]> git.cameronkatri.com Git - mandoc.git/blobdiff - validate.c
Added Fd section validation.
[mandoc.git] / validate.c
index 3d1c36871b83805a9a09337518b01a04913b7d4f..d5495d4fd66e7eb8577ed4e4606dfd55c2ae784c 100644 (file)
@@ -1,4 +1,4 @@
-/* $Id: validate.c,v 1.13 2009/01/02 14:06:16 kristaps Exp $ */
+/* $Id: validate.c,v 1.57 2009/02/24 13:57:17 kristaps Exp $ */
 /*
  * Copyright (c) 2008 Kristaps Dzonsons <kristaps@kth.se>
  *
  * PERFORMANCE OF THIS SOFTWARE.
  */
 #include <assert.h>
+#include <ctype.h>
 #include <stdlib.h>
 
 #include "private.h"
 
-/* FIXME: `.St' can only have one argument set. */
-
-typedef int    (*v_args_sz)(struct mdoc *, int, int, int);
-typedef int    (*v_args)(struct mdoc *, int, int, int, 
-                       const char *[], int, const struct mdoc_arg *);
-typedef int    (*v_post)(struct mdoc *, int, int);
-
-static int       need_head_child(struct mdoc *, int, int);
-static int       no_head_child(struct mdoc *, int, int);
-
-static int       assert_eq0(struct mdoc *, int, int, int);
-static int       assert_le1(struct mdoc *, int, int, int);
-static int       need_eq0(struct mdoc *, int, int, int);
-static int       need_eq1(struct mdoc *, int, int, int);
-static int       need_ge1(struct mdoc *, int, int, int);
-static int       need_le2(struct mdoc *, int, int, int);
-static int       want_eq0(struct mdoc *, int, int, int);
-static int       want_ge1(struct mdoc *, int, int, int);
-
-static int       args_ref(struct mdoc *, int, int, int, 
-                       const char *[], int, const struct mdoc_arg *);
-static int       args_bool(struct mdoc *, int, int, int, 
-                       const char *[], int, const struct mdoc_arg *);
-static int       args_Sh(struct mdoc *, int, int, int, 
-                       const char *[], int, const struct mdoc_arg *);
-static int       args_blocknest(struct mdoc *, int, int, int, 
-                       const char *[], int, const struct mdoc_arg *);
-static int       args_At(struct mdoc *, int, int, int, 
-                       const char *[], int, const struct mdoc_arg *);
-static int       args_Xr(struct mdoc *, int, int, int, 
-                       const char *[], int, const struct mdoc_arg *);
+/*
+ * 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.
+ */
+
+#define        PRE_ARGS        struct mdoc *mdoc, const struct mdoc_node *n
+#define        POST_ARGS       struct mdoc *mdoc
+
+typedef        int     (*v_pre)(PRE_ARGS);
+typedef        int     (*v_post)(POST_ARGS);
+
+/* FIXME: some sections should only occur in specific msecs. */
+/* FIXME: ignoring Pp. */
+/* FIXME: math symbols. */
 
 struct valids {
-       v_args_sz sz;
-       v_args    args;
-       v_post    post;
+       v_pre   *pre;
+       v_post  *post;
 };
 
-
-/* 
- * FIXME: have arrays of function pointers in case we want multiple
- * check callbacks per macro.
- */
+/* 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     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     herr_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     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[] = { herr_le1, post_bf, NULL };
+static v_post  posts_rs[] = { herr_eq0, bwarn_ge1, NULL };
+static v_post  posts_fo[] = { 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, NULL }, /* \" */
-       { NULL, NULL, NULL }, /* Dd */ /* TODO */
-       { NULL, NULL, NULL }, /* Dt */ /* TODO */
-       { NULL, NULL, NULL }, /* Os */ /* TODO */
-       { NULL, args_Sh, NULL }, /* Sh */
-       { NULL, NULL, NULL }, /* Ss */ 
-       { want_eq0, NULL, NULL }, /* Pp */ 
-       { NULL, args_blocknest, need_head_child }, /* D1 */
-       { NULL, args_blocknest, need_head_child }, /* Dl */
-       { NULL, args_blocknest, NULL }, /* Bd */
-       { NULL, NULL, no_head_child }, /* Ed */
-       { NULL, NULL, NULL }, /* Bl */
-       { NULL, NULL, no_head_child }, /* El */
-       { NULL, NULL, NULL }, /* It */
-       { need_ge1, NULL, NULL }, /* Ad */ 
-       { NULL, NULL, NULL }, /* An */  /* FIXME: no args & argv. */
-       { NULL, NULL, NULL }, /* Ar */
-       { need_ge1, NULL, NULL }, /* Cd */
-       { NULL, NULL, NULL }, /* Cm */
-       { need_ge1, NULL, NULL }, /* Dv */ 
-       { need_ge1, NULL, NULL }, /* Er */ 
-       { need_ge1, NULL, NULL }, /* Ev */ 
-       { NULL, NULL, NULL }, /* Ex */
-       { need_ge1, NULL, NULL }, /* Fa */ 
-       { NULL, NULL, NULL }, /* Fd */ 
-       { NULL, NULL, NULL }, /* Fl */
-       { need_ge1, NULL, NULL }, /* Fn */ 
-       { want_ge1, NULL, NULL }, /* Ft */ 
-       { need_ge1, NULL, NULL }, /* Ic */ 
-       { need_eq1, NULL, NULL }, /* In */ 
-       { want_ge1, NULL, NULL }, /* Li */
-       { want_ge1, NULL, NULL }, /* Nd */ 
-       { NULL, NULL, NULL }, /* Nm */ 
-       { NULL, NULL, NULL }, /* Op */
-       { NULL, NULL, NULL }, /* Ot */
-       { want_ge1, NULL, NULL }, /* Pa */
-       { NULL, NULL, NULL }, /* Rv */
-       { NULL, NULL, NULL }, /* St */
-       { need_ge1, NULL, NULL }, /* Va */
-       { need_ge1, NULL, NULL }, /* Vt */ 
-       { need_le2, args_Xr, NULL }, /* Xr */
-       { need_ge1, args_ref, NULL }, /* %A */
-       { need_ge1, args_ref, NULL }, /* %B */
-       { need_ge1, args_ref, NULL }, /* %D */
-       { need_ge1, args_ref, NULL }, /* %I */
-       { need_ge1, args_ref, NULL }, /* %J */
-       { need_ge1, args_ref, NULL }, /* %N */
-       { need_ge1, args_ref, NULL }, /* %O */
-       { need_ge1, args_ref, NULL }, /* %P */
-       { need_ge1, args_ref, NULL }, /* %R */
-       { need_ge1, args_ref, NULL }, /* %T */
-       { need_ge1, args_ref, NULL }, /* %V */
-       { NULL, NULL, NULL }, /* Ac */
-       { NULL, NULL, NULL }, /* Ao */
-       { NULL, NULL, NULL }, /* Aq */
-       { need_le2, args_At, NULL }, /* At */
-       { NULL, NULL, NULL }, /* Bc */
-       { NULL, NULL, NULL }, /* Bf */ 
-       { NULL, NULL, NULL }, /* Bo */
-       { NULL, NULL, NULL }, /* Bq */
-       { assert_le1, NULL, NULL }, /* Bsx */
-       { assert_le1, NULL, NULL }, /* Bx */
-       { need_eq1, args_bool, NULL }, /* Db */
-       { NULL, NULL, NULL }, /* Dc */
-       { NULL, NULL, NULL }, /* Do */
-       { NULL, NULL, NULL }, /* Dq */
-       { NULL, NULL, NULL }, /* Ec */
-       { NULL, NULL, NULL }, /* Ef */ /* -symbolic, etc. */
-       { need_ge1, NULL, NULL }, /* Em */ 
-       { NULL, NULL, NULL }, /* Eo */
-       { assert_le1, NULL, NULL }, /* Fx */
-       { want_ge1, NULL, NULL }, /* Ms */
-       { NULL, NULL, NULL }, /* No */
-       { NULL, NULL, NULL }, /* Ns */
-       { assert_le1, NULL, NULL }, /* Nx */
-       { assert_le1, NULL, NULL }, /* Ox */
-       { NULL, NULL, NULL }, /* Pc */
-       { NULL, NULL, NULL }, /* Pf */ /* 2 or more arguments */
-       { NULL, NULL, NULL }, /* Po */
-       { NULL, NULL, NULL }, /* Pq */
-       { NULL, NULL, NULL }, /* Qc */
-       { NULL, NULL, NULL }, /* Ql */
-       { NULL, NULL, NULL }, /* Qo */
-       { NULL, NULL, NULL }, /* Qq */
-       { NULL, NULL, NULL }, /* Re */
-       { NULL, NULL, NULL }, /* Rs */
-       { NULL, NULL, NULL }, /* Sc */
-       { NULL, NULL, NULL }, /* So */
-       { NULL, NULL, NULL }, /* Sq */
-       { need_eq1, args_bool, NULL }, /* Sm */
-       { need_ge1, NULL, NULL }, /* Sx */
-       { need_ge1, NULL, NULL }, /* Sy */
-       { want_ge1, NULL, NULL }, /* Tn */
-       { assert_eq0, NULL, NULL }, /* Ux */
-       { NULL, NULL, NULL }, /* Xc */
-       { NULL, NULL, NULL }, /* Xo */
-       { NULL, NULL, NULL }, /* Fo */ 
-       { NULL, NULL, NULL }, /* Fc */ 
-       { NULL, NULL, NULL }, /* Oo */
-       { NULL, NULL, NULL }, /* Oc */
-       { NULL, NULL, NULL }, /* Bk */
-       { NULL, NULL, NULL }, /* Ek */
-       { need_eq0, NULL, NULL }, /* Bt */
-       { need_eq1, NULL, NULL }, /* Hf */
-       { NULL, NULL, NULL }, /* Fr */
-       { need_eq0, NULL, NULL }, /* Ud */
+       { 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
-need_le2(struct mdoc *mdoc, int tok, int pos, int sz)
+int
+mdoc_valid_pre(struct mdoc *mdoc, 
+               const struct mdoc_node *node)
 {
-       if (sz <= 2)
+       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);
-       return(mdoc_err(mdoc, tok, pos, ERR_ARGS_LE2));
+       for (p = mdoc_valids[node->tok].pre; *p; p++)
+               if ( ! (*p)(mdoc, node)) 
+                       return(0);
+       return(1);
 }
 
 
-static int
-want_ge1(struct mdoc *mdoc, int tok, int pos, int sz)
+int
+mdoc_valid_post(struct mdoc *mdoc)
 {
-       if (sz > 0)
+       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);
-       return(mdoc_warn(mdoc, tok, pos, WARN_ARGS_GE1));
+       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);
+
+       return(1);
+}
+
+
+
+static inline int
+warn_count(struct mdoc *m, const char *k, 
+               int want, const char *v, int has)
+{
+
+       return(mdoc_warn(m, WARN_SYNTAX, 
+                               "suggests %s %d %s (has %d)", 
+                               v, want, k, has));
+}
+
+
+static inline int
+err_count(struct mdoc *m, const char *k,
+               int want, const char *v, int has)
+{
+
+       return(mdoc_err(m, "requires %s %d %s (has %d)",
+                               v, want, k, has));
+}
+
+
+static inline int
+count_child(struct mdoc *mdoc)
+{
+       int               i;
+       struct mdoc_node *n;
+
+       for (i = 0, n = mdoc->last->child; n; n = n->next, i++)
+               /* Do nothing */ ;
+
+       return(i);
 }
 
 
+/*
+ * 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.
+ */
+
+#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));             \
+}
+
+#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)));      \
+}
+
+#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)));           \
+}
+
+#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, "multiline parameters", (num)));      \
+}
+
+
+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_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, err, err_child_lt, 2)     /* herr_le1() */
+CHECK_HEAD_DEFN(ge1, err, err_child_gt, 0)     /* herr_ge1() */
+
+
 static int
-want_eq0(struct mdoc *mdoc, int tok, int pos, int sz)
+check_stdarg(PRE_ARGS)
 {
-       if (sz == 0)
+
+       if (MDOC_Std == n->data.elem.argv[0].arg && 
+                       1 == n->data.elem.argc)
                return(1);
-       return(mdoc_warn(mdoc, tok, pos, WARN_ARGS_EQ0));
+
+       return(mdoc_nwarn(mdoc, n, WARN_COMPAT, 
+                               "one argument suggested"));
 }
 
 
 static int
-need_eq0(struct mdoc *mdoc, int tok, int pos, int sz)
+check_msec(PRE_ARGS, int sz, enum mdoc_msec *msecs)
 {
-       if (sz == 0)
-               return(1);
-       return(mdoc_err(mdoc, tok, pos, ERR_ARGS_EQ0));
+       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"));
 }
 
 
 static int
-assert_le1(struct mdoc *mdoc, int tok, int pos, int sz)
+check_text(struct mdoc *mdoc, size_t line, size_t pos, const char *p)
 {
+       size_t           c;
+
+       for ( ; *p; p++) {
+               if ( ! isprint(*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"));
+       }
 
-       assert(sz <= 1);
        return(1);
 }
 
 
+
+
 static int
-assert_eq0(struct mdoc *mdoc, int tok, int pos, int sz)
+check_parent(PRE_ARGS, int tok, enum mdoc_type t)
 {
 
-       assert(sz == 0);
-       return(1);
+       assert(n->parent);
+       if ((MDOC_ROOT == t || tok == n->parent->tok) &&
+                       (t == n->parent->type))
+               return(1);
+
+       return(mdoc_nerr(mdoc, n, "require parent %s",
+               MDOC_ROOT == t ? "<root>" : mdoc_macronames[tok]));
 }
 
 
+
 static int
-need_eq1(struct mdoc *mdoc, int tok, int pos, int sz)
+pre_display(PRE_ARGS)
 {
-       if (sz == 1)
+       struct mdoc_node *node;
+
+       /* Display elements (`Bd', `D1'...) cannot be nested. */
+
+       if (MDOC_BLOCK != n->type)
+               return(1);
+
+       /* 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);
-       return(mdoc_err(mdoc, tok, pos, ERR_ARGS_EQ1));
+
+       return(mdoc_nerr(mdoc, n, "displays may not be nested"));
 }
 
 
 static int
-need_ge1(struct mdoc *mdoc, int tok, int pos, int sz)
+pre_bl(PRE_ARGS)
 {
-       if (sz > 0)
+       int              type, err, i;
+       struct mdoc_arg *argv;
+       size_t           argc;
+
+       if (MDOC_BLOCK != n->type)
                return(1);
-       return(mdoc_err(mdoc, tok, pos, ERR_ARGS_GE1));
+
+       argc = n->data.block.argc; 
+
+       /* Make sure that only one type of list is specified.  */
+
+       /* LINTED */
+       for (i = 0, type = err = 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;
+               }
+       }
+
+       if (type)
+               return(1);
+       return(mdoc_err(mdoc, "no type specified"));
 }
 
 
 static int
-no_head_child(struct mdoc *mdoc, int tok, int pos)
+pre_bd(PRE_ARGS)
 {
+       int              type, err, i;
+       struct mdoc_arg *argv;
+       size_t           argc;
 
-       /* TODO */
-       return(1);
+       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;
+               }
+       }
+
+       if (type)
+               return(1);
+       return(mdoc_err(mdoc, "no type specified"));
 }
 
 
 static int
-need_head_child(struct mdoc *mdoc, int tok, int pos)
+pre_ss(PRE_ARGS)
 {
-       struct mdoc_node *n;
 
-       assert(mdoc->last);
-       n = mdoc->last;
+       if (MDOC_BLOCK != n->type)
+               return(1);
+       return(check_parent(mdoc, n, MDOC_Sh, MDOC_BODY));
+}
 
-       assert(MDOC_BLOCK == n->type);
-       assert(n->child);
 
-       n = n->child;
+static int
+pre_sh(PRE_ARGS)
+{
 
-       if (MDOC_HEAD != n->type) 
-               return(mdoc_err(mdoc, tok, pos, ERR_CHILD_HEAD));
-       if (n->child)
+       if (MDOC_BLOCK != n->type)
                return(1);
-       return(mdoc_err(mdoc, tok, pos, ERR_CHILD_HEAD));
+       return(check_parent(mdoc, n, -1, MDOC_ROOT));
 }
 
 
 static int
-args_Sh(struct mdoc *mdoc, int tok, int pos, 
-               int sz, const char *args[], 
-               int argc, const struct mdoc_arg *argv)
+pre_it(PRE_ARGS)
 {
-       enum mdoc_sec    sec;
 
-       sec = mdoc_atosec((size_t)sz, args);
-       if (SEC_CUSTOM != sec && sec < mdoc->sec_lastn)
-               if ( ! mdoc_warn(mdoc, tok, pos, WARN_SEC_OO))
-                       return(0);
-       if (SEC_BODY == mdoc->sec_last && SEC_NAME != sec)
-               return(mdoc_err(mdoc, tok, pos, ERR_SEC_NAME));
+       /* TODO: -width attribute must be specified for -tag. */
+       /* TODO: children too big for -width? */
 
-       return(1);
+       if (MDOC_BLOCK != n->type)
+               return(1);
+       return(check_parent(mdoc, n, MDOC_Bl, MDOC_BODY));
 }
 
 
 static int
-args_bool(struct mdoc *mdoc, int tok, int pos, 
-               int sz, const char *args[], 
-               int argc, const struct mdoc_arg *argv)
+pre_st(PRE_ARGS)
 {
 
-       assert(1 == sz);
-       if (xstrcmp(args[0], "on"))
-               return(1);      
-       if (xstrcmp(args[0], "off"))
+       if (1 == n->data.elem.argc)
                return(1);
-       return(mdoc_err(mdoc, tok, pos, ERR_SYNTAX_ARGBAD));
+       return(mdoc_nerr(mdoc, n, "one argument required"));
 }
 
 
 static int
-args_ref(struct mdoc *mdoc, int tok, int pos, 
-               int sz, const char *args[], 
-               int argc, const struct mdoc_arg *argv)
+pre_an(PRE_ARGS)
 {
-       struct mdoc_node *n;
 
-       assert(mdoc->last);
-       for (n = mdoc->last ; n; n = n->parent) {
-               if (MDOC_BLOCK != n->type)
-                       continue;
-               if (MDOC_Rs != n->data.block.tok)
+       if (1 >= n->data.elem.argc)
+               return(1);
+       return(mdoc_nerr(mdoc, n, "one argument allowed"));
+}
+
+
+static int
+pre_rv(PRE_ARGS)
+{
+       enum mdoc_msec msecs[] = { MSEC_2, MSEC_3 };
+
+       if ( ! check_msec(mdoc, n, 2, msecs))
+               return(0);
+       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));
+}
+
+
+static int
+pre_er(PRE_ARGS)
+{
+       enum mdoc_msec msecs[] = { MSEC_2 };
+
+       return(check_msec(mdoc, n, 1, msecs));
+}
+
+
+static int
+pre_cd(PRE_ARGS)
+{
+       enum mdoc_msec msecs[] = { MSEC_4 };
+
+       return(check_msec(mdoc, n, 1, msecs));
+}
+
+
+static int
+pre_prologue(PRE_ARGS)
+{
+
+       if (SEC_PROLOGUE != mdoc->lastnamed)
+               return(mdoc_nerr(mdoc, n, "prologue only"));
+
+       /* 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
+post_bf(POST_ARGS)
+{
+       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"));
        }
 
-       return(mdoc_err(mdoc, tok, pos, ERR_SCOPE_NOCTX));
+       if (head->child)
+               return(mdoc_err(mdoc, "argument expected"));
+
+       if (1 == mdoc->last->data.block.argc)
+               return(1);
+       return(mdoc_err(mdoc, "argument expected"));
+}
+
+
+static int
+post_nm(POST_ARGS)
+{
+
+       if (mdoc->last->child)
+               return(1);
+       if (mdoc->meta.name)
+               return(1);
+       return(mdoc_err(mdoc, "not yet invoked with name"));
+}
+
+
+static int
+post_xr(POST_ARGS)
+{
+       struct mdoc_node *n;
+
+       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"));
 }
 
 
 static int
-args_Xr(struct mdoc *mdoc, int tok, int pos, 
-               int sz, const char *args[], 
-               int argc, const struct mdoc_arg *argv)
+post_at(POST_ARGS)
 {
 
-       if (1 == sz)
+       if (NULL == mdoc->last->child)
+               return(1);
+       if (ATT_DEFAULT != mdoc_atoatt(mdoc->last->child->data.text.string))
                return(1);
-       if (0 == sz)
-               return(mdoc_err(mdoc, tok, pos, ERR_ARGS_GE1));
+       return(mdoc_err(mdoc, "require valid symbol"));
+}
+
+
+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"));
 
-       if (MSEC_DEFAULT == mdoc_atomsec(args[1]))
-               return(mdoc_err(mdoc, tok, pos, ERR_SYNTAX_ARGFORM));
        return(1);
 }
 
 
 static int
-args_At(struct mdoc *mdoc, int tok, int pos, 
-               int sz, const char *args[], 
-               int argc, const struct mdoc_arg *argv)
+post_it(POST_ARGS)
 {
-       int              i;
+       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 (0 == sz)
+       if (MDOC_BLOCK != mdoc->last->type)
                return(1);
 
-       i = 0;
-       if (ATT_DEFAULT == mdoc_atoatt(args[i]))
+       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);
+
+       argc = mdoc->last->parent->parent->data.block.argv->sz;
+       n = mdoc->last->data.block.head->child;
+
+       for (i = 0; n; n = n->next)
                i++;
 
-       for ( ; i < sz; i++) {
-               if ( ! mdoc_isdelim(args[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)
+{
+       struct mdoc_node        *n;
+
+       if (MDOC_BODY != mdoc->last->type)
+               return(1);
+
+       /* LINTED */
+       for (n = mdoc->last->child; n; n = n->next) {
+               if (MDOC_BLOCK == n->type) 
+                       if (MDOC_It == n->tok)
+                               continue;
+               break;
+       }
+
+       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;
-               return(mdoc_err(mdoc, tok, pos, ERR_SYNTAX_NOPUNCT));
+               if (xstrcmp(n->data.text.string, "off"))
+                       continue;
+               break;
        }
+
+       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
-args_blocknest(struct mdoc *mdoc, int tok, int pos, 
-               int sz, const char *args[], 
-               int argc, const struct mdoc_arg *argv)
+post_sh(POST_ARGS)
 {
-       struct mdoc_node *node;
+
+       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);
 
        /*
-        * We can't be nested within any other block displays (or really
-        * any other kind of display, although Bd is the only multi-line
-        * one that will show up). 
+        * 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".
         */
-       assert(mdoc->last);
 
-       /* LINTED */
-       for (node = mdoc->last; node; node = node->parent) {
-               if (node->type != MDOC_BLOCK)
+       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 (node->data.block.tok != MDOC_Bd)
+               if (MDOC_TEXT == n->type)
                        continue;
-               break;
+               if ( ! (mdoc_nwarn(mdoc, n, WARN_SYNTAX, 
+                                       "section should have %s first",
+                                       mdoc_macronames[MDOC_Nm])))
+                       return(0);
        }
-       if (NULL == node)
+
+       if (MDOC_ELEM == n->type && MDOC_Nd == n->tok)
                return(1);
-       return(mdoc_err(mdoc, tok, pos, ERR_SCOPE_NONEST));
+
+       return(mdoc_warn(mdoc, WARN_SYNTAX, 
+                               "section should have %s last",
+                               mdoc_macronames[MDOC_Nd]));
 }
 
 
-int
-mdoc_valid_pre(struct mdoc *mdoc, int tok, int pos, 
-               int sz, const char *args[], 
-               int argc, const struct mdoc_arg *argv)
+static int
+post_sh_head(POST_ARGS)
 {
+       char              buf[64];
+       enum mdoc_sec     sec;
 
-       assert(tok < MDOC_MAX);
-       if (mdoc_valids[tok].sz) 
-               if ( ! (*mdoc_valids[tok].sz)(mdoc, tok, pos, sz))
-                       return(0);
+       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 (NULL == mdoc_valids[tok].args) 
+       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);
-       return((*mdoc_valids[tok].args)(mdoc, 
-                       tok, pos, sz, args, argc, argv));
+       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);
 }
 
 
-int
-mdoc_valid_post(struct mdoc *mdoc, int tok, int pos)
+static int
+post_fd(POST_ARGS)
 {
 
-       if (NULL == mdoc_valids[tok].post)
+       if (SEC_SYNOPSIS == mdoc->last->sec)
                return(1);
-       return((*mdoc_valids[tok].post)(mdoc, tok, pos));
+       return(mdoc_warn(mdoc, WARN_COMPAT, 
+                       "suggested only in section SYNOPSIS"));
 }