fix return values

.gitignore

@@ -1,4 +1,6 @@
 /target
 
 .idea
-*.iml
+*.iml
+
+*.snap.new

src/compile.rs

@@ -109,6 +109,7 @@ pub fn compile<'ast, 'bc, 'gc>(
 impl<'bc, 'gc> Compiler<'bc, 'gc> {
     fn compile(&mut self, ast: &Program) -> CResult {
         let global_block = FnBlock {
+            name: self.rt.intern_string("<main>"),
             code: Vec::new_in(self.bump),
             stack_sizes: Vec::new_in(self.bump),
             spans: Vec::new_in(self.bump),
@@ -188,6 +189,7 @@ impl<'bc, 'gc> Compiler<'bc, 'gc> {
 
     fn compile_fn_decl(&mut self, decl: &FnDecl) -> CResult {
         let block = FnBlock {
+            name: decl.name.sym,
             code: Vec::new_in(self.bump),
             stack_sizes: Vec::new_in(self.bump),
             spans: Vec::new_in(self.bump),
@@ -480,7 +482,14 @@ impl<'bc, 'gc> Compiler<'bc, 'gc> {
         }
 
         self.push_instr(Instr::Load(offset), StackChange::Grow, call.span);
-        self.push_instr(Instr::Call, StackChange::None, call.span);
+        // The callee gets rid of the params. We also pushed the load for the function above,
+        // but the callee also leaves behind a return value.
+        let expected_stack_shrink = params.len();
+        self.push_instr(
+            Instr::Call,
+            StackChange::ShrinkN(expected_stack_shrink),
+            call.span,
+        );
 
         Ok(())
     }

src/runtime/bytecode.rs

@@ -29,10 +29,14 @@ use std::fmt::{Debug, Formatter};
 
 use bumpalo::collections::Vec;
 
-use crate::{errors::Span, runtime::vm::Value};
+use crate::{
+    errors::Span,
+    runtime::{gc::Symbol, vm::Value},
+};
 
 /// This struct contains all data for a function.
 pub struct FnBlock<'bc> {
+    pub name: Symbol,
     /// The bytecode of the function
     pub code: Vec<'bc, Instr>,
     /// The sizes of the stack required by the function after the instruction at the same index.
@@ -111,6 +115,7 @@ pub enum Instr {
 impl dbg_pls::DebugPls for FnBlock<'_> {
     fn fmt(&self, f: dbg_pls::Formatter<'_>) {
         f.debug_struct("FnBlock")
+            .field("name", &self.name)
             .field("arity", &self.arity)
             .field("code", &self.code.as_slice())
             .field("stack_sizes", &self.stack_sizes.as_slice())

src/runtime/stack_frame.rs

@@ -58,7 +58,7 @@ impl<'s> Frame<'s> {
         vm_state.stack.push(Value::NativeU(old_pc));
         vm_state.stack.push(Value::Function(old_fn_block));
 
-        let frame_slice = &vm_state.stack[new_frame_offset..];
+        // let frame_slice = &vm_state.stack[new_frame_offset..];
 
         new_frame_offset
     }

test.dil

@@ -1,12 +1,15 @@
-fn test() {
-    let a = 5;
+fn cooler_add(a, b) {
+    return a + b;
 }
 
-test();
-test();
-
-let i = 0;
-while i < 100_000 {
-	test();
-	i = i + 1;
+fn add(a, b) {
+    return cooler_add(a, b);
 }
+
+let added = add(1, 5);
+
+if added == 6 {
+    print "correct";
+} else {
+    print "FAILED";
+}

tests/functions.rs

@@ -43,7 +43,6 @@ print "correct3";
 );
 
 run_test!(
-    #[ignore]
     parameters,
     r#"
 fn fancy_print(str) {
@@ -67,7 +66,6 @@ print x;
 );
 
 run_test!(
-    #[ignore]
     parameters_and_return,
     r#"
 fn add(a, b) {
@@ -84,6 +82,28 @@ if added == 6 {
 "#
 );
 
+run_test!(
+    #[ignore]
+    nested_calls,
+    r#"
+fn cooler_add(a, b) {
+    return a + b;
+}
+
+fn add(a, b) {
+    return cooler_add(a, b);
+}
+
+let added = add(1, 5);
+
+if added == 6 {
+    print "correct";
+} else {
+    print "FAILED";
+}
+"#
+);
+
 run_test!(
     #[ignore]
     fib5,

tests/snapshots/functions__parameters.snap

@@ -0,0 +1,5 @@
+---
+source: tests/functions.rs
+expression: output
+---
+"correct\n"

tests/snapshots/functions__parameters_and_return.snap

@@ -0,0 +1,5 @@
+---
+source: tests/functions.rs
+expression: output
+---
+"correct\n"