From f492800a28d06635f848dee4b2bf3bb55be1bf3f Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Tue, 22 Sep 2020 21:58:45 +0200
Subject: [PATCH] recursive refcount on lists

---
 compiler/gen/src/llvm/build_list.rs  | 20 ++++++++
 compiler/gen/src/llvm/refcounting.rs | 76 ++++++++++++++++++++++------
 2 files changed, 80 insertions(+), 16 deletions(-)

diff --git a/compiler/gen/src/llvm/build_list.rs b/compiler/gen/src/llvm/build_list.rs
index 078ae8bd64..25dc8fe0e5 100644
--- a/compiler/gen/src/llvm/build_list.rs
+++ b/compiler/gen/src/llvm/build_list.rs
@@ -1570,6 +1570,26 @@ pub fn list_is_not_empty<'ctx>(env: &Env<'_, 'ctx, '_>, len: IntValue<'ctx>) ->
     )
 }
 
+pub fn load_list<'ctx>(
+    builder: &Builder<'ctx>,
+    wrapper_struct: StructValue<'ctx>,
+    ptr_type: PointerType<'ctx>,
+) -> (IntValue<'ctx>, PointerValue<'ctx>) {
+    let ptr_as_int = builder
+        .build_extract_value(wrapper_struct, Builtin::WRAPPER_PTR, "read_list_ptr")
+        .unwrap()
+        .into_int_value();
+
+    let ptr = builder.build_int_to_ptr(ptr_as_int, ptr_type, "list_cast_ptr");
+
+    let length = builder
+        .build_extract_value(wrapper_struct, Builtin::WRAPPER_LEN, "list_len")
+        .unwrap()
+        .into_int_value();
+
+    (length, ptr)
+}
+
 pub fn load_list_ptr<'ctx>(
     builder: &Builder<'ctx>,
     wrapper_struct: StructValue<'ctx>,
diff --git a/compiler/gen/src/llvm/refcounting.rs b/compiler/gen/src/llvm/refcounting.rs
index d7d9113d4e..a76f56f069 100644
--- a/compiler/gen/src/llvm/refcounting.rs
+++ b/compiler/gen/src/llvm/refcounting.rs
@@ -100,7 +100,7 @@ pub fn decrement_refcount_layout<'a, 'ctx, 'env>(
 #[inline(always)]
 fn decrement_refcount_builtin<'a, 'ctx, 'env>(
     env: &Env<'a, 'ctx, 'env>,
-    _parent: FunctionValue<'ctx>,
+    parent: FunctionValue<'ctx>,
     layout_ids: &mut LayoutIds<'a>,
     value: BasicValueEnum<'ctx>,
     layout: &Layout<'a>,
@@ -109,14 +109,37 @@ fn decrement_refcount_builtin<'a, 'ctx, 'env>(
     use Builtin::*;
 
     match builtin {
-        List(MemoryMode::Refcounted, element_layout) => {
+        List(memory_mode, element_layout) => {
+            let wrapper_struct = value.into_struct_value();
             if element_layout.contains_refcounted() {
-                // TODO decrement all values
+                use crate::llvm::build_list::{incrementing_elem_loop, load_list};
+                use inkwell::types::BasicType;
+
+                let ptr_type =
+                    basic_type_from_layout(env.arena, env.context, element_layout, env.ptr_bytes)
+                        .ptr_type(AddressSpace::Generic);
+
+                let (len, ptr) = load_list(env.builder, wrapper_struct, ptr_type);
+
+                let loop_fn = |_index, element| {
+                    decrement_refcount_layout(env, parent, layout_ids, element, element_layout);
+                };
+
+                incrementing_elem_loop(
+                    env.builder,
+                    env.context,
+                    parent,
+                    ptr,
+                    len,
+                    "dec_index",
+                    loop_fn,
+                );
             }
-            build_dec_list(env, layout_ids, layout, value.into_struct_value());
-        }
-        List(MemoryMode::Unique, _element_layout) => {
-            // do nothing
+
+            if let MemoryMode::Refcounted = memory_mode {
+                build_inc_list(env, layout_ids, layout, wrapper_struct);
+            }
+            build_dec_list(env, layout_ids, layout, wrapper_struct);
         }
         Set(element_layout) => {
             if element_layout.contains_refcounted() {
@@ -158,7 +181,7 @@ pub fn increment_refcount_layout<'a, 'ctx, 'env>(
 #[inline(always)]
 fn increment_refcount_builtin<'a, 'ctx, 'env>(
     env: &Env<'a, 'ctx, 'env>,
-    _parent: FunctionValue<'ctx>,
+    parent: FunctionValue<'ctx>,
     layout_ids: &mut LayoutIds<'a>,
     value: BasicValueEnum<'ctx>,
     layout: &Layout<'a>,
@@ -167,15 +190,36 @@ fn increment_refcount_builtin<'a, 'ctx, 'env>(
     use Builtin::*;
 
     match builtin {
-        List(MemoryMode::Refcounted, element_layout) => {
-            if element_layout.contains_refcounted() {
-                // TODO decrement all values
-            }
+        List(memory_mode, element_layout) => {
             let wrapper_struct = value.into_struct_value();
-            build_inc_list(env, layout_ids, layout, wrapper_struct);
-        }
-        List(MemoryMode::Unique, _element_layout) => {
-            // do nothing
+            if element_layout.contains_refcounted() {
+                use crate::llvm::build_list::{incrementing_elem_loop, load_list};
+                use inkwell::types::BasicType;
+
+                let ptr_type =
+                    basic_type_from_layout(env.arena, env.context, element_layout, env.ptr_bytes)
+                        .ptr_type(AddressSpace::Generic);
+
+                let (len, ptr) = load_list(env.builder, wrapper_struct, ptr_type);
+
+                let loop_fn = |_index, element| {
+                    increment_refcount_layout(env, parent, layout_ids, element, element_layout);
+                };
+
+                incrementing_elem_loop(
+                    env.builder,
+                    env.context,
+                    parent,
+                    ptr,
+                    len,
+                    "inc_index",
+                    loop_fn,
+                );
+            }
+
+            if let MemoryMode::Refcounted = memory_mode {
+                build_inc_list(env, layout_ids, layout, wrapper_struct);
+            }
         }
         Set(element_layout) => {
             if element_layout.contains_refcounted() {