Give for loops a per-iteration context as well

Regular for loops also have a per iteration context for lexically
declared variables as well.

Change-Id: I35cb58bfb198c7dc32d70f41ea0ced7ddefcc37e
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

11 files changed, 55 insertions, 7 deletions

diff --git a/src/qml/compiler/qv4codegen.cpp b/src/qml/compiler/qv4codegen.cpp
index 9c63360107..49f0511116 100644
--- a/src/qml/compiler/qv4codegen.cpp
+++ b/src/qml/compiler/qv4codegen.cpp
@@ -2708,6 +2708,10 @@ bool Codegen::visit(ForStatement *ast)
     setJumpOutLocation(bytecodeGenerator, ast->statement, ast->forToken);
 
     step.link();
+    if (_context->requiresExecutionContext) {
+        Instruction::CloneBlockContext clone;
+        bytecodeGenerator->addInstruction(clone);
+    }
     statement(ast->expression);
     bytecodeGenerator->jump().link(cond);
 
diff --git a/src/qml/compiler/qv4instr_moth.cpp b/src/qml/compiler/qv4instr_moth.cpp
index d4abc59a8b..7d9dc25ced 100644
--- a/src/qml/compiler/qv4instr_moth.cpp
+++ b/src/qml/compiler/qv4instr_moth.cpp
@@ -415,6 +415,9 @@ void dumpBytecode(const char *code, int len, int nLocals, int nFormals, int /*st
             d << dumpRegister(reg, nFormals) << ", " << index;
         MOTH_END_INSTR(PushBlockContext)
 
+        MOTH_BEGIN_INSTR(CloneBlockContext)
+        MOTH_END_INSTR(CloneBlockContext)
+
         MOTH_BEGIN_INSTR(PushScriptContext)
             d << index;
         MOTH_END_INSTR(PushScriptContext)
diff --git a/src/qml/compiler/qv4instr_moth_p.h b/src/qml/compiler/qv4instr_moth_p.h
index d12d1a53cc..96ab593609 100644
--- a/src/qml/compiler/qv4instr_moth_p.h
+++ b/src/qml/compiler/qv4instr_moth_p.h
@@ -117,6 +117,7 @@ QT_BEGIN_NAMESPACE
 #define INSTR_PushCatchContext(op) INSTRUCTION(op, PushCatchContext, 3, reg, index, name)
 #define INSTR_PushWithContext(op) INSTRUCTION(op, PushWithContext, 1, reg)
 #define INSTR_PushBlockContext(op) INSTRUCTION(op, PushBlockContext, 2, reg, index)
+#define INSTR_CloneBlockContext(op) INSTRUCTION(op, CloneBlockContext, 0)
 #define INSTR_PushScriptContext(op) INSTRUCTION(op, PushScriptContext, 1, index)
 #define INSTR_PopScriptContext(op) INSTRUCTION(op, PopScriptContext, 0)
 #define INSTR_PopContext(op) INSTRUCTION(op, PopContext, 1, reg)
@@ -242,6 +243,7 @@ QT_BEGIN_NAMESPACE
     F(PushCatchContext) \
     F(PushWithContext) \
     F(PushBlockContext) \
+    F(CloneBlockContext) \
     F(PushScriptContext) \
     F(PopScriptContext) \
     F(PopContext) \
diff --git a/src/qml/jit/qv4jit.cpp b/src/qml/jit/qv4jit.cpp
index f659ddfb00..4f95232f0d 100644
--- a/src/qml/jit/qv4jit.cpp
+++ b/src/qml/jit/qv4jit.cpp
@@ -659,6 +659,19 @@ void BaselineJIT::generate_PushBlockContext(int reg, int index)
     JIT_GENERATE_RUNTIME_CALL(pushBlockContextHelper, Assembler::IgnoreResult);
 }
 
+static void cloneBlockContextHelper(QV4::Value *contextSlot)
+{
+    *contextSlot = Runtime::method_cloneBlockContext(static_cast<QV4::ExecutionContext *>(contextSlot));
+}
+
+void BaselineJIT::generate_CloneBlockContext()
+{
+    as->saveAccumulatorInFrame();
+    as->prepareCallWithArgCount(1);
+    as->passRegAsArg(CallData::Context, 0);
+    JIT_GENERATE_RUNTIME_CALL(cloneBlockContextHelper, Assembler::IgnoreResult);
+}
+
 static void pushScriptContextHelper(QV4::Value *stack, ExecutionEngine *engine, int index)
 {
     stack[CallData::Context] = Runtime::method_createScriptContext(engine, index);
@@ -1236,6 +1249,9 @@ void BaselineJIT::collectLabelsInBytecode()
         MOTH_BEGIN_INSTR(PushBlockContext)
         MOTH_END_INSTR(PushBlockContext)
 
+        MOTH_BEGIN_INSTR(CloneBlockContext)
+        MOTH_END_INSTR(CloneBlockContext)
+
         MOTH_BEGIN_INSTR(PushScriptContext)
         MOTH_END_INSTR(PushScriptContext)
 
diff --git a/src/qml/jit/qv4jit_p.h b/src/qml/jit/qv4jit_p.h
index 97dd2ef2a5..333cf05f09 100644
--- a/src/qml/jit/qv4jit_p.h
+++ b/src/qml/jit/qv4jit_p.h
@@ -181,6 +181,7 @@ public:
     void generate_PushCatchContext(int reg, int index, int name) override;
     void generate_PushWithContext(int reg) override;
     void generate_PushBlockContext(int reg, int index) override;
+    void generate_CloneBlockContext() override;
     void generate_PushScriptContext(int index) override;
     void generate_PopScriptContext() override;
     void generate_PopContext(int reg) override;
diff --git a/src/qml/jsruntime/qv4context.cpp b/src/qml/jsruntime/qv4context.cpp
index 8a6f1044b9..59b88c3160 100644
--- a/src/qml/jsruntime/qv4context.cpp
+++ b/src/qml/jsruntime/qv4context.cpp
@@ -59,7 +59,7 @@ Heap::CallContext *ExecutionContext::newBlockContext(CppStackFrame *frame, int b
     Function *function = frame->v4Function;
 
     Heap::InternalClass *ic = function->compilationUnit->runtimeBlocks.at(blockIndex);
-    int nLocals = ic->size;
+    uint nLocals = ic->size;
     size_t requiredMemory = sizeof(CallContext::Data) - sizeof(Value) + sizeof(Value) * nLocals;
 
     ExecutionEngine *v4 = function->internalClass->engine;
@@ -77,6 +77,19 @@ Heap::CallContext *ExecutionContext::newBlockContext(CppStackFrame *frame, int b
     return c;
 }
 
+Heap::CallContext *ExecutionContext::cloneBlockContext(Heap::CallContext *context)
+{
+    uint nLocals = context->locals.alloc;
+    size_t requiredMemory = sizeof(CallContext::Data) - sizeof(Value) + sizeof(Value) * nLocals;
+
+    ExecutionEngine *v4 = context->internalClass->engine;
+    Heap::CallContext *c = v4->memoryManager->allocManaged<CallContext>(requiredMemory, context->internalClass);
+    memcpy(c, context, requiredMemory);
+
+    return c;
+
+}
+
 Heap::CallContext *ExecutionContext::newCallContext(CppStackFrame *frame)
 {
     Function *function = frame->v4Function;
diff --git a/src/qml/jsruntime/qv4context_p.h b/src/qml/jsruntime/qv4context_p.h
index cd99f162d2..26e64728dc 100644
--- a/src/qml/jsruntime/qv4context_p.h
+++ b/src/qml/jsruntime/qv4context_p.h
@@ -182,6 +182,7 @@ struct Q_QML_EXPORT ExecutionContext : public Managed
     V4_INTERNALCLASS(ExecutionContext)
 
     static Heap::CallContext *newBlockContext(QV4::CppStackFrame *frame, int blockIndex);
+    static Heap::CallContext *cloneBlockContext(Heap::CallContext *context);
     static Heap::CallContext *newCallContext(QV4::CppStackFrame *frame);
     Heap::ExecutionContext *newWithContext(Heap::Object *with);
     static Heap::ExecutionContext *newCatchContext(CppStackFrame *frame, int blockIndex, Heap::String *exceptionVarName);
diff --git a/src/qml/jsruntime/qv4runtime.cpp b/src/qml/jsruntime/qv4runtime.cpp
index 8bf6d6b73f..986684302c 100644
--- a/src/qml/jsruntime/qv4runtime.cpp
+++ b/src/qml/jsruntime/qv4runtime.cpp
@@ -1230,6 +1230,12 @@ ReturnedValue Runtime::method_createBlockContext(ExecutionContext *parent, int i
     return parent->newBlockContext(e->currentStackFrame, index)->asReturnedValue();
 }
 
+ReturnedValue Runtime::method_cloneBlockContext(ExecutionContext *previous)
+{
+    return ExecutionContext::cloneBlockContext(static_cast<Heap::CallContext *>(previous->d()))->asReturnedValue();
+}
+
+
 ReturnedValue Runtime::method_createScriptContext(ExecutionEngine *engine, int index)
 {
     Q_ASSERT(engine->currentStackFrame->context()->d()->type == Heap::ExecutionContext::Type_GlobalContext ||
diff --git a/src/qml/jsruntime/qv4runtimeapi_p.h b/src/qml/jsruntime/qv4runtimeapi_p.h
index f707de00f8..c98433359b 100644
--- a/src/qml/jsruntime/qv4runtimeapi_p.h
+++ b/src/qml/jsruntime/qv4runtimeapi_p.h
@@ -128,6 +128,7 @@ struct ExceptionCheck<void (*)(QV4::NoThrowEngine *, A, B, C)> {
     F(ReturnedValue, createCatchContext, (ExecutionContext *parent, int blockIndex, int exceptionVarNameIndex)) \
     F(ReturnedValue, createBlockContext, (ExecutionContext *parent, int index)) \
     F(ReturnedValue, createScriptContext, (ExecutionEngine *engine, int index)) \
+    F(ReturnedValue, cloneBlockContext, (ExecutionContext *previous)) \
     F(ReturnedValue, popScriptContext, (ExecutionEngine *engine)) \
     \
     /* closures */ \
diff --git a/src/qml/jsruntime/qv4vme_moth.cpp b/src/qml/jsruntime/qv4vme_moth.cpp
index 3fadb6e670..5daead19d2 100644
--- a/src/qml/jsruntime/qv4vme_moth.cpp
+++ b/src/qml/jsruntime/qv4vme_moth.cpp
@@ -929,11 +929,18 @@ QV4::ReturnedValue VME::interpret(CppStackFrame &frame, const uchar *code)
     MOTH_END_INSTR(PushWithContext)
 
     MOTH_BEGIN_INSTR(PushBlockContext)
+        STORE_ACC();
         STACK_VALUE(reg) = STACK_VALUE(CallData::Context);
         ExecutionContext *c = static_cast<ExecutionContext *>(stack + CallData::Context);
         STACK_VALUE(CallData::Context) = Runtime::method_createBlockContext(c, index);
     MOTH_END_INSTR(PushBlockContext)
 
+    MOTH_BEGIN_INSTR(CloneBlockContext)
+        STORE_ACC();
+        ExecutionContext *c = static_cast<ExecutionContext *>(stack + CallData::Context);
+        STACK_VALUE(CallData::Context) = Runtime::method_cloneBlockContext(c);
+    MOTH_END_INSTR(CloneBlockContext)
+
     MOTH_BEGIN_INSTR(PushScriptContext)
         STACK_VALUE(CallData::Context) = Runtime::method_createScriptContext(engine, index);
     MOTH_END_INSTR(PushScriptContext)
diff --git a/tests/auto/qml/ecmascripttests/TestExpectations b/tests/auto/qml/ecmascripttests/TestExpectations
index bb442e0125..991af3c63b 100644
--- a/tests/auto/qml/ecmascripttests/TestExpectations
+++ b/tests/auto/qml/ecmascripttests/TestExpectations
@@ -6414,7 +6414,6 @@ language/statements/for/dstr-var-obj-ptrn-id-init-fn-name-fn.js fails
 language/statements/for/dstr-var-obj-ptrn-id-init-fn-name-gen.js fails
 language/statements/for/head-lhs-let.js sloppyFails
 language/statements/for/let-identifier-with-newline.js sloppyFails
-language/statements/for/scope-body-lex-boundary.js fails
 language/statements/for/scope-body-lex-open.js fails
 language/statements/for/tco-const-body.js strictFails
 language/statements/for/tco-let-body.js strictFails
@@ -6620,11 +6619,6 @@ language/statements/let/global-closure-get-before-initialization.js fails
 language/statements/let/global-closure-set-before-initialization.js fails
 language/statements/let/global-use-before-initialization-in-declaration-statement.js fails
 language/statements/let/global-use-before-initialization-in-prior-statement.js fails
-language/statements/let/syntax/let-closure-inside-condition.js fails
-language/statements/let/syntax/let-closure-inside-initialization.js fails
-language/statements/let/syntax/let-closure-inside-next-expression.js fails
-language/statements/let/syntax/let-iteration-variable-is-freshly-allocated-for-each-iteration-multi-let-binding.js fails
-language/statements/let/syntax/let-iteration-variable-is-freshly-allocated-for-each-iteration-single-let-binding.js fails
 language/statements/let/syntax/let.js fails
 language/statements/return/tco.js strictFails
 language/statements/switch/scope-lex-open-case.js fails