feat: reflect scope optimizations in runtime

src/main/java/me/topchetoeu/jscript/common/FunctionBody.java

@@ -3,12 +3,13 @@ package me.topchetoeu.jscript.common;
 public class FunctionBody {
     public final FunctionBody[] children;
     public final Instruction[] instructions;
-    public final int localsN, capturesN, length;
+    public final int localsN, capturablesN, capturesN, length;
 
-    public FunctionBody(int localsN, int capturesN, int length,  Instruction[] instructions, FunctionBody[] children) {
+    public FunctionBody(int localsN, int capturablesN, int capturesN, int length,  Instruction[] instructions, FunctionBody[] children) {
         this.children = children;
         this.length = length;
         this.localsN = localsN;
+        this.capturablesN = capturablesN;
         this.capturesN = capturesN;
         this.instructions = instructions;
     }

src/main/java/me/topchetoeu/jscript/common/Instruction.java

@@ -35,20 +35,21 @@ public class Instruction {
         LOAD_FUNC(0x30),
         LOAD_ARR(0x31),
         LOAD_OBJ(0x32),
-        LOAD_GLOB(0x33),
+        LOAD_REGEX(0x33),
-        LOAD_INTRINSICS(0x34),
+
-        LOAD_REGEX(0x35),
+        LOAD_GLOB(0x38),
+        LOAD_INTRINSICS(0x39),
+        LOAD_ARGS(0x3A),
+        LOAD_REST_ARGS(0x3B),
+        LOAD_CALLEE(0x3C),
+        LOAD_THIS(0x3D),
+        LOAD_ERROR(0x3E),
 
         LOAD_VAR(0x40),
         LOAD_MEMBER(0x41),
         LOAD_MEMBER_INT(0x42),
         LOAD_MEMBER_STR(0x43),
 
-        LOAD_ARGS(0x44),
-        LOAD_REST_ARGS(0x45),
-        LOAD_CALLEE(0x46),
-        LOAD_THIS(0x47),
-
         STORE_VAR(0x48),
         STORE_MEMBER(0x49),
         STORE_MEMBER_INT(0x4A),
@@ -368,6 +369,9 @@ public class Instruction {
     public static Instruction loadIntrinsics(String key) {
         return new Instruction(Type.LOAD_INTRINSICS, key);
     }
+    public static Instruction loadError() {
+        return new Instruction(Type.LOAD_ERROR);
+    }
     public static Instruction loadMember() {
         return new Instruction(Type.LOAD_MEMBER);
     }
@@ -457,12 +461,15 @@ public class Instruction {
         return new Instruction(Type.OPERATION, op);
     }
 
-    public static Instruction stackAlloc(int n) {
+    public static Instruction stackAlloc(int start, int n) {
-        return new Instruction(Type.STACK_ALLOC, n);
+        return new Instruction(Type.STACK_ALLOC, start, start + n);
     }
-    public static Instruction stackRealloc(int n) {
+    public static Instruction stackRealloc(int start, int n) {
-        return new Instruction(Type.STACK_REALLOC, n);
+        return new Instruction(Type.STACK_REALLOC, start, start + n);
     }
+    /**
+     * @deprecated
+     */
     public static Instruction stackFree(int n) {
         return new Instruction(Type.STACK_FREE, n);
     }

src/main/java/me/topchetoeu/jscript/compilation/CompileResult.java

@@ -111,7 +111,7 @@ public final class CompileResult {
         }
 
         return new FunctionBody(
-            scope.localsCount() + scope.allocCount(), scope.capturesCount(),
+            scope.localsCount(), scope.capturablesCount(), scope.capturesCount(),
             length, instrRes, builtChildren
         );
     }

src/main/java/me/topchetoeu/jscript/compilation/CompoundNode.java

@@ -25,7 +25,7 @@ public class CompoundNode extends Node {
 
         var subtarget = hasScope ? target.subtarget() : target;
         if (hasScope) {
-            subtarget.add(i -> Instruction.stackAlloc(subtarget.scope.allocCount()));
+            subtarget.add(i -> Instruction.stackAlloc(subtarget.scope.capturablesOffset(), subtarget.scope.allocCount()));
             subtarget.scope.singleEntry = singleEntry;
         }
 
@@ -45,10 +45,7 @@ public class CompoundNode extends Node {
             else stm.compile(subtarget, polluted = pollute, BreakpointType.STEP_OVER);
         }
 
-        if (hasScope) {
+        if (hasScope) subtarget.scope.end();
-            subtarget.scope.end();
-            subtarget.add(_i -> Instruction.stackFree(subtarget.scope.allocCount()));
-        }
 
         if (!polluted && pollute) {
             target.add(Instruction.pushUndefined());

src/main/java/me/topchetoeu/jscript/compilation/control/ForNode.java

@@ -26,7 +26,7 @@ public class ForNode extends Node {
     @Override public void compile(CompileResult target, boolean pollute) {
         var subtarget = target.subtarget();
         subtarget.scope.singleEntry = false;
-        subtarget.add(i -> Instruction.stackAlloc(subtarget.scope.allocCount()));
+        subtarget.add(i -> Instruction.stackAlloc(subtarget.scope.capturablesOffset(), subtarget.scope.allocCount()));
 
         declaration.compile(subtarget, false, BreakpointType.STEP_OVER);
 
@@ -40,7 +40,7 @@ public class ForNode extends Node {
         CompoundNode.compileMultiEntry(body, subtarget, false, BreakpointType.STEP_OVER);
         LabelContext.popLoop(subtarget.env, label);
 
-        subtarget.add(_i -> Instruction.stackRealloc(subtarget.scope.allocCount()));
+        subtarget.add(_i -> Instruction.stackRealloc(subtarget.scope.capturablesOffset(), subtarget.scope.allocCount()));
 
         CompoundNode.compileMultiEntry(assignment, subtarget, false, BreakpointType.STEP_OVER);
         int endI = subtarget.size();
@@ -52,7 +52,6 @@ public class ForNode extends Node {
         if (pollute) subtarget.add(Instruction.pushUndefined());
 
         subtarget.scope.end();
-        subtarget.add(_i -> Instruction.stackFree(subtarget.scope.allocCount()));
     }
 
     public ForNode(Location loc, String label, Node declaration, Node condition, Node assignment, Node body) {

src/main/java/me/topchetoeu/jscript/compilation/control/SwitchNode.java

@@ -44,7 +44,7 @@ public class SwitchNode extends Node {
         value.compile(target, true, BreakpointType.STEP_OVER);
 
         var subtarget = target.subtarget();
-        subtarget.add(_i -> Instruction.stackAlloc(subtarget.scope.allocCount()));
+        subtarget.add(_i -> Instruction.stackAlloc(subtarget.scope.capturablesOffset(), subtarget.scope.allocCount()));
 
         // TODO: create a jump map
         for (var ccase : cases) {
@@ -65,7 +65,6 @@ public class SwitchNode extends Node {
         LabelContext.getBreak(target.env).pop(label);
 
         subtarget.scope.end();
-        subtarget.add(_i -> Instruction.stackFree(subtarget.scope.allocCount()));
 
         int endI = subtarget.size();
         end.set(endI);

src/main/java/me/topchetoeu/jscript/compilation/control/TryNode.java

@@ -23,8 +23,8 @@ public class TryNode extends Node {
 
     @Override public void resolve(CompileResult target) {
         tryBody.resolve(target);
-        catchBody.resolve(target);
+        if (catchBody != null) catchBody.resolve(target);
-        finallyBody.resolve(target);
+        if (finallyBody != null) finallyBody.resolve(target);
     }
 
     @Override public void compile(CompileResult target, boolean pollute, BreakpointType bpt) {
@@ -43,8 +43,14 @@ public class TryNode extends Node {
 
             if (captureName != null) {
                 var subtarget = target.subtarget();
-                subtarget.scope.defineStrict(new Variable(captureName, false), catchBody.loc());
+                subtarget.add(i -> Instruction.stackAlloc(subtarget.scope.capturablesOffset(), subtarget.scope.allocCount()));
+                subtarget.scope.singleEntry = true;
+
+                var catchVar = subtarget.scope.defineStrict(new Variable(captureName, false), catchBody.loc());
+                subtarget.add(Instruction.loadError());
+                subtarget.add(_i -> catchVar.index().toSet(false));
                 catchBody.compile(subtarget, false);
+
                 subtarget.scope.end();
             }
             else catchBody.compile(target, false);

src/main/java/me/topchetoeu/jscript/compilation/scope/Scope.java

@@ -9,8 +9,8 @@ import me.topchetoeu.jscript.runtime.exceptions.SyntaxException;
 public class Scope {
     protected final HashMap<String, Variable> strictVarMap = new HashMap<>();
 
-    protected final VariableList variables = new VariableList(VariableIndex.IndexType.LOCALS, this::parentVarOffset);
+    protected final VariableList variables = new VariableList(VariableIndex.IndexType.LOCALS, this::variableOffset);
-    protected final VariableList captured = new VariableList(VariableIndex.IndexType.CAPTURABLES, this::parentCapOffset);
+    protected final VariableList captured = new VariableList(VariableIndex.IndexType.CAPTURABLES, this::capturablesOffset);
 
     private boolean ended = false;
     private boolean finished = false;
@@ -41,14 +41,14 @@ public class Scope {
         return var;
     }
 
-    private final int parentVarOffset() {
+    // private final int parentVarOffset() {
-        if (parent != null) return parent.variableOffset();
+    //     if (parent != null) return parent.variableOffset();
-        else return 0;
+    //     else return 0;
-    }
+    // }
-    private final int parentCapOffset() {
+    // private final int parentCapOffset() {
-        if (parent != null) return parent.capturedOffset();
+    //     if (parent != null) return parent.capturedOffset();
-        else return localsCount();
+    //     else return localsCount();
-    }
+    // }
 
     protected final SyntaxException alreadyDefinedErr(Location loc, String name) {
         return new SyntaxException(loc, String.format("Identifier '%s' has already been declared", name));
@@ -118,12 +118,28 @@ public class Scope {
      * Gets the index offset from this scope to its children
      */
     public final int variableOffset() {
-        if (parent != null) return parent.variableOffset() + variables.size();
+        var res = 0;
-        else return variables.size();
+
+        for (var curr = parent; curr != null; curr = curr.parent) {
+            res += parent.variables.size();
+        }
+
+        return res;
+
+        // if (parent != null) return parent.variableOffset() + variables.size();
+        // else return variables.size();
     }
-    public final int capturedOffset() {
+    public final int capturablesOffset() {
-        if (parent != null) return parent.capturedOffset() + captured.size();
+        var res = 0;
-        else return localsCount() + captured.size();
+
+        for (var curr = this; curr != null; curr = curr.parent) {
+            if (curr != this) res += parent.captured.size();
+            if (curr.parent == null) res += curr.localsCount();
+        }
+
+        return res;
+        // if (parent != null) return parent.capturedOffset() + captured.size();
+        // else return localsCount() + captured.size();
     }
 
     public int localsCount() {
@@ -142,7 +158,7 @@ public class Scope {
     }
     public int capturablesCount() {
         var res = captured.size();
-        for (var child : children) res += child.allocCount();
+        for (var child : children) res += child.capturablesCount();
         return res;
     }
 

src/main/java/me/topchetoeu/jscript/runtime/Frame.java

@@ -1,8 +1,7 @@
 package me.topchetoeu.jscript.runtime;
 
-import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.LinkedHashMap;
-import java.util.List;
 import java.util.Map;
 import java.util.Stack;
 
@@ -99,7 +98,8 @@ public final class Frame {
      * A list of one-element arrays of values. This is so that we can pass captures to other functions
      */
     public final Value[][] captures;
-    public final List<Value[]> locals = new ArrayList<>();
+    public final Value[] locals;
+    public final Value[][] capturables;
     public final Value argsVal;
     public Value self;
     public Value fakeArgs;
@@ -110,9 +110,20 @@ public final class Frame {
     public final Environment env;
     private final DebugContext dbg;
 
-    public Value[] getVar(int i) {
+    public Value getVar(int i) {
+        if (i < 0) return captures[~i][0];
+        else if (i < locals.length) return locals[i];
+        else return capturables[i - locals.length][0];
+    }
+    public Value setVar(int i, Value val) {
+        if (i < 0) return captures[~i][0] = val;
+        else if (i < locals.length) return locals[i] = val;
+        else return capturables[i - locals.length][0] = val;
+    }
+    public Value[] captureVar(int i) {
         if (i < 0) return captures[~i];
-        else return locals.get(i);
+        if (i >= locals.length) return capturables[i - locals.length];
+        else throw new RuntimeException("Illegal capture");
     }
 
     public Value[] stack = new Value[32];
@@ -215,12 +226,13 @@ public final class Frame {
                 if (newCtx != tryCtx) {
                     switch (newCtx.state) {
                         case CATCH:
-                            if (tryCtx.state != TryState.CATCH) locals.add(new Value[] { error.value });
+                            // TODO: may cause problems
+                            // if (tryCtx.state != TryState.CATCH) locals.add(new Value[] { error.value });
                             codePtr = tryCtx.catchStart;
                             stackPtr = tryCtx.restoreStackPtr;
                             break;
                         case FINALLY:
-                            if (tryCtx.state == TryState.CATCH) locals.remove(locals.size() - 1);
+                            // if (tryCtx.state == TryState.CATCH) locals.remove(locals.size() - 1);
                             codePtr = tryCtx.finallyStart;
                             stackPtr = tryCtx.restoreStackPtr;
                         default:
@@ -236,7 +248,7 @@ public final class Frame {
             }
             else {
                 popTryFlag = false;
-                if (tryCtx.state == TryState.CATCH) locals.remove(locals.size() - 1);
+                // if (tryCtx.state == TryState.CATCH) locals.remove(locals.size() - 1);
 
                 if (tryCtx.state != TryState.FINALLY && tryCtx.hasFinally()) {
                     codePtr = tryCtx.finallyStart;
@@ -422,8 +434,13 @@ public final class Frame {
 
         var i = 0;
 
-        for (i = 0; i < func.body.localsN; i++) {
+        this.locals = new Value[func.body.localsN];
-            this.locals.add(new Value[] { Value.UNDEFINED });
+        Arrays.fill(locals, Value.UNDEFINED);
+
+        this.capturables = new Value[func.body.capturablesN][1];
+
+        for (i = 0; i < func.body.capturablesN; i++) {
+            this.capturables[i][0] = Value.UNDEFINED;
         }
     }
 }

src/main/java/me/topchetoeu/jscript/runtime/InstructionRunner.java

@@ -140,7 +140,7 @@ public class InstructionRunner {
     private static Value execLoadVar(Environment env, Instruction instr, Frame frame) {
         int i = instr.get(0);
 
-        frame.push(frame.getVar(i)[0]);
+        frame.push(frame.getVar(i));
         frame.codePtr++;
 
         return null;
@@ -179,7 +179,7 @@ public class InstructionRunner {
         var captures = new Value[instr.params.length - 5][];
 
         for (var i = 5; i < instr.params.length; i++) {
-            captures[i - 5] = frame.getVar(instr.get(i));
+            captures[i - 5] = frame.captureVar(instr.get(i));
         }
 
         var func = new CodeFunction(env, name, frame.function.body.children[id], captures);
@@ -278,7 +278,7 @@ public class InstructionRunner {
         var val = (boolean)instr.get(1) ? frame.peek() : frame.pop();
         int i = instr.get(0);
 
-        frame.getVar(i)[0] = val;
+        frame.setVar(i, val);
         frame.codePtr++;
 
         return null;
@@ -498,29 +498,34 @@ public class InstructionRunner {
         frame.codePtr++;
         return null;
     }
+    private static Value execLoadError(Environment env, Instruction instr, Frame frame) {
+        frame.push(frame.tryStack.peek().error.value);
+        frame.codePtr++;
+        return null;
+    }
 
     private static Value execStackAlloc(Environment env, Instruction instr, Frame frame) {
-        int n = instr.get(0);
+        int offset = instr.get(0);
+        int n = instr.get(1);
 
-        for (var i = 0; i < n; i++) frame.locals.add(new Value[] { Value.UNDEFINED });
+        for (var i = offset; i < n; i++) frame.capturables[i] = new Value[] { Value.UNDEFINED };
 
         frame.codePtr++;
         return null;
     }
     private static Value execStackRealloc(Environment env, Instruction instr, Frame frame) {
-        int n = instr.get(0);
+        int offset = instr.get(0);
+        int n = instr.get(1);
 
-        for (var i = frame.locals.size() - n; i < frame.locals.size(); i++) frame.locals.set(i, new Value[] { frame.locals.get(i)[0] });
+        for (var i = offset; i < n; i++) frame.capturables[i] = new Value[] { frame.capturables[i][0] };
 
         frame.codePtr++;
         return null;
     }
     private static Value execStackFree(Environment env, Instruction instr, Frame frame) {
-        int n = instr.get(0);
+        // int n = instr.get(0);
 
-        for (var i = 0; i < n; i++) {
+        // TODO: Remove if safe to do so
-            frame.locals.remove(frame.locals.size() - 1);
-        }
 
         frame.codePtr++;
         return null;
@@ -559,6 +564,7 @@ public class InstructionRunner {
             case LOAD_REST_ARGS: return execLoadRestArgs(env, instr, frame);
             case LOAD_CALLEE: return execLoadCallee(env, instr, frame);
             case LOAD_THIS: return execLoadThis(env, instr, frame);
+            case LOAD_ERROR: return execLoadError(env, instr, frame);
 
             case DISCARD: return execDiscard(env, instr, frame);
             case STORE_MEMBER: return execStoreMember(env, instr, frame);