From 5e20cc28f804a901aa72937562912acbce1261ee Mon Sep 17 00:00:00 2001
From: Sergey Pepyakin <s.pepyakin@gmail.com>
Date: Wed, 13 Jun 2018 12:05:20 +0300
Subject: [PATCH] Tests

---
 src/isa.rs              |  4 +--
 src/validation/func.rs  |  7 +---
 src/validation/tests.rs | 72 ++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 74 insertions(+), 9 deletions(-)

diff --git a/src/isa.rs b/src/isa.rs
index 4c7f73a..7d82767 100644
--- a/src/isa.rs
+++ b/src/isa.rs
@@ -40,7 +40,7 @@
 //! - Reserved immediates are ignored for `call_indirect`, `current_memory`, `grow_memory`.
 //!
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub struct Target {
 	pub dst_pc: u32,
 	pub drop: u32,
@@ -48,7 +48,7 @@ pub struct Target {
 }
 
 #[allow(unused)] // TODO: Remove
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq)]
 pub enum Instruction {
 	/// Push a local variable or an argument from the specified depth.
 	GetLocal(u32),
diff --git a/src/validation/func.rs b/src/validation/func.rs
index c1eaed4..76137de 100644
--- a/src/validation/func.rs
+++ b/src/validation/func.rs
@@ -109,19 +109,14 @@ impl Validator {
 		context.push_label(BlockFrameType::Function, result_ty, func_label)?;
 		Validator::validate_function_block(&mut context, body.code().elements())?;
 
-
 		while !context.frame_stack.is_empty() {
 			let branch_label = context.top_label()?.branch_label;
 			context.sink.resolve_label(branch_label);
 		}
 
-		// Emit explicit return.
-		// let (drop, keep) = context.drop_keep_return()?;
-		// TODO:
-
 		context.sink.emit(isa::Instruction::Return {
 			drop: 0,
-			keep: 0,
+			keep: if result_ty == BlockType::NoResult { 0 } else { 1 },
 		});
 
 		Ok(context.into_code())
diff --git a/src/validation/tests.rs b/src/validation/tests.rs
index 38ad0cc..834ff5c 100644
--- a/src/validation/tests.rs
+++ b/src/validation/tests.rs
@@ -2,8 +2,11 @@ use super::validate_module;
 use parity_wasm::builder::module;
 use parity_wasm::elements::{
     External, GlobalEntry, GlobalType, ImportEntry, InitExpr, MemoryType,
-    Opcode, Opcodes, TableType, ValueType, BlockType
+    Opcode, Opcodes, TableType, ValueType, BlockType, deserialize_buffer,
+	Module,
 };
+use isa;
+use wabt;
 
 #[test]
 fn empty_is_valid() {
@@ -299,3 +302,70 @@ fn if_else_with_return_type_validation() {
 		.build();
 	validate_module(m).unwrap();
 }
+
+fn compile(wat: &str) -> Vec<isa::Instruction> {
+	let wasm = wabt::wat2wasm(wat).unwrap();
+	let module = deserialize_buffer::<Module>(&wasm).unwrap();
+	let validated_module = validate_module(module).unwrap();
+	let code = &validated_module.code_map[0];
+	code.code.clone()
+}
+
+#[test]
+fn explicit_return_no_value() {
+	let code = compile(r#"
+		(module
+			(func (export "call")
+			)
+		)
+	"#);
+	assert_eq!(
+		code,
+		vec![
+			isa::Instruction::Return {
+				drop: 0,
+				keep: 0,
+			}
+		]
+	)
+}
+
+#[test]
+fn explicit_return_with_value() {
+	let code = compile(r#"
+		(module
+			(func (export "call") (result i32)
+				i32.const 0
+			)
+		)
+	"#);
+	assert_eq!(
+		code,
+		vec![
+			isa::Instruction::I32Const(0),
+			isa::Instruction::Return {
+				drop: 0,
+				keep: 1,
+			}
+		]
+	)
+}
+
+#[test]
+fn explicit_return_param() {
+		let code = compile(r#"
+		(module
+			(func (export "call") (param i32)
+			)
+		)
+	"#);
+	assert_eq!(
+		code,
+		vec![
+			isa::Instruction::Return {
+				drop: 1,
+				keep: 0,
+			}
+		]
+	)
+}