+#define REW_REWIND (0) /* See rew_scope(). */
+#define REW_NOHALT (1) /* See rew_scope(). */
+#define REW_HALT (2) /* See rew_scope(). */
+
+static int in_line_eoln(MACRO_PROT_ARGS);
+static int blk_imp(MACRO_PROT_ARGS);
+static int blk_close(MACRO_PROT_ARGS);
+
+static int rew_scope(enum man_type, struct man *, int);
+static int rew_dohalt(int, enum man_type,
+ const struct man_node *);
+static int rew_block(int, enum man_type,
+ const struct man_node *);
+
+const struct man_macro __man_macros[MAN_MAX] = {
+ { in_line_eoln, 0 }, /* br */
+ { in_line_eoln, 0 }, /* TH */
+ { blk_imp, MAN_SCOPED }, /* SH */
+ { blk_imp, MAN_SCOPED }, /* SS */
+ { blk_imp, MAN_SCOPED | MAN_FSCOPED }, /* TP */
+ { blk_imp, 0 }, /* LP */
+ { blk_imp, 0 }, /* PP */
+ { blk_imp, 0 }, /* P */
+ { blk_imp, 0 }, /* IP */
+ { blk_imp, 0 }, /* HP */
+ { in_line_eoln, MAN_SCOPED }, /* SM */
+ { in_line_eoln, MAN_SCOPED }, /* SB */
+ { in_line_eoln, 0 }, /* BI */
+ { in_line_eoln, 0 }, /* IB */
+ { in_line_eoln, 0 }, /* BR */
+ { in_line_eoln, 0 }, /* RB */
+ { in_line_eoln, MAN_SCOPED }, /* R */
+ { in_line_eoln, MAN_SCOPED }, /* B */
+ { in_line_eoln, MAN_SCOPED }, /* I */
+ { in_line_eoln, 0 }, /* IR */
+ { in_line_eoln, 0 }, /* RI */
+ { in_line_eoln, 0 }, /* na */
+ { in_line_eoln, 0 }, /* i */
+ { in_line_eoln, 0 }, /* sp */
+ { in_line_eoln, 0 }, /* nf */
+ { in_line_eoln, 0 }, /* fi */
+ { in_line_eoln, 0 }, /* r */
+ { blk_close, 0 }, /* RE */
+ { blk_imp, MAN_EXPLICIT }, /* RS */
+ { in_line_eoln, 0 }, /* DT */
+ { in_line_eoln, 0 }, /* UC */
+ { in_line_eoln, 0 }, /* PD */
+};
+
+const struct man_macro * const man_macros = __man_macros;
+
+
+int
+man_unscope(struct man *m, const struct man_node *n)
+{
+
+ assert(n);
+ m->next = MAN_NEXT_SIBLING;
+
+ /* LINTED */
+ while (m->last != n) {
+ if ( ! man_valid_post(m))
+ return(0);
+ if ( ! man_action_post(m))
+ return(0);
+ m->last = m->last->parent;
+ assert(m->last);
+ }
+
+ if ( ! man_valid_post(m))
+ return(0);
+ return(man_action_post(m));
+}
+
+
+static int
+rew_block(int ntok, enum man_type type, const struct man_node *n)
+{
+
+ if (MAN_BLOCK == type && ntok == n->parent->tok &&
+ MAN_BODY == n->parent->type)
+ return(REW_REWIND);
+ return(ntok == n->tok ? REW_HALT : REW_NOHALT);
+}
+
+
+/*
+ * There are three scope levels: scoped to the root (all), scoped to the
+ * section (all less sections), and scoped to subsections (all less
+ * sections and subsections).
+ */
+static int
+rew_dohalt(int tok, enum man_type type, const struct man_node *n)
+{
+ int c;
+
+ if (MAN_ROOT == n->type)
+ return(REW_HALT);
+ assert(n->parent);
+ if (MAN_ROOT == n->parent->type)
+ return(REW_REWIND);
+ if (MAN_VALID & n->flags)
+ return(REW_NOHALT);
+
+ /* Rewind to ourselves, first. */
+ if (type == n->type && tok == n->tok)
+ return(REW_REWIND);
+
+ switch (tok) {
+ case (MAN_SH):
+ break;
+ case (MAN_SS):
+ /* Rewind to a section, if a block. */
+ if (REW_NOHALT != (c = rew_block(MAN_SH, type, n)))
+ return(c);
+ break;
+ case (MAN_RS):
+ /* Rewind to a subsection, if a block. */
+ if (REW_NOHALT != (c = rew_block(MAN_SS, type, n)))
+ return(c);
+ /* Rewind to a section, if a block. */
+ if (REW_NOHALT != (c = rew_block(MAN_SH, type, n)))
+ return(c);
+ break;
+ default:
+ /* Rewind to an offsetter, if a block. */
+ if (REW_NOHALT != (c = rew_block(MAN_RS, type, n)))
+ return(c);
+ /* Rewind to a subsection, if a block. */
+ if (REW_NOHALT != (c = rew_block(MAN_SS, type, n)))
+ return(c);
+ /* Rewind to a section, if a block. */
+ if (REW_NOHALT != (c = rew_block(MAN_SH, type, n)))
+ return(c);
+ break;
+ }
+
+ return(REW_NOHALT);
+}
+
+
+/*
+ * Rewinding entails ascending the parse tree until a coherent point,
+ * for example, the `SH' macro will close out any intervening `SS'
+ * scopes. When a scope is closed, it must be validated and actioned.
+ */
+static int
+rew_scope(enum man_type type, struct man *m, int tok)
+{
+ struct man_node *n;
+ int c;
+
+ /* LINTED */
+ for (n = m->last; n; n = n->parent) {
+ /*
+ * Whether we should stop immediately (REW_HALT), stop
+ * and rewind until this point (REW_REWIND), or keep
+ * rewinding (REW_NOHALT).
+ */
+ c = rew_dohalt(tok, type, n);
+ if (REW_HALT == c)
+ return(1);
+ if (REW_REWIND == c)
+ break;
+ }
+
+ /* Rewind until the current point. */
+
+ assert(n);
+ return(man_unscope(m, n));
+}
+
+
+/* ARGSUSED */
+int
+blk_close(MACRO_PROT_ARGS)
+{
+ int ntok;
+ const struct man_node *nn;
+
+ switch (tok) {
+ case (MAN_RE):
+ ntok = MAN_RS;
+ break;
+ default:
+ abort();
+ /* NOTREACHED */
+ }
+
+ for (nn = m->last->parent; nn; nn = nn->parent)
+ if (ntok == nn->tok)
+ break;
+
+ if (NULL == nn)
+ if ( ! man_pwarn(m, line, ppos, WNOSCOPE))
+ return(0);
+
+ if ( ! rew_scope(MAN_BODY, m, ntok))
+ return(0);
+ if ( ! rew_scope(MAN_BLOCK, m, ntok))
+ return(0);
+ m->next = MAN_NEXT_SIBLING;
+ return(1);
+}