head of the list. The rest of the
         * list is specified in the precedence order the user requested. Process
         * everything other than the head first. DTRACE_C_NOLIBS has already
         * been spcified so dt_vopen will ensure that there is always one entry
         * in dt_lib_path.
         */
        for (dirp = dt_list_next(dt_list_next(&dtp->dt_lib_path));
            dirp != NULL; dirp = dt_list_next(dirp)) {
                if (dt_load_libs_dir(dtp, dirp->dir_path) != 0) {
                        dtp->dt_cflags &= ~DTRACE_C_NOLIBS;
                        return (-1); /* errno is set for us */
                }
        }

        /* Handle /usr/lib/dtrace */
        dirp = dt_list_next(&dtp->dt_lib_path);
        if (dt_load_libs_dir(dtp, dirp->dir_path) != 0) {
                dtp->dt_cflags &= ~DTRACE_C_NOLIBS;
                return (-1); /* errno is set for us */
        }

        if (dt_load_libs_sort(dtp) < 0)
                return (-1); /* errno is set for us */

        return (0);
}

static void *
dt_compile(dtrace_hdl_t *dtp, int context, dtrace_probespec_t pspec, void *arg,
    uint_t cflags, int argc, char *const argv[], FILE *fp, const char *s)
{
        dt_node_t *dnp;
        dt_decl_t *ddp;
        dt_pcb_t pcb;
        void *volatile rv;
        int err;

        if ((fp == NULL && s == NULL) || (cflags & ~DTRACE_C_MASK) != 0) {
                (void) dt_set_errno(dtp, EINVAL);
                return (NULL);
        }

        if (dt_list_next(&dtp->dt_lib_path) != NULL && dt_load_libs(dtp) != 0)
                return (NULL); /* errno is set for us */

        if (dtp->dt_globals->dh_nelems != 0)
                (void) dt_idhash_iter(dtp->dt_globals, dt_idreset, NULL);

        if (dtp->dt_tls->dh_nelems != 0)
                (void) dt_idhash_iter(dtp->dt_tls, dt_idreset, NULL);

        if (fp && (cflags & DTRACE_C_CPP) && (fp = dt_preproc(dtp, fp)) == NULL)
                return (NULL); /* errno is set for us */

        dt_pcb_push(dtp, &pcb);

        pcb.pcb_fileptr = fp;
        pcb.pcb_string = s;
        pcb.pcb_strptr = s;
        pcb.pcb_strlen = s ? strlen(s) : 0;
        pcb.pcb_sargc = argc;
        pcb.pcb_sargv = argv;
        pcb.pcb_sflagv = argc ? calloc(argc, sizeof (ushort_t)) : NULL;
        pcb.pcb_pspec = pspec;
        pcb.pcb_cflags = dtp->dt_cflags | cflags;
        pcb.pcb_amin = dtp->dt_amin;
        pcb.pcb_yystate = -1;
        pcb.pcb_context = context;
        pcb.pcb_token = context;

        if (context != DT_CTX_DPROG)
                yybegin(YYS_EXPR);
        else if (cflags & DTRACE_C_CTL)
                yybegin(YYS_CONTROL);
        else
                yybegin(YYS_CLAUSE);

        if ((err = setjmp(yypcb->pcb_jmpbuf)) != 0)
                goto out;

        if (yypcb->pcb_sargc != 0 && yypcb->pcb_sflagv == NULL)
                longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);

        yypcb->pcb_idents = dt_idhash_create("ambiguous", NULL, 0, 0);
        yypcb->pcb_locals = dt_idhash_create("clause local", NULL,
            DIF_VAR_OTHER_UBASE, DIF_VAR_OTHER_MAX);

        if (yypcb->pcb_idents == NULL || yypcb->pcb_locals == NULL)
                longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);

        /*
         * Invoke the parser to evaluate the D source code.  If any errors
         * occur during parsing, an error function will be called and we
         * will longjmp back to pcb_jmpbuf to abort.  If parsing succeeds,
         * we optionally display the parse tree if debugging is enabled.
         */
        if (yyparse() != 0 || yypcb->pcb_root == NULL)
                xyerror(D_EMPTY, "empty D program translation unit\n");

        yybegin(YYS_DONE);

        if (cflags & DTRACE_C_CTL)
                goto out;

        if (context != DT_CTX_DTYPE && DT_TREEDUMP_PASS(dtp, 1))
                dt_node_printr(yypcb->pcb_root, stderr, 0);

        if (yypcb->pcb_pragmas != NULL)
                (void) dt_idhash_iter(yypcb->pcb_pragmas, dt_idpragma, NULL);

        if (argc > 1 && !(yypcb->pcb_cflags & DTRACE_C_ARGREF) &&
            !(yypcb->pcb_sflagv[argc - 1] & DT_IDFLG_REF)) {
                xyerror(D_MACRO_UNUSED, "extraneous argument '%s' ($%d is "
                    "not referenced)\n", yypcb->pcb_sargv[argc - 1], argc - 1);
        }

        /*
         * Perform sugar transformations (for "if" / "else") and replace the
         * existing clause chain with the new one.
         */
        if (context == DT_CTX_DPROG) {
                dt_node_t *dnp, *next_dnp;
                dt_node_t *new_list = NULL;

                for (dnp = yypcb->pcb_root->dn_list;
                    dnp != NULL; dnp = next_dnp) {
                        /* remove this node from the list */
                        next_dnp = dnp->dn_list;
                        dnp->dn_list = NULL;

                        if (dnp->dn_kind == DT_NODE_CLAUSE)
                                dnp = dt_compile_sugar(dtp, dnp);
                        /* append node to the new list */
                        new_list = dt_node_link(new_list, dnp);
                }
                yypcb->pcb_root->dn_list = new_list;
        }

        /*
         * If we have successfully created a parse tree for a D program, loop
         * over the clauses and actions and instantiate the corresponding
         * libdtrace program.  If we are parsing a D expression, then we
         * simply run the code generator and assembler on the resulting tree.
         */
        switch (context) {
        case DT_CTX_DPROG:
                assert(yypcb->pcb_root->dn_kind == DT_NODE_PROG);

                if ((dnp = yypcb->pcb_root->dn_list) == NULL &&
                    !(yypcb->pcb_cflags & DTRACE_C_EMPTY))
                        xyerror(D_EMPTY, "empty D program translation unit\n");

                if ((yypcb->pcb_prog = dt_program_create(dtp)) == NULL)
                        longjmp(yypcb->pcb_jmpbuf, dtrace_errno(dtp));

                for (; dnp != NULL; dnp = dnp->dn_list) {
                        switch (dnp->dn_kind) {
                        case DT_NODE_CLAUSE:
                                if (DT_TREEDUMP_PASS(dtp, 4))
                                        dt_printd(dnp, stderr, 0);
                                dt_compile_clause(dtp, dnp);
                                break;
                        case DT_NODE_XLATOR:
                                if (dtp->dt_xlatemode == DT_XL_DYNAMIC)
                                        dt_compile_xlator(dnp);
                                break;
                        case DT_NODE_PROVIDER:
                                (void) dt_node_cook(dnp, DT_IDFLG_REF);
                                break;
                        }
                }

                yypcb->pcb_prog->dp_xrefs = yypcb->pcb_asxrefs;
                yypcb->pcb_prog->dp_xrefslen = yypcb->pcb_asxreflen;
                yypcb->pcb_asxrefs = NULL;
                yypcb->pcb_asxreflen = 0;

                rv = yypcb->pcb_prog;
                break;

        case DT_CTX_DEXPR:
                (void) dt_node_cook(yypcb->pcb_root, DT_IDFLG_REF);
                dt_cg(yypcb, yypcb->pcb_root);
                rv = dt_as(yypcb);
                break;

        case DT_CTX_DTYPE:
                ddp = (dt_decl_t *)yypcb->pcb_root; /* root is really a decl */
                err = dt_decl_type(ddp, arg);
                dt_decl_free(ddp);

                if (err != 0)
                        longjmp(yypcb->pcb_jmpbuf, EDT_COMPILER);

                rv = NULL;
                break;
        }

out:
        if (context != DT_CTX_DTYPE && yypcb->pcb_root != NULL &&
            DT_TREEDUMP_PASS(dtp, 3))
                dt_node_printr(yypcb->pcb_root, stderr, 0);

        if (dtp->dt_cdefs_fd != -1 && (ftruncate64(dtp->dt_cdefs_fd, 0) == -1 ||
            lseek64(dtp->dt_cdefs_fd, 0, SEEK_SET) == -1 ||
            ctf_write(dtp->dt_cdefs->dm_ctfp, dtp->dt_cdefs_fd) == CTF_ERR))
                dt_dprintf("failed to update CTF cache: %s\n", strerror(errno));

        if (dtp->dt_ddefs_fd != -1 && (ftruncate64(dtp->dt_ddefs_fd, 0) == -1 ||
            lseek64(dtp->dt_ddefs_fd, 0, SEEK_SET) == -1 ||
            ctf_write(dtp->dt_ddefs->dm_ctfp, dtp->dt_ddefs_fd) == CTF_ERR))
                dt_dprintf("failed to update CTF cache: %s\n", strerror(errno));

        if (yypcb->pcb_fileptr && (cflags & DTRACE_C_CPP))
                (void) fclose(yypcb->pcb_fileptr); /* close dt_preproc() file */

        dt_pcb_pop(dtp, err);
        (void) dt_set_errno(dtp, err);
        return (err ? NULL : rv);
}

dtrace_prog_t *
dtrace_program_strcompile(dtrace_hdl_t *dtp, const char *s,
    dtrace_probespec_t spec, uint_t cflags, int argc, char *const argv[])
{
        return (dt_compile(dtp, DT_CTX_DPROG,
            spec, NULL, cflags, argc, argv, NULL, s));
}

dtrace_prog_t *
dtrace_program_fcompile(dtrace_hdl_t *dtp, FILE *fp,
    uint_t cflags, int argc, char *const argv[])
{
        return (dt_compile(dtp, DT_CTX_DPROG,
            DTRACE_PROBESPEC_NAME, NULL, cflags, argc, argv, fp, NULL));
}

int
dtrace_type_strcompile(dtrace_hdl_t *dtp, const char *s, dtrace_typeinfo_t *dtt)
{
        (void) dt_compile(dtp, DT_CTX_DTYPE,
            DTRACE_PROBESPEC_NONE, dtt, 0, 0, NULL, NULL, s);
        return (dtp->dt_errno ? -1 : 0);
}

int
dtrace_type_fcompile(dtrace_hdl_t *dtp, FILE *fp, dtrace_typeinfo_t *dtt)
{
        (void) dt_compile(dtp, DT_CTX_DTYPE,
            DTRACE_PROBESPEC_NONE, dtt, 0, 0, NULL, fp, NULL);
        return (dtp->dt_errno ? -1 : 0);
}