From 4c47216656579a0e5b81cc3fbab17362ffde3e94 Mon Sep 17 00:00:00 2001
From: David Kerkeslager <kerkeslager@gmail.com>
Date: Mon, 25 Sep 2017 17:49:12 -0400
Subject: [PATCH] Clean up stacks in the case of an exception

---
 templates/function_definition.c | 17 ++++++++++++++---
 templates/program.c             | 11 +++++++++++
 2 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/templates/function_definition.c b/templates/function_definition.c
index 72ce6f0..9ebac36 100644
--- a/templates/function_definition.c
+++ b/templates/function_definition.c
@@ -1,21 +1,32 @@
 
-Object user${{name}}$implementation(EnvironmentPool* environmentPool, Environment* parent, size_t argc, Stack* stack, jmp_buf parent_jump)
+Object user${{name}}$implementation(EnvironmentPool* environmentPool, Environment* parent, size_t argc, Stack* parentStack, jmp_buf parent_jump)
 {
   Environment* environment = EnvironmentPool_allocate(environmentPool);
   Environment_initialize(environment, parent);
 
+  Stack stackMemory;
+  Stack* stack = &stackMemory;
+  Stack_initialize(stack);
+
   jmp_buf jump;
   if(setjmp(jump) != 0)
   {
-    Environment_setLive(environment, false);
     fprintf(stderr, "\tin {{name}}\n");
+
+    while(Stack_any(stack))
+    {
+      Object item = Stack_pop(stack);
+      Object_deinitialize(&item);
+    }
+    Environment_setLive(environment, false);
+
     longjmp(parent_jump, 1);
   }
 
   Object result = builtin$nil;
 
   {% for argument_name in argument_name_list|reverse %}
-  Environment_set(environment, "{{ argument_name }}", Stack_pop(stack));
+  Environment_set(environment, "{{ argument_name }}", Stack_pop(parentStack));
   {% endfor %}
 
   {% for statement in statement_list %}
diff --git a/templates/program.c b/templates/program.c
index 08921b1..7cfd1e3 100644
--- a/templates/program.c
+++ b/templates/program.c
@@ -163,6 +163,11 @@ void Stack_initialize(Stack* self)
   self->length = 0;
 }
 
+bool Stack_any(Stack* self)
+{
+  return self->length > 0;
+}
+
 void Stack_push(Stack* self, Object item)
 {
   assert(self->length < 256);
@@ -695,6 +700,12 @@ int main(int argc, char** argv)
   if(setjmp(jump) != 0)
   {
     fprintf(stderr, "\tin __main__\n");
+
+    while(Stack_any(stack))
+    {
+      Object item = Stack_pop(stack);
+      Object_deinitialize(&item);
+    }
     Environment_setLive(environment, false);
     EnvironmentPool_destruct(environmentPool);
 
-- 
2.20.1