handle lambda set when passed as a function argument

crates/compiler/gen_dev/src/generic64/mod.rs

@@ -769,6 +769,10 @@ impl<
         // Call function and generate reloc.
         ASM::call(&mut self.buf, &mut self.relocs, fn_name);
 
+        self.move_return_value(dst, ret_layout)
+    }
+
+    fn move_return_value(&mut self, dst: &Symbol, ret_layout: &InLayout<'a>) {
         // move return value to dst.
         match *ret_layout {
             single_register_integers!() => {
@@ -786,6 +790,9 @@ impl<
                         let dst_reg = self.storage_manager.claim_general_reg(&mut self.buf, dst);
                         ASM::mov_reg64_reg64(&mut self.buf, dst_reg, CC::GENERAL_RETURN_REGS[0]);
                     }
+                    Layout::LambdaSet(lambda_set) => {
+                        self.move_return_value(dst, &lambda_set.runtime_representation())
+                    }
                     _ => {
                         CC::load_returned_complex_symbol(
                             &mut self.buf,

crates/compiler/gen_dev/src/generic64/x86_64.rs

@@ -1559,7 +1559,6 @@ impl Assembler<X86_64GeneralReg, X86_64FloatReg> for X86_64Assembler {
         src1: X86_64GeneralReg,
         src2: X86_64GeneralReg,
     ) {
-        dbg!(register_width);
         cmp_reg64_reg64(buf, register_width, src1, src2);
         sete_reg64(buf, dst);
     }
@@ -1572,7 +1571,6 @@ impl Assembler<X86_64GeneralReg, X86_64FloatReg> for X86_64Assembler {
         src1: X86_64GeneralReg,
         src2: X86_64GeneralReg,
     ) {
-        dbg!(register_width);
         cmp_reg64_reg64(buf, register_width, src1, src2);
         setne_reg64(buf, dst);
     }

crates/compiler/gen_dev/src/lib.rs

@@ -1131,6 +1131,9 @@ trait Backend<'a> {
         ret_layout: &InLayout<'a>,
     );
 
+    /// Move a returned value into `dst`
+    fn move_return_value(&mut self, dst: &Symbol, ret_layout: &InLayout<'a>);
+
     /// build_num_abs stores the absolute value of src into dst.
     fn build_num_abs(&mut self, dst: &Symbol, src: &Symbol, layout: &InLayout<'a>);
 

crates/compiler/test_gen/src/gen_primitives.rs

@@ -4124,7 +4124,7 @@ fn int_let_generalization() {
     assert_evals_to!(
         indoc!(
             r#"
-            manyAux : {} -> I32 
+            manyAux : {} -> I32
             manyAux = \_ ->
                 output = \_ -> 42
 
@@ -4403,17 +4403,17 @@ fn layout_cache_structure_with_multiple_recursive_structures() {
             LinkedList : [Nil, Cons { first : Chain, rest : LinkedList }]
 
             main =
-                base : LinkedList 
+                base : LinkedList
                 base = Nil
 
                 walker : LinkedList, Chain -> LinkedList
-                walker = \rest, first -> Cons { first, rest } 
+                walker = \rest, first -> Cons { first, rest }
 
                 list : List Chain
                 list = []
 
                 r = List.walk list base walker
-                
+
                 if r == base then 11u8 else 22u8
             "#
         ),
@@ -4460,3 +4460,23 @@ fn reset_recursive_type_wraps_in_named_type() {
         RocStr
     );
 }
+
+#[test]
+#[cfg(any(feature = "gen-llvm", feature = "gen-wasm", feature = "gen-dev"))]
+fn pass_lambda_set_to_function() {
+    assert_evals_to!(
+        indoc!(
+            r#"
+            app "test" provides [main] to "./platform"
+
+            instr = if Bool.true then Num.mul else Num.add
+
+            fn = \a -> instr a a
+
+            main = fn 3
+            "#
+        ),
+        3 * 3,
+        i64
+    );
+}

crates/compiler/test_gen/src/gen_tags.rs

@@ -2010,7 +2010,7 @@ fn unify_types_with_fixed_fixpoints_outside_fixing_region() {
 }
 
 #[test]
-#[cfg(any(feature = "gen-llvm", feature = "gen-wasm"))]
+#[cfg(any(feature = "gen-llvm", feature = "gen-wasm", feature = "gen-dev"))]
 fn lambda_set_with_imported_toplevels_issue_4733() {
     assert_evals_to!(
         indoc!(

crates/compiler/test_gen/src/helpers/dev.rs

@@ -210,7 +210,7 @@ pub fn helper(
     let builtins_host_tempfile =
         roc_bitcode::host_tempfile().expect("failed to write host builtins object to tempfile");
 
-    if true {
+    if false {
         std::fs::copy(&app_o_file, "/tmp/app.o").unwrap();
     }