C: Parser: Support parsing of c99 designated initializers

In case:

    int a[6] = { [4] = 29, [2] = 15 };
    struct point { int x, y; };
    struct point p = { .y = 3, .x = 2 };

Grammar change when c99 language feature is enabled:
old grammar:

    braced-init-list :: '{' initializer-list '}'

new grammar:

    braced-init-list :: '{' designated-initializer-list '}'
    designated-initializer-list :: designated-initializer (',' designated-initializer )*
    designated-initializer :: designator* initializer-clause
    designator :: '.' identifier
                | '[' constant-expression ']'

Task-number: QTCREATORBUG-1902
Change-Id: Ib99d6f553f8d0f50ba3eff86f3a2e86d73372426
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@digia.com>

tests/auto/cplusplus/c99/tst_c99.cpp

@@ -0,0 +1,153 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of Qt Creator.
+**
+** 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 Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/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 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+****************************************************************************/
+
+#include <cplusplus/CPlusPlus.h>
+#include <cplusplus/CppDocument.h>
+#include <cplusplus/LookupContext.h>
+
+#include <QtTest>
+#include <QObject>
+#include <QFile>
+
+//TESTED_COMPONENT=src/libs/cplusplus
+using namespace CPlusPlus;
+
+#define VERIFY_ERRORS() \
+    do { \
+      QByteArray expectedErrors; \
+      if (!errorFile.isEmpty()) { \
+        QFile e(testdata(errorFile)); \
+        if (e.open(QFile::ReadOnly)) \
+          expectedErrors = QTextStream(&e).readAll().toUtf8(); \
+      } \
+      QCOMPARE(QString::fromLatin1(errors), QString::fromLatin1(expectedErrors)); \
+    } while (0)
+
+
+class tst_c99: public QObject
+{
+    Q_OBJECT
+
+    /*
+        Returns the path to some testdata file or directory.
+    */
+    static QString testdata(const QString &name = QString())
+    {
+        static const QString dataDirectory = QLatin1String(SRCDIR "/data");
+
+        QString result = dataDirectory;
+        if (!name.isEmpty()) {
+            result += QLatin1Char('/');
+            result += name;
+        }
+        return result;
+    }
+
+    struct Client: CPlusPlus::DiagnosticClient {
+        QByteArray *errors;
+
+        Client(QByteArray *errors)
+            : errors(errors)
+        {
+        }
+
+        virtual void report(int level,
+                            const StringLiteral *fileName,
+                            unsigned line, unsigned column,
+                            const char *format, va_list ap)
+        {
+            if (! errors)
+                return;
+
+            static const char *const pretty[] = { "warning", "error", "fatal" };
+
+            QString str;
+            str.sprintf("%s:%d:%d: %s: ", fileName->chars(), line, column, pretty[level]);
+            errors->append(str.toUtf8());
+
+            str.vsprintf(format, ap);
+            errors->append(str.toUtf8());
+
+            errors->append('\n');
+        }
+    };
+
+    Document::Ptr document(const QString &fileName, QByteArray *errors = 0)
+    {
+        Document::Ptr doc = Document::create(fileName);
+        QFile file(testdata(fileName));
+        if (file.open(QFile::ReadOnly)) {
+            LanguageFeatures features;
+            features.c99Enabled = true;
+            Client client(errors);
+            doc->control()->setDiagnosticClient(&client);
+            doc->setUtf8Source(QTextStream(&file).readAll().toUtf8());
+            doc->translationUnit()->setLanguageFeatures(features);
+            doc->check();
+            doc->control()->setDiagnosticClient(0);
+        } else {
+            qWarning() << "could not read file" << fileName;
+        }
+        return doc;
+    }
+
+private Q_SLOTS:
+    //
+    // checks for the syntax
+    //
+    void parse_data();
+    void parse();
+};
+
+
+void tst_c99::parse_data()
+{
+    QTest::addColumn<QString>("file");
+    QTest::addColumn<QString>("errorFile");
+
+    QTest::newRow("designatedInitializer.1") << "designatedInitializer.1.c" << "";
+    QTest::newRow("designatedInitializer.2") << "designatedInitializer.2.c" << "";
+}
+
+void tst_c99::parse()
+{
+    QFETCH(QString, file);
+    QFETCH(QString, errorFile);
+
+    QByteArray errors;
+    Document::Ptr doc = document(file, &errors);
+
+    if (! qgetenv("DEBUG").isNull())
+        printf("%s\n", errors.constData());
+
+    VERIFY_ERRORS();
+}
+
+QTEST_APPLESS_MAIN(tst_c99)
+#include "tst_c99.moc"