Unify ForeachStatement and LocalForeachStatement in the AST

This saves quite some duplicated code, but requires a bit of care
when iterating over the AST.

Change-Id: Ic530de4be8b36b4079c9d544b4b77982c3b8be60
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

9 files changed, 30 insertions, 95 deletions

diff --git a/src/qml/compiler/qv4codegen.cpp b/src/qml/compiler/qv4codegen.cpp
index 8c6964930d..31c0764570 100644
--- a/src/qml/compiler/qv4codegen.cpp
+++ b/src/qml/compiler/qv4codegen.cpp
@@ -79,7 +79,6 @@ static inline void setJumpOutLocation(QV4::Moth::BytecodeGenerator *bytecodeGene
     case Statement::Kind_ForEachStatement:
     case Statement::Kind_ForStatement:
     case Statement::Kind_IfStatement:
-    case Statement::Kind_LocalForEachStatement:
     case Statement::Kind_LocalForStatement:
     case Statement::Kind_WhileStatement:
         bytecodeGenerator->setLocation(fallback);
@@ -2611,7 +2610,16 @@ bool Codegen::visit(ForEachStatement *ast)
     bytecodeGenerator->addInstruction(iteratorObjInstr);
     iterator.storeConsumeAccumulator();
 
-    Reference lhs = expression(ast->initialiser);
+    Reference lhs;
+    if (ExpressionNode *e = ast->lhs->expressionCast()) {
+        lhs = expression(e);
+    } else if (PatternElement *p = AST::cast<PatternElement *>(ast->lhs)) {
+        variableDeclaration(p);
+        lhs = referenceForName(p->bindingIdentifier, true).asLValue();
+    } else {
+        Q_UNREACHABLE();
+    }
+
     if (hasError)
         return false;
     if (!lhs.isLValue()) {
@@ -2625,32 +2633,6 @@ bool Codegen::visit(ForEachStatement *ast)
     return false;
 }
 
-bool Codegen::visit(LocalForEachStatement *ast)
-{
-    if (hasError)
-        return true;
-
-    RegisterScope scope(this);
-
-    Reference iterator = Reference::fromStackSlot(this);
-    Reference expr = expression(ast->expression);
-    if (hasError)
-        return true;
-
-    variableDeclaration(ast->declaration);
-
-    expr.loadInAccumulator();
-    Instruction::GetIterator iteratorObjInstr;
-    iteratorObjInstr.iterator = (ast->type == ForEachType::Of) ? 1 : 0;
-    bytecodeGenerator->addInstruction(iteratorObjInstr);
-    iterator.storeConsumeAccumulator();
-
-    Reference lhs = referenceForName(ast->declaration->bindingIdentifier, true).asLValue();
-    foreachBody(lhs, ast->statement, ast->forToken, iterator);
-
-    return false;
-}
-
 void Codegen::foreachBody(const Reference &lhs, Statement *statements, const SourceLocation &forToken, const Reference &iterator)
 {
     RegisterScope scope(this);
@@ -2771,8 +2753,7 @@ bool Codegen::visit(LabelledStatement *ast)
             AST::cast<AST::DoWhileStatement *>(ast->statement) ||
             AST::cast<AST::ForStatement *>(ast->statement) ||
             AST::cast<AST::ForEachStatement *>(ast->statement) ||
-            AST::cast<AST::LocalForStatement *>(ast->statement) ||
-            AST::cast<AST::LocalForEachStatement *>(ast->statement)) {
+            AST::cast<AST::LocalForStatement *>(ast->statement)) {
         statement(ast->statement); // labelledStatement will be associated with the ast->statement's loop.
     } else {
         BytecodeGenerator::Label breakLabel = bytecodeGenerator->newLabel();
diff --git a/src/qml/compiler/qv4codegen_p.h b/src/qml/compiler/qv4codegen_p.h
index d742fe06b7..18ccf04dc8 100644
--- a/src/qml/compiler/qv4codegen_p.h
+++ b/src/qml/compiler/qv4codegen_p.h
@@ -603,7 +603,6 @@ protected:
     bool visit(AST::ForStatement *ast) override;
     bool visit(AST::IfStatement *ast) override;
     bool visit(AST::LabelledStatement *ast) override;
-    bool visit(AST::LocalForEachStatement *ast) override;
     bool visit(AST::LocalForStatement *ast) override;
     bool visit(AST::ReturnStatement *ast) override;
     bool visit(AST::SwitchStatement *ast) override;
diff --git a/src/qml/compiler/qv4compilerscanfunctions.cpp b/src/qml/compiler/qv4compilerscanfunctions.cpp
index 4dbd11ef1c..eadbc3ae17 100644
--- a/src/qml/compiler/qv4compilerscanfunctions.cpp
+++ b/src/qml/compiler/qv4compilerscanfunctions.cpp
@@ -342,17 +342,7 @@ bool ScanFunctions::visit(LocalForStatement *ast) {
 }
 
 bool ScanFunctions::visit(ForEachStatement *ast) {
-    Node::accept(ast->initialiser, this);
-    Node::accept(ast->expression, this);
-
-    TemporaryBoolAssignment allowFuncDecls(_allowFuncDecls, !_context->isStrict);
-    Node::accept(ast->statement, this);
-
-    return false;
-}
-
-bool ScanFunctions::visit(LocalForEachStatement *ast) {
-    Node::accept(ast->declaration, this);
+    Node::accept(ast->lhs, this);
     Node::accept(ast->expression, this);
 
     TemporaryBoolAssignment allowFuncDecls(_allowFuncDecls, !_context->isStrict);
diff --git a/src/qml/compiler/qv4compilerscanfunctions_p.h b/src/qml/compiler/qv4compilerscanfunctions_p.h
index 31e260b7ad..7d29af4fa3 100644
--- a/src/qml/compiler/qv4compilerscanfunctions_p.h
+++ b/src/qml/compiler/qv4compilerscanfunctions_p.h
@@ -127,7 +127,6 @@ protected:
     bool visit(AST::ForStatement *ast) override;
     bool visit(AST::LocalForStatement *ast) override;
     bool visit(AST::ForEachStatement *ast) override;
-    bool visit(AST::LocalForEachStatement *ast) override;
     bool visit(AST::ThisExpression *ast) override;
 
     bool visit(AST::Block *ast) override;
diff --git a/src/qml/parser/qqmljs.g b/src/qml/parser/qqmljs.g
index f162d123f5..5efc392efa 100644
--- a/src/qml/parser/qqmljs.g
+++ b/src/qml/parser/qqmljs.g
@@ -3143,6 +3143,15 @@ InOrOf: T_OF;
 IterationStatement: T_FOR T_LPAREN LeftHandSideExpression InOrOf Expression_In T_RPAREN Statement;
 /.
     case $rule_number: {
+        // need to convert the LHS to an AssignmentPattern if it was an Array/ObjectLiteral
+//        if (AST::Pattern *p = sym(3).Expression->patternCast()) {
+//            AST::SourceLocation errorLoc;
+//            QString errorMsg;
+//            if (!p->convertLiteralToAssignmentPattern(pool, &errorLoc, &errorMsg)) {
+//                syntaxError(errorLoc, errorMsg);
+//                return false;
+//            }
+//        }
         AST::ForEachStatement *node = new (pool) AST::ForEachStatement(sym(3).Expression, sym(5).Expression, sym(7).Statement);
         node->forToken = loc(1);
         node->lparenToken = loc(2);
@@ -3156,10 +3165,9 @@ IterationStatement: T_FOR T_LPAREN LeftHandSideExpression InOrOf Expression_In T
 IterationStatement: T_FOR T_LPAREN ForDeclaration InOrOf Expression_In T_RPAREN Statement;
 /.
     case $rule_number: {
-        AST::LocalForEachStatement *node = new (pool) AST::LocalForEachStatement(sym(3).PatternElement, sym(5).Expression, sym(7).Statement);
+        AST::ForEachStatement *node = new (pool) AST::ForEachStatement(sym(3).PatternElement, sym(5).Expression, sym(7).Statement);
         node->forToken = loc(1);
         node->lparenToken = loc(2);
-        node->varToken = loc(3);
         node->inOfToken = loc(4);
         node->rparenToken = loc(6);
         node->type = sym(4).forEachType;
diff --git a/src/qml/parser/qqmljsast.cpp b/src/qml/parser/qqmljsast.cpp
index cc8b290bc9..bf3e193291 100644
--- a/src/qml/parser/qqmljsast.cpp
+++ b/src/qml/parser/qqmljsast.cpp
@@ -791,18 +791,7 @@ void LocalForStatement::accept0(Visitor *visitor)
 void ForEachStatement::accept0(Visitor *visitor)
 {
     if (visitor->visit(this)) {
-        accept(initialiser, visitor);
-        accept(expression, visitor);
-        accept(statement, visitor);
-    }
-
-    visitor->endVisit(this);
-}
-
-void LocalForEachStatement::accept0(Visitor *visitor)
-{
-    if (visitor->visit(this)) {
-        accept(declaration, visitor);
+        accept(lhs, visitor);
         accept(expression, visitor);
         accept(statement, visitor);
     }
diff --git a/src/qml/parser/qqmljsast_p.h b/src/qml/parser/qqmljsast_p.h
index 36060f7358..83fcb6559c 100644
--- a/src/qml/parser/qqmljsast_p.h
+++ b/src/qml/parser/qqmljsast_p.h
@@ -174,7 +174,6 @@ public:
         Kind_ComputedPropertyName,
         Kind_IfStatement,
         Kind_LabelledStatement,
-        Kind_LocalForEachStatement,
         Kind_LocalForStatement,
         Kind_NewExpression,
         Kind_NewMemberExpression,
@@ -1711,37 +1710,12 @@ class QML_PARSER_EXPORT ForEachStatement: public Statement
 public:
     QQMLJS_DECLARE_AST_NODE(ForEachStatement)
 
-    ForEachStatement(ExpressionNode *i, ExpressionNode *e, Statement *stmt):
-        initialiser (i), expression (e), statement (stmt)
-        { kind = K; }
-
-    void accept0(Visitor *visitor) override;
-
-    SourceLocation firstSourceLocation() const override
-    { return forToken; }
-
-    SourceLocation lastSourceLocation() const override
-    { return statement->lastSourceLocation(); }
-
-// attributes
-    ExpressionNode *initialiser;
-    ExpressionNode *expression;
-    Statement *statement;
-    SourceLocation forToken;
-    SourceLocation lparenToken;
-    SourceLocation inOfToken;
-    SourceLocation rparenToken;
-    ForEachType type;
-};
-
-class QML_PARSER_EXPORT LocalForEachStatement: public Statement
-{
-public:
-    QQMLJS_DECLARE_AST_NODE(LocalForEachStatement)
-
-    LocalForEachStatement(PatternElement *v, ExpressionNode *e, Statement *stmt):
-        declaration (v), expression (e), statement (stmt)
-        { kind = K; }
+    ForEachStatement(ExpressionNode *i, ExpressionNode *e, Statement *stmt)
+        : lhs(i), expression(e), statement(stmt)
+    { kind = K; }
+    ForEachStatement(PatternElement *v, ExpressionNode *e, Statement *stmt)
+        : lhs(v), expression(e), statement(stmt)
+    { kind = K; }
 
     void accept0(Visitor *visitor) override;
 
@@ -1752,12 +1726,11 @@ public:
     { return statement->lastSourceLocation(); }
 
 // attributes
-    PatternElement *declaration;
+    Node *lhs;
     ExpressionNode *expression;
     Statement *statement;
     SourceLocation forToken;
     SourceLocation lparenToken;
-    SourceLocation varToken;
     SourceLocation inOfToken;
     SourceLocation rparenToken;
     ForEachType type;
diff --git a/src/qml/parser/qqmljsastfwd_p.h b/src/qml/parser/qqmljsastfwd_p.h
index 465f227b6d..22cf88919d 100644
--- a/src/qml/parser/qqmljsastfwd_p.h
+++ b/src/qml/parser/qqmljsastfwd_p.h
@@ -142,7 +142,6 @@ class WhileStatement;
 class ForStatement;
 class LocalForStatement;
 class ForEachStatement;
-class LocalForEachStatement;
 class ContinueStatement;
 class BreakStatement;
 class ReturnStatement;
diff --git a/src/qml/parser/qqmljsastvisitor_p.h b/src/qml/parser/qqmljsastvisitor_p.h
index b3b54364c4..4dfc50d122 100644
--- a/src/qml/parser/qqmljsastvisitor_p.h
+++ b/src/qml/parser/qqmljsastvisitor_p.h
@@ -272,9 +272,6 @@ public:
     virtual bool visit(ForEachStatement *) { return true; }
     virtual void endVisit(ForEachStatement *) {}
 
-    virtual bool visit(LocalForEachStatement *) { return true; }
-    virtual void endVisit(LocalForEachStatement *) {}
-
     virtual bool visit(ContinueStatement *) { return true; }
     virtual void endVisit(ContinueStatement *) {}