Generate Patio code for try statements

3 files changed, 109 insertions, 7 deletions

diff --git a/src/main/java/org/shedlang/compiler/patio/PatioCodeGen.java b/src/main/java/org/shedlang/compiler/patio/PatioCodeGen.java
index d97eeeff..dc4733f4 100644
--- a/src/main/java/org/shedlang/compiler/patio/PatioCodeGen.java
+++ b/src/main/java/org/shedlang/compiler/patio/PatioCodeGen.java
@@ -13,10 +13,7 @@ import org.shedlang.compiler.stackir.StackIrNamespace;
 import org.shedlang.compiler.stackir.instructions.*;
 import org.shedlang.compiler.types.NamespaceName;
 
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-import java.util.Map;
+import java.util.*;
 
 public class PatioCodeGen {
     private PatioCodeGen() {}
@@ -607,7 +604,26 @@ public class PatioCodeGen {
             }
 
             case TryInstruction try_ -> {
-                throw new UnsupportedOperationException("TODO");
+                var handlerMethodsByName = new HashMap<String, PatioOperand>();
+
+                for (var handlerMethodName : try_.handlerMethodNames().reversed()) {
+                    var handlerMethodResult = context.temporaryPop();
+                    var handlerMethod = handlerMethodResult.value();
+                    context = handlerMethodResult.context();
+
+                    handlerMethodsByName.put(handlerMethodName, handlerMethod);
+                }
+
+                context = PatioCodeGenEffects.try_(
+                    try_.handledEffect(),
+                    handlerMethodsByName,
+                    bodyContext ->
+                        generateInstructions(try_.body(), bodyContext),
+                    try_.source(),
+                    context
+                );
+
+                yield context;
             }
 
             case TupleCreateInstruction tupleCreate -> {
diff --git a/src/main/java/org/shedlang/compiler/patio/PatioCodeGenEffects.java b/src/main/java/org/shedlang/compiler/patio/PatioCodeGenEffects.java
index fa83c187..2ade62ee 100644
--- a/src/main/java/org/shedlang/compiler/patio/PatioCodeGenEffects.java
+++ b/src/main/java/org/shedlang/compiler/patio/PatioCodeGenEffects.java
@@ -6,6 +6,7 @@ import org.shedlang.compiler.patio.ast.PatioLocal;
 import org.shedlang.compiler.patio.ast.instructions.*;
 import org.shedlang.compiler.patio.ast.operands.PatioInt;
 import org.shedlang.compiler.patio.ast.operands.PatioLocalRef;
+import org.shedlang.compiler.patio.ast.operands.PatioOperand;
 import org.shedlang.compiler.patio.ast.types.PatioDataLayout;
 import org.shedlang.compiler.patio.ast.types.PatioDataLayouts;
 import org.shedlang.compiler.patio.ast.types.PatioType;
@@ -19,11 +20,14 @@ import org.shedlang.compiler.util.Lists;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
+import java.util.function.Function;
 import java.util.stream.IntStream;
 
 public class PatioCodeGenEffects {
     private static final PatioType EFFECT_TAG_TYPE = PatioTypes.INT;
     private static final PatioType EFFECT_METHOD_INDEX_TYPE = PatioTypes.INT;
+    private static final PatioType EFFECT_HANDLER_TYPE = PatioTypes.DATA_POINTER;
+    private static final PatioType EFFECT_HANDLER_METHOD_TYPE = PatioCodeGenClosures.CLOSURE_TYPE;
 
     private static final PatioFunctionDeclaration FIND_HANDLER_METHOD_DECLARATION = new PatioFunctionDeclaration(
         "shed__runtime__effects_find_handler_method",
@@ -31,7 +35,34 @@ public class PatioCodeGenEffects {
             new PatioLocal.Param("effectTag", EFFECT_TAG_TYPE),
             new PatioLocal.Param("methodIndex", EFFECT_METHOD_INDEX_TYPE)
         ),
-        PatioCodeGenTypes.VALUE_TYPE,
+        EFFECT_HANDLER_METHOD_TYPE,
+        Sources.RUNTIME
+    );
+
+    private static final PatioFunctionDeclaration PUSH_HANDLER_DECLARATION = new PatioFunctionDeclaration(
+        "shed__runtime__effects_push_handler",
+        List.of(
+            new PatioLocal.Param("effectTag", EFFECT_TAG_TYPE)
+        ),
+        EFFECT_HANDLER_TYPE,
+        Sources.RUNTIME
+    );
+
+    private static final PatioFunctionDeclaration SET_HANDLER_METHOD_DECLARATION = new PatioFunctionDeclaration(
+        "shed__runtime__effects_set_handler_method",
+        List.of(
+            new PatioLocal.Param("handler", EFFECT_HANDLER_TYPE),
+            new PatioLocal.Param("methodIndex", EFFECT_METHOD_INDEX_TYPE),
+            new PatioLocal.Param("handlerMethod", EFFECT_HANDLER_METHOD_TYPE)
+        ),
+        PatioTypes.VOID,
+        Sources.RUNTIME
+    );
+
+    private static final PatioFunctionDeclaration POP_HANDLER_DECLARATION = new PatioFunctionDeclaration(
+        "shed__runtime__effects_pop_handler",
+        List.of(),
+        PatioTypes.VOID,
         Sources.RUNTIME
     );
 
@@ -88,7 +119,7 @@ public class PatioCodeGenEffects {
 
                     var handlerMethodResult = bodyContext.allocateVal(
                         PatioCodeGenLocalSpace.EFFECT_HANDLER_METHOD,
-                        PatioCodeGenClosures.CLOSURE_TYPE
+                        EFFECT_HANDLER_METHOD_TYPE
                     );
                     var handlerMethod = handlerMethodResult.value();
                     bodyContext = handlerMethodResult.context();
@@ -191,6 +222,60 @@ public class PatioCodeGenEffects {
         return context;
     }
 
+    public static PatioCodeGenContext try_(
+        UserDefinedEffect effect,
+        Map<String, PatioOperand> handlerMethodsByName,
+        Function<PatioCodeGenContext, PatioCodeGenContext> generateBody,
+        Source source,
+        PatioCodeGenContext context
+    ) {
+        context = context
+            .ensureCompilationUnitElement(PUSH_HANDLER_DECLARATION)
+            .ensureCompilationUnitElement(SET_HANDLER_METHOD_DECLARATION)
+            .ensureCompilationUnitElement(POP_HANDLER_DECLARATION);
+
+        var effectHandlerResult = context.allocateVal(
+            PatioCodeGenLocalSpace.EFFECT_HANDLER,
+            EFFECT_HANDLER_TYPE
+        );
+        var effectHandler = effectHandlerResult.value();
+        context = effectHandlerResult.context();
+
+        context = context.addInstruction(new PatioCall(
+            Optional.of(effectHandler),
+            PUSH_HANDLER_DECLARATION.name(),
+            List.of(
+                new PatioInt(context.effectTag(effect))
+            ),
+            source
+        ));
+
+        var effectInfo = context.userDefinedEffectInfo(effect);
+        for (var handlerMethodInfo : effectInfo.methods()) {
+            context = context.addInstruction(new PatioCall(
+                Optional.empty(),
+                SET_HANDLER_METHOD_DECLARATION.name(),
+                List.of(
+                    effectHandler,
+                    new PatioInt(handlerMethodInfo.fieldIndex()),
+                    handlerMethodsByName.get(handlerMethodInfo.name())
+                ),
+                source
+            ));
+        }
+
+        context = generateBody.apply(context);
+
+        context = context.addInstruction(new PatioCall(
+            Optional.of(effectHandler),
+            POP_HANDLER_DECLARATION.name(),
+            List.of(),
+            source
+        ));
+
+        return context;
+    }
+
     private static PatioDataLayout userDefinedEffectLayout(
         UserDefinedEffect effect,
         PatioCodeGenContext context
diff --git a/src/main/java/org/shedlang/compiler/patio/PatioCodeGenLocalSpace.java b/src/main/java/org/shedlang/compiler/patio/PatioCodeGenLocalSpace.java
index 255a69c5..14ba666c 100644
--- a/src/main/java/org/shedlang/compiler/patio/PatioCodeGenLocalSpace.java
+++ b/src/main/java/org/shedlang/compiler/patio/PatioCodeGenLocalSpace.java
@@ -7,6 +7,7 @@ public enum PatioCodeGenLocalSpace {
     CLOSURE("closure"),
     CLOSURE_POINTER("closurePointer"),
     CLOSURE_FUNCTION_POINTER("closureFunctionPointer"),
+    EFFECT_HANDLER("effectHandler"),
     EFFECT_HANDLER_METHOD("effectHandlerMethod"),
     MAIN("main"),
     NAMESPACE_IS_INITED_POINTER("namespaceIsInitedPointer"),