Support for destructuring arrays

add support for destructuring of arrays when passing
arguments to functions.

Change-Id: I19feb39aa3ae520ec7591d49d1b14ceaa78783c6
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

4 files changed, 96 insertions, 26 deletions

diff --git a/src/qml/compiler/qv4codegen.cpp b/src/qml/compiler/qv4codegen.cpp
index 973d5cd992..1aceb0f619 100644
--- a/src/qml/compiler/qv4codegen.cpp
+++ b/src/qml/compiler/qv4codegen.cpp
@@ -58,6 +58,8 @@
 #include <cmath>
 #include <iostream>
 
+static const bool disable_lookups = false;
+
 #ifdef CONST
 #undef CONST
 #endif
@@ -456,9 +458,6 @@ void Codegen::initializeAndDestructureBindingElement(AST::BindingElement *e, con
 
 void Codegen::destructurePropertyList(const Codegen::Reference &object, BindingPropertyList *bindingList)
 {
-    Q_UNUSED(object);
-    Q_UNUSED(bindingList);
-
     RegisterScope scope(this);
 
     for (BindingPropertyList *p = bindingList; p; p = p->next) {
@@ -467,14 +466,28 @@ void Codegen::destructurePropertyList(const Codegen::Reference &object, BindingP
         Reference property = Reference::fromMember(object, propertyName);
         initializeAndDestructureBindingElement(p->binding, property);
     }
-
 }
 
 void Codegen::destructureElementList(const Codegen::Reference &array, BindingElementList *bindingList)
 {
-    Q_UNUSED(array);
-    // #### implement me
-    throwSyntaxError(bindingList->firstSourceLocation(), QString::fromLatin1("Support for binding element lists not implemented!"));
+    RegisterScope scope(this);
+
+    int index = 0;
+    for (BindingElementList *p = bindingList; p; p = p->next) {
+        for (Elision *elision = p->elision; elision; elision = elision->next)
+            ++index;
+
+        RegisterScope scope(this);
+
+        Reference idx = Reference::fromConst(this, Encode(index));
+        Reference property = Reference::fromSubscript(array, idx);
+        BindingElement *e = p->bindingElement();
+        if (e)
+            initializeAndDestructureBindingElement(e, property);
+        else {
+            throwSyntaxError(bindingList->firstSourceLocation(), QString::fromLatin1("Support for rest elements in binding arrays not implemented!"));
+        }
+    }
 }
 
 
@@ -1354,7 +1367,7 @@ void Codegen::handleCall(Reference &base, Arguments calldata)
         call.argv = calldata.argv;
         bytecodeGenerator->addInstruction(call);
     } else if (base.type == Reference::Member) {
-        if (useFastLookups) {
+        if (!disable_lookups && useFastLookups) {
             Instruction::CallPropertyLookup call;
             call.base = base.propertyBase.stackSlot();
             call.lookupIndex = registerGetterLookup(base.propertyNameIndex);
@@ -1382,7 +1395,7 @@ void Codegen::handleCall(Reference &base, Arguments calldata)
             call.argc = calldata.argc;
             call.argv = calldata.argv;
             bytecodeGenerator->addInstruction(call);
-        } else if (useFastLookups && base.global) {
+        } else if (!disable_lookups && useFastLookups && base.global) {
             Instruction::CallGlobalLookup call;
             call.index = registerGlobalGetterLookup(base.nameAsIndex());
             call.argc = calldata.argc;
@@ -3528,7 +3541,7 @@ void Codegen::Reference::storeAccumulator() const
         }
     } return;
     case Member:
-        if (codegen->useFastLookups) {
+        if (!disable_lookups && codegen->useFastLookups) {
             Instruction::SetLookup store;
             store.base = propertyBase.stackSlot();
             store.index = codegen->registerSetterLookup(propertyNameIndex);
@@ -3644,7 +3657,7 @@ QT_WARNING_POP
                 return;
             }
         }
-        if (codegen->useFastLookups && global) {
+        if (!disable_lookups && codegen->useFastLookups && global) {
             Instruction::LoadGlobalLookup load;
             load.index = codegen->registerGlobalGetterLookup(nameAsIndex());
             codegen->bytecodeGenerator->addInstruction(load);
@@ -3655,7 +3668,7 @@ QT_WARNING_POP
         }
         return;
     case Member:
-        if (codegen->useFastLookups) {
+        if (!disable_lookups && codegen->useFastLookups) {
             if (propertyBase.isAccumulator()) {
                 Instruction::GetLookupA load;
                 load.index = codegen->registerGetterLookup(propertyNameIndex);
diff --git a/src/qml/parser/qqmljs.g b/src/qml/parser/qqmljs.g
index 376edb9f85..5b75ba2f8a 100644
--- a/src/qml/parser/qqmljs.g
+++ b/src/qml/parser/qqmljs.g
@@ -275,6 +275,7 @@ public:
       AST::VariableDeclarationList *VariableDeclarationList;
       AST::BindingElement *BindingElement;
       AST::BindingPropertyList *BindingPropertyList;
+      AST::BindingElementList *BindingElementList;
 
       AST::UiProgram *UiProgram;
       AST::UiHeaderItemList *UiHeaderItemList;
@@ -1608,6 +1609,11 @@ case $rule_number: {
 ./
 
 ElisionOpt: Elision ;
+/.
+case $rule_number: {
+    sym(1).Node = sym(1).Elision->finish();
+} break;
+./
 
 PropertyAssignment: PropertyName T_COLON AssignmentExpression ;
 /.
@@ -3200,13 +3206,6 @@ case $rule_number: {
 BindingPattern: ObjectBindingPattern ;
 
 BindingPattern: ArrayBindingPattern ;
-/.
-case $rule_number: {
-    AST::BindingElementList *node = new (pool) AST::BindingElementList();
-    node->loc = loc(1);
-    sym(1).Node = node;
-} break;
-./
 
 ObjectBindingPattern: T_LBRACE T_RBRACE ;
 /.
@@ -3225,8 +3224,28 @@ case $rule_number: {
 ./
 
 ArrayBindingPattern: T_LBRACKET ElisionOpt BindingRestElementOpt T_RBRACKET ;
+/.
+case $rule_number: {
+    AST::BindingElementList *l = new (pool) AST::BindingElementList(sym(4).Elision, sym(5).Node);
+    sym(1).Node = l->finish();
+} break;
+./
+
 ArrayBindingPattern: T_LBRACKET BindingElementList T_RBRACKET ;
+/.
+case $rule_number: {
+    sym(1).Node = sym(2).BindingElementList->finish();
+} break;
+./
+
 ArrayBindingPattern: T_LBRACKET BindingElementList T_COMMA ElisionOpt BindingRestElementOpt T_RBRACKET ;
+/.
+case $rule_number: {
+    AST::BindingElementList *l = new (pool) AST::BindingElementList(sym(4).Elision, sym(5).Node);
+    l = sym(2).BindingElementList->append(l);
+    sym(1).Node = l->finish();
+} break;
+./
 
 BindingPropertyList: BindingProperty ;
 
@@ -3239,8 +3258,19 @@ case $rule_number: {
 
 BindingElementList: BindingElisionElement ;
 BindingElementList: BindingElementList T_COMMA BindingElisionElement ;
+/.
+case $rule_number: {
+    sym(1).BindingElementList->append(sym(3).BindingElementList);
+} break;
+./
 
 BindingElisionElement: ElisionOpt BindingElement ;
+/.
+case $rule_number: {
+    sym(1).Node = new (pool) AST::BindingElementList(sym(1).Elision, sym(2).BindingElement);
+} break;
+./
+
 
 BindingProperty: BindingIdentifier InitializerOpt ;
 /.
diff --git a/src/qml/parser/qqmljsast.cpp b/src/qml/parser/qqmljsast.cpp
index 60064319c9..8b253abbef 100644
--- a/src/qml/parser/qqmljsast.cpp
+++ b/src/qml/parser/qqmljsast.cpp
@@ -1093,9 +1093,12 @@ void BindingElementList::accept0(Visitor *visitor)
 
 void BindingElementList::boundNames(QStringList *names)
 {
-    // ###
-    Q_UNUSED(names);
-
+    for (BindingElementList *it = this; it; it = it->next) {
+        if (BindingElement *e = it->bindingElement())
+            e->boundNames(names);
+        else if (BindingRestElement *r = it->bindingRestElement())
+            names->append(r->name.toString());
+    }
 }
 
 void BindingPropertyList::accept0(Visitor *visitor)
diff --git a/src/qml/parser/qqmljsast_p.h b/src/qml/parser/qqmljsast_p.h
index 6142b00712..52f6aeb1a2 100644
--- a/src/qml/parser/qqmljsast_p.h
+++ b/src/qml/parser/qqmljsast_p.h
@@ -2128,20 +2128,44 @@ class QML_PARSER_EXPORT BindingElementList : public Node
 public:
     QQMLJS_DECLARE_AST_NODE(BindingElementList)
 
-    BindingElementList()
+    BindingElementList(Elision *e, Node *p)
+        : elision(e), param(p), next(this)
     { kind = K; }
 
+    BindingElementList *append(BindingElementList *n) {
+        n->next = next;
+        next = n;
+        return n;
+    }
+
+    inline BindingElementList *finish ()
+    {
+        BindingElementList *front = next;
+        next = 0;
+        return front;
+    }
+
+    BindingRestElement *bindingRestElement() const {
+        return cast<BindingRestElement *>(param);
+    }
+
+    BindingElement *bindingElement() const {
+        return cast<BindingElement *>(param);
+    }
+
     void accept0(Visitor *visitor) override;
 
     void boundNames(QStringList *names);
 
     SourceLocation firstSourceLocation() const override
-    { return loc; }
+    { return elision ? elision->firstSourceLocation() : param->firstSourceLocation(); }
 
     SourceLocation lastSourceLocation() const override
-    { return loc; }
+    { return next ? next->lastSourceLocation() : param->lastSourceLocation(); }
 
-    SourceLocation loc;
+    Elision *elision = nullptr;
+    Node *param = nullptr;
+    BindingElementList *next;
 };
 
 class QML_PARSER_EXPORT BindingPropertyList : public Node