Add explicit return instruction to function bodies

4 files changed, 53 insertions, 2 deletions

diff --git a/src/test/java/org/shedlang/compiler/backends/llvm/LlvmCompilerDefineFunctionTests.java b/src/test/java/org/shedlang/compiler/backends/llvm/LlvmCompilerDefineFunctionTests.java
index 1575c2ad..f7e86765 100644
--- a/src/test/java/org/shedlang/compiler/backends/llvm/LlvmCompilerDefineFunctionTests.java
+++ b/src/test/java/org/shedlang/compiler/backends/llvm/LlvmCompilerDefineFunctionTests.java
@@ -25,7 +25,8 @@ public class LlvmCompilerDefineFunctionTests {
             List.of(),
             Set.of(),
             List.of(
-                Instructions.pushUnit()
+                Instructions.pushUnit(),
+                Instructions.return_()
             ),
             Sources.NULL
         );
diff --git a/src/test/java/org/shedlang/compiler/backends/llvm/LlvmCompilerReturnTests.java b/src/test/java/org/shedlang/compiler/backends/llvm/LlvmCompilerReturnTests.java
new file mode 100644
index 00000000..f76383af
--- /dev/null
+++ b/src/test/java/org/shedlang/compiler/backends/llvm/LlvmCompilerReturnTests.java
@@ -0,0 +1,43 @@
+package org.shedlang.compiler.backends.llvm;
+
+import org.junit.jupiter.api.Test;
+import org.shedlang.compiler.backends.llvm.ir.ast.LlvmIr;
+import org.shedlang.compiler.backends.llvm.ir.ast.types.LlvmTypes;
+import org.shedlang.compiler.stackir.instructions.Instructions;
+
+import static org.shedlang.compiler.backends.llvm.ir.ast.LlvmIrMatchers.*;
+import static org.zwobble.precisely.AssertThat.assertThat;
+import static org.zwobble.precisely.Matchers.equalTo;
+import static org.zwobble.precisely.Matchers.isSequence;
+
+public class LlvmCompilerReturnTests {
+    @Test
+    public void returnCompilesToReturnInstruction() {
+        var instruction = Instructions.return_();
+        var add = LlvmIr.add(
+            LlvmIr.variableLocal("x"),
+            LlvmTypes.INT_64,
+            LlvmIr.variableLocal("left"),
+            LlvmIr.variableLocal("right")
+        );
+        var context = LlvmCompilerContext.EMPTY
+            .addInstruction(add)
+            .push(LlvmIr.variableLocal("a"))
+            .push(LlvmIr.variableLocal("b"));
+
+        var result = LlvmCompiler.compileInstruction(instruction, context);
+
+        assertThat(result.basicBlocks(), isSequence(
+            isLlvmBasicBlock(
+                isSequence(
+                    equalTo(add)
+                ),
+                isLlvmReturn(LlvmCompilerTypes.VALUE_TYPE, isLlvmVariableLocal("b"))
+            )
+        ));
+        assertThat(result.instructions(), isSequence());
+        assertThat(result.stack(), isSequence(
+            isLlvmVariableLocal("a")
+        ));
+    }
+}
diff --git a/src/test/java/org/shedlang/compiler/stackir/StackCompilerFunctionDefinitionTests.java b/src/test/java/org/shedlang/compiler/stackir/StackCompilerFunctionDefinitionTests.java
index 1c90a0a7..05063961 100644
--- a/src/test/java/org/shedlang/compiler/stackir/StackCompilerFunctionDefinitionTests.java
+++ b/src/test/java/org/shedlang/compiler/stackir/StackCompilerFunctionDefinitionTests.java
@@ -37,7 +37,8 @@ public class StackCompilerFunctionDefinitionTests {
                 has("body", x -> x.body(), isSequence(
                     isPushStringInstruction("hello"),
                     isDiscardInstruction(),
-                    isPushUnitInstruction()
+                    isPushUnitInstruction(),
+                    isReturnInstruction()
                 ))
             ),
             isLocalStoreInstruction("f")
diff --git a/src/test/java/org/shedlang/compiler/stackir/instructions/InstructionMatchers.java b/src/test/java/org/shedlang/compiler/stackir/instructions/InstructionMatchers.java
index 7e8a2f4d..8e24e131 100644
--- a/src/test/java/org/shedlang/compiler/stackir/instructions/InstructionMatchers.java
+++ b/src/test/java/org/shedlang/compiler/stackir/instructions/InstructionMatchers.java
@@ -81,4 +81,10 @@ public class InstructionMatchers {
             PushUnitInstruction.class
         );
     }
+
+    public static Matcher<Instruction> isReturnInstruction() {
+        return instanceOf(
+            ReturnInstruction.class
+        );
+    }
 }