vcc: Cross reference VMOD symbols

With a default read mask based on the type of symbol. Starting with a
default comprehensive mask should then help implement the $Restrict
stanza from VIP4, simply by AND-ing the masks.

lib/libvcc/vcc_expr.c

@@ -455,14 +455,14 @@ vcc_do_arg(struct vcc *tl, struct func_arg *fa)
 
 static void
 vcc_func(struct vcc *tl, struct expr **e, const void *priv,
-    const char *extra, const struct symbol *sym)
+    const char *extra, struct symbol *sym)
 {
 	vcc_type_t rfmt;
 	const char *cfunc;
 	struct expr *e1;
 	struct func_arg *fa, *fa2;
 	VTAILQ_HEAD(,func_arg) head;
-	struct token *t1;
+	struct token *tf, *t1;
 	const struct vjsn_val *vv, *vvp;
 	const char *sa, *extra_sep;
 	char ssa[64];
@@ -492,6 +492,7 @@ vcc_func(struct vcc *tl, struct expr **e, const void *priv,
 		AN((*e)->instance);
 		extra = (*e)->instance->rname;
 	}
+	tf = VTAILQ_PREV(tl->t, tokenhead, list);
 	SkipToken(tl, '(');
 	if (extra == NULL) {
 		extra = "";
@@ -631,6 +632,7 @@ vcc_func(struct vcc *tl, struct expr **e, const void *priv,
 		*e = vcc_expr_edit(tl, e1->fmt, "\v1\v-\n)", e1, NULL);
 	}
 	SkipToken(tl, ')');
+	vcc_AddUses(tl, tf, NULL, sym, XREF_READ);
 }
 
 

lib/libvcc/vcc_vmod.c

@@ -97,6 +97,7 @@ func_sym(struct vcc *tl, vcc_kind_t kind, const struct symbol *psym,
 	if (kind == SYM_OBJECT) {
 		sym->eval_priv = v;
 		sym->vmod_name = psym->vmod_name;
+		sym->r_methods = VCL_MET_INIT;
 		vcc_VmodObject(tl, sym);
 		vcc_VmodSymbols(tl, sym);
 		return;
@@ -118,6 +119,7 @@ func_sym(struct vcc *tl, vcc_kind_t kind, const struct symbol *psym,
 	assert(v->type == VJSN_STRING);
 	sym->type = VCC_Type(v->value);
 	AN(sym->type);
+	sym->r_methods = VCL_MET_TASK_C|VCL_MET_TASK_B|VCL_MET_TASK_H;
 }
 
 static void