Fix destructuring of arrow function parameters

Change-Id: I64b49ae77ecd81eafb320cda04a1a7bf4b2dc90c
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

3 files changed, 54 insertions, 31 deletions

diff --git a/src/qml/parser/qqmljs.g b/src/qml/parser/qqmljs.g
index ce641accd8..bb0f53f4ab 100644
--- a/src/qml/parser/qqmljs.g
+++ b/src/qml/parser/qqmljs.g
@@ -387,7 +387,6 @@ protected:
 
     AST::UiQualifiedId *reparseAsQualifiedId(AST::ExpressionNode *expr);
     AST::UiQualifiedPragmaId *reparseAsQualifiedPragmaId(AST::ExpressionNode *expr);
-    AST::FormalParameterList *reparseAsFormalParameterList(AST::ExpressionNode *expr);
 
     void pushToken(int token);
     int lookaheadToken(Lexer *lexer);
@@ -553,34 +552,6 @@ AST::UiQualifiedPragmaId *Parser::reparseAsQualifiedPragmaId(AST::ExpressionNode
     return 0;
 }
 
-AST::FormalParameterList *Parser::reparseAsFormalParameterList(AST::ExpressionNode *expr)
-{
-    AST::FormalParameterList *f = nullptr;
-    if (AST::Expression *commaExpr = AST::cast<AST::Expression *>(expr)) {
-        f = reparseAsFormalParameterList(commaExpr->left);
-        if (!f)
-            return nullptr;
-
-        expr = commaExpr->right;
-    }
-
-    AST::ExpressionNode *rhs = nullptr;
-    if (AST::BinaryExpression *assign = AST::cast<AST::BinaryExpression *>(expr)) {
-            if (assign->op != QSOperator::Assign)
-                return nullptr;
-        expr = assign->left;
-        rhs = assign->right;
-    }
-    AST::PatternElement *binding = nullptr;
-    if (AST::IdentifierExpression *idExpr = AST::cast<AST::IdentifierExpression *>(expr)) {
-        binding = new (pool) AST::PatternElement(idExpr->name, rhs);
-        binding->identifierToken = idExpr->identifierToken;
-    }
-    if (!binding)
-        return nullptr;
-    return new (pool) AST::FormalParameterList(f, binding);
-}
-
 void Parser::pushToken(int token)
 {
     last_token->token = yytoken;
@@ -1506,7 +1477,7 @@ CoverParenthesizedExpressionAndArrowParameterList: T_LPAREN BindingRestElement T
 CoverParenthesizedExpressionAndArrowParameterList: T_LPAREN Expression_In T_COMMA BindingRestElementOpt T_RPAREN;
 /.
     case $rule_number: {
-        AST::FormalParameterList *list = reparseAsFormalParameterList(sym(2).Expression);
+        AST::FormalParameterList *list = sym(2).Expression->reparseAsFormalParameterList(pool);
         if (!list) {
             syntaxError(loc(1), "Invalid Arrow parameter list.");
             return false;
@@ -2867,6 +2838,7 @@ BindingPattern:  T_LBRACE ObjectBindingPattern T_RBRACE;
         auto *node = new (pool) AST::ObjectPattern(sym(2).PatternPropertyList);
         node->lbraceToken = loc(1);
         node->rbraceToken = loc(3);
+        node->parseMode = AST::Pattern::Binding;
         sym(1).Node = node;
     } break;
 ./
@@ -2877,6 +2849,7 @@ BindingPattern: T_LBRACKET ArrayBindingPattern T_RBRACKET;
         auto *node = new (pool) AST::ArrayPattern(sym(2).PatternElementList);
         node->lbracketToken = loc(1);
         node->rbracketToken = loc(3);
+        node->parseMode = AST::Pattern::Binding;
         sym(1).Node = node;
     } break;
 ./
@@ -3612,7 +3585,7 @@ ArrowParameters: CoverParenthesizedExpressionAndArrowParameterList;
     case $rule_number: {
         if (coverExpressionType != CE_FormalParameterList) {
             AST::NestedExpression *ne = static_cast<AST::NestedExpression *>(sym(1).Node);
-            AST::FormalParameterList *list = reparseAsFormalParameterList(ne->expression);
+            AST::FormalParameterList *list = ne->expression->reparseAsFormalParameterList(pool);
             if (!list) {
                 syntaxError(loc(1), "Invalid Arrow parameter list.");
                 return false;
diff --git a/src/qml/parser/qqmljsast.cpp b/src/qml/parser/qqmljsast.cpp
index eef7a33f26..c86fb24e82 100644
--- a/src/qml/parser/qqmljsast.cpp
+++ b/src/qml/parser/qqmljsast.cpp
@@ -110,6 +110,42 @@ ExpressionNode *ExpressionNode::expressionCast()
     return this;
 }
 
+FormalParameterList *ExpressionNode::reparseAsFormalParameterList(MemoryPool *pool)
+{
+    AST::ExpressionNode *expr = this;
+    AST::FormalParameterList *f = nullptr;
+    if (AST::Expression *commaExpr = AST::cast<AST::Expression *>(expr)) {
+        f = commaExpr->left->reparseAsFormalParameterList(pool);
+        if (!f)
+            return nullptr;
+
+        expr = commaExpr->right;
+    }
+
+    AST::ExpressionNode *rhs = nullptr;
+    if (AST::BinaryExpression *assign = AST::cast<AST::BinaryExpression *>(expr)) {
+            if (assign->op != QSOperator::Assign)
+                return nullptr;
+        expr = assign->left;
+        rhs = assign->right;
+    }
+    AST::PatternElement *binding = nullptr;
+    if (AST::IdentifierExpression *idExpr = AST::cast<AST::IdentifierExpression *>(expr)) {
+        binding = new (pool) AST::PatternElement(idExpr->name, rhs);
+        binding->identifierToken = idExpr->identifierToken;
+    } else if (AST::Pattern *p = expr->patternCast()) {
+        SourceLocation loc;
+        QString s;
+        if (!p->convertLiteralToAssignmentPattern(pool, &loc, &s))
+            return nullptr;
+        binding = new (pool) AST::PatternElement(p, rhs);
+        binding->identifierToken = p->firstSourceLocation();
+    }
+    if (!binding)
+        return nullptr;
+    return new (pool) AST::FormalParameterList(f, binding);
+}
+
 BinaryExpression *BinaryExpression::binaryExpressionCast()
 {
     return this;
@@ -319,6 +355,8 @@ PropertyName:
 */
 bool ArrayPattern::convertLiteralToAssignmentPattern(MemoryPool *pool, SourceLocation *errorLocation, QString *errorMessage)
 {
+    if (parseMode == Binding)
+        return true;
     for (auto *it = elements; it; it = it->next) {
         if (it->element->type == PatternElement::SpreadElement && it->next) {
             *errorLocation = it->element->firstSourceLocation();
@@ -328,15 +366,19 @@ bool ArrayPattern::convertLiteralToAssignmentPattern(MemoryPool *pool, SourceLoc
         if (!it->element->convertLiteralToAssignmentPattern(pool, errorLocation, errorMessage))
             return false;
     }
+    parseMode = Binding;
     return true;
 }
 
 bool ObjectPattern::convertLiteralToAssignmentPattern(MemoryPool *pool, SourceLocation *errorLocation, QString *errorMessage)
 {
+    if (parseMode == Binding)
+        return true;
     for (auto *it = properties; it; it = it->next) {
         if (!it->property->convertLiteralToAssignmentPattern(pool, errorLocation, errorMessage))
             return false;
     }
+    parseMode = Binding;
     return true;
 }
 
diff --git a/src/qml/parser/qqmljsast_p.h b/src/qml/parser/qqmljsast_p.h
index e14e058e83..c83a459506 100644
--- a/src/qml/parser/qqmljsast_p.h
+++ b/src/qml/parser/qqmljsast_p.h
@@ -279,6 +279,9 @@ public:
     ExpressionNode() {}
 
     ExpressionNode *expressionCast() override;
+
+    AST::FormalParameterList *reparseAsFormalParameterList(MemoryPool *pool);
+
 };
 
 class QML_PARSER_EXPORT LeftHandSideExpression : public ExpressionNode
@@ -527,8 +530,13 @@ public:
 class QML_PARSER_EXPORT Pattern : public LeftHandSideExpression
 {
 public:
+    enum ParseMode {
+        Literal,
+        Binding
+    };
     Pattern *patternCast() override;
     virtual bool convertLiteralToAssignmentPattern(MemoryPool *pool, SourceLocation *errorLocation, QString *errorMessage) = 0;
+    ParseMode parseMode = Literal;
 };
 
 class QML_PARSER_EXPORT ArrayPattern : public Pattern