From 579836f2cf1d9c60f1f60bc107e1fff869b8c6a0 Mon Sep 17 00:00:00 2001
From: Marko Luukkainen <marko.luukkainen@semantum.fi>
Date: Mon, 19 Aug 2019 09:08:46 +0300
Subject: [PATCH] Safe SCL cast for Java objects

gitlab #28

Change-Id: I7e8fa4b9bfc6bf3803c8dbfb5c65eb2d631a968b
---
 org.simantics.g3d/META-INF/MANIFEST.MF        |  3 +-
 org.simantics.g3d/scl/g3d/SCLUtil.scl         |  7 ++
 .../src/org/simantics/g3d/scl/SCLUtil.java    | 79 +++++++++++++++++++
 .../scl/plant3d/utils/Loader.scl              |  4 -
 4 files changed, 88 insertions(+), 5 deletions(-)
 create mode 100644 org.simantics.g3d/scl/g3d/SCLUtil.scl
 create mode 100644 org.simantics.g3d/src/org/simantics/g3d/scl/SCLUtil.java

diff --git a/org.simantics.g3d/META-INF/MANIFEST.MF b/org.simantics.g3d/META-INF/MANIFEST.MF
index c479403d..97772dc1 100644
--- a/org.simantics.g3d/META-INF/MANIFEST.MF
+++ b/org.simantics.g3d/META-INF/MANIFEST.MF
@@ -18,7 +18,8 @@ Require-Bundle: org.eclipse.core.runtime,
  gnu.trove3;bundle-version="3.0.0",
  org.simantics.objmap2;bundle-version="1.0.0",
  org.eclipse.nebula.widgets.tablecombo;bundle-version="1.0.0",
- org.simantics.ui;bundle-version="1.0.0"
+ org.simantics.ui;bundle-version="1.0.0",
+ org.simantics.scl.osgi;bundle-version="1.0.4"
 Bundle-RequiredExecutionEnvironment: JavaSE-1.6
 Bundle-ActivationPolicy: lazy
 Export-Package: org.simantics.g3d,
diff --git a/org.simantics.g3d/scl/g3d/SCLUtil.scl b/org.simantics.g3d/scl/g3d/SCLUtil.scl
new file mode 100644
index 00000000..3a30a95d
--- /dev/null
+++ b/org.simantics.g3d/scl/g3d/SCLUtil.scl
@@ -0,0 +1,7 @@
+
+importJava "org.simantics.g3d.scl.SCLUtil" where
+  
+  javaSafeCoerce :: Typeable b => a -> Maybe b
+  javaIsInstanceOf :: Typeable b => a -> Boolean
+  
+
diff --git a/org.simantics.g3d/src/org/simantics/g3d/scl/SCLUtil.java b/org.simantics.g3d/src/org/simantics/g3d/scl/SCLUtil.java
new file mode 100644
index 00000000..99563462
--- /dev/null
+++ b/org.simantics.g3d/src/org/simantics/g3d/scl/SCLUtil.java
@@ -0,0 +1,79 @@
+package org.simantics.g3d.scl;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.cojen.classfile.TypeDesc;
+import org.simantics.scl.compiler.environment.specification.EnvironmentSpecification;
+import org.simantics.scl.compiler.errors.Failable;
+import org.simantics.scl.compiler.internal.codegen.types.JavaTypeTranslator;
+import org.simantics.scl.compiler.module.Module;
+import org.simantics.scl.compiler.module.repository.ImportFailureException;
+import org.simantics.scl.compiler.runtime.RuntimeEnvironment;
+import org.simantics.scl.compiler.types.TCon;
+import org.simantics.scl.compiler.types.Type;
+import org.simantics.scl.osgi.SCLOsgi;
+
+public class SCLUtil {
+    
+    static Map<TCon,Class<?>> typeMap = new HashMap<TCon, Class<?>>();
+ // copied from org.simantics.scl.db.SCLFunctions
+    public static Class<?> possibleFromDynamic(Type expectedType, String moduleName) {
+        
+        try {
+
+            
+            Failable<Module> failable = SCLOsgi.MODULE_REPOSITORY.getModule(moduleName);
+            Module module = failable.getResult();
+            
+            RuntimeEnvironment env = SCLOsgi.MODULE_REPOSITORY.createRuntimeEnvironment(
+                    EnvironmentSpecification.of(moduleName, ""), module.getParentClassLoader());
+
+            JavaTypeTranslator tr = new JavaTypeTranslator(env.getEnvironment());
+            TypeDesc desc = tr.toTypeDesc(expectedType);
+            String className = desc.getFullName();
+            Class<?> clazz = env.getMutableClassLoader().loadClass(className);
+            return clazz;
+        } catch (ImportFailureException e) {
+            return null;
+        } catch (ClassNotFoundException e) {
+            return null;
+        }
+    }
+    
+    public static Class<?> possibleClass(TCon type) {
+        Class<?> clazz = typeMap.get(type);
+        if (clazz == null) {
+            clazz = possibleFromDynamic(type, type.module);
+            typeMap.put(type, clazz);
+        }
+        return clazz;
+    }
+    
+    public static boolean javaIsInstanceOf(org.simantics.scl.compiler.types.Type t, Object o) {
+        if (t instanceof TCon) {
+            Class<?> clazz = possibleClass((TCon)t);
+            if (clazz == null)
+                return false;
+            if (!clazz.isAssignableFrom(o.getClass()))
+                return false;
+     
+            return true;
+        }
+        return false;
+    }
+    
+    public static Object javaSafeCoerce(org.simantics.scl.compiler.types.Type t, Object o) {
+        if (t instanceof TCon) {
+            Class<?> clazz = possibleClass((TCon)t);
+            if (clazz == null)
+                return null;
+            if (!clazz.isAssignableFrom(o.getClass()))
+                return null;
+     
+            return o;
+        }
+        return null;
+    }
+
+}
diff --git a/org.simantics.plant3d/scl/plant3d/utils/Loader.scl b/org.simantics.plant3d/scl/plant3d/utils/Loader.scl
index a039f7e7..6b2f2d99 100644
--- a/org.simantics.plant3d/scl/plant3d/utils/Loader.scl
+++ b/org.simantics.plant3d/scl/plant3d/utils/Loader.scl
@@ -1,13 +1,9 @@
 import "Simantics/DB"
 import "plant3d/scenegraph/P3DRootNode"
 import "./P3DScriptNodeMap"
-import "JavaBuiltin"
 
 importJava "org.simantics.plant3d.scl.SCLUtil" where
   
   loadReadOnly :: Resource -> P3DRootNode
   load :: Resource -> P3DScriptNodeMap
   
-safeCoerce :: a -> Maybe b
-safeCoerce a = do
- (Just $ unsafeCoerce a) `catch` (\(_ :: Exception) -> Nothing)
\ No newline at end of file
-- 
2.47.0