]> git.cameronkatri.com Git - mandoc.git/blobdiff - validate.c
Formatting.
[mandoc.git] / validate.c
index 7eb665c3ad7b15c3e4df5c63f487bc05f0da705a..72a5dea0659b3a924d635a207a7980490e97306a 100644 (file)
@@ -1,4 +1,4 @@
-/* $Id: validate.c,v 1.2 2008/11/29 16:11:42 kristaps Exp $ */
+/* $Id: validate.c,v 1.60 2009/02/25 12:32:50 kristaps Exp $ */
 /*
  * Copyright (c) 2008 Kristaps Dzonsons <kristaps@kth.se>
  *
  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  * PERFORMANCE OF THIS SOFTWARE.
  */
-#include <sys/param.h>
-
 #include <assert.h>
 #include <ctype.h>
-#include <err.h>
-#include <stdio.h>
 #include <stdlib.h>
-#include <string.h>
 
-#include "libmdocml.h"
 #include "private.h"
 
-#define        INDENT           4
+/*
+ * Pre- and post-validate macros as they're parsed.  Pre-validation
+ * occurs when the macro has been detected and its arguments parsed.
+ * Post-validation occurs when all child macros have also been parsed.
+ * In the ELEMENT case, this is simply the parameters of the macro; in
+ * the BLOCK case, this is the HEAD, BODY, TAIL and so on.
+ */
 
-#ifdef __linux__ /* FIXME */
-#define        strlcat          strncat
-#endif
+#define        PRE_ARGS        struct mdoc *mdoc, const struct mdoc_node *n
+#define        POST_ARGS       struct mdoc *mdoc
 
-struct md_valid {
-       const struct md_args    *args;
-       const struct md_rbuf    *rbuf;
-       struct md_mbuf  *mbuf;
-       struct rofftree *tree;
+typedef        int     (*v_pre)(PRE_ARGS);
+typedef        int     (*v_post)(POST_ARGS);
 
-       size_t           indent;
-       size_t           pos;
+/* FIXME: some sections should only occur in specific msecs. */
+/* FIXME: ignoring Pp. */
+/* FIXME: math symbols. */
 
-       int              flags;
-#define        MD_LITERAL      (1 << 0)
+struct valids {
+       v_pre   *pre;
+       v_post  *post;
 };
 
-static void             roffmsg(void *arg, enum roffmsg, 
-                               const char *, const char *, char *);
-static int              roffhead(void *);
-static int              rofftail(void *);
-static int              roffin(void *, int, int *, char **);
-static int              roffdata(void *, char *);
-static int              roffout(void *, int);
-static int              roffblkin(void *, int, int *, char **);
-static int              roffblkout(void *, int);
-static int              roffspecial(void *, int);
-
-static int              mbuf_newline(struct md_valid *);
-static int              mbuf_indent(struct md_valid *);
-static int              mbuf_data(struct md_valid *, char *);
+/* Utility checks. */
+
+static int     check_parent(PRE_ARGS, int, enum mdoc_type);
+static int     check_msec(PRE_ARGS, int, enum mdoc_msec *);
+static int     check_stdarg(PRE_ARGS);
+
+static int     check_text(struct mdoc *, 
+                       size_t, size_t, const char *);
+
+static int     err_child_lt(struct mdoc *, const char *, int);
+static int     warn_child_lt(struct mdoc *, const char *, int);
+static int     err_child_gt(struct mdoc *, const char *, int);
+static int     warn_child_gt(struct mdoc *, const char *, int);
+static int     err_child_eq(struct mdoc *, const char *, int);
+static int     warn_child_eq(struct mdoc *, const char *, int);
+
+/* Utility auxiliaries. */
+
+static inline int count_child(struct mdoc *);
+static inline int warn_count(struct mdoc *, const char *, 
+                       int, const char *, int);
+static inline int err_count(struct mdoc *, const char *, 
+                       int, const char *, int);
+
+/* Specific pre-child-parse routines. */
+
+static int     pre_display(PRE_ARGS);
+static int     pre_sh(PRE_ARGS);
+static int     pre_ss(PRE_ARGS);
+static int     pre_bd(PRE_ARGS);
+static int     pre_bl(PRE_ARGS);
+static int     pre_it(PRE_ARGS);
+static int     pre_cd(PRE_ARGS);
+static int     pre_er(PRE_ARGS);
+static int     pre_ex(PRE_ARGS);
+static int     pre_rv(PRE_ARGS);
+static int     pre_an(PRE_ARGS);
+static int     pre_st(PRE_ARGS);
+static int     pre_prologue(PRE_ARGS);
+static int     pre_prologue(PRE_ARGS);
+static int     pre_prologue(PRE_ARGS);
+
+/* Specific post-child-parse routines. */
+
+static int     herr_ge1(POST_ARGS);
+static int     hwarn_le1(POST_ARGS);
+static int     herr_eq0(POST_ARGS);
+static int     eerr_eq0(POST_ARGS);
+static int     eerr_le1(POST_ARGS);
+static int     eerr_le2(POST_ARGS);
+static int     eerr_eq1(POST_ARGS);
+static int     eerr_ge1(POST_ARGS);
+static int     ewarn_eq0(POST_ARGS);
+static int     ewarn_eq1(POST_ARGS);
+static int     bwarn_ge1(POST_ARGS);
+static int     hwarn_eq1(POST_ARGS);
+static int     ewarn_ge1(POST_ARGS);
+static int     ebool(POST_ARGS);
+
+static int     post_sh(POST_ARGS);
+static int     post_sh_body(POST_ARGS);
+static int     post_sh_head(POST_ARGS);
+static int     post_fd(POST_ARGS);
+static int     post_bl(POST_ARGS);
+static int     post_it(POST_ARGS);
+static int     post_ex(POST_ARGS);
+static int     post_an(POST_ARGS);
+static int     post_at(POST_ARGS);
+static int     post_xr(POST_ARGS);
+static int     post_nm(POST_ARGS);
+static int     post_bf(POST_ARGS);
+static int     post_root(POST_ARGS);
+
+/* Collections of pre-child-parse routines. */
+
+static v_pre   pres_prologue[] = { pre_prologue, NULL };
+static v_pre   pres_d1[] = { pre_display, NULL };
+static v_pre   pres_bd[] = { pre_display, pre_bd, NULL };
+static v_pre   pres_bl[] = { pre_bl, NULL };
+static v_pre   pres_it[] = { pre_it, NULL };
+static v_pre   pres_ss[] = { pre_ss, NULL };
+static v_pre   pres_sh[] = { pre_sh, NULL };
+static v_pre   pres_cd[] = { pre_cd, NULL };
+static v_pre   pres_er[] = { pre_er, NULL };
+static v_pre   pres_ex[] = { pre_ex, NULL };
+static v_pre   pres_rv[] = { pre_rv, NULL };
+static v_pre   pres_an[] = { pre_an, NULL };
+static v_pre   pres_st[] = { pre_st, NULL };
+
+/* Collections of post-child-parse routines. */
+
+static v_post  posts_bool[] = { eerr_eq1, ebool, NULL };
+static v_post  posts_bd[] = { herr_eq0, bwarn_ge1, NULL };
+static v_post  posts_text[] = { eerr_ge1, NULL };
+static v_post  posts_wtext[] = { ewarn_ge1, NULL };
+static v_post  posts_notext[] = { eerr_eq0, NULL };
+static v_post  posts_wline[] = { bwarn_ge1, herr_eq0, NULL };
+static v_post  posts_sh[] = { herr_ge1, bwarn_ge1, post_sh, NULL };
+static v_post  posts_bl[] = { herr_eq0, bwarn_ge1, post_bl, NULL };
+static v_post  posts_it[] = { post_it, NULL };
+static v_post  posts_in[] = { ewarn_eq1, NULL };
+static v_post  posts_ss[] = { herr_ge1, NULL };
+static v_post  posts_pf[] = { eerr_eq1, NULL };
+static v_post  posts_pp[] = { ewarn_eq0, NULL };
+static v_post  posts_ex[] = { eerr_le1, post_ex, NULL };
+static v_post  posts_an[] = { post_an, NULL };
+static v_post  posts_at[] = { post_at, NULL };
+static v_post  posts_xr[] = { eerr_ge1, eerr_le2, post_xr, NULL };
+static v_post  posts_nm[] = { post_nm, NULL };
+static v_post  posts_bf[] = { hwarn_le1, post_bf, NULL };
+static v_post  posts_rs[] = { herr_eq0, bwarn_ge1, NULL };
+static v_post  posts_fo[] = { hwarn_eq1, bwarn_ge1, NULL };
+static v_post  posts_bk[] = { herr_eq0, bwarn_ge1, NULL };
+static v_post  posts_fd[] = { ewarn_ge1, post_fd, NULL };
+
+/* Per-macro pre- and post-child-check routine collections. */
+
+const  struct valids mdoc_valids[MDOC_MAX] = {
+       { NULL, NULL },                         /* \" */
+       { pres_prologue, posts_text },          /* Dd */
+       { pres_prologue, NULL },                /* Dt */
+       { pres_prologue, NULL },                /* Os */
+       { pres_sh, posts_sh },                  /* Sh */ 
+       { pres_ss, posts_ss },                  /* Ss */ 
+       { NULL, posts_pp },                     /* Pp */ 
+       { pres_d1, posts_wline },               /* D1 */
+       { pres_d1, posts_wline },               /* Dl */
+       { pres_bd, posts_bd },                  /* Bd */
+       { NULL, NULL },                         /* Ed */
+       { pres_bl, posts_bl },                  /* Bl */ 
+       { NULL, NULL },                         /* El */
+       { pres_it, posts_it },                  /* It */
+       { NULL, posts_text },                   /* Ad */ 
+       { pres_an, posts_an },                  /* An */ 
+       { NULL, NULL },                         /* Ar */
+       { pres_cd, posts_text },                /* Cd */ 
+       { NULL, NULL },                         /* Cm */
+       { NULL, posts_text },                   /* Dv */ 
+       { pres_er, posts_text },                /* Er */ 
+       { NULL, posts_text },                   /* Ev */ 
+       { pres_ex, posts_ex },                  /* Ex */ 
+       { NULL, posts_text },                   /* Fa */ 
+       { NULL, posts_fd },                     /* Fd */
+       { NULL, NULL },                         /* Fl */
+       { NULL, posts_text },                   /* Fn */ 
+       { NULL, posts_wtext },                  /* Ft */ 
+       { NULL, posts_text },                   /* Ic */ 
+       { NULL, posts_in },                     /* In */ 
+       { NULL, posts_text },                   /* Li */
+       { NULL, posts_wtext },                  /* Nd */
+       { NULL, posts_nm },                     /* Nm */
+       { NULL, posts_wline },                  /* Op */
+       { NULL, NULL },                         /* Ot */
+       { NULL, NULL },                         /* Pa */
+       { pres_rv, posts_notext },              /* Rv */
+       { pres_st, posts_notext },              /* St */ 
+       { NULL, posts_text },                   /* Va */
+       { NULL, posts_text },                   /* Vt */ 
+       { NULL, posts_xr },                     /* Xr */ 
+       { NULL, posts_text },                   /* %A */
+       { NULL, posts_text },                   /* %B */
+       { NULL, posts_text },                   /* %D */
+       { NULL, posts_text },                   /* %I */
+       { NULL, posts_text },                   /* %J */
+       { NULL, posts_text },                   /* %N */
+       { NULL, posts_text },                   /* %O */
+       { NULL, posts_text },                   /* %P */
+       { NULL, posts_text },                   /* %R */
+       { NULL, posts_text },                   /* %T */
+       { NULL, posts_text },                   /* %V */
+       { NULL, NULL },                         /* Ac */
+       { NULL, NULL },                         /* Ao */
+       { NULL, posts_wline },                  /* Aq */
+       { NULL, posts_at },                     /* At */ 
+       { NULL, NULL },                         /* Bc */
+       { NULL, posts_bf },                     /* Bf */
+       { NULL, NULL },                         /* Bo */
+       { NULL, posts_wline },                  /* Bq */
+       { NULL, NULL },                         /* Bsx */
+       { NULL, NULL },                         /* Bx */
+       { NULL, posts_bool },                   /* Db */
+       { NULL, NULL },                         /* Dc */
+       { NULL, NULL },                         /* Do */
+       { NULL, posts_wline },                  /* Dq */
+       { NULL, NULL },                         /* Ec */
+       { NULL, NULL },                         /* Ef */ 
+       { NULL, posts_text },                   /* Em */ 
+       { NULL, NULL },                         /* Eo */
+       { NULL, NULL },                         /* Fx */
+       { NULL, posts_text },                   /* Ms */ 
+       { NULL, posts_notext },                 /* No */
+       { NULL, posts_notext },                 /* Ns */
+       { NULL, NULL },                         /* Nx */
+       { NULL, NULL },                         /* Ox */
+       { NULL, NULL },                         /* Pc */
+       { NULL, posts_pf },                     /* Pf */
+       { NULL, NULL },                         /* Po */
+       { NULL, posts_wline },                  /* Pq */
+       { NULL, NULL },                         /* Qc */
+       { NULL, posts_wline },                  /* Ql */
+       { NULL, NULL },                         /* Qo */
+       { NULL, posts_wline },                  /* Qq */
+       { NULL, NULL },                         /* Re */
+       { NULL, posts_rs },                     /* Rs */
+       { NULL, NULL },                         /* Sc */
+       { NULL, NULL },                         /* So */
+       { NULL, posts_wline },                  /* Sq */
+       { NULL, posts_bool },                   /* Sm */ 
+       { NULL, posts_text },                   /* Sx */
+       { NULL, posts_text },                   /* Sy */
+       { NULL, posts_text },                   /* Tn */
+       { NULL, NULL },                         /* Ux */
+       { NULL, NULL },                         /* Xc */
+       { NULL, NULL },                         /* Xo */
+       { NULL, posts_fo },                     /* Fo */ 
+       { NULL, NULL },                         /* Fc */ 
+       { NULL, NULL },                         /* Oo */
+       { NULL, NULL },                         /* Oc */
+       { NULL, posts_bk },                     /* Bk */
+       { NULL, NULL },                         /* Ek */
+       { NULL, posts_notext },                 /* Bt */
+       { NULL, NULL },                         /* Hf */
+       { NULL, NULL },                         /* Fr */
+       { NULL, posts_notext },                 /* Ud */
+};
 
 
-static int
-mbuf_indent(struct md_valid *p)
+int
+mdoc_valid_pre(struct mdoc *mdoc, 
+               const struct mdoc_node *node)
 {
-       size_t           i;
+       v_pre           *p;
+       struct mdoc_arg *argv;
+       size_t           argc, i, j, line, pos;
+       const char      *tp;
+
+       if (MDOC_TEXT == node->type) {
+               tp = node->data.text.string;
+               line = node->line;
+               pos = node->pos;
+               return(check_text(mdoc, line, pos, tp));
+       }
+
+       if (MDOC_BLOCK == node->type || MDOC_ELEM == node->type) {
+               argv = MDOC_BLOCK == node->type ?
+                       node->data.block.argv :
+                       node->data.elem.argv;
+               argc = MDOC_BLOCK == node->type ?
+                       node->data.block.argc :
+                       node->data.elem.argc;
+
+               for (i = 0; i < argc; i++) {
+                       if (0 == argv[i].sz)
+                               continue;
+                       for (j = 0; j < argv[i].sz; j++) {
+                               tp = argv[i].value[j];
+                               line = argv[i].line;
+                               pos = argv[i].pos;
+                               if ( ! check_text(mdoc, line, pos, tp))
+                                       return(0);
+                       }
+               }
+       }
+
+       if (NULL == mdoc_valids[node->tok].pre)
+               return(1);
+       for (p = mdoc_valids[node->tok].pre; *p; p++)
+               if ( ! (*p)(mdoc, node)) 
+                       return(0);
+       return(1);
+}
 
-       assert(p->pos == 0);
 
-       for (i = 0; i < MIN(p->indent, INDENT); i++)
-               if ( ! md_buf_putstring(p->mbuf, "    "))
+int
+mdoc_valid_post(struct mdoc *mdoc)
+{
+       v_post          *p;
+
+       /*
+        * This check occurs after the macro's children have been filled
+        * in: postfix validation.  Since this happens when we're
+        * rewinding the scope tree, it's possible to have multiple
+        * invocations (as by design, for now), we set bit MDOC_VALID to
+        * indicate that we've validated.
+        */
+
+       if (MDOC_VALID & mdoc->last->flags)
+               return(1);
+       mdoc->last->flags |= MDOC_VALID;
+
+       if (MDOC_TEXT == mdoc->last->type)
+               return(1);
+       if (MDOC_ROOT == mdoc->last->type)
+               return(post_root(mdoc));
+
+       if (NULL == mdoc_valids[mdoc->last->tok].post)
+               return(1);
+       for (p = mdoc_valids[mdoc->last->tok].post; *p; p++)
+               if ( ! (*p)(mdoc)) 
                        return(0);
 
-       p->pos += i * INDENT;
        return(1);
 }
 
 
-static int
-mbuf_newline(struct md_valid *p)
+
+static inline int
+warn_count(struct mdoc *m, const char *k, 
+               int want, const char *v, int has)
 {
 
-       if ( ! md_buf_putchar(p->mbuf, '\n'))
-               return(0);
+       return(mdoc_warn(m, WARN_SYNTAX, 
+                               "suggests %s %s %d (has %d)", 
+                               v, k, want, has));
+}
 
-       p->pos = 0;
-       return(1);
+
+static inline int
+err_count(struct mdoc *m, const char *k,
+               int want, const char *v, int has)
+{
+
+       return(mdoc_err(m, "requires %s %s %d (has %d)",
+                               v, k, want, has));
 }
 
 
-static int
-mbuf_data(struct md_valid *p, char *buf)
+static inline int
+count_child(struct mdoc *mdoc)
 {
-       size_t           sz;
-       char            *bufp;
+       int               i;
+       struct mdoc_node *n;
 
-       assert(p->mbuf);
-       assert(0 != p->indent);
+       for (i = 0, n = mdoc->last->child; n; n = n->next, i++)
+               /* Do nothing */ ;
 
-       if (MD_LITERAL & p->flags)
-               return(md_buf_putstring(p->mbuf, buf));
+       return(i);
+}
 
-       while (*buf) {
-               while (*buf && isspace(*buf))
-                       buf++;
 
-               if (0 == *buf)
-                       break;
+/*
+ * Build these up with macros because they're basically the same check
+ * for different inequalities.  Yes, this could be done with functions,
+ * but this is reasonable for now.
+ */
 
-               bufp = buf;
-               while (*buf && ! isspace(*buf))
-                       buf++;
+#define CHECK_CHILD_DEFN(lvl, name, ineq)                      \
+static int                                                     \
+lvl##_child_##name(struct mdoc *mdoc, const char *p, int sz)   \
+{                                                              \
+       int i;                                                  \
+       if ((i = count_child(mdoc)) ineq sz)                    \
+               return(1);                                      \
+       return(lvl##_count(mdoc, #ineq, sz, p, i));             \
+}
 
-               if (0 != *buf)
-                       *buf++ = 0;
+#define CHECK_BODY_DEFN(name, lvl, func, num)                  \
+static int                                                     \
+b##lvl##_##name(POST_ARGS)                                     \
+{                                                              \
+       if (MDOC_BODY != mdoc->last->type)                      \
+               return(1);                                      \
+       return(func(mdoc, "multiline parameters", (num)));      \
+}
 
-               /* Process word. */
+#define CHECK_ELEM_DEFN(name, lvl, func, num)                  \
+static int                                                     \
+e##lvl##_##name(POST_ARGS)                                     \
+{                                                              \
+       assert(MDOC_ELEM == mdoc->last->type);                  \
+       return(func(mdoc, "line parameters", (num)));           \
+}
 
-               sz = strlen(bufp);
+#define CHECK_HEAD_DEFN(name, lvl, func, num)                  \
+static int                                                     \
+h##lvl##_##name(POST_ARGS)                                     \
+{                                                              \
+       if (MDOC_HEAD != mdoc->last->type)                      \
+               return(1);                                      \
+       return(func(mdoc, "line parameters", (num)));           \
+}
 
-               if (0 == p->pos) {
-                       if ( ! mbuf_indent(p))
-                               return(0);
-                       if ( ! md_buf_putstring(p->mbuf, bufp))
-                               return(0);
 
-                       if (p->indent * INDENT + sz >= 72) {
-                               if ( ! mbuf_newline(p))
-                                       return(0);
-                               continue;
-                       }
+CHECK_CHILD_DEFN(warn, gt, >)                  /* warn_child_gt() */
+CHECK_CHILD_DEFN(err, gt, >)                   /* err_child_gt() */
+CHECK_CHILD_DEFN(warn, eq, ==)                 /* warn_child_eq() */
+CHECK_CHILD_DEFN(err, eq, ==)                  /* err_child_eq() */
+CHECK_CHILD_DEFN(err, lt, <)                   /* err_child_lt() */
+CHECK_CHILD_DEFN(warn, lt, <)                  /* warn_child_lt() */
+CHECK_BODY_DEFN(ge1, warn, warn_child_gt, 0)   /* bwarn_ge1() */
+CHECK_ELEM_DEFN(eq1, warn, warn_child_eq, 1)   /* ewarn_eq1() */
+CHECK_ELEM_DEFN(eq0, warn, warn_child_eq, 0)   /* ewarn_eq0() */
+CHECK_ELEM_DEFN(ge1, warn, warn_child_gt, 0)   /* ewarn_gt1() */
+CHECK_ELEM_DEFN(eq1, err, err_child_eq, 1)     /* eerr_eq1() */
+CHECK_ELEM_DEFN(le2, err, err_child_lt, 3)     /* eerr_le2() */
+CHECK_ELEM_DEFN(le1, err, err_child_lt, 2)     /* eerr_le1() */
+CHECK_ELEM_DEFN(eq0, err, err_child_eq, 0)     /* eerr_eq0() */
+CHECK_ELEM_DEFN(ge1, err, err_child_gt, 0)     /* eerr_ge1() */
+CHECK_HEAD_DEFN(eq0, err, err_child_eq, 0)     /* herr_eq0() */
+CHECK_HEAD_DEFN(le1, warn, warn_child_lt, 2)   /* hwarn_le1() */
+CHECK_HEAD_DEFN(ge1, err, err_child_gt, 0)     /* herr_ge1() */
+CHECK_HEAD_DEFN(eq1, warn, warn_child_eq, 1)   /* hwarn_eq1() */
 
-                       if ( ! md_buf_putchar(p->mbuf, ' '))
-                               return(0);
 
-                       p->pos += sz + 1;
-                       continue;
-               }
+static int
+check_stdarg(PRE_ARGS)
+{
 
-               if (sz + p->pos >= 72) {
-                       if ( ! mbuf_newline(p))
-                               return(0);
-                       if ( ! mbuf_indent(p))
-                               return(0);
-               }
+       if (MDOC_Std == n->data.elem.argv[0].arg && 
+                       1 == n->data.elem.argc)
+               return(1);
 
-               if ( ! md_buf_putstring(p->mbuf, bufp))
-                       return(0);
-               if ( ! md_buf_putchar(p->mbuf, ' '))
-                       return(0);
+       return(mdoc_nwarn(mdoc, n, WARN_COMPAT, 
+                               "one argument suggested"));
+}
 
-               p->pos += sz + 1;
-       }
 
-       return(1);
+static int
+check_msec(PRE_ARGS, int sz, enum mdoc_msec *msecs)
+{
+       int              i;
+
+       for (i = 0; i < sz; i++)
+               if (msecs[i] == mdoc->meta.msec)
+                       return(1);
+       return(mdoc_nwarn(mdoc, n, WARN_COMPAT, 
+                               "invalid manual section"));
 }
 
 
-int
-md_line_valid(void *arg, char *buf)
+static int
+check_text(struct mdoc *mdoc, size_t line, size_t pos, const char *p)
 {
-       struct md_valid *p;
+       size_t           c;
+
+       for ( ; *p; p++) {
+               if ( ! isprint((int)*p) && '\t' != *p)
+                       return(mdoc_perr(mdoc, line, pos,
+                                       "invalid characters"));
+               if ('\\' != *p)
+                       continue;
+               if ((c = mdoc_isescape(p))) {
+                       p += (c - 1);
+                       continue;
+               }
+               return(mdoc_perr(mdoc, line, pos,
+                                       "invalid escape sequence"));
+       }
 
-       p = (struct md_valid *)arg;
-       return(roff_engine(p->tree, buf));
+       return(1);
 }
 
 
-int
-md_exit_valid(void *data, int flush)
+
+
+static int
+check_parent(PRE_ARGS, int tok, enum mdoc_type t)
 {
-       int              c;
-       struct md_valid *p;
 
-       p = (struct md_valid *)data;
-       c = roff_free(p->tree, flush);
-       free(p);
+       assert(n->parent);
+       if ((MDOC_ROOT == t || tok == n->parent->tok) &&
+                       (t == n->parent->type))
+               return(1);
 
-       return(c);
+       return(mdoc_nerr(mdoc, n, "require parent %s",
+               MDOC_ROOT == t ? "<root>" : mdoc_macronames[tok]));
 }
 
 
-void *
-md_init_valid(const struct md_args *args,
-               struct md_mbuf *mbuf, const struct md_rbuf *rbuf)
+
+static int
+pre_display(PRE_ARGS)
 {
-       struct roffcb    cb;
-       struct md_valid *p;
+       struct mdoc_node *node;
+
+       /* Display elements (`Bd', `D1'...) cannot be nested. */
 
-       cb.roffhead = roffhead;
-       cb.rofftail = rofftail;
-       cb.roffin = roffin;
-       cb.roffout = roffout;
-       cb.roffblkin = roffblkin;
-       cb.roffblkout = roffblkout;
-       cb.roffspecial = roffspecial;
-       cb.roffmsg = roffmsg;
-       cb.roffdata = roffdata;
+       if (MDOC_BLOCK != n->type)
+               return(1);
 
-       if (NULL == (p = calloc(1, sizeof(struct md_valid))))
-               err(1, "malloc");
+       /* LINTED */
+       for (node = mdoc->last->parent; node; node = node->parent) 
+               if (MDOC_BLOCK == node->type)
+                       if (MDOC_Bd == node->tok)
+                               break;
+       if (NULL == node)
+               return(1);
 
-       p->args = args;
-       p->mbuf = mbuf;
-       p->rbuf = rbuf;
+       return(mdoc_nerr(mdoc, n, "displays may not be nested"));
+}
 
-       assert(mbuf);
 
-       if (NULL == (p->tree = roff_alloc(&cb, p))) {
-               free(p);
-               return(NULL);
+static int
+pre_bl(PRE_ARGS)
+{
+       int              type, i;
+       struct mdoc_arg *argv;
+       size_t           argc;
+
+       if (MDOC_BLOCK != n->type)
+               return(1);
+
+       argc = n->data.block.argc; 
+
+       /* Make sure that only one type of list is specified.  */
+
+       /* LINTED */
+       for (i = 0, type = 0; i < (int)argc; i++) {
+               argv = &n->data.block.argv[i];
+
+               switch (argv->arg) {
+               case (MDOC_Bullet):
+                       /* FALLTHROUGH */
+               case (MDOC_Dash):
+                       /* FALLTHROUGH */
+               case (MDOC_Enum):
+                       /* FALLTHROUGH */
+               case (MDOC_Hyphen):
+                       /* FALLTHROUGH */
+               case (MDOC_Item):
+                       /* FALLTHROUGH */
+               case (MDOC_Tag):
+                       /* FALLTHROUGH */
+               case (MDOC_Diag):
+                       /* FALLTHROUGH */
+               case (MDOC_Hang):
+                       /* FALLTHROUGH */
+               case (MDOC_Ohang):
+                       /* FALLTHROUGH */
+               case (MDOC_Inset):
+                       /* FALLTHROUGH */
+               case (MDOC_Column):
+                       if (0 == type++)
+                               break;
+                       return(mdoc_perr(mdoc, argv->line, argv->pos, 
+                                       "multiple types specified"));
+               default:
+                       break;
+               }
        }
 
-       return(p);
+       if (type)
+               return(1);
+       return(mdoc_err(mdoc, "no type specified"));
 }
 
 
-/* ARGSUSED */
 static int
-roffhead(void *arg)
+pre_bd(PRE_ARGS)
 {
-       struct md_valid *p;
+       int              type, err, i;
+       struct mdoc_arg *argv;
+       size_t           argc;
+
+       if (MDOC_BLOCK != n->type)
+               return(1);
+
+       argc = n->data.block.argc;
+
+       /* Make sure that only one type of display is specified.  */
+
+       /* LINTED */
+       for (i = 0, err = type = 0; ! err && i < (int)argc; i++) {
+               argv = &n->data.block.argv[i];
+
+               switch (argv->arg) {
+               case (MDOC_Ragged):
+                       /* FALLTHROUGH */
+               case (MDOC_Unfilled):
+                       /* FALLTHROUGH */
+               case (MDOC_Filled):
+                       /* FALLTHROUGH */
+               case (MDOC_Literal):
+                       /* FALLTHROUGH */
+               case (MDOC_File):
+                       if (0 == type++) 
+                               break;
+                       return(mdoc_perr(mdoc, argv->line, argv->pos, 
+                                       "multiple types specified"));
+               default:
+                       break;
+               }
+       }
 
-       assert(arg);
-       p = (struct md_valid *)arg;
+       if (type)
+               return(1);
+       return(mdoc_err(mdoc, "no type specified"));
+}
 
-       if ( ! md_buf_putstring(p->mbuf, "BEGIN"))
-               return(0);
-       p->indent++;
-       if ( ! mbuf_newline(p))
-               return(0);
 
-       return(1);
+static int
+pre_ss(PRE_ARGS)
+{
+
+       if (MDOC_BLOCK != n->type)
+               return(1);
+       return(check_parent(mdoc, n, MDOC_Sh, MDOC_BODY));
 }
 
 
 static int
-rofftail(void *arg)
+pre_sh(PRE_ARGS)
 {
-       struct md_valid *p;
 
-       assert(arg);
-       p = (struct md_valid *)arg;
+       if (MDOC_BLOCK != n->type)
+               return(1);
+       return(check_parent(mdoc, n, -1, MDOC_ROOT));
+}
 
-       if (0 != p->pos && ! mbuf_newline(p))
-               return(0);
 
-       if ( ! md_buf_putstring(p->mbuf, "END\n"))
-               return(0);
-       return(1);
+static int
+pre_it(PRE_ARGS)
+{
+
+       /* TODO: -width attribute must be specified for -tag. */
+       /* TODO: children too big for -width? */
+
+       if (MDOC_BLOCK != n->type)
+               return(1);
+       return(check_parent(mdoc, n, MDOC_Bl, MDOC_BODY));
 }
 
 
 static int
-roffspecial(void *arg, int tok)
+pre_st(PRE_ARGS)
 {
 
-       return(1);
+       if (1 == n->data.elem.argc)
+               return(1);
+       return(mdoc_nerr(mdoc, n, "one argument required"));
 }
 
 
 static int
-roffblkin(void *arg, int tok, int *argc, char **argv)
+pre_an(PRE_ARGS)
 {
-       struct md_valid *p;
 
-       assert(arg);
-       p = (struct md_valid *)arg;
+       if (1 >= n->data.elem.argc)
+               return(1);
+       return(mdoc_nerr(mdoc, n, "one argument allowed"));
+}
 
-       if (0 != p->pos) {
-               if ( ! mbuf_newline(p))
-                       return(0);
-               if ( ! mbuf_indent(p))
-                       return(0);
-       } else if ( ! mbuf_indent(p))
-               return(0);
 
-       if ( ! md_buf_putchar(p->mbuf, '<'))
-               return(0);
-       if ( ! md_buf_putstring(p->mbuf, toknames[tok]))
-               return(0);
-       if ( ! md_buf_putchar(p->mbuf, '>'))
+static int
+pre_rv(PRE_ARGS)
+{
+       enum mdoc_msec msecs[] = { MSEC_2, MSEC_3 };
+
+       if ( ! check_msec(mdoc, n, 2, msecs))
                return(0);
-       if ( ! mbuf_newline(p))
+       return(check_stdarg(mdoc, n));
+}
+
+
+static int
+pre_ex(PRE_ARGS)
+{
+       enum mdoc_msec msecs[] = { MSEC_1, MSEC_6, MSEC_8 };
+
+       if ( ! check_msec(mdoc, n, 3, msecs))
                return(0);
+       return(check_stdarg(mdoc, n));
+}
 
-       p->indent++;
-       return(1);
+
+static int
+pre_er(PRE_ARGS)
+{
+       enum mdoc_msec msecs[] = { MSEC_2 };
+
+       return(check_msec(mdoc, n, 1, msecs));
 }
 
 
 static int
-roffblkout(void *arg, int tok)
+pre_cd(PRE_ARGS)
 {
-       struct md_valid *p;
+       enum mdoc_msec msecs[] = { MSEC_4 };
 
-       assert(arg);
-       p = (struct md_valid *)arg;
+       return(check_msec(mdoc, n, 1, msecs));
+}
 
-       p->indent--;
 
-       if (0 != p->pos) {
-               if ( ! mbuf_newline(p))
-                       return(0);
-               if ( ! mbuf_indent(p))
-                       return(0);
-       } else if ( ! mbuf_indent(p))
-               return(0);
+static int
+pre_prologue(PRE_ARGS)
+{
 
-       if ( ! md_buf_putstring(p->mbuf, "</"))
-               return(0);
-       if ( ! md_buf_putstring(p->mbuf, toknames[tok]))
-               return(0);
-       if ( ! md_buf_putstring(p->mbuf, ">"))
-               return(0);
-       if ( ! mbuf_newline(p))
-               return(0);
+       if (SEC_PROLOGUE != mdoc->lastnamed)
+               return(mdoc_nerr(mdoc, n, "prologue only"));
 
-       return(1);
+       /* Check for ordering. */
+
+       switch (n->tok) {
+       case (MDOC_Os):
+               if (mdoc->meta.title && mdoc->meta.date)
+                       break;
+               return(mdoc_nerr(mdoc, n, "prologue out-of-order"));
+       case (MDOC_Dt):
+               if (NULL == mdoc->meta.title && mdoc->meta.date)
+                       break;
+               return(mdoc_nerr(mdoc, n, "prologue out-of-order"));
+       case (MDOC_Dd):
+               if (NULL == mdoc->meta.title && 0 == mdoc->meta.date)
+                       break;
+               return(mdoc_nerr(mdoc, n, "prologue out-of-order"));
+       default:
+               abort();
+               /* NOTREACHED */
+       }
+
+       /* Check for repetition. */
+
+       switch (n->tok) {
+       case (MDOC_Os):
+               if (NULL == mdoc->meta.os)
+                       return(1);
+               break;
+       case (MDOC_Dd):
+               if (0 == mdoc->meta.date)
+                       return(1);
+               break;
+       case (MDOC_Dt):
+               if (NULL == mdoc->meta.title)
+                       return(1);
+               break;
+       default:
+               abort();
+               /* NOTREACHED */
+       }
+
+       return(mdoc_nerr(mdoc, n, "prologue repetition"));
 }
 
 
 static int
-roffin(void *arg, int tok, int *argcp, char **argvp)
+post_bf(POST_ARGS)
 {
-       struct md_valid *p;
+       char             *p;
+       struct mdoc_node *head;
+
+       if (MDOC_BLOCK != mdoc->last->type)
+               return(1);
+
+       head = mdoc->last->data.block.head;
+
+       if (0 == mdoc->last->data.block.argc) {
+               if (NULL == head->child)
+                       return(mdoc_err(mdoc, "argument expected"));
+
+               p = head->child->data.text.string;
+               if (xstrcmp(p, "Em"))
+                       return(1);
+               else if (xstrcmp(p, "Li"))
+                       return(1);
+               else if (xstrcmp(p, "Sm"))
+                       return(1);
+               return(mdoc_nerr(mdoc, head->child, "invalid font"));
+       }
 
-       assert(arg);
-       p = (struct md_valid *)arg;
+       if (head->child)
+               return(mdoc_err(mdoc, "argument expected"));
 
-       if (0 == p->pos && ! mbuf_indent(p))
-               return(0);
+       if (1 == mdoc->last->data.block.argc)
+               return(1);
+       return(mdoc_err(mdoc, "argument expected"));
+}
 
-       if ( ! md_buf_putstring(p->mbuf, "<"))
-               return(0);
-       if ( ! md_buf_putstring(p->mbuf, toknames[tok]))
-               return(0);
-       if ( ! md_buf_putstring(p->mbuf, ">"))
-               return(0);
 
-       p->pos += strlen(toknames[tok]) + 2;
+static int
+post_nm(POST_ARGS)
+{
 
-       return(1);
+       if (mdoc->last->child)
+               return(1);
+       if (mdoc->meta.name)
+               return(1);
+       return(mdoc_err(mdoc, "not yet invoked with name"));
 }
 
 
 static int
-roffout(void *arg, int tok)
+post_xr(POST_ARGS)
 {
-       struct md_valid *p;
+       struct mdoc_node *n;
 
-       assert(arg);
-       p = (struct md_valid *)arg;
+       if (NULL == (n = mdoc->last->child->next))
+               return(1);
+       if (MSEC_DEFAULT != mdoc_atomsec(n->data.text.string))
+               return(1);
+       return(mdoc_nerr(mdoc, n, "invalid manual section"));
+}
 
-       if (0 == p->pos && ! mbuf_indent(p))
-               return(0);
 
-       if ( ! md_buf_putstring(p->mbuf, "</"))
-               return(0);
-       if ( ! md_buf_putstring(p->mbuf, toknames[tok]))
-               return(0);
-       if ( ! md_buf_putstring(p->mbuf, "> "))
-               return(0);
+static int
+post_at(POST_ARGS)
+{
+
+       if (NULL == mdoc->last->child)
+               return(1);
+       if (ATT_DEFAULT != mdoc_atoatt(mdoc->last->child->data.text.string))
+               return(1);
+       return(mdoc_err(mdoc, "require valid symbol"));
+}
+
 
-       p->pos += strlen(toknames[tok]) + 3;
+static int
+post_an(POST_ARGS)
+{
+
+       if (0 != mdoc->last->data.elem.argc) {
+               if (NULL == mdoc->last->child)
+                       return(1);
+               return(mdoc_err(mdoc, "argument(s) expected"));
+       }
+
+       if (mdoc->last->child)
+               return(1);
+       return(mdoc_err(mdoc, "argument(s) expected"));
+}
+
+
+static int
+post_ex(POST_ARGS)
+{
+
+       if (0 == mdoc->last->data.elem.argc) {
+               if (mdoc->last->child)
+                       return(1);
+               return(mdoc_err(mdoc, "argument(s) expected"));
+       }
+       if (mdoc->last->child)
+               return(mdoc_err(mdoc, "argument(s) expected"));
+       if (1 != mdoc->last->data.elem.argc)
+               return(mdoc_err(mdoc, "argument(s) expected"));
+       if (MDOC_Std != mdoc->last->data.elem.argv[0].arg)
+               return(mdoc_err(mdoc, "argument(s) expected"));
 
        return(1);
 }
 
 
+static int
+post_it(POST_ARGS)
+{
+       int               type, sv, i;
+#define        TYPE_NONE        (0)
+#define        TYPE_BODY        (1)
+#define        TYPE_HEAD        (2)
+#define        TYPE_OHEAD       (3)
+       size_t            argc;
+       struct mdoc_node *n;
+
+       if (MDOC_BLOCK != mdoc->last->type)
+               return(1);
+
+       n = mdoc->last->parent->parent;
+
+       argc = n->data.block.argc;
+       type = TYPE_NONE;
+       sv = -1;
+       
+       /* Some types require block-head, some not. */
+
+       /* LINTED */
+       for (i = 0; TYPE_NONE == type && i < (int)argc; i++)
+               switch (n->data.block.argv[i].arg) {
+               case (MDOC_Tag):
+                       /* FALLTHROUGH */
+               case (MDOC_Diag):
+                       /* FALLTHROUGH */
+               case (MDOC_Hang):
+                       /* FALLTHROUGH */
+               case (MDOC_Ohang):
+                       /* FALLTHROUGH */
+               case (MDOC_Inset):
+                       type = TYPE_HEAD;
+                       sv = n->data.block.argv[i].arg;
+                       break;
+               case (MDOC_Bullet):
+                       /* FALLTHROUGH */
+               case (MDOC_Dash):
+                       /* FALLTHROUGH */
+               case (MDOC_Enum):
+                       /* FALLTHROUGH */
+               case (MDOC_Hyphen):
+                       /* FALLTHROUGH */
+               case (MDOC_Item):
+                       type = TYPE_BODY;
+                       sv = n->data.block.argv[i].arg;
+                       break;
+               case (MDOC_Column):
+                       type = TYPE_OHEAD;
+                       sv = n->data.block.argv[i].arg;
+                       break;
+               default:
+                       break;
+               }
+
+       assert(TYPE_NONE != type);
+
+       n = mdoc->last->data.block.head;
+
+       if (TYPE_HEAD == type) {
+               if (NULL == n->child)
+                       if ( ! mdoc_warn(mdoc, WARN_SYNTAX, 
+                                       "argument(s) suggested"))
+                               return(0);
+
+               n = mdoc->last->data.block.body;
+               if (NULL == n->child)
+                       if ( ! mdoc_warn(mdoc, WARN_SYNTAX, 
+                                       "multiline body suggested"))
+                               return(0);
+
+       } else if (TYPE_BODY == type) {
+               if (n->child)
+                       if ( ! mdoc_warn(mdoc, WARN_SYNTAX, 
+                                       "no argument suggested"))
+                               return(0);
+       
+               n = mdoc->last->data.block.body;
+               if (NULL == n->child)
+                       if ( ! mdoc_warn(mdoc, WARN_SYNTAX, 
+                                       "multiline body suggested"))
+                               return(0);
+       } else {
+               if (NULL == n->child)
+                       if ( ! mdoc_warn(mdoc, WARN_SYNTAX, 
+                                       "argument(s) suggested"))
+                               return(0);
+       
+               n = mdoc->last->data.block.body;
+               if (n->child)
+                       if ( ! mdoc_warn(mdoc, WARN_SYNTAX, 
+                                       "no multiline body suggested"))
+                               return(0);
+       }
+
+       if (MDOC_Column != sv)
+               return(1);
 
-static void
-roffmsg(void *arg, enum roffmsg lvl, 
-               const char *buf, const char *pos, char *msg)
+       argc = mdoc->last->parent->parent->data.block.argv->sz;
+       n = mdoc->last->data.block.head->child;
+
+       for (i = 0; n; n = n->next)
+               i++;
+
+       if (i == (int)argc)
+               return(1);
+
+       return(mdoc_err(mdoc, "need %zu columns (have %d)", argc, i));
+#undef TYPE_NONE
+#undef TYPE_BODY
+#undef TYPE_HEAD
+#undef TYPE_OHEAD
+}
+
+
+static int
+post_bl(POST_ARGS)
 {
-       char            *level;
-       struct md_valid *p;
+       struct mdoc_node        *n;
 
-       assert(arg);
-       p = (struct md_valid *)arg;
+       if (MDOC_BODY != mdoc->last->type)
+               return(1);
 
-       switch (lvl) {
-       case (ROFF_WARN):
-               if ( ! (MD_WARN_ALL & p->args->warnings))
-                       return;
-               level = "warning";
+       /* LINTED */
+       for (n = mdoc->last->child; n; n = n->next) {
+               if (MDOC_BLOCK == n->type) 
+                       if (MDOC_It == n->tok)
+                               continue;
                break;
-       case (ROFF_ERROR):
-               level = "error";
+       }
+
+       if (NULL == n)
+               return(1);
+
+       return(mdoc_nerr(mdoc, n, "bad child of parent list"));
+}
+
+
+static int
+ebool(struct mdoc *mdoc)
+{
+       struct mdoc_node *n;
+
+       /* LINTED */
+       for (n = mdoc->last->child; n; n = n->next) {
+               if (MDOC_TEXT != n->type)
+                       break;
+               if (xstrcmp(n->data.text.string, "on"))
+                       continue;
+               if (xstrcmp(n->data.text.string, "off"))
+                       continue;
                break;
-       default:
-               abort();
        }
-       
-       if (pos)
-               (void)fprintf(stderr, "%s:%zu: %s: %s\n", 
-                               p->rbuf->name, p->rbuf->line, level, msg);
-       else
-               (void)fprintf(stderr, "%s: %s: %s\n", 
-                               p->rbuf->name, level, msg);
 
+       if (NULL == n)
+               return(1);
+       return(mdoc_nerr(mdoc, n, "expected boolean"));
+}
+
+
+static int
+post_root(POST_ARGS)
+{
+
+       if (NULL == mdoc->first->child)
+               return(mdoc_err(mdoc, "document lacks data"));
+       if (SEC_PROLOGUE == mdoc->lastnamed)
+               return(mdoc_err(mdoc, "document lacks prologue"));
+
+       if (MDOC_BLOCK != mdoc->first->child->type)
+               return(mdoc_err(mdoc, "lacking post-prologue %s", 
+                                       mdoc_macronames[MDOC_Sh]));
+       if (MDOC_Sh != mdoc->first->child->tok)
+               return(mdoc_err(mdoc, "lacking post-prologue %s", 
+                                       mdoc_macronames[MDOC_Sh]));
+
+       return(1);
+}
+
+
+static int
+post_sh(POST_ARGS)
+{
+
+       if (MDOC_HEAD == mdoc->last->type)
+               return(post_sh_head(mdoc));
+       if (MDOC_BODY == mdoc->last->type)
+               return(post_sh_body(mdoc));
+
+       return(1);
+}
+
+
+static int
+post_sh_body(POST_ARGS)
+{
+       struct mdoc_node *n;
+
+       if (SEC_NAME != mdoc->lastnamed)
+               return(1);
+
+       /*
+        * Warn if the NAME section doesn't contain the `Nm' and `Nd'
+        * macros (can have multiple `Nm' and one `Nd').  Note that the
+        * children of the BODY declaration can also be "text".
+        */
+
+       if (NULL == (n = mdoc->last->child))
+               return(mdoc_warn(mdoc, WARN_SYNTAX, 
+                                       "section should have %s and %s",
+                                       mdoc_macronames[MDOC_Nm],
+                                       mdoc_macronames[MDOC_Nd]));
+
+       for ( ; n && n->next; n = n->next) {
+               if (MDOC_ELEM == n->type && MDOC_Nm == n->tok)
+                       continue;
+               if (MDOC_TEXT == n->type)
+                       continue;
+               if ( ! (mdoc_nwarn(mdoc, n, WARN_SYNTAX, 
+                                       "section should have %s first",
+                                       mdoc_macronames[MDOC_Nm])))
+                       return(0);
+       }
+
+       if (MDOC_ELEM == n->type && MDOC_Nd == n->tok)
+               return(1);
+
+       return(mdoc_warn(mdoc, WARN_SYNTAX, 
+                               "section should have %s last",
+                               mdoc_macronames[MDOC_Nd]));
+}
+
+
+static int
+post_sh_head(POST_ARGS)
+{
+       char              buf[64];
+       enum mdoc_sec     sec;
+
+       assert(MDOC_Sh == mdoc->last->tok);
+
+       if ( ! xstrlcats(buf, mdoc->last->child, sizeof(buf)))
+               return(mdoc_err(mdoc, "argument too long"));
+
+       sec = mdoc_atosec(buf);
+
+       if (SEC_BODY == mdoc->lastnamed && SEC_NAME != sec)
+               return(mdoc_warn(mdoc, WARN_SYNTAX, 
+                               "section NAME should be first"));
+       if (SEC_CUSTOM == sec)
+               return(1);
+       if (sec == mdoc->lastnamed)
+               return(mdoc_warn(mdoc, WARN_SYNTAX, 
+                               "section repeated"));
+       if (sec < mdoc->lastnamed)
+               return(mdoc_warn(mdoc, WARN_SYNTAX, 
+                               "section out of order"));
+
+       return(1);
 }
 
 
 static int
-roffdata(void *arg, char *buf)
+post_fd(POST_ARGS)
 {
-       struct md_valid *p;
 
-       assert(arg);
-       p = (struct md_valid *)arg;
-       return(mbuf_data(p, buf));
+       if (SEC_SYNOPSIS == mdoc->last->sec)
+               return(1);
+       return(mdoc_warn(mdoc, WARN_COMPAT, 
+                       "suggested only in section SYNOPSIS"));
 }