Support exception handler method break

5 files changed, 97 insertions, 9 deletions

diff --git a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmPatioCodeGen.java b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmPatioCodeGen.java
index 37cda648..097eb2d8 100644
--- a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmPatioCodeGen.java
+++ b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmPatioCodeGen.java
@@ -633,6 +633,9 @@ public class LlvmPatioCodeGen {
                     )
                 ));
 
+                // TODO: construct a test for this in PatioExampleTests
+                context = context.addTerminatorInstruction(new LlvmUnreachable());
+
                 yield context;
             }
 
diff --git a/src/main/java/org/shedlang/compiler/patio/PatioCodeGen.java b/src/main/java/org/shedlang/compiler/patio/PatioCodeGen.java
index 733152b4..a555d181 100644
--- a/src/main/java/org/shedlang/compiler/patio/PatioCodeGen.java
+++ b/src/main/java/org/shedlang/compiler/patio/PatioCodeGen.java
@@ -309,7 +309,18 @@ public class PatioCodeGen {
             }
 
             case ShedEffectHandlerBreak effectHandlerBreak -> {
-                throw new UnsupportedOperationException("TODO");
+                var valueResult = context.temporaryPop();
+                var value = valueResult.value();
+                context = valueResult.context();
+
+                context = PatioCodeGenEffects.break_(
+                    effectHandlerBreak.effect(),
+                    value,
+                    effectHandlerBreak.source(),
+                    context
+                );
+
+                yield context;
             }
 
             case ShidFieldLoad fieldLoad -> {
@@ -668,15 +679,25 @@ public class PatioCodeGen {
                     handlerMethodsByName.put(handlerMethodName, handlerMethod);
                 }
 
+                var targetResult = context.allocateVal(
+                    PatioCodeGenLocalSpace.TEMPORARY,
+                    PatioCodeGenTypes.VALUE_TYPE
+                );
+                var target = targetResult.value();
+                context = targetResult.context();
+
                 context = PatioCodeGenEffects.try_(
+                    target,
                     try_.handledEffect(),
                     handlerMethodsByName,
                     bodyContext ->
-                        generateInstructions(try_.body(), bodyContext),
+                        generateBlock(1, try_.body(), try_.source(), bodyContext),
                     try_.source(),
                     context
                 );
 
+                context = context.temporaryPush(target);
+
                 yield context;
             }
 
diff --git a/src/main/java/org/shedlang/compiler/patio/PatioCodeGenContext.java b/src/main/java/org/shedlang/compiler/patio/PatioCodeGenContext.java
index 219f9ec1..5dcd91eb 100644
--- a/src/main/java/org/shedlang/compiler/patio/PatioCodeGenContext.java
+++ b/src/main/java/org/shedlang/compiler/patio/PatioCodeGenContext.java
@@ -709,6 +709,12 @@ public record PatioCodeGenContext(
     }
 
     @CheckReturnValue
+    public String exceptionTypeName(UserDefinedEffect effect) {
+        // TODO: Allocate properly
+        return "shed__effect__exception__" + String.join("_", effect.namespaceName().parts()) + "__" + effect.name();
+    }
+
+    @CheckReturnValue
     private PatioCodeGenContext withCompilationUnitContext(CompilationUnitContext compilationUnitContext) {
         return new PatioCodeGenContext(this.globalContext, compilationUnitContext, this.blockStack, this.functionContext);
     }
diff --git a/src/main/java/org/shedlang/compiler/patio/PatioCodeGenEffects.java b/src/main/java/org/shedlang/compiler/patio/PatioCodeGenEffects.java
index 74073b2f..4dbb7438 100644
--- a/src/main/java/org/shedlang/compiler/patio/PatioCodeGenEffects.java
+++ b/src/main/java/org/shedlang/compiler/patio/PatioCodeGenEffects.java
@@ -1,6 +1,7 @@
 package org.shedlang.compiler.patio;
 
 import org.shedlang.compiler.ast.typed.FreeVariables;
+import org.shedlang.compiler.patio.ast.PatioExceptionTypeDefinition;
 import org.shedlang.compiler.patio.ast.PatioFunctionDeclaration;
 import org.shedlang.compiler.patio.ast.PatioLocal;
 import org.shedlang.compiler.patio.ast.PatioVisibility;
@@ -13,9 +14,9 @@ import org.shedlang.compiler.patio.ast.types.PatioDataLayout;
 import org.shedlang.compiler.patio.ast.types.PatioDataLayouts;
 import org.shedlang.compiler.patio.ast.types.PatioType;
 import org.shedlang.compiler.patio.ast.types.PatioTypes;
+import org.shedlang.compiler.shid.instructions.ShidDefineFunction;
 import org.shedlang.compiler.sources.Source;
 import org.shedlang.compiler.sources.Sources;
-import org.shedlang.compiler.shid.instructions.ShidDefineFunction;
 import org.shedlang.compiler.types.UserDefinedEffect;
 import org.shedlang.compiler.util.Lists;
 
@@ -116,6 +117,12 @@ public class PatioCodeGenEffects {
         Source source,
         PatioCodeGenContext context
     ) {
+        context = context.addCompilationUnitElement(new PatioExceptionTypeDefinition(
+            context.exceptionTypeName(effect),
+            PatioCodeGenTypes.VALUE_TYPE,
+            source
+        ));
+
         var effectPointerResult = context.allocateVal(
             PatioCodeGenLocalSpace.USER_DEFINED_EFFECT_POINTER,
             effect.name(),
@@ -264,9 +271,10 @@ public class PatioCodeGenEffects {
     }
 
     public static PatioCodeGenContext try_(
+        PatioLocalRef target,
         UserDefinedEffect effect,
         Map<String, PatioOperand> handlerMethodsByName,
-        Function<PatioCodeGenContext, PatioCodeGenContext> generateBody,
+        Function<PatioCodeGenContext, PatioCodeGenResult<PatioBlock>> generateBody,
         Source source,
         PatioCodeGenContext context
     ) {
@@ -307,12 +315,37 @@ public class PatioCodeGenEffects {
             ));
         }
 
-        context = generateBody.apply(context);
+        var bodyResult = generateBody.apply(context);
+        var body = bodyResult.value();
+        context = bodyResult.context();
 
-        context = context.addInstruction(new PatioCall(
-            Optional.empty(),
-            POP_HANDLER_DECLARATION.name(),
-            List.of(),
+        var exceptionValueResult = context.allocateVal(
+            PatioCodeGenLocalSpace.TEMPORARY,
+            PatioCodeGenTypes.VALUE_TYPE
+        );
+        var exceptionValue = exceptionValueResult.value();
+        context = exceptionValueResult.context();
+
+        context = context.addInstruction(new PatioTry(
+            List.of(target),
+            List.of(
+                new PatioCatchClause(
+                    context.exceptionTypeName(effect),
+                    exceptionValue,
+                    new PatioBlock(
+                        List.of(),
+                        List.of(exceptionValue),
+                        source
+                    ),
+                    source
+                )
+            ),
+            body.addInstruction(new PatioCall(
+                Optional.empty(),
+                POP_HANDLER_DECLARATION.name(),
+                List.of(),
+                source
+            )),
             source
         ));
 
@@ -472,6 +505,23 @@ public class PatioCodeGenEffects {
         return context;
     }
 
+    public static PatioCodeGenContext break_(
+        UserDefinedEffect effect,
+        PatioOperand value,
+        Source source,
+        PatioCodeGenContext context
+    ) {
+        var exceptionTypeName = context.exceptionTypeName(effect);
+
+        context = context.addInstruction(new PatioThrow(
+            exceptionTypeName,
+            value,
+            source
+        ));
+
+        return context;
+    }
+
     private static PatioCodeGenContext getCurrentEffectHandler(
         PatioLocalRef target,
         Source source,
diff --git a/src/main/java/org/shedlang/compiler/patio/ast/instructions/PatioBlock.java b/src/main/java/org/shedlang/compiler/patio/ast/instructions/PatioBlock.java
index 8eecfa84..50c59fbf 100644
--- a/src/main/java/org/shedlang/compiler/patio/ast/instructions/PatioBlock.java
+++ b/src/main/java/org/shedlang/compiler/patio/ast/instructions/PatioBlock.java
@@ -2,6 +2,7 @@ package org.shedlang.compiler.patio.ast.instructions;
 
 import org.shedlang.compiler.patio.ast.operands.PatioOperand;
 import org.shedlang.compiler.sources.Source;
+import org.shedlang.compiler.util.Lists;
 
 import java.util.List;
 
@@ -10,4 +11,11 @@ public record PatioBlock(
     List<PatioOperand> results,
     Source source
 ) {
+    public PatioBlock addInstruction(PatioInstruction instruction) {
+        return new PatioBlock(
+            Lists.concat(this.body, List.of(instruction)),
+            this.results,
+            this.source
+        );
+    }
 }