Remove reliance on exit code for Patio tests

4 files changed, 174 insertions, 121 deletions

diff --git a/src/test/java/org/shedlang/compiler/backends/llvm/PatioToLlvmTests.java b/src/test/java/org/shedlang/compiler/backends/llvm/PatioToLlvmTests.java
index 2873a855..802287ce 100644
--- a/src/test/java/org/shedlang/compiler/backends/llvm/PatioToLlvmTests.java
+++ b/src/test/java/org/shedlang/compiler/backends/llvm/PatioToLlvmTests.java
@@ -6,11 +6,11 @@ import org.shedlang.compiler.backends.llvm.ir.ast.LlvmBasicBlock;
 import org.shedlang.compiler.backends.llvm.ir.ast.LlvmFunctionDefinition;
 import org.shedlang.compiler.backends.llvm.ir.ast.instructions.LlvmCall;
 import org.shedlang.compiler.backends.llvm.ir.ast.instructions.LlvmReturn;
-import org.shedlang.compiler.backends.llvm.ir.ast.instructions.LlvmTrunc;
+import org.shedlang.compiler.backends.llvm.ir.ast.operands.LlvmOperandInt;
 import org.shedlang.compiler.backends.llvm.ir.ast.operands.LlvmVariableGlobal;
-import org.shedlang.compiler.backends.llvm.ir.ast.operands.LlvmVariableLocal;
 import org.shedlang.compiler.backends.llvm.ir.ast.types.LlvmTypes;
 import org.shedlang.compiler.backends.paths.PartialTargetPath;
+import org.shedlang.compiler.filesystem.ShedCompilerFiles;
 import org.shedlang.compiler.patio.PatioCompilationUnit;
 import org.shedlang.compiler.patio.PatioExampleTests;
 import org.shedlang.compiler.testing.ExecutionResult;
@@ -24,7 +24,7 @@ import java.util.Optional;
 
 public abstract class PatioToLlvmTests extends PatioExampleTests {
     @Override
-    protected ExecutionResult run(PatioCompilationUnit patio) throws IOException, InterruptedException {
+    protected ExecutionResult executeCompilationUnit(PatioCompilationUnit patio) throws IOException, InterruptedException {
         var llvmModuleResult = PatioToLlvm.generateCompilationUnit(
             patio,
             PatioToLlvmGlobalContext.empty(this.llvmTarget())
@@ -40,19 +40,13 @@ public abstract class PatioToLlvmTests extends PatioExampleTests {
                     Optional.empty(),
                     List.of(
                         new LlvmCall(
-                            new LlvmVariableLocal("exitCode"),
-                            LlvmTypes.INT_64,
+                            Optional.empty(),
+                            LlvmTypes.VOID,
                             new LlvmVariableGlobal(FUNCTION_NAME),
                             List.of()
-                        ),
-                        new LlvmTrunc(
-                            new LlvmVariableLocal("exitCode32"),
-                            LlvmTypes.INT_64,
-                            new LlvmVariableLocal("exitCode"),
-                            LlvmTypes.INT_32
                         )
                     ),
-                    new LlvmReturn(LlvmTypes.INT_32, new LlvmVariableLocal("exitCode32"))
+                    new LlvmReturn(LlvmTypes.INT_32, new LlvmOperandInt(0))
                 )
             )
         ));
@@ -69,7 +63,13 @@ public abstract class PatioToLlvmTests extends PatioExampleTests {
         var executablePath = workingDirectory.resolve("main");
 
         LlvmBackend.forTarget(this.llvmTarget()).link(
-            List.of(objectFilePath),
+            List.of(
+                objectFilePath,
+                ShedCompilerFiles.getRoot()
+                    .resolve("runtime/target")
+                    .resolve(this.llvmTarget().targetName())
+                    .resolve("libpatio_test.a")
+            ),
             executablePath
         );
 
diff --git a/src/test/java/org/shedlang/compiler/backends/wasm/PatioToWasmTests.java b/src/test/java/org/shedlang/compiler/backends/wasm/PatioToWasmTests.java
index d3a929e8..ed0380ea 100644
--- a/src/test/java/org/shedlang/compiler/backends/wasm/PatioToWasmTests.java
+++ b/src/test/java/org/shedlang/compiler/backends/wasm/PatioToWasmTests.java
@@ -3,14 +3,9 @@ package org.shedlang.compiler.backends.wasm;
 import org.shedlang.compiler.backends.wasm.structure.WasmBinaryFormat;
 import org.shedlang.compiler.backends.wasm.structure.ast.instructions.WasmCall;
 import org.shedlang.compiler.backends.wasm.structure.ast.instructions.WasmExpression;
-import org.shedlang.compiler.backends.wasm.structure.ast.instructions.WasmI32WrapI64;
 import org.shedlang.compiler.backends.wasm.structure.ast.instructions.WasmInstruction;
 import org.shedlang.compiler.backends.wasm.structure.ast.modules.WasmFuncName;
 import org.shedlang.compiler.backends.wasm.structure.ast.modules.WasmFunction;
-import org.shedlang.compiler.backends.wasm.structure.ast.modules.WasmImport;
-import org.shedlang.compiler.backends.wasm.structure.ast.modules.WasmImportDescriptor;
-import org.shedlang.compiler.backends.wasm.structure.ast.types.WasmFuncType;
-import org.shedlang.compiler.backends.wasm.structure.ast.types.WasmValueType;
 import org.shedlang.compiler.backends.wasm.structure.binary.WasmBinaryFormatTesting;
 import org.shedlang.compiler.patio.PatioCompilationUnit;
 import org.shedlang.compiler.patio.PatioExampleTests;
@@ -27,19 +22,13 @@ import java.util.List;
 
 public abstract class PatioToWasmTests extends PatioExampleTests {
     @Override
-    protected ExecutionResult run(PatioCompilationUnit patio) throws IOException, InterruptedException {
+    protected ExecutionResult executeCompilationUnit(PatioCompilationUnit patio) throws IOException, InterruptedException {
         var wasmModule = PatioToWasm.generateCompilationUnit(patio, wasmTarget());
 
         wasmModule = WasmBackend.generateNativeRuntime(wasmModule);
 
         var body = P.<WasmInstruction>vector(new WasmCall(new WasmFuncName(FUNCTION_NAME)));
 
-        if (wasmTarget() == WasmTarget.WASM64) {
-            body = body.plus(new WasmI32WrapI64());
-        }
-
-        body = body.plus(new WasmCall(new WasmFuncName("proc_exit")));
-
         wasmModule = wasmModule.addFunction(new WasmFunction(
             "_start",
             List.of(),
@@ -48,15 +37,6 @@ public abstract class PatioToWasmTests extends PatioExampleTests {
             new WasmExpression(body)
         ));
 
-        wasmModule = wasmModule.addImport(new WasmImport(
-            "wasi_snapshot_preview1",
-            "proc_exit",
-            new WasmImportDescriptor.Func("proc_exit", new WasmFuncType(
-                List.of(WasmValueType.I32),
-                List.of()
-            ))
-        ));
-
         Files.createDirectories(Path.of("tests-tmp"));
         var workingDirectory = Files.createTempDirectory(Path.of("tests-tmp"), "PatioToWasmTests");
 
diff --git a/src/test/java/org/shedlang/compiler/patio/PatioExampleTests.java b/src/test/java/org/shedlang/compiler/patio/PatioExampleTests.java
index bc44f2ea..b55755d4 100644
--- a/src/test/java/org/shedlang/compiler/patio/PatioExampleTests.java
+++ b/src/test/java/org/shedlang/compiler/patio/PatioExampleTests.java
@@ -2,15 +2,19 @@ package org.shedlang.compiler.patio;
 
 import org.junit.jupiter.api.Test;
 import org.shedlang.compiler.patio.instructions.Patio;
+import org.shedlang.compiler.patio.instructions.PatioInstruction;
+import org.shedlang.compiler.patio.operands.PatioOperand;
 import org.shedlang.compiler.patio.types.PatioDataLayouts;
 import org.shedlang.compiler.patio.types.PatioDataValues;
 import org.shedlang.compiler.patio.types.PatioTypes;
 import org.shedlang.compiler.sources.Sources;
 import org.shedlang.compiler.testing.ExecutionResult;
+import org.shedlang.compiler.util.Lists;
 import org.zwobble.precisely.Matcher;
 
 import java.io.IOException;
 import java.util.List;
+import java.util.Optional;
 
 import static org.zwobble.precisely.AssertThat.assertThat;
 import static org.zwobble.precisely.Matchers.*;
@@ -28,7 +32,7 @@ public abstract class PatioExampleTests {
         );
         var patioFunction = PatioFunctionDefinition.builder()
             .withName(FUNCTION_NAME)
-            .withReturnType(PatioTypes.INT)
+            .withReturnType(PatioTypes.VOID)
             .addLocal(Patio.val("x", PatioTypes.INT))
             .addBodyInstruction(Patio.memoryLoad(
                 Patio.localRef("x"),
@@ -36,9 +40,10 @@ public abstract class PatioExampleTests {
                 PatioDataLayouts.INT,
                 List.of()
             ))
-            .addBodyInstruction(Patio.return_(
+            .addBodyInstruction(emitInt(
                 Patio.localRef("x")
             ))
+            .addBodyInstruction(Patio.returnVoid())
             .build();
         var patio = Patio.compilationUnit(List.of(
             patioDataElement,
@@ -47,7 +52,9 @@ public abstract class PatioExampleTests {
 
         var result = run(patio);
 
-        assertThat(result, isSilentExit(42));
+        assertThat(result, isSequence(
+            isInt(42)
+        ));
     }
 
     @Test
@@ -64,7 +71,7 @@ public abstract class PatioExampleTests {
         );
         var patioFunction = PatioFunctionDefinition.builder()
             .withName(FUNCTION_NAME)
-            .withReturnType(PatioTypes.INT)
+            .withReturnType(PatioTypes.VOID)
             .addLocal(Patio.val("x", PatioTypes.INT))
             .addBodyInstruction(Patio.memoryLoad(
                 Patio.localRef("x"),
@@ -76,9 +83,8 @@ public abstract class PatioExampleTests {
                 )),
                 List.of(1)
             ))
-            .addBodyInstruction(Patio.return_(
-                Patio.localRef("x")
-            ))
+            .addBodyInstruction(emitInt(Patio.localRef("x")))
+            .addBodyInstruction(Patio.returnVoid())
             .build();
         var patio = Patio.compilationUnit(List.of(
             patioDataElement,
@@ -87,14 +93,16 @@ public abstract class PatioExampleTests {
 
         var result = run(patio);
 
-        assertThat(result, isSilentExit(42));
+        assertThat(result, isSequence(
+            isInt(42)
+        ));
     }
 
     @Test
     public void allocStack() throws IOException, InterruptedException {
         var patioFunction = PatioFunctionDefinition.builder()
             .withName(FUNCTION_NAME)
-            .withReturnType(PatioTypes.INT)
+            .withReturnType(PatioTypes.VOID)
             .addLocal(Patio.val("x", PatioTypes.DATA_PTR))
             .addLocal(Patio.val("y", PatioTypes.INT))
             .addLocal(Patio.val("z", PatioTypes.INT))
@@ -129,22 +137,23 @@ public abstract class PatioExampleTests {
                 PatioDataLayouts.INT,
                 List.of()
             ))
-            .addBodyInstruction(Patio.return_(
-                Patio.localRef("r")
-            ))
+            .addBodyInstruction(emitInt(Patio.localRef("r")))
+            .addBodyInstruction(Patio.returnVoid())
             .build();
         var patio = Patio.compilationUnit(List.of(patioFunction));
 
         var result = run(patio);
 
-        assertThat(result, isSilentExit(47));
+        assertThat(result, isSequence(
+            isInt(47)
+        ));
     }
 
     @Test
     public void block() throws IOException, InterruptedException {
         var patioFunction = PatioFunctionDefinition.builder()
             .withName(FUNCTION_NAME)
-            .withReturnType(PatioTypes.INT)
+            .withReturnType(PatioTypes.VOID)
             .addLocal(Patio.val("x", PatioTypes.INT))
             .addBodyInstruction(Patio.block(
                 List.of(
@@ -155,20 +164,23 @@ public abstract class PatioExampleTests {
                 ),
                 List.of(Patio.localRef("x"))
             ))
-            .addBodyInstruction(Patio.return_(Patio.localRef("x")))
+            .addBodyInstruction(emitInt(Patio.localRef("x")))
+            .addBodyInstruction(Patio.returnVoid())
             .build();
         var patio = Patio.compilationUnit(List.of(patioFunction));
 
         var result = run(patio);
 
-        assertThat(result, isSilentExit(42));
+        assertThat(result, isSequence(
+            isInt(42)
+        ));
     }
 
     @Test
     public void boolToIntToBoolIsIdentityForFalse() throws IOException, InterruptedException {
         var patioFunction = PatioFunctionDefinition.builder()
             .withName(FUNCTION_NAME)
-            .withReturnType(PatioTypes.INT)
+            .withReturnType(PatioTypes.VOID)
             .addLocal(Patio.val("x", PatioTypes.BOOL))
             .addLocal(Patio.val("y", PatioTypes.INT))
             .addLocal(Patio.val("z", PatioTypes.BOOL))
@@ -191,20 +203,23 @@ public abstract class PatioExampleTests {
                 Patio.block(List.of(), List.of(Patio.intConst(42))),
                 Patio.block(List.of(), List.of(Patio.intConst(47)))
             ))
-            .addBodyInstruction(Patio.return_(Patio.localRef("r")))
+            .addBodyInstruction(emitInt(Patio.localRef("r")))
+            .addBodyInstruction(Patio.returnVoid())
             .build();
         var patio = Patio.compilationUnit(List.of(patioFunction));
 
         var result = run(patio);
 
-        assertThat(result, isSilentExit(47));
+        assertThat(result, isSequence(
+            isInt(47)
+        ));
     }
 
     @Test
     public void boolToIntToBoolIsIdentityForTrue() throws IOException, InterruptedException {
         var patioFunction = PatioFunctionDefinition.builder()
             .withName(FUNCTION_NAME)
-            .withReturnType(PatioTypes.INT)
+            .withReturnType(PatioTypes.VOID)
             .addLocal(Patio.val("x", PatioTypes.BOOL))
             .addLocal(Patio.val("y", PatioTypes.INT))
             .addLocal(Patio.val("z", PatioTypes.BOOL))
@@ -227,20 +242,23 @@ public abstract class PatioExampleTests {
                 Patio.block(List.of(), List.of(Patio.intConst(42))),
                 Patio.block(List.of(), List.of(Patio.intConst(47)))
             ))
-            .addBodyInstruction(Patio.return_(Patio.localRef("r")))
+            .addBodyInstruction(emitInt(Patio.localRef("r")))
+            .addBodyInstruction(Patio.returnVoid())
             .build();
         var patio = Patio.compilationUnit(List.of(patioFunction));
 
         var result = run(patio);
 
-        assertThat(result, isSilentExit(42));
+        assertThat(result, isSequence(
+            isInt(42)
+        ));
     }
 
     @Test
     public void intAdd() throws IOException, InterruptedException {
         var patioFunction = PatioFunctionDefinition.builder()
             .withName(FUNCTION_NAME)
-            .withReturnType(PatioTypes.INT)
+            .withReturnType(PatioTypes.VOID)
             .addLocal(Patio.val("x", PatioTypes.INT))
             .addLocal(Patio.val("y", PatioTypes.INT))
             .addLocal(Patio.val("z", PatioTypes.INT))
@@ -257,20 +275,23 @@ public abstract class PatioExampleTests {
                 Patio.localRef("x"),
                 Patio.localRef("y")
             ))
-            .addBodyInstruction(Patio.return_(Patio.localRef("z")))
+            .addBodyInstruction(emitInt(Patio.localRef("z")))
+            .addBodyInstruction(Patio.returnVoid())
             .build();
         var patio = Patio.compilationUnit(List.of(patioFunction));
 
         var result = run(patio);
 
-        assertThat(result, isSilentExit(47));
+        assertThat(result, isSequence(
+            isInt(47)
+        ));
     }
 
     @Test
     public void switchWithUnreachableDefault() throws IOException, InterruptedException {
         var patioFunction = PatioFunctionDefinition.builder()
             .withName(FUNCTION_NAME)
-            .withReturnType(PatioTypes.INT)
+            .withReturnType(PatioTypes.VOID)
             .addLocal(Patio.val("x", PatioTypes.INT))
             .addLocal(Patio.val("x1", PatioTypes.INT))
             .addLocal(Patio.val("x2", PatioTypes.INT))
@@ -302,20 +323,23 @@ public abstract class PatioExampleTests {
                     List.of()
                 )
             ))
-            .addBodyInstruction(Patio.return_(Patio.localRef("x")))
+            .addBodyInstruction(emitInt(Patio.localRef("x")))
+            .addBodyInstruction(Patio.returnVoid())
             .build();
         var patio = Patio.compilationUnit(List.of(patioFunction));
 
         var result = run(patio);
 
-        assertThat(result, isSilentExit(47));
+        assertThat(result, isSequence(
+            isInt(47)
+        ));
     }
 
     @Test
     public void switchWithReachableDefault() throws IOException, InterruptedException {
         var patioFunction = PatioFunctionDefinition.builder()
             .withName(FUNCTION_NAME)
-            .withReturnType(PatioTypes.INT)
+            .withReturnType(PatioTypes.VOID)
             .addLocal(Patio.val("x", PatioTypes.INT))
             .addLocal(Patio.val("x1", PatioTypes.INT))
             .addLocal(Patio.val("x2", PatioTypes.INT))
@@ -340,20 +364,23 @@ public abstract class PatioExampleTests {
                     List.of(Patio.localRef("x2"))
                 )
             ))
-            .addBodyInstruction(Patio.return_(Patio.localRef("x")))
+            .addBodyInstruction(emitInt(Patio.localRef("x")))
+            .addBodyInstruction(Patio.returnVoid())
             .build();
         var patio = Patio.compilationUnit(List.of(patioFunction));
 
         var result = run(patio);
 
-        assertThat(result, isSilentExit(47));
+        assertThat(result, isSequence(
+            isInt(47)
+        ));
     }
 
     @Test
     public void whenExceptionIsNotThrownThenTryReturnsFromBody() throws IOException, InterruptedException {
         var patioFunction = PatioFunctionDefinition.builder()
             .withName(FUNCTION_NAME)
-            .withReturnType(PatioTypes.INT)
+            .withReturnType(PatioTypes.VOID)
             .addLocal(Patio.val("r1", PatioTypes.INT))
             .addLocal(Patio.val("r2", PatioTypes.INT))
             .addLocal(Patio.val("e1", PatioTypes.INT))
@@ -375,9 +402,8 @@ public abstract class PatioExampleTests {
                     List.of(Patio.intConst(0))
                 )
             ))
-            .addBodyInstruction(Patio.return_(
-                Patio.localRef("r1")
-            ))
+            .addBodyInstruction(emitInt(Patio.localRef("r1")))
+            .addBodyInstruction(Patio.returnVoid())
             .build();
         var patio = Patio.compilationUnit(List.of(
             Patio.exceptionTypeDefinition("Error", PatioTypes.INT),
@@ -386,14 +412,16 @@ public abstract class PatioExampleTests {
 
         var result = run(patio);
 
-        assertThat(result, isSilentExit(0));
+        assertThat(result, isSequence(
+            isInt(0)
+        ));
     }
 
     @Test
     public void whenExceptionIsThrownThenFirstMatchingExceptionHandlerIsUsed() throws IOException, InterruptedException {
         var patioFunction = PatioFunctionDefinition.builder()
             .withName(FUNCTION_NAME)
-            .withReturnType(PatioTypes.INT)
+            .withReturnType(PatioTypes.VOID)
             .addLocal(Patio.val("r1", PatioTypes.INT))
             .addLocal(Patio.val("r2", PatioTypes.INT))
             .addLocal(Patio.val("e1", PatioTypes.INT))
@@ -435,9 +463,8 @@ public abstract class PatioExampleTests {
                     List.of(Patio.localRef("r2"))
                 )
             ))
-            .addBodyInstruction(Patio.return_(
-                Patio.localRef("r1")
-            ))
+            .addBodyInstruction(emitInt(Patio.localRef("r1")))
+            .addBodyInstruction(Patio.returnVoid())
             .build();
         var patio = Patio.compilationUnit(List.of(
             Patio.exceptionTypeDefinition("Error", PatioTypes.INT),
@@ -446,14 +473,16 @@ public abstract class PatioExampleTests {
 
         var result = run(patio);
 
-        assertThat(result, isSilentExit(2));
+        assertThat(result, isSequence(
+            isInt(2)
+        ));
     }
 
     @Test
     public void multipleCatchClausesCanBeAttachedToSameTry() throws IOException, InterruptedException {
         var patioFunction = PatioFunctionDefinition.builder()
             .withName(FUNCTION_NAME)
-            .withReturnType(PatioTypes.INT)
+            .withReturnType(PatioTypes.VOID)
             .addLocal(Patio.val("r1", PatioTypes.INT))
             .addLocal(Patio.val("r2", PatioTypes.INT))
             .addLocal(Patio.val("e1", PatioTypes.INT))
@@ -485,9 +514,8 @@ public abstract class PatioExampleTests {
                     List.of(Patio.intConst(0))
                 )
             ))
-            .addBodyInstruction(Patio.return_(
-                Patio.localRef("r1")
-            ))
+            .addBodyInstruction(emitInt(Patio.localRef("r1")))
+            .addBodyInstruction(Patio.returnVoid())
             .build();
         var patio = Patio.compilationUnit(List.of(
             Patio.exceptionTypeDefinition("Error1", PatioTypes.INT),
@@ -497,14 +525,16 @@ public abstract class PatioExampleTests {
 
         var result = run(patio);
 
-        assertThat(result, isSilentExit(2));
+        assertThat(result, isSequence(
+            isInt(2)
+        ));
     }
 
     @Test
     public void whenExceptionIsThrownThenExceptionHandlerForOtherExceptionsIsIgnored() throws IOException, InterruptedException {
         var patioFunction = PatioFunctionDefinition.builder()
             .withName(FUNCTION_NAME)
-            .withReturnType(PatioTypes.INT)
+            .withReturnType(PatioTypes.VOID)
             .addLocal(Patio.val("r1", PatioTypes.INT))
             .addLocal(Patio.val("r2", PatioTypes.INT))
             .addLocal(Patio.val("e1", PatioTypes.INT))
@@ -546,9 +576,8 @@ public abstract class PatioExampleTests {
                     List.of(Patio.localRef("r2"))
                 )
             ))
-            .addBodyInstruction(Patio.return_(
-                Patio.localRef("r1")
-            ))
+            .addBodyInstruction(emitInt(Patio.localRef("r1")))
+            .addBodyInstruction(Patio.returnVoid())
             .build();
         var patio = Patio.compilationUnit(List.of(
             Patio.exceptionTypeDefinition("Error", PatioTypes.INT),
@@ -558,14 +587,16 @@ public abstract class PatioExampleTests {
 
         var result = run(patio);
 
-        assertThat(result, isSilentExit(1));
+        assertThat(result, isSequence(
+            isInt(1)
+        ));
     }
 
     @Test
     public void catchClauseCanThrow() throws IOException, InterruptedException {
         var patioFunction = PatioFunctionDefinition.builder()
             .withName(FUNCTION_NAME)
-            .withReturnType(PatioTypes.INT)
+            .withReturnType(PatioTypes.VOID)
             .addLocal(Patio.val("r1", PatioTypes.INT))
             .addLocal(Patio.val("r2", PatioTypes.INT))
             .addLocal(Patio.val("e1", PatioTypes.INT))
@@ -609,9 +640,8 @@ public abstract class PatioExampleTests {
                     List.of(Patio.localRef("r2"))
                 )
             ))
-            .addBodyInstruction(Patio.return_(
-                Patio.localRef("r1")
-            ))
+            .addBodyInstruction(emitInt(Patio.localRef("r1")))
+            .addBodyInstruction(Patio.returnVoid())
             .build();
         var patio = Patio.compilationUnit(List.of(
             Patio.exceptionTypeDefinition("Error", PatioTypes.INT),
@@ -620,14 +650,16 @@ public abstract class PatioExampleTests {
 
         var result = run(patio);
 
-        assertThat(result, isSilentExit(1));
+        assertThat(result, isSequence(
+            isInt(1)
+        ));
     }
 
     @Test
     public void exceptionHandlerIsDiscardedAfterTry() throws IOException, InterruptedException {
         var patioFunction = PatioFunctionDefinition.builder()
             .withName(FUNCTION_NAME)
-            .withReturnType(PatioTypes.INT)
+            .withReturnType(PatioTypes.VOID)
             .addLocal(Patio.val("r1", PatioTypes.INT))
             .addLocal(Patio.val("r2", PatioTypes.INT))
             .addLocal(Patio.val("e1", PatioTypes.INT))
@@ -668,9 +700,8 @@ public abstract class PatioExampleTests {
                     List.of(Patio.localRef("r2"))
                 )
             ))
-            .addBodyInstruction(Patio.return_(
-                Patio.localRef("r1")
-            ))
+            .addBodyInstruction(emitInt(Patio.localRef("r1")))
+            .addBodyInstruction(Patio.returnVoid())
             .build();
         var patio = Patio.compilationUnit(List.of(
             Patio.exceptionTypeDefinition("Error", PatioTypes.INT),
@@ -679,14 +710,16 @@ public abstract class PatioExampleTests {
 
         var result = run(patio);
 
-        assertThat(result, isSilentExit(1));
+        assertThat(result, isSequence(
+            isInt(1)
+        ));
     }
 
     @Test
     public void thrownValueIsPassedToCatchClause() throws IOException, InterruptedException {
         var patioFunction = PatioFunctionDefinition.builder()
             .withName(FUNCTION_NAME)
-            .withReturnType(PatioTypes.INT)
+            .withReturnType(PatioTypes.VOID)
             .addLocal(Patio.val("r", PatioTypes.INT))
             .addLocal(Patio.val("e", PatioTypes.INT))
             .addBodyInstruction(Patio.try_(
@@ -708,9 +741,8 @@ public abstract class PatioExampleTests {
                     List.of(Patio.intConst(0))
                 )
             ))
-            .addBodyInstruction(Patio.return_(
-                Patio.localRef("r")
-            ))
+            .addBodyInstruction(emitInt(Patio.localRef("r")))
+            .addBodyInstruction(Patio.returnVoid())
             .build();
         var patio = Patio.compilationUnit(List.of(
             Patio.exceptionTypeDefinition("Error", PatioTypes.INT),
@@ -719,14 +751,16 @@ public abstract class PatioExampleTests {
 
         var result = run(patio);
 
-        assertThat(result, isSilentExit(1));
+        assertThat(result, isSequence(
+            isInt(1)
+        ));
     }
 
     @Test
     public void vars() throws IOException, InterruptedException {
         var patioFunction = PatioFunctionDefinition.builder()
             .withName(FUNCTION_NAME)
-            .withReturnType(PatioTypes.INT)
+            .withReturnType(PatioTypes.VOID)
             .addLocal(Patio.var("x", PatioTypes.INT))
             .addLocal(Patio.val("y", PatioTypes.INT))
             .addLocal(Patio.val("z", PatioTypes.INT))
@@ -752,22 +786,23 @@ public abstract class PatioExampleTests {
                 Patio.localRef("r"),
                 Patio.localRef("x")
             ))
-            .addBodyInstruction(Patio.return_(
-                Patio.localRef("r")
-            ))
+            .addBodyInstruction(emitInt(Patio.localRef("r")))
+            .addBodyInstruction(Patio.returnVoid())
             .build();
         var patio = Patio.compilationUnit(List.of(patioFunction));
 
         var result = run(patio);
 
-        assertThat(result, isSilentExit(47));
+        assertThat(result, isSequence(
+            isInt(47)
+        ));
     }
 
     @Test
     public void canGetByteOffsetOf() throws IOException, InterruptedException {
         var patioFunction = PatioFunctionDefinition.builder()
             .withName(FUNCTION_NAME)
-            .withReturnType(PatioTypes.INT)
+            .withReturnType(PatioTypes.VOID)
             .addLocal(Patio.val("x", PatioTypes.INT))
             .addBodyInstruction(Patio.localStore(
                 Patio.localRef("x"),
@@ -788,9 +823,8 @@ public abstract class PatioExampleTests {
                     List.of(1, 2)
                 ))
             ))
-            .addBodyInstruction(Patio.return_(
-                Patio.localRef("x")
-            ))
+            .addBodyInstruction(emitInt(Patio.localRef("x")))
+            .addBodyInstruction(Patio.returnVoid())
             .build();
         var patio = Patio.compilationUnit(List.of(
             patioFunction
@@ -798,14 +832,16 @@ public abstract class PatioExampleTests {
 
         var result = run(patio);
 
-        assertThat(result, isSilentExit(4));
+        assertThat(result, isSequence(
+            isInt(4)
+        ));
     }
 
     @Test
     public void canGetByteSizeOf() throws IOException, InterruptedException {
         var patioFunction = PatioFunctionDefinition.builder()
             .withName(FUNCTION_NAME)
-            .withReturnType(PatioTypes.INT)
+            .withReturnType(PatioTypes.VOID)
             .addLocal(Patio.val("x", PatioTypes.INT))
             .addBodyInstruction(Patio.localStore(
                 Patio.localRef("x"),
@@ -825,9 +861,8 @@ public abstract class PatioExampleTests {
                     ))
                 ))
             ))
-            .addBodyInstruction(Patio.return_(
-                Patio.localRef("x")
-            ))
+            .addBodyInstruction(emitInt(Patio.localRef("x")))
+            .addBodyInstruction(Patio.returnVoid())
             .build();
         var patio = Patio.compilationUnit(List.of(
             patioFunction
@@ -835,16 +870,45 @@ public abstract class PatioExampleTests {
 
         var result = run(patio);
 
-        assertThat(result, isSilentExit(7));
+        assertThat(result, isSequence(
+            isInt(7)
+        ));
+    }
+
+    private PatioInstruction emitInt(PatioOperand value) {
+        return Patio.call(Optional.empty(), "patio__test__emit_int", List.of(value));
     }
 
-    private Matcher<ExecutionResult> isSilentExit(int exitCode) {
-        return allOf(
-            has("stderr", x -> x.stderr(), equalTo("")),
-            has("stdout", x -> x.stdout(), equalTo("")),
-            has("exitCode", x -> x.exitCode(), equalTo(exitCode))
+    private Matcher<PatioTestOutput> isInt(int value) {
+        return instanceOf(
+            PatioTestOutput.Int.class,
+            has("value", PatioTestOutput.Int::value, equalTo(value))
         );
     }
 
-    protected abstract ExecutionResult run(PatioCompilationUnit patio) throws IOException, InterruptedException;
+    private List<PatioTestOutput> run(PatioCompilationUnit patio) throws IOException, InterruptedException {
+        var emitIntDeclaration = PatioFunctionDeclaration.builder()
+            .withName("patio__test__emit_int")
+            .addParam(PatioLocal.param("value", PatioTypes.INT))
+            .withReturnType(PatioTypes.VOID)
+            .build();
+
+        var result = executeCompilationUnit(new PatioCompilationUnit(
+            Lists.concat(patio.elements(), List.of(emitIntDeclaration)),
+            patio.source()
+        ));
+        assertThat(result.stderr(), equalTo(""));
+        assertThat(result.exitCode(), equalTo(0));
+        return parseTestOutput(result.stdout());
+    }
+
+    private List<PatioTestOutput> parseTestOutput(String stdout) {
+        return stdout.lines()
+            .map(line -> PatioTestOutput.int_(Integer.parseInt(line)))
+            .toList();
+    }
+
+    protected abstract ExecutionResult executeCompilationUnit(
+        PatioCompilationUnit patio
+    ) throws IOException, InterruptedException;
 }
diff --git a/src/test/java/org/shedlang/compiler/patio/PatioTestOutput.java b/src/test/java/org/shedlang/compiler/patio/PatioTestOutput.java
new file mode 100644
index 00000000..8f7956a9
--- /dev/null
+++ b/src/test/java/org/shedlang/compiler/patio/PatioTestOutput.java
@@ -0,0 +1,9 @@
+package org.shedlang.compiler.patio;
+
+public sealed interface PatioTestOutput {
+    static PatioTestOutput int_(int value) {
+        return new Int(value);
+    }
+
+    record Int(int value) implements PatioTestOutput {}
+}