/* $OpenBSD: man_validate.c,v 1.131 2025/07/09 12:49:32 schwarze Exp $ */
/*
 * Copyright (c) 2010-2020, 2023, 2025 Ingo Schwarze <schwarze@openbsd.org>
 * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * Validation module for man(7) syntax trees used by mandoc(1).
 */
#include <sys/types.h>

#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <limits.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

#include "mandoc_aux.h"
#include "mandoc.h"
#include "mandoc_xr.h"
#include "roff.h"
#include "man.h"
#include "libmandoc.h"
#include "roff_int.h"
#include "libman.h"
#include "tag.h"

#define CHKARGS   struct roff_man *man, struct roff_node *n

typedef void    (*v_check)(CHKARGS);

static  void      check_par(CHKARGS);
static  void      check_part(CHKARGS);
static  void      check_root(CHKARGS);
static  void      check_tag(struct roff_node *, struct roff_node *);
static  void      check_text(CHKARGS);

static  void      post_AT(CHKARGS);
static  void      post_EE(CHKARGS);
static  void      post_EX(CHKARGS);
static  void      post_IP(CHKARGS);
static  void      post_MR(CHKARGS);
static  void      post_OP(CHKARGS);
static  void      post_SH(CHKARGS);
static  void      post_TH(CHKARGS);
static  void      post_TP(CHKARGS);
static  void      post_UC(CHKARGS);
static  void      post_UR(CHKARGS);
static  void      post_in(CHKARGS);

static  const v_check man_valids[MAN_MAX - MAN_TH] = {
        post_TH,    /* TH */
        post_SH,    /* SH */
        post_SH,    /* SS */
        post_TP,    /* TP */
        post_TP,    /* TQ */
        check_par,  /* LP */
        check_par,  /* PP */
        check_par,  /* P */
        post_IP,    /* IP */
        NULL,       /* HP */
        NULL,       /* SM */
        NULL,       /* SB */
        NULL,       /* BI */
        NULL,       /* IB */
        NULL,       /* BR */
        NULL,       /* RB */
        NULL,       /* R */
        NULL,       /* B */
        NULL,       /* I */
        NULL,       /* IR */
        NULL,       /* RI */
        NULL,       /* RE */
        check_part, /* RS */
        NULL,       /* DT */
        post_UC,    /* UC */
        NULL,       /* PD */
        post_AT,    /* AT */
        post_in,    /* in */
        NULL,       /* SY */
        NULL,       /* YS */
        post_OP,    /* OP */
        post_EX,    /* EX */
        post_EE,    /* EE */
        post_UR,    /* UR */
        NULL,       /* UE */
        post_UR,    /* MT */
        NULL,       /* ME */
        post_MR,    /* MR */
};


/* Validate the subtree rooted at man->last. */
void
man_validate(struct roff_man *man)
{
        struct roff_node *n;
        const v_check    *cp;

        /*
         * Iterate over all children, recursing into each one
         * in turn, depth-first.
         */

        n = man->last;
        man->last = man->last->child;
        while (man->last != NULL) {
                man_validate(man);
                if (man->last == n)
                        man->last = man->last->child;
                else
                        man->last = man->last->next;
        }

        /* Finally validate the macro itself. */

        man->last = n;
        man->next = ROFF_NEXT_SIBLING;
        switch (n->type) {
        case ROFFT_TEXT:
                check_text(man, n);
                break;
        case ROFFT_ROOT:
                check_root(man, n);
                break;
        case ROFFT_COMMENT:
        case ROFFT_EQN:
        case ROFFT_TBL:
                break;
        default:
                if (n->tok < ROFF_MAX) {
                        roff_validate(man);
                        break;
                }
                assert(n->tok >= MAN_TH && n->tok < MAN_MAX);
                cp = man_valids + (n->tok - MAN_TH);
                if (*cp)
                        (*cp)(man, n);
                if (man->last == n)
                        n->flags |= NODE_VALID;
                break;
        }
}

static void
check_root(CHKARGS)
{
        assert((man->flags & (MAN_BLINE | MAN_ELINE)) == 0);

        if (n->last == NULL || n->last->type == ROFFT_COMMENT)
                mandoc_msg(MANDOCERR_DOC_EMPTY, n->line, n->pos, NULL);
        else
                man->meta.hasbody = 1;

        if (NULL == man->meta.title) {
                mandoc_msg(MANDOCERR_TH_NOTITLE, n->line, n->pos, NULL);

                /*
                 * If a title hasn't been set, do so now (by
                 * implication, date and section also aren't set).
                 */

                man->meta.title = mandoc_strdup("");
                man->meta.msec = mandoc_strdup("");
                man->meta.date = mandoc_normdate(NULL, NULL);
        }

        if (man->meta.os_e &&
            (man->meta.rcsids & (1 << man->meta.os_e)) == 0)
                mandoc_msg(MANDOCERR_RCS_MISSING, 0, 0,
                    man->meta.os_e == MANDOC_OS_OPENBSD ?
                    "(OpenBSD)" : "(NetBSD)");
}

/*
 * Skip leading whitespace, dashes, backslashes, and font escapes,
 * then create a tag if the first following byte is a letter.
 * Priority is high unless whitespace is present.
 */
static void
check_tag(struct roff_node *n, struct roff_node *nt)
{
        const char      *cp, *arg;
        int              prio, sz;

        if (nt == NULL || nt->type != ROFFT_TEXT)
                return;

        cp = nt->string;
        prio = TAG_STRONG;
        for (;;) {
                switch (*cp) {
                case ' ':
                case '\t':
                        prio = TAG_WEAK;
                        /* FALLTHROUGH */
                case '-':
                        cp++;
                        break;
                case '\\':
                        cp++;
                        switch (mandoc_escape(&cp, &arg, &sz)) {
                        case ESCAPE_FONT:
                        case ESCAPE_FONTBOLD:
                        case ESCAPE_FONTITALIC:
                        case ESCAPE_FONTBI:
                        case ESCAPE_FONTROMAN:
                        case ESCAPE_FONTCR:
                        case ESCAPE_FONTCB:
                        case ESCAPE_FONTCI:
                        case ESCAPE_FONTPREV:
                        case ESCAPE_IGNORE:
                                break;
                        case ESCAPE_SPECIAL:
                                if (sz != 1)
                                        return;
                                switch (*arg) {
                                case '-':
                                case 'e':
                                        break;
                                default:
                                        return;
                                }
                                break;
                        default:
                                return;
                        }
                        break;
                default:
                        if (isalpha((unsigned char)*cp))
                                tag_put(cp, prio, n);
                        return;
                }
        }
}

static void
check_text(CHKARGS)
{
        char            *cp, *p;

        if (n->flags & NODE_NOFILL)
                return;

        cp = n->string;
        for (p = cp; NULL != (p = strchr(p, '\t')); p++)
                mandoc_msg(MANDOCERR_FI_TAB,
                    n->line, n->pos + (int)(p - cp), NULL);
}

static void
post_EE(CHKARGS)
{
        if ((n->flags & NODE_NOFILL) == 0)
                mandoc_msg(MANDOCERR_FI_SKIP, n->line, n->pos, "EE");
}

static void
post_EX(CHKARGS)
{
        if (n->flags & NODE_NOFILL)
                mandoc_msg(MANDOCERR_NF_SKIP, n->line, n->pos, "EX");
}

static void
post_OP(CHKARGS)
{

        if (n->child == NULL)
                mandoc_msg(MANDOCERR_OP_EMPTY, n->line, n->pos, "OP");
        else if (n->child->next != NULL && n->child->next->next != NULL) {
                n = n->child->next->next;
                mandoc_msg(MANDOCERR_ARG_EXCESS,
                    n->line, n->pos, "OP ... %s", n->string);
        }
}

static void
post_SH(CHKARGS)
{
        struct roff_node        *nc;
        char                    *cp, *tag;

        nc = n->child;
        switch (n->type) {
        case ROFFT_BLOCK:
                if ((nc = n->prev) != NULL && nc->tok == ROFF_br) {
                        mandoc_msg(MANDOCERR_PAR_SKIP, nc->line, nc->pos,
                            "%s before first %s", roff_name[nc->tok],
                            roff_name[n->tok]);
                        roff_node_delete(man, nc);
                }
                return;
        case ROFFT_HEAD:
                tag = NULL;
                deroff(&tag, n);
                if (tag != NULL) {
                        for (cp = tag; *cp != '\0'; cp++)
                                if (*cp == ' ')
                                        *cp = '_';
                        if (nc != NULL && nc->type == ROFFT_TEXT &&
                            strcmp(nc->string, tag) == 0)
                                tag_put(NULL, TAG_STRONG, n);
                        else
                                tag_put(tag, TAG_FALLBACK, n);
                        free(tag);
                }
                return;
        case ROFFT_BODY:
                if (nc != NULL)
                        break;
                return;
        default:
                return;
        }

        if ((nc->tok == MAN_LP || nc->tok == MAN_PP || nc->tok == MAN_P) &&
            nc->body->child != NULL) {
                while (nc->body->last != NULL) {
                        man->next = ROFF_NEXT_CHILD;
                        roff_node_relink(man, nc->body->last);
                        man->last = n;
                }
        }

        if (nc->tok == MAN_LP || nc->tok == MAN_PP || nc->tok == MAN_P ||
            nc->tok == ROFF_sp || nc->tok == ROFF_br) {
                mandoc_msg(MANDOCERR_PAR_SKIP, nc->line, nc->pos,
                    "%s after %s", roff_name[nc->tok], roff_name[n->tok]);
                roff_node_delete(man, nc);
        }

        /*
         * Trailing PP is empty, so it is deleted by check_par().
         * Trailing sp is significant.
         */

        if ((nc = n->last) != NULL && nc->tok == ROFF_br) {
                mandoc_msg(MANDOCERR_PAR_SKIP,
                    nc->line, nc->pos, "%s at the end of %s",
                    roff_name[nc->tok], roff_name[n->tok]);
                roff_node_delete(man, nc);
        }
}

static void
post_UR(CHKARGS)
{
        if (n->type == ROFFT_HEAD && n->child == NULL)
                mandoc_msg(MANDOCERR_UR_NOHEAD, n->line, n->pos,
                    "%s", roff_name[n->tok]);
}

static void
check_part(CHKARGS)
{
        if (n->type == ROFFT_BODY && n->child == NULL)
                mandoc_msg(MANDOCERR_BLK_EMPTY, n->line, n->pos,
                    "%s", roff_name[n->tok]);
}

static void
check_par(CHKARGS)
{

        switch (n->type) {
        case ROFFT_BLOCK:
                if (n->body->child == NULL)
                        roff_node_delete(man, n);
                break;
        case ROFFT_BODY:
                if (n->child != NULL &&
                    (n->child->tok == ROFF_sp || n->child->tok == ROFF_br)) {
                        mandoc_msg(MANDOCERR_PAR_SKIP,
                            n->child->line, n->child->pos,
                            "%s after %s", roff_name[n->child->tok],
                            roff_name[n->tok]);
                        roff_node_delete(man, n->child);
                }
                if (n->child == NULL)
                        mandoc_msg(MANDOCERR_PAR_SKIP, n->line, n->pos,
                            "%s empty", roff_name[n->tok]);
                break;
        case ROFFT_HEAD:
                if (n->child != NULL)
                        mandoc_msg(MANDOCERR_ARG_SKIP,
                            n->line, n->pos, "%s %s%s",
                            roff_name[n->tok], n->child->string,
                            n->child->next != NULL ? " ..." : "");
                break;
        default:
                break;
        }
}

static void
post_IP(CHKARGS)
{
        switch (n->type) {
        case ROFFT_BLOCK:
                if (n->head->child == NULL && n->body->child == NULL)
                        roff_node_delete(man, n);
                break;
        case ROFFT_HEAD:
                check_tag(n, n->child);
                break;
        case ROFFT_BODY:
                if (n->parent->head->child == NULL && n->child == NULL)
                        mandoc_msg(MANDOCERR_PAR_SKIP, n->line, n->pos,
                            "%s empty", roff_name[n->tok]);
                break;
        default:
                break;
        }
}

/*
 * The first next-line element in the head is the tag.
 * If that's a font macro, use its first child instead.
 */
static void
post_TP(CHKARGS)
{
        struct roff_node *nt;

        if (n->type != ROFFT_HEAD || (nt = n->child) == NULL)
                return;

        while ((nt->flags & NODE_LINE) == 0)
                if ((nt = nt->next) == NULL)
                        return;

        switch (nt->tok) {
        case MAN_B:
        case MAN_BI:
        case MAN_BR:
        case MAN_I:
        case MAN_IB:
        case MAN_IR:
                nt = nt->child;
                break;
        default:
                break;
        }
        check_tag(n, nt);
}

static void
post_TH(CHKARGS)
{
        struct roff_node *nb;
        const char      *p;

        free(man->meta.title);
        free(man->meta.vol);
        free(man->meta.os);
        free(man->meta.msec);
        free(man->meta.date);

        man->meta.title = man->meta.vol = man->meta.date =
            man->meta.msec = man->meta.os = NULL;

        nb = n;

        /* ->TITLE<- MSEC DATE OS VOL */

        n = n->child;
        if (n != NULL && n->string != NULL && *n->string != '\0') {
                for (p = n->string; *p != '\0'; p++) {
                        /* Only warn about this once... */
                        if (isalpha((unsigned char)*p) &&
                            ! isupper((unsigned char)*p)) {
                                mandoc_msg(MANDOCERR_TITLE_CASE, n->line,
                                    n->pos + (int)(p - n->string),
                                    "TH %s", n->string);
                                break;
                        }
                }
                man->meta.title = mandoc_strdup(n->string);
        } else {
                man->meta.title = mandoc_strdup("UNTITLED");
                mandoc_msg(MANDOCERR_DT_NOTITLE, nb->line, nb->pos, "TH");
        }

        /* TITLE ->MSEC<- DATE OS VOL */

        if (n != NULL)
                n = n->next;
        if (n != NULL && n->string != NULL) {
                man->meta.msec = mandoc_strdup(n->string);
                if (man->filesec != '\0' &&
                    man->filesec != *n->string &&
                    *n->string >= '1' && *n->string <= '9')
                        mandoc_msg(MANDOCERR_MSEC_FILE, n->line, n->pos,
                            "*.%c vs TH ... %c", man->filesec, *n->string);
        } else {
                man->meta.msec = mandoc_strdup("");
                mandoc_msg(MANDOCERR_MSEC_MISSING,
                    nb->line, nb->pos, "TH %s", man->meta.title);
        }

        /* TITLE MSEC ->DATE<- OS VOL */

        if (n != NULL)
                n = n->next;
        if (man->quick && n != NULL)
                man->meta.date = mandoc_strdup("");
        else
                man->meta.date = mandoc_normdate(n, nb);

        /* TITLE MSEC DATE ->OS<- VOL */

        if (n && (n = n->next))
                man->meta.os = mandoc_strdup(n->string);
        else if (man->os_s != NULL)
                man->meta.os = mandoc_strdup(man->os_s);
        if (man->meta.os_e == MANDOC_OS_OTHER && man->meta.os != NULL) {
                if (strstr(man->meta.os, "OpenBSD") != NULL)
                        man->meta.os_e = MANDOC_OS_OPENBSD;
                else if (strstr(man->meta.os, "NetBSD") != NULL)
                        man->meta.os_e = MANDOC_OS_NETBSD;
        }

        /* TITLE MSEC DATE OS ->VOL<- */
        /* If missing, use the default VOL name for MSEC. */

        if (n && (n = n->next))
                man->meta.vol = mandoc_strdup(n->string);
        else if ('\0' != man->meta.msec[0] &&
            (NULL != (p = mandoc_a2msec(man->meta.msec))))
                man->meta.vol = mandoc_strdup(p);

        if (n != NULL && (n = n->next) != NULL)
                mandoc_msg(MANDOCERR_ARG_EXCESS,
                    n->line, n->pos, "TH ... %s", n->string);

        /*
         * Remove the `TH' node after we've processed it for our
         * meta-data.
         */
        roff_node_delete(man, man->last);
}

static void
post_MR(CHKARGS)
{
        struct roff_node *nch;

        if ((nch = n->child) == NULL) {
                mandoc_msg(MANDOCERR_NM_NONAME, n->line, n->pos, "MR");
                return;
        }
        if (nch->next == NULL) {
                mandoc_msg(MANDOCERR_XR_NOSEC,
                    n->line, n->pos, "MR %s", nch->string);
                return;
        }
        if (mandoc_xr_add(nch->next->string, nch->string, nch->line, nch->pos))
                mandoc_msg(MANDOCERR_XR_SELF, nch->line, nch->pos,
                    "MR %s %s", nch->string, nch->next->string);
        if ((nch = nch->next->next) == NULL || nch->next == NULL)
                return;

        mandoc_msg(MANDOCERR_ARG_EXCESS, nch->next->line, nch->next->pos,
            "MR ... %s", nch->next->string);
        while (nch->next != NULL)
                roff_node_delete(man, nch->next);
}

static void
post_UC(CHKARGS)
{
        static const char * const bsd_versions[] = {
            "3rd Berkeley Distribution",
            "4th Berkeley Distribution",
            "4.2 Berkeley Distribution",
            "4.3 Berkeley Distribution",
            "4.4 Berkeley Distribution",
        };

        const char      *p, *s;

        n = n->child;

        if (n == NULL || n->type != ROFFT_TEXT)
                p = bsd_versions[0];
        else {
                s = n->string;
                if (0 == strcmp(s, "3"))
                        p = bsd_versions[0];
                else if (0 == strcmp(s, "4"))
                        p = bsd_versions[1];
                else if (0 == strcmp(s, "5"))
                        p = bsd_versions[2];
                else if (0 == strcmp(s, "6"))
                        p = bsd_versions[3];
                else if (0 == strcmp(s, "7"))
                        p = bsd_versions[4];
                else
                        p = bsd_versions[0];
        }

        free(man->meta.os);
        man->meta.os = mandoc_strdup(p);
}

static void
post_AT(CHKARGS)
{
        static const char * const unix_versions[] = {
            "7th Edition",
            "System III",
            "System V",
            "System V Release 2",
        };

        struct roff_node *nn;
        const char      *p, *s;

        n = n->child;

        if (n == NULL || n->type != ROFFT_TEXT)
                p = unix_versions[0];
        else {
                s = n->string;
                if (0 == strcmp(s, "3"))
                        p = unix_versions[0];
                else if (0 == strcmp(s, "4"))
                        p = unix_versions[1];
                else if (0 == strcmp(s, "5")) {
                        nn = n->next;
                        if (nn != NULL &&
                            nn->type == ROFFT_TEXT &&
                            nn->string[0] != '\0')
                                p = unix_versions[3];
                        else
                                p = unix_versions[2];
                } else
                        p = unix_versions[0];
        }

        free(man->meta.os);
        man->meta.os = mandoc_strdup(p);
}

static void
post_in(CHKARGS)
{
        char    *s;

        if (n->parent->tok != MAN_TP ||
            n->parent->type != ROFFT_HEAD ||
            n->child == NULL ||
            *n->child->string == '+' ||
            *n->child->string == '-')
                return;
        mandoc_asprintf(&s, "+%s", n->child->string);
        free(n->child->string);
        n->child->string = s;
}