From 3ca0ca7f7aad5cd273646371ffab14a29002aa25 Mon Sep 17 00:00:00 2001
From: Chris Fallin <chris@cfallin.org>
Date: Thu, 3 Nov 2022 00:21:07 -0700
Subject: [PATCH] WIP.

---
 src/passes/dom_pass.rs | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100644 src/passes/dom_pass.rs

diff --git a/src/passes/dom_pass.rs b/src/passes/dom_pass.rs
new file mode 100644
index 0000000..75fb03a
--- /dev/null
+++ b/src/passes/dom_pass.rs
@@ -0,0 +1,21 @@
+//! Domtree-based pass.
+
+use crate::cfg::CFGInfo;
+use crate::ir::{Block, FunctionBody};
+
+pub trait DomtreePass {
+    fn enter(&mut self, _block: Block, _body: &mut FunctionBody) {}
+    fn leave(&mut self, _block: Block, _body: &mut FunctionBody) {}
+}
+
+pub fn dom_pass<P: DomtreePass>(body: &mut FunctionBody, cfg: &CFGInfo, pass: &mut P) {
+    visit::<P>(body, cfg, pass, body.entry);
+}
+
+fn visit<P: DomtreePass>(body: &mut FunctionBody, cfg: &CFGInfo, pass: &mut P, block: Block) {
+    pass.enter(block, body);
+    for child in cfg.dom_children(block) {
+        visit(body, cfg, pass, child);
+    }
+    pass.leave(block, body);
+}