From 176b70b1cd465329d8762f07cf1d917421b13d39 Mon Sep 17 00:00:00 2001
From: Adrian Wielgosik <adrian.wielgosik@gmail.com>
Date: Mon, 9 Sep 2024 20:49:53 +0200
Subject: [PATCH] avm2: Cache method body index on Method

---
 core/src/avm2/method.rs | 19 ++++---------------
 swf/src/avm2/read.rs    | 11 +++++++++--
 swf/src/avm2/types.rs   |  2 ++
 swf/src/test_data.rs    |  2 ++
 4 files changed, 17 insertions(+), 17 deletions(-)

diff --git a/core/src/avm2/method.rs b/core/src/avm2/method.rs
index 0eaa3e7bb588..aa3e7ef0da94 100644
--- a/core/src/avm2/method.rs
+++ b/core/src/avm2/method.rs
@@ -166,6 +166,7 @@ impl<'gc> BytecodeMethod<'gc> {
         let abc = txunit.abc();
         let mut signature = Vec::new();
         let mut return_type = Multiname::any();
+        let mut abc_method_body = None;
 
         if abc.methods.get(abc_method.0 as usize).is_some() {
             let method = &abc.methods[abc_method.0 as usize];
@@ -178,20 +179,8 @@ impl<'gc> BytecodeMethod<'gc> {
                 .deref()
                 .clone();
 
-            for (index, method_body) in abc.method_bodies.iter().enumerate() {
-                if method_body.method.0 == abc_method.0 {
-                    return Ok(Self {
-                        txunit,
-                        abc: txunit.abc(),
-                        abc_method: abc_method.0,
-                        abc_method_body: Some(index as u32),
-                        verified_info: GcCell::new(activation.context.gc_context, None),
-                        signature,
-                        return_type,
-                        is_function,
-                        activation_class: Lock::new(None),
-                    });
-                }
+            if let Some(body) = method.body {
+                abc_method_body = Some(body.0);
             }
         }
 
@@ -199,7 +188,7 @@ impl<'gc> BytecodeMethod<'gc> {
             txunit,
             abc: txunit.abc(),
             abc_method: abc_method.0,
-            abc_method_body: None,
+            abc_method_body,
             verified_info: GcCell::new(activation.context.gc_context, None),
             signature,
             return_type,
diff --git a/swf/src/avm2/read.rs b/swf/src/avm2/read.rs
index febc2c03f712..a4a258629c07 100644
--- a/swf/src/avm2/read.rs
+++ b/swf/src/avm2/read.rs
@@ -67,8 +67,14 @@ impl<'a> Reader<'a> {
 
         let len = self.read_u30()?;
         let mut method_bodies = Vec::with_capacity(len as usize);
-        for _ in 0..len {
-            method_bodies.push(self.read_method_body()?);
+        for body_idx in 0..len {
+            let body = self.read_method_body()?;
+            if methods[body.method.0 as usize].body.is_some() {
+                // TODO: this should somehow throw error 1121 in FP.
+                return Err(Error::invalid_data("Duplicate method body"));
+            }
+            methods[body.method.0 as usize].body = Some(Index::new(body_idx));
+            method_bodies.push(body);
         }
 
         Ok(AbcFile {
@@ -279,6 +285,7 @@ impl<'a> Reader<'a> {
             params,
             return_type,
             flags,
+            body: None,
         })
     }
 
diff --git a/swf/src/avm2/types.rs b/swf/src/avm2/types.rs
index 4cf622ab5027..4fca9fdf266b 100644
--- a/swf/src/avm2/types.rs
+++ b/swf/src/avm2/types.rs
@@ -98,6 +98,8 @@ pub struct Method {
     pub params: Vec<MethodParam>,
     pub return_type: Index<Multiname>,
     pub flags: MethodFlags,
+    // not an ABC MethodInfo property; bound when parsing MethodBodies
+    pub body: Option<Index<MethodBody>>,
 }
 
 bitflags! {
diff --git a/swf/src/test_data.rs b/swf/src/test_data.rs
index 65342e92a558..8fc6d4859a72 100644
--- a/swf/src/test_data.rs
+++ b/swf/src/test_data.rs
@@ -2688,12 +2688,14 @@ pub fn avm2_tests() -> Vec<Avm2TestData> {
                     params: vec![],
                     return_type: Index::new(1),
                     flags: MethodFlags::empty(),
+                    body: Some(Index::new(0)),
                 },
                 Method {
                     name: Index::new(0),
                     params: vec![],
                     return_type: Index::new(0),
                     flags: MethodFlags::empty(),
+                    body: Some(Index::new(1)),
                 },
             ],
             metadata: vec![],