From 39c095d12c6d6f17d3575126452a4f85c89a38e9 Mon Sep 17 00:00:00 2001
From: Windel Bouwman <windel@windel.nl>
Date: Sun, 18 Aug 2019 12:12:27 +0200
Subject: [PATCH] Add Free enum variant to the symbol scope to be able to
 distuingish between true local and free variables.

---
 src/compile.rs     | 12 ++++++------
 src/symboltable.rs | 18 +++++++++---------
 2 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/src/compile.rs b/src/compile.rs
index 23b46f1..2a95190 100644
--- a/src/compile.rs
+++ b/src/compile.rs
@@ -282,8 +282,8 @@ impl<O: OutputStream> Compiler<O> {
         match symbol.scope {
             SymbolScope::Global => bytecode::NameScope::Global,
             SymbolScope::Nonlocal => bytecode::NameScope::NonLocal,
-            SymbolScope::Unknown => bytecode::NameScope::Local,
-            SymbolScope::Local => bytecode::NameScope::Local,
+            SymbolScope::Unknown => bytecode::NameScope::Free,
+            SymbolScope::Local => bytecode::NameScope::Free,
         }
     }
 
@@ -500,7 +500,7 @@ impl<O: OutputStream> Compiler<O> {
                     self.compile_jump_if(test, true, end_label)?;
                     self.emit(Instruction::LoadName {
                         name: String::from("AssertionError"),
-                        scope: bytecode::NameScope::Local,
+                        scope: bytecode::NameScope::Global,
                     });
                     match msg {
                         Some(e) => {
@@ -736,7 +736,7 @@ impl<O: OutputStream> Compiler<O> {
                 // Check exception type:
                 self.emit(Instruction::LoadName {
                     name: String::from("isinstance"),
-                    scope: bytecode::NameScope::Local,
+                    scope: bytecode::NameScope::Global,
                 });
                 self.emit(Instruction::Rotate { amount: 2 });
                 self.compile_expression(exc_type)?;
@@ -931,11 +931,11 @@ impl<O: OutputStream> Compiler<O> {
 
         self.emit(Instruction::LoadName {
             name: "__name__".to_string(),
-            scope: bytecode::NameScope::Local,
+            scope: bytecode::NameScope::Free,
         });
         self.emit(Instruction::StoreName {
             name: "__module__".to_string(),
-            scope: bytecode::NameScope::Local,
+            scope: bytecode::NameScope::Free,
         });
         self.compile_statements(new_body)?;
         self.emit(Instruction::LoadConst {
diff --git a/src/symboltable.rs b/src/symboltable.rs
index 46174c3..d99ae82 100644
--- a/src/symboltable.rs
+++ b/src/symboltable.rs
@@ -213,21 +213,21 @@ impl SymbolTableAnalyzer {
                 if symbol.is_assigned || symbol.is_parameter {
                     symbol.scope = SymbolScope::Local;
                 } else {
-                    // TODO: comment this out and make it work properly:
-                    /*
-                     */
-                    let found_in_outer_scope = self
-                        .tables
-                        .iter()
-                        .skip(1)
-                        .any(|t| t.symbols.contains_key(&symbol.name));
+                    // Interesting stuff about the __class__ variable:
+                    // https://docs.python.org/3/reference/datamodel.html?highlight=__class__#creating-the-class-object
+                    let found_in_outer_scope = (symbol.name == "__class__")
+                        || self
+                            .tables
+                            .iter()
+                            .skip(1)
+                            .any(|t| t.symbols.contains_key(&symbol.name));
 
                     if found_in_outer_scope {
                         // Symbol is in some outer scope.
                         symbol.is_free = true;
                     } else {
                         // Well, it must be a global then :)
-                        // symbol.scope = SymbolScope::Global;
+                        symbol.scope = SymbolScope::Global;
                     }
                 }
             }