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>

4 files changed, 12 insertions, 43 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;