/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (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 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */
/*
 * Copyright (c) 2013 by Delphix. All rights reserved.
 * Copyright (c) 2013 Joyent, Inc. All rights reserved.
 */

#include <sys/types.h>
#include <strings.h>
#include <stdlib.h>
#include <assert.h>

#include <dt_impl.h>
#include <dt_parser.h>
#include <dt_as.h>

void
dt_irlist_create(dt_irlist_t *dlp)
{
        bzero(dlp, sizeof (dt_irlist_t));
        dlp->dl_label = 1;
}

void
dt_irlist_destroy(dt_irlist_t *dlp)
{
        dt_irnode_t *dip, *nip;

        for (dip = dlp->dl_list; dip != NULL; dip = nip) {
                nip = dip->di_next;
                free(dip);
        }
}

void
dt_irlist_append(dt_irlist_t *dlp, dt_irnode_t *dip)
{
        if (dlp->dl_last != NULL)
                dlp->dl_last->di_next = dip;
        else
                dlp->dl_list = dip;

        dlp->dl_last = dip;

        if (dip->di_label == DT_LBL_NONE || dip->di_instr != DIF_INSTR_NOP)
                dlp->dl_len++; /* don't count forward refs in instr count */
}

uint_t
dt_irlist_label(dt_irlist_t *dlp)
{
        return (dlp->dl_label++);
}

/*ARGSUSED*/
static int
dt_countvar(dt_idhash_t *dhp, dt_ident_t *idp, void *data)
{
        size_t *np = data;

        if (idp->di_flags & (DT_IDFLG_DIFR | DT_IDFLG_DIFW))
                (*np)++; /* include variable in vartab */

        return (0);
}

/*ARGSUSED*/
static int
dt_copyvar(dt_idhash_t *dhp, dt_ident_t *idp, void *data)
{
        dt_pcb_t *pcb = data;
        dtrace_difv_t *dvp;
        ssize_t stroff;
        dt_node_t dn;

        if (!(idp->di_flags & (DT_IDFLG_DIFR | DT_IDFLG_DIFW)))
                return (0); /* omit variable from vartab */

        dvp = &pcb->pcb_difo->dtdo_vartab[pcb->pcb_asvidx++];
        stroff = dt_strtab_insert(pcb->pcb_strtab, idp->di_name);

        if (stroff == -1L)
                longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
        if (stroff > DIF_STROFF_MAX)
                longjmp(pcb->pcb_jmpbuf, EDT_STR2BIG);

        dvp->dtdv_name = (uint_t)stroff;
        dvp->dtdv_id = idp->di_id;
        dvp->dtdv_flags = 0;

        dvp->dtdv_kind = (idp->di_kind == DT_IDENT_ARRAY) ?
            DIFV_KIND_ARRAY : DIFV_KIND_SCALAR;

        if (idp->di_flags & DT_IDFLG_LOCAL)
                dvp->dtdv_scope = DIFV_SCOPE_LOCAL;
        else if (idp->di_flags & DT_IDFLG_TLS)
                dvp->dtdv_scope = DIFV_SCOPE_THREAD;
        else
                dvp->dtdv_scope = DIFV_SCOPE_GLOBAL;

        if (idp->di_flags & DT_IDFLG_DIFR)
                dvp->dtdv_flags |= DIFV_F_REF;
        if (idp->di_flags & DT_IDFLG_DIFW)
                dvp->dtdv_flags |= DIFV_F_MOD;

        bzero(&dn, sizeof (dn));
        dt_node_type_assign(&dn, idp->di_ctfp, idp->di_type, B_FALSE);
        dt_node_diftype(pcb->pcb_hdl, &dn, &dvp->dtdv_type);

        idp->di_flags &= ~(DT_IDFLG_DIFR | DT_IDFLG_DIFW);
        return (0);
}

static ssize_t
dt_copystr(const char *s, size_t n, size_t off, dt_pcb_t *pcb)
{
        bcopy(s, pcb->pcb_difo->dtdo_strtab + off, n);
        return (n);
}

/*
 * Rewrite the xlate/xlarg instruction at dtdo_buf[i] so that the instruction's
 * xltab index reflects the offset 'xi' of the assigned dtdo_xlmtab[] location.
 * We track the cumulative references to translators and members in the pcb's
 * pcb_asxrefs[] array, a two-dimensional array of bitmaps indexed by the
 * global translator id and then by the corresponding translator member id.
 */
static void
dt_as_xlate(dt_pcb_t *pcb, dtrace_difo_t *dp,
    uint_t i, uint_t xi, dt_node_t *dnp)
{
        dtrace_hdl_t *dtp = pcb->pcb_hdl;
        dt_xlator_t *dxp = dnp->dn_membexpr->dn_xlator;

        assert(i < dp->dtdo_len);
        assert(xi < dp->dtdo_xlmlen);

        assert(dnp->dn_kind == DT_NODE_MEMBER);
        assert(dnp->dn_membexpr->dn_kind == DT_NODE_XLATOR);

        assert(dxp->dx_id < dtp->dt_xlatorid);
        assert(dnp->dn_membid < dxp->dx_nmembers);

        if (pcb->pcb_asxrefs == NULL) {
                pcb->pcb_asxreflen = dtp->dt_xlatorid;
                pcb->pcb_asxrefs =
                    dt_zalloc(dtp, sizeof (ulong_t *) * pcb->pcb_asxreflen);
                if (pcb->pcb_asxrefs == NULL)
                        longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
        }

        if (pcb->pcb_asxrefs[dxp->dx_id] == NULL) {
                pcb->pcb_asxrefs[dxp->dx_id] =
                    dt_zalloc(dtp, BT_SIZEOFMAP(dxp->dx_nmembers));
                if (pcb->pcb_asxrefs[dxp->dx_id] == NULL)
                        longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
        }

        dp->dtdo_buf[i] = DIF_INSTR_XLATE(
            DIF_INSTR_OP(dp->dtdo_buf[i]), xi, DIF_INSTR_RD(dp->dtdo_buf[i]));

        BT_SET(pcb->pcb_asxrefs[dxp->dx_id], dnp->dn_membid);
        dp->dtdo_xlmtab[xi] = dnp;
}

static void
dt_as_undef(const dt_ident_t *idp, uint_t offset)
{
        const char *kind, *mark = (idp->di_flags & DT_IDFLG_USER) ? "``" : "`";
        const dtrace_syminfo_t *dts = idp->di_data;

        if (idp->di_flags & DT_IDFLG_USER)
                kind = "user";
        else if (idp->di_flags & DT_IDFLG_PRIM)
                kind = "primary kernel";
        else
                kind = "loadable kernel";

        yylineno = idp->di_lineno;

        xyerror(D_ASRELO, "relocation remains against %s symbol %s%s%s (offset "
            "0x%x)\n", kind, dts->dts_object, mark, dts->dts_name, offset);
}

dtrace_difo_t *
dt_as(dt_pcb_t *pcb)
{
        dtrace_hdl_t *dtp = pcb->pcb_hdl;
        dt_irlist_t *dlp = &pcb->pcb_ir;
        uint_t *labels = NULL;
        dt_irnode_t *dip;
        dtrace_difo_t *dp;
        dt_ident_t *idp;

        size_t n = 0;
        uint_t i;

        uint_t kmask, kbits, umask, ubits;
        uint_t krel = 0, urel = 0, xlrefs = 0;

        /*
         * Select bitmasks based upon the desired symbol linking policy.  We
         * test (di_extern->di_flags & xmask) == xbits to determine if the
         * symbol should have a relocation entry generated in the loop below.
         *
         * DT_LINK_KERNEL = kernel symbols static, user symbols dynamic
         * DT_LINK_PRIMARY = primary kernel symbols static, others dynamic
         * DT_LINK_DYNAMIC = all symbols dynamic
         * DT_LINK_STATIC = all symbols static
         *
         * By 'static' we mean that we use the symbol's value at compile-time
         * in the final DIF.  By 'dynamic' we mean that we create a relocation
         * table entry for the symbol's value so it can be relocated later.
         */
        switch (dtp->dt_linkmode) {
        case DT_LINK_KERNEL:
                kmask = 0;
                kbits = -1u;
                umask = DT_IDFLG_USER;
                ubits = DT_IDFLG_USER;
                break;
        case DT_LINK_PRIMARY:
                kmask = DT_IDFLG_USER | DT_IDFLG_PRIM;
                kbits = 0;
                umask = DT_IDFLG_USER;
                ubits = DT_IDFLG_USER;
                break;
        case DT_LINK_DYNAMIC:
                kmask = DT_IDFLG_USER;
                kbits = 0;
                umask = DT_IDFLG_USER;
                ubits = DT_IDFLG_USER;
                break;
        case DT_LINK_STATIC:
                kmask = umask = 0;
                kbits = ubits = -1u;
                break;
        default:
                xyerror(D_UNKNOWN, "internal error -- invalid link mode %u\n",
                    dtp->dt_linkmode);
        }

        assert(pcb->pcb_difo == NULL);
        pcb->pcb_difo = dt_zalloc(dtp, sizeof (dtrace_difo_t));

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

        dp->dtdo_buf = dt_alloc(dtp, sizeof (dif_instr_t) * dlp->dl_len);

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

        if ((labels = dt_alloc(dtp, sizeof (uint_t) * dlp->dl_label)) == NULL)
                longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);

        /*
         * Make an initial pass through the instruction list, filling in the
         * instruction buffer with valid instructions and skipping labeled nops.
         * While doing this, we also fill in our labels[] translation table
         * and we count up the number of relocation table entries we will need.
         */
        for (i = 0, dip = dlp->dl_list; dip != NULL; dip = dip->di_next) {
                if (dip->di_label != DT_LBL_NONE)
                        labels[dip->di_label] = i;

                if (dip->di_label == DT_LBL_NONE ||
                    dip->di_instr != DIF_INSTR_NOP)
                        dp->dtdo_buf[i++] = dip->di_instr;

                if (dip->di_extern == NULL)
                        continue; /* no external references needed */

                switch (DIF_INSTR_OP(dip->di_instr)) {
                case DIF_OP_SETX:
                        idp = dip->di_extern;
                        if ((idp->di_flags & kmask) == kbits)
                                krel++;
                        else if ((idp->di_flags & umask) == ubits)
                                urel++;
                        break;
                case DIF_OP_XLATE:
                case DIF_OP_XLARG:
                        xlrefs++;
                        break;
                default:
                        xyerror(D_UNKNOWN, "unexpected assembler relocation "
                            "for opcode 0x%x\n", DIF_INSTR_OP(dip->di_instr));
                }
        }

        assert(i == dlp->dl_len);
        dp->dtdo_len = dlp->dl_len;

        /*
         * Make a second pass through the instructions, relocating each branch
         * label to the index of the final instruction in the buffer and noting
         * any other instruction-specific DIFO flags such as dtdo_destructive.
         */
        for (i = 0; i < dp->dtdo_len; i++) {
                dif_instr_t instr = dp->dtdo_buf[i];
                uint_t op = DIF_INSTR_OP(instr);

                if (op == DIF_OP_CALL) {
                        if (DIF_INSTR_SUBR(instr) == DIF_SUBR_COPYOUT ||
                            DIF_INSTR_SUBR(instr) == DIF_SUBR_COPYOUTSTR)
                                dp->dtdo_destructive = 1;
                        continue;
                }

                if (op >= DIF_OP_BA && op <= DIF_OP_BLEU) {
                        assert(DIF_INSTR_LABEL(instr) < dlp->dl_label);
                        dp->dtdo_buf[i] = DIF_INSTR_BRANCH(op,
                            labels[DIF_INSTR_LABEL(instr)]);
                }
        }

        dt_free(dtp, labels);
        pcb->pcb_asvidx = 0;

        /*
         * Allocate memory for the appropriate number of variable records and
         * then fill in each variable record.  As we populate the variable
         * table we insert the corresponding variable names into the strtab.
         */
        (void) dt_idhash_iter(dtp->dt_tls, dt_countvar, &n);
        (void) dt_idhash_iter(dtp->dt_globals, dt_countvar, &n);
        (void) dt_idhash_iter(pcb->pcb_locals, dt_countvar, &n);

        if (n != 0) {
                dp->dtdo_vartab = dt_alloc(dtp, n * sizeof (dtrace_difv_t));
                dp->dtdo_varlen = (uint32_t)n;

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

                (void) dt_idhash_iter(dtp->dt_tls, dt_copyvar, pcb);
                (void) dt_idhash_iter(dtp->dt_globals, dt_copyvar, pcb);
                (void) dt_idhash_iter(pcb->pcb_locals, dt_copyvar, pcb);
        }

        /*
         * Allocate memory for the appropriate number of relocation table
         * entries based upon our kernel and user counts from the first pass.
         */
        if (krel != 0) {
                dp->dtdo_kreltab = dt_alloc(dtp,
                    krel * sizeof (dof_relodesc_t));
                dp->dtdo_krelen = krel;

                if (dp->dtdo_kreltab == NULL)
                        longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
        }

        if (urel != 0) {
                dp->dtdo_ureltab = dt_alloc(dtp,
                    urel * sizeof (dof_relodesc_t));
                dp->dtdo_urelen = urel;

                if (dp->dtdo_ureltab == NULL)
                        longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
        }

        if (xlrefs != 0) {
                dp->dtdo_xlmtab = dt_zalloc(dtp, sizeof (dt_node_t *) * xlrefs);
                dp->dtdo_xlmlen = xlrefs;

                if (dp->dtdo_xlmtab == NULL)
                        longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
        }

        /*
         * If any relocations are needed, make another pass through the
         * instruction list and fill in the relocation table entries.
         */
        if (krel + urel + xlrefs != 0) {
                uint_t knodef = pcb->pcb_cflags & DTRACE_C_KNODEF;
                uint_t unodef = pcb->pcb_cflags & DTRACE_C_UNODEF;

                dof_relodesc_t *krp = dp->dtdo_kreltab;
                dof_relodesc_t *urp = dp->dtdo_ureltab;
                dt_node_t **xlp = dp->dtdo_xlmtab;

                i = 0; /* dtdo_buf[] index */

                for (dip = dlp->dl_list; dip != NULL; dip = dip->di_next) {
                        dof_relodesc_t *rp;
                        ssize_t soff;
                        uint_t nodef;

                        if (dip->di_label != DT_LBL_NONE &&
                            dip->di_instr == DIF_INSTR_NOP)
                                continue; /* skip label declarations */

                        i++; /* advance dtdo_buf[] index */

                        if (DIF_INSTR_OP(dip->di_instr) == DIF_OP_XLATE ||
                            DIF_INSTR_OP(dip->di_instr) == DIF_OP_XLARG) {
                                assert(dp->dtdo_buf[i - 1] == dip->di_instr);
                                dt_as_xlate(pcb, dp, i - 1, (uint_t)
                                    (xlp++ - dp->dtdo_xlmtab), dip->di_extern);
                                continue;
                        }

                        if ((idp = dip->di_extern) == NULL)
                                continue; /* no relocation entry needed */

                        if ((idp->di_flags & kmask) == kbits) {
                                nodef = knodef;
                                rp = krp++;
                        } else if ((idp->di_flags & umask) == ubits) {
                                nodef = unodef;
                                rp = urp++;
                        } else
                                continue;

                        if (!nodef)
                                dt_as_undef(idp, i);

                        assert(DIF_INSTR_OP(dip->di_instr) == DIF_OP_SETX);
                        soff = dt_strtab_insert(pcb->pcb_strtab, idp->di_name);

                        if (soff == -1L)
                                longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
                        if (soff > DIF_STROFF_MAX)
                                longjmp(pcb->pcb_jmpbuf, EDT_STR2BIG);

                        rp->dofr_name = (dof_stridx_t)soff;
                        rp->dofr_type = DOF_RELO_SETX;
                        rp->dofr_offset = DIF_INSTR_INTEGER(dip->di_instr) *
                            sizeof (uint64_t);
                        rp->dofr_data = 0;
                }

                assert(krp == dp->dtdo_kreltab + dp->dtdo_krelen);
                assert(urp == dp->dtdo_ureltab + dp->dtdo_urelen);
                assert(xlp == dp->dtdo_xlmtab + dp->dtdo_xlmlen);
                assert(i == dp->dtdo_len);
        }

        /*
         * Allocate memory for the compiled string table and then copy the
         * chunks from the string table into the final string buffer.
         */
        if ((n = dt_strtab_size(pcb->pcb_strtab)) != 0) {
                if ((dp->dtdo_strtab = dt_alloc(dtp, n)) == NULL)
                        longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);

                (void) dt_strtab_write(pcb->pcb_strtab,
                    (dt_strtab_write_f *)dt_copystr, pcb);
                dp->dtdo_strlen = (uint32_t)n;
        }

        /*
         * Allocate memory for the compiled integer table and then copy the
         * integer constants from the table into the final integer buffer.
         */
        if ((n = dt_inttab_size(pcb->pcb_inttab)) != 0) {
                if ((dp->dtdo_inttab = dt_alloc(dtp,
                    n * sizeof (uint64_t))) == NULL)
                        longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);

                dt_inttab_write(pcb->pcb_inttab, dp->dtdo_inttab);
                dp->dtdo_intlen = (uint32_t)n;
        }

        /*
         * Fill in the DIFO return type from the type associated with the
         * node saved in pcb_dret, and then clear pcb_difo and pcb_dret
         * now that the assembler has completed successfully.
         */
        dt_node_diftype(dtp, pcb->pcb_dret, &dp->dtdo_rtype);
        pcb->pcb_difo = NULL;
        pcb->pcb_dret = NULL;

        if (pcb->pcb_cflags & DTRACE_C_DIFV)
                dt_dis(dp, stderr);

        return (dp);
}