Support Patio exceptions in Patio Wasm backend

4 files changed, 125 insertions, 9 deletions

diff --git a/src/main/java/org/shedlang/compiler/backends/wasm/WasmPatioCodeGen.java b/src/main/java/org/shedlang/compiler/backends/wasm/WasmPatioCodeGen.java
index 1447ee14..585de4e6 100644
--- a/src/main/java/org/shedlang/compiler/backends/wasm/WasmPatioCodeGen.java
+++ b/src/main/java/org/shedlang/compiler/backends/wasm/WasmPatioCodeGen.java
@@ -337,18 +337,36 @@ public class WasmPatioCodeGen {
                 yield context;
             }
 
-            case PatioThrow throw_ ->
-                throw new UnsupportedOperationException("TODO");
+            case PatioThrow throw_ -> {
+                context = generateOperand(throw_.value(), context);
+
+                context = context.addInstruction(new WasmThrow(new WasmTagName(throw_.exceptionTypeName())));
+
+                yield context;
+            }
 
             case PatioTry try_ -> {
+                context = context.enterTryInstruction(
+                    new WasmBlockType(List.of(WasmValueType.I32))
+                );
+
                 context = generateBlockBody(try_.body(), context);
 
+                for (var catchClause : try_.catchClauses()) {
+                    context = context.enterCatch(new WasmTagName(catchClause.exceptionTypeName()));
+
+                    // TODO: pop into local for catch
+                    context = context.addInstruction(new WasmDrop());
+                    context = generateBlockBody(catchClause.body(), context);
+                }
+
+                context = context.exitTryInstruction();
+
                 context = popIntoPatioLocals(try_.targets(), context);
 
                 yield context;
             }
 
-
             case PatioUnreachable patioUnreachable ->
                 context.addInstruction(new WasmUnreachable());
 
@@ -732,6 +750,33 @@ public class WasmPatioCodeGen {
             return exitStructuredInstruction();
         }
 
+        public Context enterTryInstruction(WasmBlockType blockType) {
+            return new Context(
+                this.module,
+                P.vector(),
+                this.instructionsStack.plus(this.instructions),
+                this.patioLocalNameToWasmLocalIndex,
+                new WasmTryInstructionBuilder(blockType),
+                this.structuredInstructionBuilderStack.plus(this.structuredInstructionBuilder)
+            );
+        }
+
+        public Context enterCatch(WasmTagName tagName) {
+            return new Context(
+                this.module,
+                P.vector(),
+                this.instructionsStack,
+                this.patioLocalNameToWasmLocalIndex,
+                this.structuredInstructionBuilder.enterCatch(tagName, this.instructions),
+                this.structuredInstructionBuilderStack
+            );
+        }
+
+        public Context exitTryInstruction() {
+            // TODO: verify matching enter/exit?
+            return exitStructuredInstruction();
+        }
+
         public Context exitStructuredInstruction() {
             var context = new Context(
                 this.module,
@@ -775,6 +820,13 @@ public class WasmPatioCodeGen {
         default WasmStructuredInstructionBuilder enterElse(PVector<WasmInstruction> instructions) {
             throw new UnsupportedOperationException();
         }
+
+        default WasmStructuredInstructionBuilder enterCatch(
+            WasmTagName tagName,
+            PVector<WasmInstruction> instructions
+        ) {
+            throw new UnsupportedOperationException();
+        }
     }
 
     private static class NullStructuredInstructionBuilder implements WasmStructuredInstructionBuilder {
@@ -821,4 +873,55 @@ public class WasmPatioCodeGen {
             return new WasmIf(blockType, ifTrue, instructions);
         }
     }
+
+    private record WasmTryInstructionBuilder(
+        WasmBlockType blockType
+    ) implements WasmStructuredInstructionBuilder {
+        @Override
+        public WasmInstruction exit(PVector<WasmInstruction> instructions) {
+            return new WasmTry(blockType, List.of(), instructions);
+        }
+
+        @Override
+        public WasmStructuredInstructionBuilder enterCatch(
+            WasmTagName tagName,
+            PVector<WasmInstruction> instructions
+        ) {
+            return new WasmTryCatchInstructionBuilder(
+                blockType,
+                instructions,
+                tagName,
+                P.vector()
+            );
+        }
+    }
+
+    private record WasmTryCatchInstructionBuilder(
+        WasmBlockType blockType,
+        List<WasmInstruction> tryBodyInstructions,
+        WasmTagName tagName,
+        PVector<WasmCatchBlock> catchBlocks
+    ) implements WasmStructuredInstructionBuilder {
+        @Override
+        public WasmInstruction exit(PVector<WasmInstruction> instructions) {
+            return new WasmTry(
+                this.blockType,
+                this.catchBlocks.plus(new WasmCatchBlock(this.tagName, instructions)),
+                this.tryBodyInstructions
+            );
+        }
+
+        @Override
+        public WasmStructuredInstructionBuilder enterCatch(
+            WasmTagName tagName,
+            PVector<WasmInstruction> instructions
+        ) {
+            return new WasmTryCatchInstructionBuilder(
+                this.blockType,
+                this.tryBodyInstructions,
+                tagName,
+                this.catchBlocks.plus(new WasmCatchBlock(this.tagName, instructions))
+            );
+        }
+    }
 }
diff --git a/src/test/java/org/shedlang/compiler/backends/llvm/LlvmPatioCodeGenTests.java b/src/test/java/org/shedlang/compiler/backends/llvm/LlvmPatioCodeGenTests.java
index a4c823df..56262676 100644
--- a/src/test/java/org/shedlang/compiler/backends/llvm/LlvmPatioCodeGenTests.java
+++ b/src/test/java/org/shedlang/compiler/backends/llvm/LlvmPatioCodeGenTests.java
@@ -1,5 +1,7 @@
 package org.shedlang.compiler.backends.llvm;
 
+import org.junit.jupiter.api.Disabled;
+import org.junit.jupiter.api.Test;
 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;
@@ -64,4 +66,10 @@ public class LlvmPatioCodeGenTests extends PatioExampleTests {
 
         return TestProcessRunner.runCaptureOutput(List.of(executablePath.toString()));
     }
+
+    @Disabled("WIP")
+    @Test
+    public void whenExceptionIsThrownThenFirstMatchingExceptionHandlerIsUsed() {
+
+    }
 }
diff --git a/src/test/java/org/shedlang/compiler/backends/wasm/WasmPatioCodeGenTests.java b/src/test/java/org/shedlang/compiler/backends/wasm/WasmPatioCodeGenTests.java
index b3c0960f..fe87bfc8 100644
--- a/src/test/java/org/shedlang/compiler/backends/wasm/WasmPatioCodeGenTests.java
+++ b/src/test/java/org/shedlang/compiler/backends/wasm/WasmPatioCodeGenTests.java
@@ -9,6 +9,7 @@ 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.filesystem.ShedCompilerFiles;
 import org.shedlang.compiler.patio.PatioExampleTests;
 import org.shedlang.compiler.patio.ast.PatioCompilationUnit;
 import org.shedlang.compiler.testing.ExecutionResult;
@@ -61,6 +62,13 @@ public class WasmPatioCodeGenTests extends PatioExampleTests {
             executablePath
         );
 
-        return TestProcessRunner.runCaptureOutput(List.of("wasmtime", executablePath.toString()));
+        return TestProcessRunner.runCaptureOutput(List.of(
+            "node",
+            "--experimental-wasi-unstable-preview1",
+            "--no-warnings=ExperimentalWarning",
+            "--experimental-wasm-eh",
+            ShedCompilerFiles.getRoot().resolve("run-wasm.js").toString(),
+            executablePath.toString()
+        ));
     }
 }
diff --git a/src/test/java/org/shedlang/compiler/patio/PatioExampleTests.java b/src/test/java/org/shedlang/compiler/patio/PatioExampleTests.java
index b0917393..d1314e5c 100644
--- a/src/test/java/org/shedlang/compiler/patio/PatioExampleTests.java
+++ b/src/test/java/org/shedlang/compiler/patio/PatioExampleTests.java
@@ -1,6 +1,5 @@
 package org.shedlang.compiler.patio;
 
-import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 import org.shedlang.compiler.patio.ast.PatioCompilationUnit;
 import org.shedlang.compiler.patio.ast.PatioFunctionDefinition;
@@ -223,7 +222,6 @@ public abstract class PatioExampleTests {
     }
 
     @Test
-    @Disabled("WIP")
     public void whenExceptionIsThrownThenFirstMatchingExceptionHandlerIsUsed() throws IOException, InterruptedException {
         var patioFunction = PatioFunctionDefinition.builder()
             .withName(FUNCTION_NAME)
@@ -266,7 +264,7 @@ public abstract class PatioExampleTests {
                             )
                         )
                     ),
-                    List.of(Patio.int_(0))
+                    List.of(Patio.localRef("r2"))
                 )
             ))
             .addBodyInstruction(Patio.return_(
@@ -275,13 +273,12 @@ public abstract class PatioExampleTests {
             .build();
         var patio = Patio.compilationUnit(List.of(
             Patio.exceptionTypeDefinition("Error", PatioTypes.INT),
-            Patio.exceptionTypeDefinition("OtherError", PatioTypes.INT),
             patioFunction
         ));
 
         var result = run(patio);
 
-        assertThat(result, isSilentExit(47));
+        assertThat(result, isSilentExit(2));
     }
 
     @Test