From 0c110cf7428f403075d84d19855e0490144e52fb Mon Sep 17 00:00:00 2001
From: Brian Carroll <brian.carroll.ireland@gmail.com>
Date: Sun, 26 Jun 2022 16:46:47 +0100
Subject: [PATCH] wasm: List.concat

---
 compiler/gen_wasm/src/low_level.rs | 31 ++++++++++++++++++-
 compiler/test_gen/src/gen_list.rs  | 48 +++++++-----------------------
 2 files changed, 41 insertions(+), 38 deletions(-)

diff --git a/compiler/gen_wasm/src/low_level.rs b/compiler/gen_wasm/src/low_level.rs
index ffd917263b..9d9fc9f9d6 100644
--- a/compiler/gen_wasm/src/low_level.rs
+++ b/compiler/gen_wasm/src/low_level.rs
@@ -439,7 +439,36 @@ impl<'a> LowLevelCall<'a> {
             }
             ListRepeat => todo!("{:?}", self.lowlevel),
             ListReverse => todo!("{:?}", self.lowlevel),
-            ListConcat => todo!("{:?}", self.lowlevel),
+            ListConcat => {
+                // Zig arguments          Wasm types
+                //  (return pointer)       i32
+                //  list_a: RocList        i64, i32
+                //  list_b: RocList        i64, i32
+                //  alignment: u32         i32
+                //  element_width: usize   i32
+
+                // Load the arguments that have symbols
+                backend.storage.load_symbols_for_call(
+                    backend.env.arena,
+                    &mut backend.code_builder,
+                    self.arguments,
+                    self.ret_symbol,
+                    &WasmLayout::new(&self.ret_layout),
+                    CallConv::Zig,
+                );
+
+                // Load monomorphization constants
+                if let Layout::Builtin(Builtin::List(elem_layout)) = self.ret_layout {
+                    let (elem_width, elem_align) =
+                        elem_layout.stack_size_and_alignment(TARGET_INFO);
+                    backend.code_builder.i32_const(elem_align as i32);
+                    backend.code_builder.i32_const(elem_width as i32);
+                } else {
+                    internal_error!("Invalid return layout for ListConcat {:?}", self.ret_layout);
+                }
+
+                backend.call_host_fn_after_loading_args(bitcode::LIST_CONCAT, 7, false);
+            }
             ListContains => todo!("{:?}", self.lowlevel),
             ListAppend => todo!("{:?}", self.lowlevel),
             ListPrepend => todo!("{:?}", self.lowlevel),
diff --git a/compiler/test_gen/src/gen_list.rs b/compiler/test_gen/src/gen_list.rs
index 6b8f8e16f9..72ac1d598e 100644
--- a/compiler/test_gen/src/gen_list.rs
+++ b/compiler/test_gen/src/gen_list.rs
@@ -1393,29 +1393,7 @@ fn list_reverse_empty_list() {
 }
 
 #[test]
-#[cfg(any(feature = "gen-llvm"))]
-fn list_concat() {
-    assert_evals_to!(
-        indoc!(
-            r#"
-                firstList : List I64
-                firstList =
-                    []
-
-                secondList : List I64
-                secondList =
-                    []
-
-                List.concat firstList secondList
-            "#
-        ),
-        RocList::<i64>::from_slice(&[]),
-        RocList<i64>
-    );
-}
-
-#[test]
-#[cfg(any(feature = "gen-llvm"))]
+#[cfg(any(feature = "gen-llvm", feature = "gen-wasm"))]
 fn list_concat_two_empty_lists() {
     assert_evals_to!(
         "List.concat [] []",
@@ -1425,7 +1403,7 @@ fn list_concat_two_empty_lists() {
 }
 
 #[test]
-#[cfg(any(feature = "gen-llvm"))]
+#[cfg(any(feature = "gen-llvm", feature = "gen-wasm"))]
 fn list_concat_two_empty_lists_of_int() {
     assert_evals_to!(
         indoc!(
@@ -1447,22 +1425,18 @@ fn list_concat_two_empty_lists_of_int() {
 }
 
 #[test]
-#[cfg(any(feature = "gen-llvm"))]
+#[cfg(any(feature = "gen-llvm", feature = "gen-wasm"))]
 fn list_concat_second_list_is_empty() {
     assert_evals_to!(
         "List.concat [12, 13] []",
         RocList::from_slice(&[12, 13]),
         RocList<i64>
     );
-    assert_evals_to!(
-        "List.concat [34, 43] [64, 55, 66]",
-        RocList::from_slice(&[34, 43, 64, 55, 66]),
-        RocList<i64>
-    );
+
 }
 
 #[test]
-#[cfg(any(feature = "gen-llvm"))]
+#[cfg(any(feature = "gen-llvm", feature = "gen-wasm"))]
 fn list_concat_first_list_is_empty() {
     assert_evals_to!(
         "List.concat [] [23, 24]",
@@ -1472,7 +1446,7 @@ fn list_concat_first_list_is_empty() {
 }
 
 #[test]
-#[cfg(any(feature = "gen-llvm"))]
+#[cfg(any(feature = "gen-llvm", feature = "gen-wasm"))]
 fn list_concat_two_non_empty_lists() {
     assert_evals_to!(
         "List.concat [1, 2] [3, 4]",
@@ -1482,7 +1456,7 @@ fn list_concat_two_non_empty_lists() {
 }
 
 #[test]
-#[cfg(any(feature = "gen-llvm"))]
+#[cfg(any(feature = "gen-llvm", feature = "gen-wasm"))]
 fn list_concat_two_bigger_non_empty_lists() {
     assert_evals_to!(
         "List.concat [1.1, 2.2] [3.3, 4.4, 5.5]",
@@ -1492,7 +1466,7 @@ fn list_concat_two_bigger_non_empty_lists() {
 }
 
 #[allow(dead_code)]
-#[cfg(any(feature = "gen-llvm"))]
+#[cfg(any(feature = "gen-llvm", feature = "gen-wasm"))]
 fn assert_concat_worked(num_elems1: i64, num_elems2: i64) {
     let vec1: Vec<i64> = (0..num_elems1)
         .map(|i| 12345 % (i + num_elems1 + num_elems2 + 1))
@@ -1514,7 +1488,7 @@ fn assert_concat_worked(num_elems1: i64, num_elems2: i64) {
 }
 
 #[test]
-#[cfg(any(feature = "gen-llvm"))]
+#[cfg(any(feature = "gen-llvm", feature = "gen-wasm"))]
 fn list_concat_empty_list() {
     assert_concat_worked(0, 0);
     assert_concat_worked(1, 0);
@@ -1538,7 +1512,7 @@ fn list_concat_empty_list() {
 }
 
 #[test]
-#[cfg(any(feature = "gen-llvm"))]
+#[cfg(any(feature = "gen-llvm", feature = "gen-wasm"))]
 fn list_concat_nonempty_lists() {
     assert_concat_worked(1, 1);
     assert_concat_worked(1, 2);
@@ -1554,7 +1528,7 @@ fn list_concat_nonempty_lists() {
 }
 
 #[test]
-#[cfg(any(feature = "gen-llvm"))]
+#[cfg(any(feature = "gen-llvm", feature = "gen-wasm"))]
 fn list_concat_large() {
     with_larger_debug_stack(|| {
         // these values produce mono ASTs so large that