From 5410764249f70d3a20c12bdfc867890ae633516b Mon Sep 17 00:00:00 2001
From: Volker Berlin <volker.berlin@googlemail.com>
Date: Sat, 1 Feb 2020 20:29:29 +0100
Subject: [PATCH] implement CAST operation, WIP

---
 .../module/JavaMethodWasmCodeBuilder.java         |  8 +++++---
 .../module/WasmStructInstruction.java             |  2 ++
 .../jwebassembly/wasm/StructOperator.java         |  1 +
 .../jwebassembly/runtime/RuntimeErrors.java       | 15 +++++++++++++--
 4 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/src/de/inetsoftware/jwebassembly/module/JavaMethodWasmCodeBuilder.java b/src/de/inetsoftware/jwebassembly/module/JavaMethodWasmCodeBuilder.java
index 15fec3d..438d3f1 100644
--- a/src/de/inetsoftware/jwebassembly/module/JavaMethodWasmCodeBuilder.java
+++ b/src/de/inetsoftware/jwebassembly/module/JavaMethodWasmCodeBuilder.java
@@ -653,10 +653,12 @@ class JavaMethodWasmCodeBuilder extends WasmCodeBuilder {
                     case 191: // athrow
                         addBlockInstruction( WasmBlockOperator.THROW, null, codePos, lineNumber );
                         break;
-                    //TODO case 192: // checkcast
+                    case 192: // checkcast
+                        name = ((ConstantClass)constantPool.get( byteCode.readUnsignedShort() )).getName();
+                        addStructInstruction( StructOperator.CAST, name, null, codePos, lineNumber );
+                        break;
                     case 193: // instanceof
-                        idx = byteCode.readUnsignedShort();
-                        name = ((ConstantClass)constantPool.get( idx )).getName();
+                        name = ((ConstantClass)constantPool.get( byteCode.readUnsignedShort() )).getName();
                         addStructInstruction( StructOperator.INSTANCEOF, name, null, codePos, lineNumber );
                         break;
                     case 194: // monitorenter
diff --git a/src/de/inetsoftware/jwebassembly/module/WasmStructInstruction.java b/src/de/inetsoftware/jwebassembly/module/WasmStructInstruction.java
index ec9a420..8e72152 100644
--- a/src/de/inetsoftware/jwebassembly/module/WasmStructInstruction.java
+++ b/src/de/inetsoftware/jwebassembly/module/WasmStructInstruction.java
@@ -203,6 +203,7 @@ class WasmStructInstruction extends WasmInstruction {
                 return ValueType.anyref;
             case NEW:
             case NEW_DEFAULT:
+            case CAST:
                 return type;
             case GET:
                 return fieldName.getType();
@@ -223,6 +224,7 @@ class WasmStructInstruction extends WasmInstruction {
         switch( op ) {
             case GET:
             case INSTANCEOF:
+            case CAST:
                 return 1;
             case SET:
                 return 2;
diff --git a/src/de/inetsoftware/jwebassembly/wasm/StructOperator.java b/src/de/inetsoftware/jwebassembly/wasm/StructOperator.java
index d086e98..96bdcba 100644
--- a/src/de/inetsoftware/jwebassembly/wasm/StructOperator.java
+++ b/src/de/inetsoftware/jwebassembly/wasm/StructOperator.java
@@ -27,5 +27,6 @@ public enum StructOperator {
     GET,
     SET,
     NULL,
+    CAST,
     INSTANCEOF,
 }
\ No newline at end of file
diff --git a/test/de/inetsoftware/jwebassembly/runtime/RuntimeErrors.java b/test/de/inetsoftware/jwebassembly/runtime/RuntimeErrors.java
index c50d4ac..97c5e69 100644
--- a/test/de/inetsoftware/jwebassembly/runtime/RuntimeErrors.java
+++ b/test/de/inetsoftware/jwebassembly/runtime/RuntimeErrors.java
@@ -76,7 +76,6 @@ public class RuntimeErrors {
         }
     }
 
-
     @Test
     public void nonStaticImport() throws IOException {
         compileErrorTest( "Import method must be static:", NonStaticImport.class );
@@ -127,7 +126,6 @@ public class RuntimeErrors {
         }
     }
 
-
     @Test
     public void instanceofCall() throws IOException {
         compileErrorTest( "Unknown operator: INSTANCEOF", InstanceofMethod.class );
@@ -140,4 +138,17 @@ public class RuntimeErrors {
             return obj instanceof Integer;
         }
     }
+
+    @Test
+    public void checkcast() throws IOException {
+        compileErrorTest( "Unknown operator: CAST", CheckcastMethod.class );
+    }
+
+    static class CheckcastMethod {
+        @Export
+        static Integer runnable() {
+            Object obj = new Integer(0);
+            return (Integer)obj;
+        }
+    }
 }