Long live qbs-pkgconfig!

This patchset introduce a static library for parsing .pc files. Code is
based on the original pkg-config source code https://
gitlab.freedesktop.org/pkg-config/pkg-config and is written in pure C++
(except for the places where we need access to filesystem as
std::filesystem is not available for all platforms - in that case, Qt
classes are used)

Parsing .pc files manually allows to have more control over dependencies
between modules, e.g. to generate a standalone module per one .pc file
and merge properties using Qbs itself, not via pkg-config.

Library is almost feature-complete and all tests copied from pkg-config
pass. Some functionality is omitted (e.g. prefix variables (what is
this?) or validating dependencies since Qbs does this as well)

Bechmark shows that parsing ~100 files takes about 10-15ms. Running
pkg-config on the same set of files takes ~4 seconds:

RESULT : TestPkgConfig::benchSystem():
     14 msecs per iteration (total: 57, iterations: 4)

Fixes: QBS-1615
Change-Id: I5bfdfa588aa04d9d69fd738dd2beea14174c0242
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

1 files changed, 106 insertions, 0 deletions

diff --git a/src/lib/corelib/jsextensions/pkgconfigjs.h b/src/lib/corelib/jsextensions/pkgconfigjs.h
new file mode 100644
index 000000000..66575d8f3
--- /dev/null
+++ b/src/lib/corelib/jsextensions/pkgconfigjs.h
@@ -0,0 +1,106 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 Ivan Komissarov (abbapoh@gmail.com)
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qbs.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** 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 "tools/qbs_export.h"
+#include <tools/stlutils.h>
+
+#include <pkgconfig.h>
+
+#include <QtCore/qobject.h>
+#include <QtCore/qvariant.h>
+
+#include <QtScript/qscriptable.h>
+
+#include <memory>
+
+class QProcessEnvironment;
+
+namespace qbs {
+namespace Internal {
+
+class QBS_AUTOTEST_EXPORT PkgConfigJs : public QObject, QScriptable
+{
+    Q_OBJECT
+public:
+
+    // can we trick moc here to avoid duplication?
+    enum class FlagType {
+        LibraryName = toUnderlying(PcPackage::Flag::Type::LibraryName),
+        LibraryPath = toUnderlying(PcPackage::Flag::Type::LibraryPath),
+        StaticLibraryName = toUnderlying(PcPackage::Flag::Type::StaticLibraryName),
+        Framework = toUnderlying(PcPackage::Flag::Type::Framework),
+        FrameworkPath = toUnderlying(PcPackage::Flag::Type::FrameworkPath),
+        LinkerFlags = toUnderlying(PcPackage::Flag::Type::LinkerFlag),
+        IncludePath = toUnderlying(PcPackage::Flag::Type::IncludePath),
+        SystemIncludePath = toUnderlying(PcPackage::Flag::Type::SystemIncludePath),
+        Define = toUnderlying(PcPackage::Flag::Type::Define),
+        CompilerFlags = toUnderlying(PcPackage::Flag::Type::CompilerFlag),
+    };
+    Q_ENUM(FlagType);
+
+    enum class ComparisonType {
+        LessThan,
+        GreaterThan,
+        LessThanEqual,
+        GreaterThanEqual,
+        Equal,
+        NotEqual,
+        AlwaysMatch
+    };
+    Q_ENUM(ComparisonType);
+
+    static QScriptValue ctor(QScriptContext *context, QScriptEngine *engine);
+
+    explicit PkgConfigJs(
+            QScriptContext *context, QScriptEngine *engine, const QVariantMap &options = {});
+
+    Q_INVOKABLE QVariantMap packages() const { return m_packages; }
+    Q_INVOKABLE QVariantList brokenPackages() const { return m_brokenPackages; }
+
+    // also used in tests
+    static PkgConfig::Options convertOptions(const QProcessEnvironment &env, const QVariantMap &map);
+
+private:
+    std::unique_ptr<PkgConfig> m_pkgConfig;
+    QVariantMap m_packages;
+    QVariantList m_brokenPackages;
+};
+
+} // namespace Internal
+} // namespace qbs