Add tags when generating Patio code for structs

4 files changed, 73 insertions, 5 deletions

diff --git a/src/main/java/org/shedlang/compiler/patio/PatioCodeGen.java b/src/main/java/org/shedlang/compiler/patio/PatioCodeGen.java
index 66c2faf4..faa8007e 100644
--- a/src/main/java/org/shedlang/compiler/patio/PatioCodeGen.java
+++ b/src/main/java/org/shedlang/compiler/patio/PatioCodeGen.java
@@ -524,6 +524,20 @@ public class PatioCodeGen {
                 var value = valueResult.value();
                 context = valueResult.context();
 
+                var tagResult = context.allocateVal(
+                    PatioCodeGenLocalSpace.SWITCH_TAG,
+                    PatioCodeGenTypes.TAG_TYPE
+                );
+                var tag = tagResult.value();
+                context = tagResult.context();
+
+                context = PatioCodeGenStructs.tagLoad(
+                    tag,
+                    value,
+                    switch_.source(),
+                    context
+                );
+
                 var cases = new ArrayList<PatioSwitch.Case>();
 
                 for (var stackIrCase : switch_.cases()) {
@@ -545,7 +559,7 @@ public class PatioCodeGen {
 
                 context = context.addInstruction(new PatioSwitch(
                     List.of(target),
-                    value,
+                    tag,
                     cases,
                     new PatioBlock(
                         List.of(
diff --git a/src/main/java/org/shedlang/compiler/patio/PatioCodeGenLocalSpace.java b/src/main/java/org/shedlang/compiler/patio/PatioCodeGenLocalSpace.java
index 6a5f40e1..cbe6c9b5 100644
--- a/src/main/java/org/shedlang/compiler/patio/PatioCodeGenLocalSpace.java
+++ b/src/main/java/org/shedlang/compiler/patio/PatioCodeGenLocalSpace.java
@@ -14,9 +14,11 @@ public enum PatioCodeGenLocalSpace {
     LOCAL("local"),
     RECEIVER("receiver"),
     STRING("string"),
+    STRUCT_TAG_POINTER("structTagPointer"),
     STRUCT_TYPE("structType"),
     STRUCT_VALUE("structValue"),
     STRUCT_VALUE_POINTER("structValuePointer"),
+    SWITCH_TAG("switchTag"),
     TEMPORARY("tmp"),
     TUPLE("tuple"),
     TUPLE_ELEMENT("tupleElement"),
diff --git a/src/main/java/org/shedlang/compiler/patio/PatioCodeGenStructs.java b/src/main/java/org/shedlang/compiler/patio/PatioCodeGenStructs.java
index e5f645f2..0f0b2920 100644
--- a/src/main/java/org/shedlang/compiler/patio/PatioCodeGenStructs.java
+++ b/src/main/java/org/shedlang/compiler/patio/PatioCodeGenStructs.java
@@ -2,6 +2,7 @@ package org.shedlang.compiler.patio;
 
 import org.shedlang.compiler.ast.typed.FreeVariables;
 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.types.PatioDataLayout;
 import org.shedlang.compiler.patio.ast.types.PatioDataLayouts;
@@ -49,6 +50,15 @@ public class PatioCodeGenStructs {
                     source
                 ));
 
+                bodyContext = bodyContext
+                    .addInstruction(new PatioMemoryStore(
+                        valuePointer,
+                        structDataLayout,
+                        List.of(0),
+                        new PatioInt(context.tag(type)),
+                        source
+                    ));
+
                 for (var fieldIndex = 0; fieldIndex < fields.size(); fieldIndex++) {
                     var field = fields.get(fieldIndex);
 
@@ -56,7 +66,7 @@ public class PatioCodeGenStructs {
                         .addInstruction(new PatioMemoryStore(
                             valuePointer,
                             structDataLayout,
-                            List.of(fieldIndex),
+                            List.of(1, fieldIndex),
                             bodyContext.stackIrLocalNameToLocal(field.name()),
                             source
                         ));
@@ -114,22 +124,63 @@ public class PatioCodeGenStructs {
             target,
             valuePointer,
             structDataLayout,
-            List.of(fieldIndex),
+            List.of(1, fieldIndex),
             source
         ));
 
         return context;
     }
 
+    public static PatioCodeGenContext tagLoad(
+        PatioLocalRef target,
+        PatioLocalRef receiver,
+        Source source,
+        PatioCodeGenContext context
+    ) {
+        var valuePointerResult = context.allocateVal(
+            PatioCodeGenLocalSpace.STRUCT_VALUE_POINTER,
+            PatioTypes.DATA_POINTER
+        );
+        var valuePointer = valuePointerResult.value();
+        context = valuePointerResult.context();
+
+        context = context.addInstruction(new PatioIntToDataPtr(
+            valuePointer,
+            receiver,
+            source
+        ));
+
+        var structDataLayout = unknownStructDataLayout();
+
+        context = context.addInstruction(new PatioMemoryLoad(
+            target,
+            valuePointer,
+            structDataLayout,
+            List.of(0),
+            source
+        ));
+
+        return context;
+    }
+
+    private static PatioDataLayout unknownStructDataLayout() {
+        return PatioDataLayouts.struct(List.of(
+            PatioDataLayouts.INT
+        ));
+    }
+
     private static PatioDataLayout structDataLayout(
         StructType type,
         PatioCodeGenContext context
     ) {
         var structTypeInfo = context.structTypeInfo(type);
 
-        return PatioDataLayouts.struct(Lists.repeat(
+        return PatioDataLayouts.struct(List.of(
             PatioDataLayouts.INT,
-            structTypeInfo.fieldCount()
+            PatioDataLayouts.struct(Lists.repeat(
+                PatioDataLayouts.INT,
+                structTypeInfo.fieldCount()
+            ))
         ));
     }
 }
diff --git a/src/main/java/org/shedlang/compiler/patio/PatioCodeGenTypes.java b/src/main/java/org/shedlang/compiler/patio/PatioCodeGenTypes.java
index d399fa08..26d164fe 100644
--- a/src/main/java/org/shedlang/compiler/patio/PatioCodeGenTypes.java
+++ b/src/main/java/org/shedlang/compiler/patio/PatioCodeGenTypes.java
@@ -6,5 +6,6 @@ import org.shedlang.compiler.patio.ast.types.PatioTypes;
 public class PatioCodeGenTypes {
     private PatioCodeGenTypes() {}
 
+    public static final PatioType TAG_TYPE = PatioTypes.INT;
     public static final PatioType VALUE_TYPE = PatioTypes.INT;
 }