+rew_warn(struct man *m, struct man_node *n, enum mandocerr er)
+{
+
+ if (er == MANDOCERR_MAX || MAN_BLOCK != n->type)
+ return(1);
+ if (MAN_VALID & n->flags)
+ return(1);
+ if ( ! (MAN_EXPLICIT & man_macros[n->tok].flags))
+ return(1);
+ return(man_nmsg(m, n, er));
+}
+
+
+/*
+ * Rewind scope. If a code "er" != MANDOCERR_MAX has been provided, it
+ * will be used if an explicit block scope is being closed out.
+ */
+int
+man_unscope(struct man *m, const struct man_node *n,
+ enum mandocerr er)
+{
+
+ assert(n);
+
+ /* LINTED */
+ while (m->last != n) {
+ if ( ! rew_warn(m, m->last, er))
+ return(0);
+ if ( ! man_valid_post(m))
+ return(0);
+ if ( ! man_action_post(m))
+ return(0);
+ m->last = m->last->parent;
+ assert(m->last);
+ }
+
+ if ( ! rew_warn(m, m->last, er))
+ return(0);
+ if ( ! man_valid_post(m))
+ return(0);
+ if ( ! man_action_post(m))
+ return(0);
+
+ m->next = MAN_ROOT == m->last->type ?
+ MAN_NEXT_CHILD : MAN_NEXT_SIBLING;
+
+ return(1);
+}
+
+
+static enum rew
+rew_block(enum mant 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 enum rew
+rew_dohalt(enum mant tok, enum man_type type, const struct man_node *n)
+{
+ enum rew c;
+
+ /* We cannot progress beyond the root ever. */
+ if (MAN_ROOT == n->type)
+ return(REW_HALT);
+
+ assert(n->parent);
+
+ /* Normal nodes shouldn't go to the level of the root. */
+ if (MAN_ROOT == n->parent->type)
+ return(REW_REWIND);
+
+ /* Already-validated nodes should be closed out. */
+ if (MAN_VALID & n->flags)
+ return(REW_NOHALT);
+
+ /* First: rewind to ourselves. */
+ if (type == n->type && tok == n->tok)
+ return(REW_REWIND);
+
+ /*
+ * Next follow the implicit scope-smashings as defined by man.7:
+ * section, sub-section, etc.
+ */
+
+ 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, enum mant tok)
+{
+ struct man_node *n;
+ enum rew 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. Warn if we're a roff
+ * instruction that's mowing over explicit scopes.
+ */
+ assert(n);
+
+ return(man_unscope(m, n, MANDOCERR_MAX));
+}
+
+
+/*
+ * Close out a generic explicit macro.
+ */
+/* ARGSUSED */
+int
+blk_close(MACRO_PROT_ARGS)
+{
+ enum mant 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_pmsg(m, line, ppos, MANDOCERR_NOSCOPE))
+ return(0);
+
+ if ( ! rew_scope(MAN_BODY, m, ntok))
+ return(0);
+ if ( ! rew_scope(MAN_BLOCK, m, ntok))
+ return(0);
+
+ return(1);
+}
+
+
+/* ARGSUSED */
+int
+blk_exp(MACRO_PROT_ARGS)