Move Codegen::ScanFunctions into it's own file

Change-Id: I2c6c2fa09bc58a26a350011f5d525ec9f4b89d7f
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

1 files changed, 412 insertions, 0 deletions

diff --git a/src/qml/compiler/qv4compilerscanfunctions.cpp b/src/qml/compiler/qv4compilerscanfunctions.cpp
new file mode 100644
index 0000000000..80980cf394
--- /dev/null
+++ b/src/qml/compiler/qv4compilerscanfunctions.cpp
@@ -0,0 +1,412 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qv4compilerscanfunctions_p.h"
+
+#include <QtCore/QCoreApplication>
+#include <QtCore/QStringList>
+#include <QtCore/QSet>
+#include <QtCore/QBuffer>
+#include <QtCore/QBitArray>
+#include <QtCore/QLinkedList>
+#include <QtCore/QStack>
+#include <private/qqmljsast_p.h>
+#include <private/qv4compilercontext_p.h>
+#include <private/qv4codegen_p.h>
+#include <private/qv4string_p.h>
+
+QT_USE_NAMESPACE
+using namespace QV4;
+using namespace QV4::Compiler;
+using namespace QQmlJS::AST;
+
+ScanFunctions::ScanFunctions(Codegen *cg, const QString &sourceCode, CompilationMode defaultProgramMode)
+    : _cg(cg)
+    , _sourceCode(sourceCode)
+    , _context(0)
+    , _allowFuncDecls(true)
+    , defaultProgramMode(defaultProgramMode)
+{
+}
+
+void ScanFunctions::operator()(Node *node)
+{
+    if (node)
+        node->accept(this);
+}
+
+void ScanFunctions::enterEnvironment(Node *node, CompilationMode compilationMode)
+{
+    Context *e = _cg->_module->newContext(node, _context, compilationMode);
+    if (!e->isStrict)
+        e->isStrict = _cg->_strictMode;
+    _contextStack.append(e);
+    _context = e;
+}
+
+void ScanFunctions::leaveEnvironment()
+{
+    _contextStack.pop();
+    _context = _contextStack.isEmpty() ? 0 : _contextStack.top();
+}
+
+void ScanFunctions::checkDirectivePrologue(SourceElements *ast)
+{
+    for (SourceElements *it = ast; it; it = it->next) {
+        if (StatementSourceElement *stmt = cast<StatementSourceElement *>(it->element)) {
+            if (ExpressionStatement *expr = cast<ExpressionStatement *>(stmt->statement)) {
+                if (StringLiteral *strLit = cast<StringLiteral *>(expr->expression)) {
+                    // Use the source code, because the StringLiteral's
+                    // value might have escape sequences in it, which is not
+                    // allowed.
+                    if (strLit->literalToken.length < 2)
+                        continue;
+                    QStringRef str = _sourceCode.midRef(strLit->literalToken.offset + 1, strLit->literalToken.length - 2);
+                    if (str == QLatin1String("use strict")) {
+                        _context->isStrict = true;
+                    } else {
+                        // TODO: give a warning.
+                    }
+                    continue;
+                }
+            }
+        }
+
+        break;
+    }
+}
+
+void ScanFunctions::checkName(const QStringRef &name, const SourceLocation &loc)
+{
+    if (_context->isStrict) {
+        if (name == QLatin1String("implements")
+                || name == QLatin1String("interface")
+                || name == QLatin1String("let")
+                || name == QLatin1String("package")
+                || name == QLatin1String("private")
+                || name == QLatin1String("protected")
+                || name == QLatin1String("public")
+                || name == QLatin1String("static")
+                || name == QLatin1String("yield")) {
+            _cg->throwSyntaxError(loc, QStringLiteral("Unexpected strict mode reserved word"));
+        }
+    }
+}
+void ScanFunctions::checkForArguments(AST::FormalParameterList *parameters)
+{
+    while (parameters) {
+        if (parameters->name == QLatin1String("arguments"))
+            _context->usesArgumentsObject = Context::ArgumentsObjectNotUsed;
+        parameters = parameters->next;
+    }
+}
+
+bool ScanFunctions::visit(Program *ast)
+{
+    enterEnvironment(ast, defaultProgramMode);
+    checkDirectivePrologue(ast->elements);
+    return true;
+}
+
+void ScanFunctions::endVisit(Program *)
+{
+    leaveEnvironment();
+}
+
+bool ScanFunctions::visit(CallExpression *ast)
+{
+    if (! _context->hasDirectEval) {
+        if (IdentifierExpression *id = cast<IdentifierExpression *>(ast->base)) {
+            if (id->name == QLatin1String("eval")) {
+                if (_context->usesArgumentsObject == Context::ArgumentsObjectUnknown)
+                    _context->usesArgumentsObject = Context::ArgumentsObjectUsed;
+                _context->hasDirectEval = true;
+            }
+        }
+    }
+    int argc = 0;
+    for (ArgumentList *it = ast->arguments; it; it = it->next)
+        ++argc;
+    _context->maxNumberOfArguments = qMax(_context->maxNumberOfArguments, argc);
+    return true;
+}
+
+bool ScanFunctions::visit(NewMemberExpression *ast)
+{
+    int argc = 0;
+    for (ArgumentList *it = ast->arguments; it; it = it->next)
+        ++argc;
+    _context->maxNumberOfArguments = qMax(_context->maxNumberOfArguments, argc);
+    return true;
+}
+
+bool ScanFunctions::visit(ArrayLiteral *ast)
+{
+    int index = 0;
+    for (ElementList *it = ast->elements; it; it = it->next) {
+        for (Elision *elision = it->elision; elision; elision = elision->next)
+            ++index;
+        ++index;
+    }
+    if (ast->elision) {
+        for (Elision *elision = ast->elision->next; elision; elision = elision->next)
+            ++index;
+    }
+    _context->maxNumberOfArguments = qMax(_context->maxNumberOfArguments, index);
+    return true;
+}
+
+bool ScanFunctions::visit(VariableDeclaration *ast)
+{
+    if (_context->isStrict && (ast->name == QLatin1String("eval") || ast->name == QLatin1String("arguments")))
+        _cg->throwSyntaxError(ast->identifierToken, QStringLiteral("Variable name may not be eval or arguments in strict mode"));
+    checkName(ast->name, ast->identifierToken);
+    if (ast->name == QLatin1String("arguments"))
+        _context->usesArgumentsObject = Context::ArgumentsObjectNotUsed;
+    if (ast->scope == AST::VariableDeclaration::VariableScope::ReadOnlyBlockScope && !ast->expression) {
+        _cg->throwSyntaxError(ast->identifierToken, QStringLiteral("Missing initializer in const declaration"));
+        return false;
+    }
+    QString name = ast->name.toString();
+    const Context::Member *m = 0;
+    if (_context->memberInfo(name, &m)) {
+        if (m->isLexicallyScoped() || ast->isLexicallyScoped()) {
+            _cg->throwSyntaxError(ast->identifierToken, QStringLiteral("Identifier %1 has already been declared").arg(name));
+            return false;
+        }
+    }
+    _context->addLocalVar(ast->name.toString(), ast->expression ? Context::VariableDefinition : Context::VariableDeclaration, ast->scope);
+    return true;
+}
+
+bool ScanFunctions::visit(IdentifierExpression *ast)
+{
+    checkName(ast->name, ast->identifierToken);
+    if (_context->usesArgumentsObject == Context::ArgumentsObjectUnknown && ast->name == QLatin1String("arguments"))
+        _context->usesArgumentsObject = Context::ArgumentsObjectUsed;
+    return true;
+}
+
+bool ScanFunctions::visit(ExpressionStatement *ast)
+{
+    if (FunctionExpression* expr = AST::cast<AST::FunctionExpression*>(ast->expression)) {
+        if (!_allowFuncDecls)
+            _cg->throwSyntaxError(expr->functionToken, QStringLiteral("conditional function or closure declaration"));
+
+        enterFunction(expr, /*enterName*/ true);
+        Node::accept(expr->formals, this);
+        Node::accept(expr->body, this);
+        leaveEnvironment();
+        return false;
+    } else {
+        SourceLocation firstToken = ast->firstSourceLocation();
+        if (_sourceCode.midRef(firstToken.offset, firstToken.length) == QLatin1String("function")) {
+            _cg->throwSyntaxError(firstToken, QStringLiteral("unexpected token"));
+        }
+    }
+    return true;
+}
+
+bool ScanFunctions::visit(FunctionExpression *ast)
+{
+    enterFunction(ast, /*enterName*/ false);
+    return true;
+}
+
+void ScanFunctions::enterFunction(FunctionExpression *ast, bool enterName, bool isExpression)
+{
+    if (_context->isStrict && (ast->name == QLatin1String("eval") || ast->name == QLatin1String("arguments")))
+        _cg->throwSyntaxError(ast->identifierToken, QStringLiteral("Function name may not be eval or arguments in strict mode"));
+    enterFunction(ast, ast->name.toString(), ast->formals, ast->body, enterName ? ast : 0, isExpression);
+}
+
+void ScanFunctions::endVisit(FunctionExpression *)
+{
+    leaveEnvironment();
+}
+
+bool ScanFunctions::visit(ObjectLiteral *ast)
+{
+    int argc = 0;
+    for (PropertyAssignmentList *it = ast->properties; it; it = it->next) {
+        QString key = it->assignment->name->asString();
+        if (QV4::String::toArrayIndex(key) != UINT_MAX)
+            ++argc;
+        ++argc;
+        if (AST::cast<AST::PropertyGetterSetter *>(it->assignment))
+            ++argc;
+    }
+    _context->maxNumberOfArguments = qMax(_context->maxNumberOfArguments, argc);
+
+    TemporaryBoolAssignment allowFuncDecls(_allowFuncDecls, true);
+    Node::accept(ast->properties, this);
+    return false;
+}
+
+bool ScanFunctions::visit(PropertyGetterSetter *ast)
+{
+    TemporaryBoolAssignment allowFuncDecls(_allowFuncDecls, true);
+    enterFunction(ast, QString(), ast->formals, ast->functionBody, /*FunctionExpression*/0, /*isExpression*/false);
+    return true;
+}
+
+void ScanFunctions::endVisit(PropertyGetterSetter *)
+{
+    leaveEnvironment();
+}
+
+bool ScanFunctions::visit(FunctionDeclaration *ast)
+{
+    enterFunction(ast, /*enterName*/ true, /*isExpression */false);
+    return true;
+}
+
+void ScanFunctions::endVisit(FunctionDeclaration *)
+{
+    leaveEnvironment();
+}
+
+bool ScanFunctions::visit(WithStatement *ast)
+{
+    if (_context->isStrict) {
+        _cg->throwSyntaxError(ast->withToken, QStringLiteral("'with' statement is not allowed in strict mode"));
+        return false;
+    }
+
+    return true;
+}
+
+bool ScanFunctions::visit(DoWhileStatement *ast) {
+    {
+        TemporaryBoolAssignment allowFuncDecls(_allowFuncDecls, !_context->isStrict);
+        Node::accept(ast->statement, this);
+    }
+    Node::accept(ast->expression, this);
+    return false;
+}
+
+bool ScanFunctions::visit(ForStatement *ast) {
+    Node::accept(ast->initialiser, this);
+    Node::accept(ast->condition, this);
+    Node::accept(ast->expression, this);
+
+    TemporaryBoolAssignment allowFuncDecls(_allowFuncDecls, !_context->isStrict);
+    Node::accept(ast->statement, this);
+
+    return false;
+}
+
+bool ScanFunctions::visit(LocalForStatement *ast) {
+    Node::accept(ast->declarations, this);
+    Node::accept(ast->condition, this);
+    Node::accept(ast->expression, this);
+
+    TemporaryBoolAssignment allowFuncDecls(_allowFuncDecls, !_context->isStrict);
+    Node::accept(ast->statement, this);
+
+    return false;
+}
+
+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->expression, this);
+
+    TemporaryBoolAssignment allowFuncDecls(_allowFuncDecls, !_context->isStrict);
+    Node::accept(ast->statement, this);
+
+    return false;
+}
+
+bool ScanFunctions::visit(ThisExpression *)
+{
+    _context->usesThis = true;
+    return false;
+}
+
+bool ScanFunctions::visit(Block *ast) {
+    TemporaryBoolAssignment allowFuncDecls(_allowFuncDecls, _context->isStrict ? false : _allowFuncDecls);
+    Node::accept(ast->statements, this);
+    return false;
+}
+
+void ScanFunctions::enterFunction(Node *ast, const QString &name, FormalParameterList *formals, FunctionBody *body, FunctionExpression *expr, bool isExpression)
+{
+    if (_context) {
+        _context->hasNestedFunctions = true;
+        // The identifier of a function expression cannot be referenced from the enclosing environment.
+        if (expr)
+            _context->addLocalVar(name, Context::FunctionDefinition, AST::VariableDeclaration::FunctionScope, expr);
+        if (name == QLatin1String("arguments"))
+            _context->usesArgumentsObject = Context::ArgumentsObjectNotUsed;
+    }
+
+    enterEnvironment(ast, FunctionCode);
+    checkForArguments(formals);
+
+    _context->isNamedFunctionExpression = isExpression && !name.isEmpty();
+    _context->formals = formals;
+
+    if (body && !_context->isStrict)
+        checkDirectivePrologue(body->elements);
+
+    for (FormalParameterList *it = formals; it; it = it->next) {
+        QString arg = it->name.toString();
+        if (_context->isStrict) {
+            if (_context->arguments.contains(arg)) {
+                _cg->throwSyntaxError(it->identifierToken, QStringLiteral("Duplicate parameter name '%1' is not allowed in strict mode").arg(arg));
+                return;
+            }
+            if (arg == QLatin1String("eval") || arg == QLatin1String("arguments")) {
+                _cg->throwSyntaxError(it->identifierToken, QStringLiteral("'%1' cannot be used as parameter name in strict mode").arg(arg));
+                return;
+            }
+        }
+        _context->arguments += arg;
+    }
+}