Move conversion of this object into generated code

When a non strict mode function uses the this object, we
need to make sure it's being correctly converted into a
object before being accessed. So far this was being done
by ScriptFunction::call. Move this into the generated code to
avoid overhead for methods not using 'this', and simplify our
ScriptFunction::call() implementation.

Change-Id: I739f4a89d29ed8082ce59e48d1523776224fc29d
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/src/qml/compiler/qv4codegen.cpp b/src/qml/compiler/qv4codegen.cpp
index 58c9fc59bb..4810e4dace 100644
--- a/src/qml/compiler/qv4codegen.cpp
+++ b/src/qml/compiler/qv4codegen.cpp
@@ -355,6 +355,12 @@ bool Codegen::ScanFunctions::visit(LocalForEachStatement *ast) {
     return false;
 }
 
+bool Codegen::ScanFunctions::visit(ThisExpression *)
+{
+    _env->usesThis = true;
+    return false;
+}
+
 bool Codegen::ScanFunctions::visit(Block *ast) {
     TemporaryBoolAssignment allowFuncDecls(_allowFuncDecls, _env->isStrict ? false : _allowFuncDecls);
     Node::accept(ast->statements, this);
@@ -1953,6 +1959,7 @@ int Codegen::defineFunction(const QString &name, AST::Node *ast,
     V4IR::BasicBlock *exitBlock = function->newBasicBlock(groupStartBlock(), 0, V4IR::Function::DontInsertBlock);
     function->hasDirectEval = _env->hasDirectEval;
     function->usesArgumentsObject = _env->parent && (_env->usesArgumentsObject == Environment::ArgumentsObjectUsed);
+    function->usesThis = _env->usesThis;
     function->maxNumberOfArguments = qMax(_env->maxNumberOfArguments, (int)QV4::Global::ReservedArgumentCount);
     function->isStrict = _env->isStrict;
     function->isNamedExpression = _env->isNamedFunctionExpression;
@@ -2036,6 +2043,11 @@ int Codegen::defineFunction(const QString &name, AST::Node *ast,
              _block->CALL(_block->NAME(V4IR::Name::builtin_setup_argument_object,
                      ast->firstSourceLocation().startLine, ast->firstSourceLocation().startColumn), 0));
     }
+    if (_function->usesThis && !_function->isStrict) {
+        // make sure we convert this to an object
+        _block->EXP(_block->CALL(_block->NAME(V4IR::Name::builtin_convert_this_to_object,
+                ast->firstSourceLocation().startLine, ast->firstSourceLocation().startColumn), 0));
+    }
 
     sourceElements(body);