implement simple VFS to support caching during project parsing

this tremendously speeds up loading of qt 5.1 based projects (including
qt itself) under mac os, as these look up the sdk dynamically, and use
caching to avoid doing that in every subproject.

Change-Id: I833253f81c3159056fab2ff888f293b36cc2ef56
Reviewed-by: Daniel Teske <daniel.teske@digia.com>

src/plugins/qt4projectmanager/qt4nodes.cpp

@@ -56,6 +56,7 @@
 #include <utils/hostosinfo.h>
 #include <utils/stringutils.h>
 #include <proparser/prowriter.h>
+#include <proparser/qmakevfs.h>
 #include <algorithm>
 
 #include <QDebug>
@@ -1135,8 +1136,9 @@ void Qt4PriFileNode::changeFiles(const FileType fileType,
             lines = contents.split(QLatin1Char('\n'));
         }
 
+        QMakeVfs vfs;
         QtSupport::ProMessageHandler handler;
-        QMakeParser parser(0, &handler);
+        QMakeParser parser(0, &vfs, &handler);
         includeFile = parser.parsedProBlock(contents, m_projectFilePath, 1);
     }
 

src/plugins/qt4projectmanager/qt4project.cpp

@@ -46,6 +46,7 @@
 #include <coreplugin/documentmanager.h>
 #include <cpptools/cppmodelmanagerinterface.h>
 #include <qmljstools/qmljsmodelmanager.h>
+#include <projectexplorer/buildmanager.h>
 #include <projectexplorer/buildtargetinfo.h>
 #include <projectexplorer/deploymentdata.h>
 #include <projectexplorer/toolchain.h>
@@ -53,6 +54,7 @@
 #include <projectexplorer/target.h>
 #include <projectexplorer/projectexplorer.h>
 #include <projectexplorer/projectmacroexpander.h>
+#include <proparser/qmakevfs.h>
 #include <qtsupport/profilereader.h>
 #include <qtsupport/qtkitinformation.h>
 
@@ -344,6 +346,7 @@ Qt4Project::Qt4Project(Qt4Manager *manager, const QString& fileName) :
     m_nodesWatcher(new Internal::Qt4NodesWatcher(this)),
     m_fileInfo(new Qt4ProjectFile(fileName, this)),
     m_projectFiles(new Qt4ProjectFiles),
+    m_qmakeVfs(new QMakeVfs),
     m_qmakeGlobals(0),
     m_asyncUpdateFutureInterface(0),
     m_pendingEvaluateFuturesCount(0),
@@ -358,6 +361,10 @@ Qt4Project::Qt4Project(Qt4Manager *manager, const QString& fileName) :
     m_asyncUpdateTimer.setSingleShot(true);
     m_asyncUpdateTimer.setInterval(3000);
     connect(&m_asyncUpdateTimer, SIGNAL(timeout()), this, SLOT(asyncUpdate()));
+
+    connect(ProjectExplorerPlugin::instance()->buildManager(),
+            SIGNAL(buildQueueFinished(bool)),
+            SLOT(buildFinished(bool)));
 }
 
 Qt4Project::~Qt4Project()
@@ -365,6 +372,7 @@ Qt4Project::~Qt4Project()
     m_codeModelFuture.cancel();
     m_asyncUpdateState = ShuttingDown;
     m_manager->unregisterProject(this);
+    delete m_qmakeVfs;
     delete m_projectFiles;
     m_cancelEvaluate = true;
     // Deleting the root node triggers a few things, make sure rootProjectNode
@@ -847,6 +855,9 @@ void Qt4Project::asyncUpdate()
 {
     if (debug)
         qDebug()<<"async update, timer expired, doing now";
+
+    m_qmakeVfs->invalidateCache();
+
     Q_ASSERT(!m_asyncUpdateFutureInterface);
     m_asyncUpdateFutureInterface = new QFutureInterface<void>();
 
@@ -877,6 +888,12 @@ void Qt4Project::asyncUpdate()
     m_asyncUpdateState = AsyncUpdateInProgress;
 }
 
+void Qt4Project::buildFinished(bool success)
+{
+    if (success)
+        m_qmakeVfs->invalidateContents();
+}
+
 ProjectExplorer::IProjectManager *Qt4Project::projectManager() const
 {
     return m_manager;
@@ -1002,7 +1019,7 @@ QtSupport::ProFileReader *Qt4Project::createProFileReader(const Qt4ProFileNode *
     }
     ++m_qmakeGlobalsRefCnt;
 
-    QtSupport::ProFileReader *reader = new QtSupport::ProFileReader(m_qmakeGlobals);
+    QtSupport::ProFileReader *reader = new QtSupport::ProFileReader(m_qmakeGlobals, m_qmakeVfs);
 
     reader->setOutputDir(qt4ProFileNode->buildDir());
 

src/plugins/qt4projectmanager/qt4project.h

@@ -42,6 +42,7 @@
 
 QT_BEGIN_NAMESPACE
 class ProFileGlobals;
+class QMakeVfs;
 QT_END_NAMESPACE
 
 namespace ProjectExplorer { class DeploymentData; }
@@ -158,6 +159,7 @@ protected:
 
 private slots:
     void asyncUpdate();
+    void buildFinished(bool success);
 
     void activeTargetWasChanged();
 
@@ -198,6 +200,8 @@ private:
     // cached lists of all of files
     Internal::Qt4ProjectFiles *m_projectFiles;
 
+    QMakeVfs *m_qmakeVfs;
+
     // cached data during project rescan
     ProFileGlobals *m_qmakeGlobals;
     int m_qmakeGlobalsRefCnt;

src/plugins/qtsupport/baseqtversion.cpp

@@ -36,6 +36,7 @@
 
 #include "qtversionmanager.h"
 #include "profilereader.h"
+#include <proparser/qmakevfs.h>
 #include <projectexplorer/toolchainmanager.h>
 #include <projectexplorer/toolchain.h>
 #include <projectexplorer/projectexplorer.h>
@@ -780,12 +781,13 @@ void BaseQtVersion::ensureMkSpecParsed() const
     if (mkspecPath().isEmpty())
         return;
 
+    QMakeVfs vfs;
     ProFileGlobals option;
     option.setProperties(versionInfo());
     ProMessageHandler msgHandler(true);
     ProFileCacheManager::instance()->incRefCount();
-    QMakeParser parser(ProFileCacheManager::instance()->cache(), &msgHandler);
-    ProFileEvaluator evaluator(&option, &parser, &msgHandler);
+    QMakeParser parser(ProFileCacheManager::instance()->cache(), &vfs, &msgHandler);
+    ProFileEvaluator evaluator(&option, &parser, &vfs, &msgHandler);
     evaluator.loadNamedSpec(mkspecPath().toString(), false);
 
     parseMkSpec(&evaluator);

src/plugins/qtsupport/profilereader.cpp

@@ -65,9 +65,9 @@ void ProMessageHandler::fileMessage(const QString &)
 }
 
 
-ProFileReader::ProFileReader(ProFileGlobals *option)
-    : QMakeParser(ProFileCacheManager::instance()->cache(), this)
-    , ProFileEvaluator(option, this, this)
+ProFileReader::ProFileReader(ProFileGlobals *option, QMakeVfs *vfs)
+    : QMakeParser(ProFileCacheManager::instance()->cache(), vfs, this)
+    , ProFileEvaluator(option, this, vfs, this)
     , m_ignoreLevel(0)
 {
 }

src/plugins/qtsupport/profilereader.h

@@ -69,7 +69,7 @@ class QTSUPPORT_EXPORT ProFileReader : public ProMessageHandler, public QMakePar
     Q_OBJECT
 
 public:
-    ProFileReader(ProFileGlobals *option);
+    ProFileReader(ProFileGlobals *option, QMakeVfs *vfs);
     ~ProFileReader();
 
     QList<ProFile*> includeFiles() const;

src/plugins/qtsupport/qtversionfactory.cpp

@@ -31,6 +31,8 @@
 #include "profilereader.h"
 #include "baseqtversion.h"
 
+#include <proparser/qmakevfs.h>
+
 #include <extensionsystem/pluginmanager.h>
 #include <utils/environment.h>
 
@@ -61,12 +63,13 @@ BaseQtVersion *QtVersionFactory::createQtVersionFromQMakePath(const Utils::FileN
         return 0;
     Utils::FileName mkspec = BaseQtVersion::mkspecFromVersionInfo(versionInfo);
 
+    QMakeVfs vfs;
     ProFileGlobals globals;
     globals.setProperties(versionInfo);
     ProMessageHandler msgHandler(true);
     ProFileCacheManager::instance()->incRefCount();
-    QMakeParser parser(ProFileCacheManager::instance()->cache(), &msgHandler);
-    ProFileEvaluator evaluator(&globals, &parser, &msgHandler);
+    QMakeParser parser(ProFileCacheManager::instance()->cache(), &vfs, &msgHandler);
+    ProFileEvaluator evaluator(&globals, &parser, &vfs, &msgHandler);
     evaluator.loadNamedSpec(mkspec.toString(), false);
 
     QList<QtVersionFactory *> factories = ExtensionSystem::PluginManager::getObjects<QtVersionFactory>();

src/shared/proparser/profileevaluator.cpp

@@ -43,9 +43,9 @@ void ProFileEvaluator::initialize()
     QMakeEvaluator::initStatics();
 }
 
-ProFileEvaluator::ProFileEvaluator(ProFileGlobals *option, QMakeParser *parser,
+ProFileEvaluator::ProFileEvaluator(ProFileGlobals *option, QMakeParser *parser, QMakeVfs *vfs,
                                    QMakeHandler *handler)
-  : d(new QMakeEvaluator(option, parser, handler))
+  : d(new QMakeEvaluator(option, parser, vfs, handler))
 {
 }
 

src/shared/proparser/profileevaluator.h

@@ -40,6 +40,7 @@
 
 QT_BEGIN_NAMESPACE
 
+class QMakeVfs;
 class QMakeParser;
 class QMakeEvaluator;
 class QMakeHandler;
@@ -65,7 +66,8 @@ public:
     // Call this from a concurrency-free context
     static void initialize();
 
-    ProFileEvaluator(ProFileGlobals *option, QMakeParser *parser, QMakeHandler *handler);
+    ProFileEvaluator(ProFileGlobals *option, QMakeParser *parser, QMakeVfs *vfs,
+                     QMakeHandler *handler);
     ~ProFileEvaluator();
 
     ProFileEvaluator::TemplateType templateType() const;

src/shared/proparser/proparser.pri

@@ -14,6 +14,7 @@ HEADERS += \
         profileevaluator.h \
         proitems.h \
         prowriter.h \
+        qmakevfs.h \
         ioutils.h
 
 SOURCES += \
@@ -24,6 +25,7 @@ SOURCES += \
         qmakebuiltins.cpp \
         proitems.cpp \
         prowriter.cpp \
+        qmakevfs.cpp \
         ioutils.cpp
 
 RESOURCES += proparser.qrc

src/shared/proparser/qmakebuiltins.cpp

@@ -32,6 +32,7 @@
 #include "qmakeevaluator_p.h"
 #include "qmakeglobals.h"
 #include "qmakeparser.h"
+#include "qmakevfs.h"
 #include "ioutils.h"
 
 #include <qbytearray.h>
@@ -269,41 +270,12 @@ quoteValue(const ProString &val)
     return ret;
 }
 
-static bool
-doWriteFile(const QString &name, QIODevice::OpenMode mode, const QString &contents, QString *errStr)
-{
-    QByteArray bytes = contents.toLocal8Bit();
-    QFile cfile(name);
-    if (!(mode & QIODevice::Append) && cfile.open(QIODevice::ReadOnly | QIODevice::Text)) {
-        if (cfile.readAll() == bytes)
-            return true;
-        cfile.close();
-    }
-    if (!cfile.open(mode | QIODevice::WriteOnly | QIODevice::Text)) {
-        *errStr = cfile.errorString();
-        return false;
-    }
-    cfile.write(bytes);
-    cfile.close();
-    if (cfile.error() != QFile::NoError) {
-        *errStr = cfile.errorString();
-        return false;
-    }
-    return true;
-}
-
 QMakeEvaluator::VisitReturn
 QMakeEvaluator::writeFile(const QString &ctx, const QString &fn, QIODevice::OpenMode mode,
                           const QString &contents)
 {
-    QFileInfo qfi(fn);
-    if (!QDir::current().mkpath(qfi.path())) {
-        evalError(fL1S("Cannot create %1directory %2.")
-                  .arg(ctx, QDir::toNativeSeparators(qfi.path())));
-        return ReturnFalse;
-    }
     QString errStr;
-    if (!doWriteFile(fn, mode, contents, &errStr)) {
+    if (!m_vfs->writeFile(fn, mode, contents, &errStr)) {
         evalError(fL1S("Cannot write %1file %2: %3.")
                   .arg(ctx, QDir::toNativeSeparators(fn), errStr));
         return ReturnFalse;
@@ -1413,6 +1385,9 @@ QMakeEvaluator::VisitReturn QMakeEvaluator::evaluateBuiltinConditional(
         }
         const QString &file = resolvePath(m_option->expandEnvVars(args.at(0).toQString(m_tmp1)));
 
+        // Don't use VFS here:
+        // - it supports neither listing nor even directories
+        // - it's unlikely that somebody would test for files they created themselves
         if (IoUtils::exists(file))
             return ReturnTrue;
         int slsh = file.lastIndexOf(QLatin1Char('/'));
@@ -1444,7 +1419,6 @@ QMakeEvaluator::VisitReturn QMakeEvaluator::evaluateBuiltinConditional(
             evalError(fL1S("write_file(name, [content var, [append]]) requires one to three arguments."));
             return ReturnFalse;
         }
-#ifdef PROEVALUATOR_FULL
         QIODevice::OpenMode mode = QIODevice::Truncate;
         QString contents;
         if (args.count() >= 2) {
@@ -1456,9 +1430,6 @@ QMakeEvaluator::VisitReturn QMakeEvaluator::evaluateBuiltinConditional(
                     mode = QIODevice::Append;
         }
         return writeFile(QString(), resolvePath(args.at(0).toQString(m_tmp1)), mode, contents);
-#else
-        return ReturnTrue;
-#endif
     }
     case T_TOUCH: {
         if (args.count() != 2) {
@@ -1510,7 +1481,6 @@ QMakeEvaluator::VisitReturn QMakeEvaluator::evaluateBuiltinConditional(
             evalError(fL1S("cache(var, [set|add|sub] [transient] [super], [srcvar]) requires one to three arguments."));
             return ReturnFalse;
         }
-#ifdef PROEVALUATOR_FULL
         bool persist = true;
         bool super = false;
         enum { CacheSet, CacheAdd, CacheSub } mode = CacheSet;
@@ -1636,9 +1606,6 @@ QMakeEvaluator::VisitReturn QMakeEvaluator::evaluateBuiltinConditional(
             fn = m_cachefile;
         }
         return writeFile(fL1S("cache "), fn, QIODevice::Append, varstr);
-#else
-        return ReturnTrue;
-#endif
     }
     default:
         evalError(fL1S("Function '%1' is not implemented.").arg(function.toQString(m_tmp1)));

src/shared/proparser/qmakeevaluator.cpp

@@ -32,6 +32,7 @@
 
 #include "qmakeglobals.h"
 #include "qmakeparser.h"
+#include "qmakevfs.h"
 #include "ioutils.h"
 
 #include <qbytearray.h>
@@ -162,13 +163,13 @@ const ProKey &QMakeEvaluator::map(const ProKey &var)
 }
 
 
-QMakeEvaluator::QMakeEvaluator(QMakeGlobals *option,
-                               QMakeParser *parser, QMakeHandler *handler)
+QMakeEvaluator::QMakeEvaluator(QMakeGlobals *option, QMakeParser *parser, QMakeVfs *vfs,
+                               QMakeHandler *handler)
   :
 #ifdef PROEVALUATOR_DEBUG
     m_debugLevel(option->debugLevel),
 #endif
-    m_option(option), m_parser(parser), m_handler(handler)
+    m_option(option), m_parser(parser), m_handler(handler), m_vfs(vfs)
 {
     // So that single-threaded apps don't have to call initialize() for now.
     initStatics();
@@ -1049,7 +1050,7 @@ bool QMakeEvaluator::prepareProject(const QString &inDir)
             superdir = m_outputDir;
             forever {
                 QString superfile = superdir + QLatin1String("/.qmake.super");
-                if (IoUtils::exists(superfile)) {
+                if (m_vfs->exists(superfile)) {
                     m_superfile = QDir::cleanPath(superfile);
                     break;
                 }
@@ -1064,10 +1065,10 @@ bool QMakeEvaluator::prepareProject(const QString &inDir)
             QString dir = m_outputDir;
             forever {
                 conffile = sdir + QLatin1String("/.qmake.conf");
-                if (!IoUtils::exists(conffile))
+                if (!m_vfs->exists(conffile))
                     conffile.clear();
                 cachefile = dir + QLatin1String("/.qmake.cache");
-                if (!IoUtils::exists(cachefile))
+                if (!m_vfs->exists(cachefile))
                     cachefile.clear();
                 if (!conffile.isEmpty() || !cachefile.isEmpty()) {
                     if (dir != sdir)
@@ -1158,7 +1159,7 @@ bool QMakeEvaluator::loadSpec()
                 m_hostBuild ? m_option->qmakespec : m_option->xqmakespec);
 
     {
-        QMakeEvaluator evaluator(m_option, m_parser, m_handler);
+        QMakeEvaluator evaluator(m_option, m_parser, m_vfs, m_handler);
         if (!m_superfile.isEmpty()) {
             valuesRef(ProKey("_QMAKE_SUPER_CACHE_")) << ProString(m_superfile);
             if (evaluator.evaluateFile(
@@ -1315,7 +1316,7 @@ QMakeEvaluator::VisitReturn QMakeEvaluator::visitProFile(
                 locker.unlock();
 #endif
 
-                QMakeEvaluator *baseEval = new QMakeEvaluator(m_option, m_parser, m_handler);
+                QMakeEvaluator *baseEval = new QMakeEvaluator(m_option, m_parser, m_vfs, m_handler);
                 baseEnv->evaluator = baseEval;
                 baseEval->m_superfile = m_superfile;
                 baseEval->m_conffile = m_conffile;
@@ -1810,7 +1811,7 @@ QMakeEvaluator::VisitReturn QMakeEvaluator::evaluateFile(
 #endif
         return ok;
     } else {
-        if (!(flags & LoadSilent) && !IoUtils::exists(fileName))
+        if (!(flags & LoadSilent) && !m_vfs->exists(fileName))
             evalError(fL1S("WARNING: Include file %1 not found").arg(fileName));
         return ReturnFalse;
     }
@@ -1893,7 +1894,7 @@ QMakeEvaluator::VisitReturn QMakeEvaluator::evaluateFeatureFile(
 QMakeEvaluator::VisitReturn QMakeEvaluator::evaluateFileInto(
         const QString &fileName, ProValueMap *values, LoadFlags flags)
 {
-    QMakeEvaluator visitor(m_option, m_parser, m_handler);
+    QMakeEvaluator visitor(m_option, m_parser, m_vfs, m_handler);
     visitor.m_caller = this;
     visitor.m_outputDir = m_outputDir;
     visitor.m_featureRoots = m_featureRoots;

src/shared/proparser/qmakeevaluator.h

@@ -96,7 +96,7 @@ public:
 
     static void initStatics();
     static void initFunctionStatics();
-    QMakeEvaluator(QMakeGlobals *option, QMakeParser *parser,
+    QMakeEvaluator(QMakeGlobals *option, QMakeParser *parser, QMakeVfs *vfs,
                    QMakeHandler *handler);
     ~QMakeEvaluator();
 
@@ -282,6 +282,7 @@ public:
     QMakeGlobals *m_option;
     QMakeParser *m_parser;
     QMakeHandler *m_handler;
+    QMakeVfs *m_vfs;
 };
 
 Q_DECLARE_OPERATORS_FOR_FLAGS(QMakeEvaluator::LoadFlags)

src/shared/proparser/qmakeparser.cpp

@@ -29,6 +29,7 @@
 
 #include "qmakeparser.h"
 
+#include "qmakevfs.h"
 #include "ioutils.h"
 using namespace QMakeInternal;
 
@@ -130,9 +131,10 @@ void QMakeParser::initialize()
     statics.strLITERAL_WHITESPACE = QLatin1String("LITERAL_WHITESPACE");
 }
 
-QMakeParser::QMakeParser(ProFileCache *cache, QMakeParserHandler *handler)
+QMakeParser::QMakeParser(ProFileCache *cache, QMakeVfs *vfs, QMakeParserHandler *handler)
     : m_cache(cache)
     , m_handler(handler)
+    , m_vfs(vfs)
 {
     // So that single-threaded apps don't have to call initialize() for now.
     initialize();
@@ -218,24 +220,14 @@ void QMakeParser::discardFileFromCache(const QString &fileName)
 
 bool QMakeParser::read(ProFile *pro)
 {
-    QFile file(pro->fileName());
-    if (!file.open(QIODevice::ReadOnly)) {
-        if (m_handler && IoUtils::exists(pro->fileName()))
+    QString content;
+    QString errStr;
+    if (!m_vfs->readFile(pro->fileName(), &content, &errStr)) {
+        if (m_handler && m_vfs->exists(pro->fileName()))
             m_handler->message(QMakeParserHandler::ParserIoError,
-                               fL1S("Cannot read %1: %2").arg(pro->fileName(), file.errorString()));
+                               fL1S("Cannot read %1: %2").arg(pro->fileName(), errStr));
         return false;
     }
-
-    QByteArray bcont = file.readAll();
-    if (bcont.startsWith("\xef\xbb\xbf")) {
-        // UTF-8 BOM will cause subtle errors
-        m_handler->message(QMakeParserHandler::ParserIoError,
-                           fL1S("Unexpected UTF-8 BOM in %1").arg(pro->fileName()));
-        return false;
-    }
-    QString content(QString::fromLocal8Bit(bcont));
-    bcont.clear();
-    file.close();
     return read(pro, content, 1, FullGrammar);
 }
 

src/shared/proparser/qmakeparser.h

@@ -67,6 +67,7 @@ public:
 };
 
 class ProFileCache;
+class QMakeVfs;
 
 class QMAKE_EXPORT QMakeParser
 {
@@ -74,7 +75,7 @@ public:
     // Call this from a concurrency-free context
     static void initialize();
 
-    QMakeParser(ProFileCache *cache, QMakeParserHandler *handler);
+    QMakeParser(ProFileCache *cache, QMakeVfs *vfs, QMakeParserHandler *handler);
 
     enum SubGrammar { FullGrammar, TestGrammar, ValueGrammar };
     // fileName is expected to be absolute and cleanPath()ed.
@@ -163,6 +164,7 @@ private:
 
     ProFileCache *m_cache;
     QMakeParserHandler *m_handler;
+    QMakeVfs *m_vfs;
 
     // This doesn't help gcc 3.3 ...
     template<typename T> friend class QTypeInfo;

src/shared/proparser/qmakevfs.cpp

@@ -0,0 +1,178 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 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 "qmakevfs.h"
+
+#include "ioutils.h"
+using namespace QMakeInternal;
+
+#include <qdir.h>
+#include <qfile.h>
+#include <qfileinfo.h>
+
+#define fL1S(s) QString::fromLatin1(s)
+
+QMakeVfs::QMakeVfs()
+#ifndef PROEVALUATOR_FULL
+    : m_magicMissing(fL1S("missing"))
+    , m_magicExisting(fL1S("existing"))
+#endif
+{
+}
+
+bool QMakeVfs::writeFile(const QString &fn, QIODevice::OpenMode mode, const QString &contents,
+                         QString *errStr)
+{
+#ifndef PROEVALUATOR_FULL
+# ifdef PROEVALUATOR_THREAD_SAFE
+    QMutexLocker locker(&m_mutex);
+# endif
+    QString *cont = &m_files[fn];
+    if (mode & QIODevice::Append)
+        *cont += contents;
+    else
+        *cont = contents;
+    Q_UNUSED(errStr)
+    return true;
+#else
+    QFileInfo qfi(fn);
+    if (!QDir::current().mkpath(qfi.path())) {
+        *errStr = fL1S("Cannot create parent directory");
+        return false;
+    }
+    QByteArray bytes = contents.toLocal8Bit();
+    QFile cfile(fn);
+    if (!(mode & QIODevice::Append) && cfile.open(QIODevice::ReadOnly | QIODevice::Text)) {
+        if (cfile.readAll() == bytes)
+            return true;
+        cfile.close();
+    }
+    if (!cfile.open(mode | QIODevice::WriteOnly | QIODevice::Text)) {
+        *errStr = cfile.errorString();
+        return false;
+    }
+    cfile.write(bytes);
+    cfile.close();
+    if (cfile.error() != QFile::NoError) {
+        *errStr = cfile.errorString();
+        return false;
+    }
+    return true;
+#endif
+}
+
+bool QMakeVfs::readFile(const QString &fn, QString *contents, QString *errStr)
+{
+#ifndef PROEVALUATOR_FULL
+# ifdef PROEVALUATOR_THREAD_SAFE
+    QMutexLocker locker(&m_mutex);
+# endif
+    QHash<QString, QString>::ConstIterator it = m_files.constFind(fn);
+    if (it != m_files.constEnd()) {
+        if (it->constData() == m_magicMissing.constData()) {
+            *errStr = fL1S("No such file or directory");
+            return false;
+        }
+        if (it->constData() != m_magicExisting.constData()) {
+            *contents = *it;
+            return true;
+        }
+    }
+#endif
+
+    QFile file(fn);
+    if (!file.open(QIODevice::ReadOnly)) {
+#ifndef PROEVALUATOR_FULL
+        if (!IoUtils::exists(fn)) {
+            m_files[fn] = m_magicMissing;
+            *errStr = fL1S("No such file or directory");
+        } else
+#endif
+            *errStr = file.errorString();
+        return false;
+    }
+#ifndef PROEVALUATOR_FULL
+    m_files[fn] = m_magicExisting;
+#endif
+
+    QByteArray bcont = file.readAll();
+    if (bcont.startsWith("\xef\xbb\xbf")) {
+        // UTF-8 BOM will cause subtle errors
+        *errStr = fL1S("Unexpected UTF-8 BOM");
+        return false;
+    }
+    *contents = QString::fromLocal8Bit(bcont);
+    return true;
+}
+
+bool QMakeVfs::exists(const QString &fn)
+{
+#ifndef PROEVALUATOR_FULL
+# ifdef PROEVALUATOR_THREAD_SAFE
+    QMutexLocker locker(&m_mutex);
+# endif
+    QHash<QString, QString>::ConstIterator it = m_files.constFind(fn);
+    if (it != m_files.constEnd())
+        return it->constData() != m_magicMissing.constData();
+#endif
+    bool ex = IoUtils::exists(fn);
+#ifndef PROEVALUATOR_FULL
+    m_files[fn] = ex ? m_magicExisting : m_magicMissing;
+#endif
+    return ex;
+}
+
+#ifndef PROEVALUATOR_FULL
+// This should be called when the sources may have changed (e.g., VCS update).
+void QMakeVfs::invalidateCache()
+{
+# ifdef PROEVALUATOR_THREAD_SAFE
+    QMutexLocker locker(&m_mutex);
+# endif
+    QHash<QString, QString>::Iterator it = m_files.begin(), eit = m_files.end();
+    while (it != eit) {
+        if (it->constData() == m_magicMissing.constData()
+                ||it->constData() == m_magicExisting.constData())
+            it = m_files.erase(it);
+        else
+            ++it;
+    }
+}
+
+// This should be called when generated files may have changed (e.g., actual build).
+void QMakeVfs::invalidateContents()
+{
+# ifdef PROEVALUATOR_THREAD_SAFE
+    QMutexLocker locker(&m_mutex);
+# endif
+    m_files.clear();
+}
+#endif
+
+QT_END_NAMESPACE

src/shared/proparser/qmakevfs.h

@@ -0,0 +1,73 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 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.
+**
+****************************************************************************/
+
+#ifndef QMAKEVFS_H
+#define QMAKEVFS_H
+
+#include "qmake_global.h"
+
+# include <QIODevice>
+#ifndef PROEVALUATOR_FULL
+# include <QHash>
+# include <QString>
+# ifdef PROEVALUATOR_THREAD_SAFE
+#  include <qmutex.h>
+# endif
+#endif
+
+QT_BEGIN_NAMESPACE
+
+class QMAKE_EXPORT QMakeVfs
+{
+public:
+    QMakeVfs();
+
+    bool writeFile(const QString &fn, QIODevice::OpenMode mode, const QString &contents, QString *errStr);
+    bool readFile(const QString &fn, QString *contents, QString *errStr);
+    bool exists(const QString &fn);
+
+#ifndef PROEVALUATOR_FULL
+    void invalidateCache();
+    void invalidateContents();
+#endif
+
+private:
+#ifndef PROEVALUATOR_FULL
+# ifdef PROEVALUATOR_THREAD_SAFE
+    QMutex m_mutex;
+# endif
+    QHash<QString, QString> m_files;
+    QString m_magicMissing;
+    QString m_magicExisting;
+#endif
+};
+
+QT_END_NAMESPACE
+
+#endif // QMAKEVFS_H

tests/auto/profilewriter/tst_profilewriter.cpp

@@ -27,6 +27,7 @@
 **
 ****************************************************************************/
 
+#include <qmakevfs.h>
 #include <qmakeparser.h>
 #include <prowriter.h>
 
@@ -449,7 +450,8 @@ void tst_ProFileWriter::adds()
     QStringList lines = input.isEmpty() ? QStringList() : input.split(QLatin1String("\n"));
     QString var = QLatin1String("SOURCES");
 
-    QMakeParser parser(0, &parseHandler);
+    QMakeVfs vfs;
+    QMakeParser parser(0, &vfs, &parseHandler);
     ProFile *proFile = parser.parsedProBlock(input, QLatin1String(BASE_DIR "/test.pro"), 1);
     QVERIFY(proFile);
     PW::putVarValues(proFile, &lines, values, var, PW::PutFlags(flags), scope);
@@ -619,7 +621,8 @@ void tst_ProFileWriter::removes()
     QStringList lines = input.split(QLatin1String("\n"));
     QStringList vars; vars << QLatin1String("SOURCES");
 
-    QMakeParser parser(0, &parseHandler);
+    QMakeVfs vfs;
+    QMakeParser parser(0, &vfs, &parseHandler);
     ProFile *proFile = parser.parsedProBlock(input, QLatin1String(BASE_DIR "/test.pro"), 1);
     QVERIFY(proFile);
     Qt4ProjectManager::Internal::ProWriter::removeVarValues(proFile, &lines, values, vars);
@@ -647,7 +650,8 @@ void tst_ProFileWriter::multiVar()
             << QString::fromLatin1(BASE_DIR "/bak");
     QStringList vars; vars << QLatin1String("SOURCES") << QLatin1String("HEADERS");
 
-    QMakeParser parser(0, &parseHandler);
+    QMakeVfs vfs;
+    QMakeParser parser(0, &vfs, &parseHandler);
     ProFile *proFile = parser.parsedProBlock(input, QLatin1String(BASE_DIR "/test.pro"), 1);
     QVERIFY(proFile);
     Qt4ProjectManager::Internal::ProWriter::removeFiles(proFile, &lines, baseDir, files, vars);
@@ -667,7 +671,8 @@ void tst_ProFileWriter::addFiles()
             "    sub/bar.cpp"
             );
 
-    QMakeParser parser(0, &parseHandler);
+    QMakeVfs vfs;
+    QMakeParser parser(0, &vfs, &parseHandler);
     ProFile *proFile = parser.parsedProBlock(input, QLatin1String(BASE_DIR "/test.pro"), 1);
     QVERIFY(proFile);
     Qt4ProjectManager::Internal::ProWriter::addFiles(proFile, &lines, QDir(BASE_DIR),
@@ -688,7 +693,8 @@ void tst_ProFileWriter::removeFiles()
             "SOURCES = foo.cpp"
             );
 
-    QMakeParser parser(0, &parseHandler);
+    QMakeVfs vfs;
+    QMakeParser parser(0, &vfs, &parseHandler);
     ProFile *proFile = parser.parsedProBlock(input, QLatin1String(BASE_DIR "/test.pro"), 1);
     QVERIFY(proFile);
     Qt4ProjectManager::Internal::ProWriter::removeFiles(proFile, &lines, QDir(BASE_DIR),

tests/manual/proparser/main.cpp

@@ -28,6 +28,7 @@
 ****************************************************************************/
 
 #include "qmakeglobals.h"
+#include "qmakevfs.h"
 #include "qmakeparser.h"
 #include "qmakeevaluator.h"
 #include "profileevaluator.h"
@@ -69,14 +70,15 @@ public:
 static EvalHandler evalHandler;
 
 static int evaluate(const QString &fileName, const QString &in_pwd, const QString &out_pwd,
-                    bool cumulative, ProFileGlobals *option, QMakeParser *parser, int level)
+                    bool cumulative, ProFileGlobals *option, QMakeParser *parser, QMakeVfs *vfs,
+                    int level)
 {
     static QSet<QString> visited;
     if (visited.contains(fileName))
         return 0;
     visited.insert(fileName);
 
-    ProFileEvaluator visitor(option, parser, &evalHandler);
+    ProFileEvaluator visitor(option, parser, vfs, &evalHandler);
 #ifdef PROEVALUATOR_CUMULATIVE
     visitor.setCumulative(cumulative);
 #endif
@@ -130,7 +132,7 @@ static int evaluate(const QString &fileName, const QString &in_pwd, const QStrin
                 fflush(stdout);
                 nlevel++;
             }
-            evaluate(inFile, inPwd, outPwd, cumulative, option, parser, nlevel);
+            evaluate(inFile, inPwd, outPwd, cumulative, option, parser, vfs, nlevel);
         }
     }
 
@@ -195,6 +197,7 @@ int main(int argc, char **argv)
         out_pwd = in_pwd;
     option.setDirectories(in_pwd, out_pwd);
 
-    QMakeParser parser(0, &evalHandler);
-    return evaluate(file, in_pwd, out_pwd, cumulative, &option, &parser, level);
+    QMakeVfs vfs;
+    QMakeParser parser(0, &vfs, &evalHandler);
+    return evaluate(file, in_pwd, out_pwd, cumulative, &option, &parser, &vfs, level);
 }

tests/manual/proparser/testreader.pro

@@ -15,8 +15,27 @@ build_all:!build_pass {
     CONFIG += release
 }
 
-SOURCES = main.cpp qmakeglobals.cpp qmakeparser.cpp qmakeevaluator.cpp profileevaluator.cpp qmakebuiltins.cpp proitems.cpp ioutils.cpp
-HEADERS = qmakeglobals.h qmakeparser.h profileevaluator.h qmakeevaluator.h qmakeevaluator_p.h proitems.h ioutils.h
+SOURCES += \
+    main.cpp \
+    qmakeglobals.cpp \
+    qmakeparser.cpp \
+    qmakeevaluator.cpp \
+    profileevaluator.cpp \
+    qmakebuiltins.cpp \
+    proitems.cpp \
+    qmakevfs.cpp \
+    ioutils.cpp
+
+HEADERS += \
+    qmake_global.h \
+    qmakeglobals.h \
+    qmakeparser.h \
+    qmakeevaluator.h \
+    qmakeevaluator_p.h \
+    profileevaluator.h \
+    proitems.h \
+    qmakevfs.h \
+    ioutils.h
 
 RESOURCES += proparser.qrc
 DEFINES += QMAKE_BUILTIN_PRFS