initial implementation of function rest parameter support (arrow func…

…tions are not supported as of now)
mozilla · Feb 26, 2024 · 2d2693e · 2d2693e
1 parent 6ec1085
commit 2d2693e
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Showing 18 changed files with 397 additions and 25 deletions.
diff --git a/src/org/mozilla/javascript/CodeGenerator.java b/src/org/mozilla/javascript/CodeGenerator.java
@@ -186,6 +186,7 @@ private void generateICodeFromTree(Node tree) {
         itsData.argNames = scriptOrFn.getParamAndVarNames();
         itsData.argIsConst = scriptOrFn.getParamAndVarConst();
         itsData.argCount = scriptOrFn.getParamCount();
+        itsData.argsHasRest = scriptOrFn.hasRestParameter();
 
         itsData.encodedSourceStart = scriptOrFn.getEncodedSourceStart();
         itsData.encodedSourceEnd = scriptOrFn.getEncodedSourceEnd();

diff --git a/src/org/mozilla/javascript/Decompiler.java b/src/org/mozilla/javascript/Decompiler.java
@@ -782,6 +782,10 @@ else if (nextToken == Token.NAME) {
                     i = printSourceString(source, i + 1, false, result);
                     continue;
 
+                case Token.DOTDOTDOT:
+                    result.append("...");
+                    break;
+
                 default:
                     // If we don't know how to decompile it, raise an exception.
                     throw new RuntimeException("Token: " + Token.name(source.charAt(i)));

diff --git a/src/org/mozilla/javascript/IRFactory.java b/src/org/mozilla/javascript/IRFactory.java
@@ -2450,11 +2450,15 @@ Node decompileFunctionHeader(FunctionNode fn) {
             decompiler.addToken(Token.LP);
         }
         List<AstNode> params = fn.getParams();
-        for (int i = 0; i < params.size(); i++) {
-            decompile(params.get(i));
-            if (i < params.size() - 1) {
+        int last = params.size() - 1;
+        for (int i = 0; i <= last; i++) {
+            if (i > 0) {
                 decompiler.addToken(Token.COMMA);
             }
+            if (fn.hasRestParameter() && i == last) {
+                decompiler.addToken(Token.DOTDOTDOT);
+            }
+            decompile(params.get(i));
         }
         if (!noParen) {
             decompiler.addToken(Token.RP);

diff --git a/src/org/mozilla/javascript/InterpretedFunction.java b/src/org/mozilla/javascript/InterpretedFunction.java
@@ -133,6 +133,9 @@ protected int getLanguageVersion() {
 
     @Override
     protected int getParamCount() {
+        if (idata.argsHasRest) {
+            return idata.argCount - 1;
+        }
         return idata.argCount;
     }
 

diff --git a/src/org/mozilla/javascript/Interpreter.java b/src/org/mozilla/javascript/Interpreter.java
@@ -188,6 +188,26 @@ void initializeArgs(
             for (int i = definedArgs; i != idata.itsMaxVars; ++i) {
                 stack[i] = Undefined.instance;
             }
+
+            if (idata.argsHasRest) {
+                Object[] vals;
+                int offset = idata.argCount - 1;
+                if (argCount >= idata.argCount) {
+                    vals = new Object[argCount - offset];
+
+                    argShift = argShift + offset;
+                    for (int valsIdx = 0; valsIdx != vals.length; ++argShift, ++valsIdx) {
+                        Object val = args[argShift];
+                        if (val == UniqueTag.DOUBLE_MARK) {
+                            val = ScriptRuntime.wrapNumber(argsDbl[argShift]);
+                        }
+                        vals[valsIdx] = val;
+                    }
+                } else {
+                    vals = ScriptRuntime.emptyArgs;
+                }
+                stack[offset] = cx.newArray(scope, vals);
+            }
         }
 
         CallFrame cloneFrozen() {

diff --git a/src/org/mozilla/javascript/InterpreterData.java b/src/org/mozilla/javascript/InterpreterData.java
@@ -68,6 +68,7 @@ private void init() {
     String[] argNames;
     boolean[] argIsConst;
     int argCount;
+    boolean argsHasRest;
 
     int itsMaxCalleeArgs;
 

diff --git a/src/org/mozilla/javascript/Parser.java b/src/org/mozilla/javascript/Parser.java
@@ -787,10 +787,20 @@ private void parseFunctionParams(FunctionNode fnNode) throws IOException {
         do {
             int tt = peekToken();
             if (tt == Token.RP) {
+                if (fnNode.hasRestParameter()) {
+                    // Error: parameter after rest parameter
+                    reportError("msg.parm.after.rest", ts.tokenBeg, ts.tokenEnd - ts.tokenBeg);
+                }
+
                 fnNode.putIntProp(Node.TRAILING_COMMA, 1);
                 break;
             }
             if (tt == Token.LB || tt == Token.LC) {
+                if (fnNode.hasRestParameter()) {
+                    // Error: parameter after rest parameter
+                    reportError("msg.parm.after.rest", ts.tokenBeg, ts.tokenEnd - ts.tokenBeg);
+                }
+
                 AstNode expr = destructuringPrimaryExpr();
                 markDestructuring(expr);
                 fnNode.addParam(expr);
@@ -804,7 +814,24 @@ private void parseFunctionParams(FunctionNode fnNode) throws IOException {
                 defineSymbol(Token.LP, pname, false);
                 destructuring.put(pname, expr);
             } else {
+                boolean wasRest = false;
+                if (tt == Token.DOTDOTDOT) {
+                    if (fnNode.hasRestParameter()) {
+                        // Error: parameter after rest parameter
+                        reportError("msg.parm.after.rest", ts.tokenBeg, ts.tokenEnd - ts.tokenBeg);
+                    }
+
+                    fnNode.setHasRestParameter(true);
+                    wasRest = true;
+                    consumeToken();
+                }
+
                 if (mustMatchToken(Token.NAME, "msg.no.parm", true)) {
+                    if (!wasRest && fnNode.hasRestParameter()) {
+                        // Error: parameter after rest parameter
+                        reportError("msg.parm.after.rest", ts.tokenBeg, ts.tokenEnd - ts.tokenBeg);
+                    }
+
                     Name paramNameNode = createNameNode();
                     Comment jsdocNodeForName = getAndResetJsDoc();
                     if (jsdocNodeForName != null) {

diff --git a/src/org/mozilla/javascript/ScriptRuntime.java b/src/org/mozilla/javascript/ScriptRuntime.java
@@ -876,6 +876,33 @@ public static Object[] padArguments(Object[] args, int count) {
         return result;
     }
 
+    /**
+     * Helper function for builtin objects that use the varargs form. ECMA function formal arguments
+     * are undefined if not supplied; this function pads the argument array out to the expected
+     * length, if necessary. Also the rest parameter array construction is done here.
+     */
+    public static Object[] padAndRestArguments(
+            Context cx, Scriptable scope, Object[] args, int argCount) {
+        Object[] result = new Object[argCount];
+        int paramCount = argCount - 1;
+        if (args.length < paramCount) {
+            System.arraycopy(args, 0, result, 0, args.length);
+            Arrays.fill(result, args.length, paramCount, Undefined.instance);
+        } else {
+            System.arraycopy(args, 0, result, 0, paramCount);
+        }
+
+        Object[] restValues;
+        if (args.length > paramCount) {
+            restValues = new Object[args.length - paramCount];
+            System.arraycopy(args, paramCount, restValues, 0, restValues.length);
+        } else {
+            restValues = ScriptRuntime.emptyArgs;
+        }
+        result[paramCount] = cx.newArray(scope, restValues);
+        return result;
+    }
+
     public static String escapeString(String s) {
         return escapeString(s, '"');
     }

diff --git a/src/org/mozilla/javascript/Token.java b/src/org/mozilla/javascript/Token.java
@@ -225,7 +225,8 @@ public static enum CommentType {
             TEMPLATE_CHARS = 171, // template literal - literal section
             TEMPLATE_LITERAL_SUBST = 172, // template literal - substitution
             TAGGED_TEMPLATE_LITERAL = 173, // template literal - tagged/handler
-            LAST_TOKEN = 173;
+            DOTDOTDOT = 174, // spread/rest ...
+            LAST_TOKEN = 174;
 
     /**
      * Returns a name for the token. If Rhino is compiled with certain hardcoded debugging flags in

diff --git a/src/org/mozilla/javascript/TokenStream.java b/src/org/mozilla/javascript/TokenStream.java
@@ -1152,6 +1152,10 @@ && peekChar() == '!'
                     return Token.COLON;
                 case '.':
                     if (matchChar('.')) {
+                        if (parser.compilerEnv.getLanguageVersion() >= Context.VERSION_1_8
+                                && matchChar('.')) {
+                            return Token.DOTDOTDOT;
+                        }
                         return Token.DOTDOT;
                     } else if (matchChar('(')) {
                         return Token.DOTQUERY;

diff --git a/src/org/mozilla/javascript/ast/FunctionNode.java b/src/org/mozilla/javascript/ast/FunctionNode.java
@@ -80,6 +80,7 @@ public static enum Form {
     private Form functionForm = Form.FUNCTION;
     private int lp = -1;
     private int rp = -1;
+    private boolean hasRestParameter;
 
     // codegen variables
     private int functionType;
@@ -284,6 +285,15 @@ public void setIsES6Generator() {
         isGenerator = true;
     }
 
+    @Override
+    public boolean hasRestParameter() {
+        return hasRestParameter;
+    }
+
+    public void setHasRestParameter(boolean hasRestParameter) {
+        this.hasRestParameter = hasRestParameter;
+    }
+
     public void addResumptionPoint(Node target) {
         if (generatorResumePoints == null) generatorResumePoints = new ArrayList<>();
         generatorResumePoints.add(target);

diff --git a/src/org/mozilla/javascript/ast/ScriptNode.java b/src/org/mozilla/javascript/ast/ScriptNode.java
@@ -251,6 +251,10 @@ public boolean[] getParamAndVarConst() {
         return isConsts;
     }
 
+    public boolean hasRestParameter() {
+        return false;
+    }
+
     void addSymbol(Symbol symbol) {
         if (variableNames != null) codeBug();
         if (symbol.getDeclType() == Token.LP) {

diff --git a/src/org/mozilla/javascript/optimizer/BodyCodegen.java b/src/org/mozilla/javascript/optimizer/BodyCodegen.java
@@ -322,18 +322,34 @@ private void generatePrologue() {
             int parmCount = scriptOrFn.getParamCount();
             if (parmCount > 0 && !inDirectCallFunction) {
                 // Set up args array
-                // check length of arguments, pad if need be
-                cfw.addALoad(argsLocal);
-                cfw.add(ByteCode.ARRAYLENGTH);
-                cfw.addPush(parmCount);
-                int label = cfw.acquireLabel();
-                cfw.add(ByteCode.IF_ICMPGE, label);
-                cfw.addALoad(argsLocal);
-                cfw.addPush(parmCount);
-                addScriptRuntimeInvoke(
-                        "padArguments", "([Ljava/lang/Object;I" + ")[Ljava/lang/Object;");
-                cfw.addAStore(argsLocal);
-                cfw.markLabel(label);
+                if (scriptOrFn.hasRestParameter()) {
+                    cfw.addALoad(contextLocal);
+                    cfw.addALoad(variableObjectLocal);
+                    cfw.addALoad(argsLocal);
+                    cfw.addPush(parmCount);
+                    addScriptRuntimeInvoke(
+                            "padAndRestArguments",
+                            "("
+                                    + "Lorg/mozilla/javascript/Context;"
+                                    + "Lorg/mozilla/javascript/Scriptable;"
+                                    + "[Ljava/lang/Object;"
+                                    + "I"
+                                    + ")[Ljava/lang/Object;");
+                    cfw.addAStore(argsLocal);
+                } else {
+                    // check length of arguments, pad if need be
+                    cfw.addALoad(argsLocal);
+                    cfw.add(ByteCode.ARRAYLENGTH);
+                    cfw.addPush(parmCount);
+                    int label = cfw.acquireLabel();
+                    cfw.add(ByteCode.IF_ICMPGE, label);
+                    cfw.addALoad(argsLocal);
+                    cfw.addPush(parmCount);
+                    addScriptRuntimeInvoke(
+                            "padArguments", "([Ljava/lang/Object;I)[Ljava/lang/Object;");
+                    cfw.addAStore(argsLocal);
+                    cfw.markLabel(label);
+                }
             }
 
             int paramCount = fnCurrent.fnode.getParamCount();

diff --git a/src/org/mozilla/javascript/optimizer/Codegen.java b/src/org/mozilla/javascript/optimizer/Codegen.java
@@ -743,7 +743,8 @@ private void generateNativeFunctionOverrides(ClassFileWriter cfw, String encoded
         final int Do_getEncodedSource = 4;
         final int Do_getParamOrVarConst = 5;
         final int Do_isGeneratorFunction = 6;
-        final int SWITCH_COUNT = 7;
+        final int Do_hasRestParameter = 7;
+        final int SWITCH_COUNT = 8;
 
         for (int methodIndex = 0; methodIndex != SWITCH_COUNT; ++methodIndex) {
             if (methodIndex == Do_getEncodedSource && encodedSource == null) {
@@ -786,6 +787,10 @@ private void generateNativeFunctionOverrides(ClassFileWriter cfw, String encoded
                     methodLocals = 1; // Only this
                     cfw.startMethod("isGeneratorFunction", "()Z", ACC_PROTECTED);
                     break;
+                case Do_hasRestParameter:
+                    methodLocals = 1; // Only this
+                    cfw.startMethod("hasRestParameter", "()Z", ACC_PUBLIC);
+                    break;
                 default:
                     throw Kit.codeBug();
             }
@@ -830,7 +835,11 @@ private void generateNativeFunctionOverrides(ClassFileWriter cfw, String encoded
 
                     case Do_getParamCount:
                         // Push number of defined parameters
-                        cfw.addPush(n.getParamCount());
+                        if (n.hasRestParameter()) {
+                            cfw.addPush(n.getParamCount() - 1);
+                        } else {
+                            cfw.addPush(n.getParamCount());
+                        }
                         cfw.add(ByteCode.IRETURN);
                         break;
 
@@ -920,6 +929,12 @@ private void generateNativeFunctionOverrides(ClassFileWriter cfw, String encoded
                         cfw.add(ByteCode.IRETURN);
                         break;
 
+                    case Do_hasRestParameter:
+                        // Push boolean of defined hasRestParameter
+                        cfw.addPush(n.hasRestParameter());
+                        cfw.add(ByteCode.IRETURN);
+                        break;
+
                     case Do_getEncodedSource:
                         // Push number encoded source start and end
                         // to prepare for encodedSource.substring(start, end)

diff --git a/src/org/mozilla/javascript/resources/Messages.properties b/src/org/mozilla/javascript/resources/Messages.properties
@@ -312,6 +312,9 @@ msg.no.parm =\
 msg.no.paren.after.parms =\
     missing ) after formal parameters
 
+msg.parm.after.rest =\
+    parameter after rest parameter
+
 msg.no.brace.body =\
     missing '{' before function body
 

diff --git a/src/org/mozilla/javascript/resources/Messages_fr.properties b/src/org/mozilla/javascript/resources/Messages_fr.properties
@@ -276,6 +276,9 @@ msg.no.parm =\
 msg.no.paren.after.parms =\
     il manque '')'' apr\u00E8s les param\u00E8tres formels
 
+msg.parm.after.rest =\
+    parameter after rest parameter
+
 msg.no.brace.body =\
     il manque ''{'' avant le corps d''une fonction