From 460363bff151cc60fcc83601848c96c928038abb Mon Sep 17 00:00:00 2001
From: Rerumu <25379555+Rerumu@users.noreply.github.com>
Date: Fri, 23 Jun 2023 16:02:06 -0400
Subject: [PATCH] Reduce `Statement` memory footprint

---
 wasm-ast/src/factory.rs | 14 ++++++--------
 wasm-ast/src/node.rs    | 16 ++++++++--------
 2 files changed, 14 insertions(+), 16 deletions(-)

diff --git a/wasm-ast/src/factory.rs b/wasm-ast/src/factory.rs
index 6b3be54..15f6e51 100644
--- a/wasm-ast/src/factory.rs
+++ b/wasm-ast/src/factory.rs
@@ -57,7 +57,7 @@ impl From<BlockData> for LabelType {
 struct StatList {
 	stack: Stack,
 	code: Vec<Statement>,
-	last: Option<Terminator>,
+	last: Option<Box<Terminator>>,
 
 	block_data: BlockData,
 	has_reference: bool,
@@ -199,7 +199,7 @@ impl StatList {
 
 	fn set_terminator(&mut self, term: Terminator) {
 		self.leak_all();
-		self.last = Some(term);
+		self.last = Some(term.into());
 	}
 }
 
@@ -310,15 +310,13 @@ impl<'a> Factory<'a> {
 			BlockData::Forward { .. } | BlockData::Backward { .. } => Statement::Block(now.into()),
 			BlockData::If { .. } => Statement::If(If {
 				condition: self.target.stack.pop().into(),
-				on_true: now.into(),
+				on_true: Box::new(now.into()),
 				on_false: None,
 			}),
 			BlockData::Else { .. } => {
-				if let Statement::If(v) = self.target.code.last_mut().unwrap() {
-					v.on_false = Some(now.into());
-				} else {
-					unreachable!()
-				}
+				let Statement::If(last) = self.target.code.last_mut().unwrap() else { unreachable!() };
+
+				last.on_false = Some(Box::new(now.into()));
 
 				return;
 			}
diff --git a/wasm-ast/src/node.rs b/wasm-ast/src/node.rs
index 7c2bc8e..7e17e79 100644
--- a/wasm-ast/src/node.rs
+++ b/wasm-ast/src/node.rs
@@ -887,7 +887,7 @@ pub enum Terminator {
 pub struct Block {
 	pub(crate) label_type: Option<LabelType>,
 	pub(crate) code: Vec<Statement>,
-	pub(crate) last: Option<Terminator>,
+	pub(crate) last: Option<Box<Terminator>>,
 }
 
 impl Block {
@@ -902,8 +902,8 @@ impl Block {
 	}
 
 	#[must_use]
-	pub const fn last(&self) -> Option<&Terminator> {
-		self.last.as_ref()
+	pub fn last(&self) -> Option<&Terminator> {
+		self.last.as_deref()
 	}
 }
 
@@ -926,8 +926,8 @@ impl BrIf {
 
 pub struct If {
 	pub(crate) condition: Box<Expression>,
-	pub(crate) on_true: Block,
-	pub(crate) on_false: Option<Block>,
+	pub(crate) on_true: Box<Block>,
+	pub(crate) on_false: Option<Box<Block>>,
 }
 
 impl If {
@@ -937,13 +937,13 @@ impl If {
 	}
 
 	#[must_use]
-	pub const fn on_true(&self) -> &Block {
+	pub fn on_true(&self) -> &Block {
 		&self.on_true
 	}
 
 	#[must_use]
-	pub const fn on_false(&self) -> Option<&Block> {
-		self.on_false.as_ref()
+	pub fn on_false(&self) -> Option<&Block> {
+		self.on_false.as_deref()
 	}
 }