CppTools: Make FollowSymbol respect projects

Finding the class definition for a forward declaration or finding the
function definition from its declaration is mostly determined by the
file iteration order. Documents with the most common path prefix are
checked first.

This works fine as long as the files of your project have a common
ancestor. If that's not the case, FollowSymbol might take you to the
definition within another project.

Fix that issue by considering the project part id when constructing the
file iteration order. Since the cached file iteration order now depends
on the projects, ensure to clear it if projects are added, changed or
removed.

Task-number: QTCREATORBUG-15116
Change-Id: I529166bac363959c9fee0b946747fd0370a88809
Reviewed-by: Marco Bubke <marco.bubke@theqtcompany.com>

7 files changed, 283 insertions, 23 deletions

diff --git a/src/plugins/cpptools/cppfileiterationorder.cpp b/src/plugins/cpptools/cppfileiterationorder.cpp
new file mode 100644
index 0000000000..807e26f8ff
--- /dev/null
+++ b/src/plugins/cpptools/cppfileiterationorder.cpp
@@ -0,0 +1,161 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing
+**
+** 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 The Qt Company.  For licensing terms and
+** conditions see http://www.qt.io/terms-conditions.  For further information
+** use the contact form at http://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 2.1 or version 3 as published by the Free
+** Software Foundation and appearing in the file LICENSE.LGPLv21 and
+** LICENSE.LGPLv3 included in the packaging of this file.  Please review the
+** following information to ensure the GNU Lesser General Public License
+** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, The Qt Company gives you certain additional
+** rights.  These rights are described in The Qt Company LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+****************************************************************************/
+
+#include "cppfileiterationorder.h"
+
+#include <utils/qtcassert.h>
+
+namespace CppTools {
+
+FileIterationOrder::Entry::Entry(const QString &filePath,
+                                 const QString &projectPartId,
+                                 int commonPrefixLength,
+                                 int commonProjectPartPrefixLength)
+    : filePath(filePath)
+    , projectPartId(projectPartId)
+    , commonFilePathPrefixLength(commonPrefixLength)
+    , commonProjectPartPrefixLength(commonProjectPartPrefixLength)
+{}
+
+namespace {
+
+bool cmpPrefixLengthAndText(int prefixLength1, int prefixLength2)
+{
+    return prefixLength1 > prefixLength2;
+}
+
+bool cmpLessFilePath(const FileIterationOrder::Entry &first,
+                     const FileIterationOrder::Entry &second)
+{
+    return cmpPrefixLengthAndText(first.commonFilePathPrefixLength,
+                                  second.commonFilePathPrefixLength);
+}
+
+bool cmpLessProjectPartId(const FileIterationOrder::Entry &first,
+                          const FileIterationOrder::Entry &second)
+{
+    return cmpPrefixLengthAndText(first.commonProjectPartPrefixLength,
+                                  second.commonProjectPartPrefixLength);
+}
+
+bool hasProjectPart(const FileIterationOrder::Entry &entry)
+{
+    return !entry.projectPartId.isEmpty();
+}
+
+} // anonymous namespace
+
+bool operator<(const FileIterationOrder::Entry &first, const FileIterationOrder::Entry &second)
+{
+    if (hasProjectPart(first)) {
+        if (hasProjectPart(second)) {
+            if (first.projectPartId == second.projectPartId)
+                return cmpLessFilePath(first, second);
+            else
+                return cmpLessProjectPartId(first, second);
+        } else {
+            return true;
+        }
+    } else {
+        if (hasProjectPart(second))
+            return false;
+        else
+            return cmpLessFilePath(first, second);
+    }
+}
+
+FileIterationOrder::FileIterationOrder()
+{
+}
+
+FileIterationOrder::FileIterationOrder(const QString &referenceFilePath,
+                                       const QString &referenceProjectPartId)
+{
+    setReference(referenceFilePath, referenceProjectPartId);
+}
+
+void FileIterationOrder::setReference(const QString &filePath,
+                                      const QString &projectPartId)
+{
+    m_referenceFilePath = filePath;
+    m_referenceProjectPartId = projectPartId;
+}
+
+bool FileIterationOrder::isValid() const
+{
+    return !m_referenceFilePath.isEmpty();
+}
+
+static int commonPrefixLength(const QString &filePath1, const QString &filePath2)
+{
+    const auto mismatches = std::mismatch(filePath1.begin(),
+                                          filePath1.end(),
+                                          filePath2.begin());
+    return mismatches.first - filePath1.begin();
+}
+
+FileIterationOrder::Entry FileIterationOrder::createEntryFromFilePath(
+        const QString &filePath,
+        const QString &projectPartId) const
+{
+    const int filePrefixLength = commonPrefixLength(m_referenceFilePath, filePath);
+    const int projectPartPrefixLength = commonPrefixLength(m_referenceProjectPartId, projectPartId);
+    return Entry(filePath, projectPartId, filePrefixLength, projectPartPrefixLength);
+}
+
+void FileIterationOrder::insert(const QString &filePath, const QString &projectPartId)
+{
+    const Entry entry = createEntryFromFilePath(filePath, projectPartId);
+    m_set.insert(entry);
+}
+
+void FileIterationOrder::remove(const QString &filePath, const QString &projectPartId)
+{
+    const auto needleElement = createEntryFromFilePath(filePath, projectPartId);
+    const auto range = m_set.equal_range(needleElement);
+
+    const auto toRemove = std::find_if(range.first, range.second, [filePath] (const Entry &entry) {
+        return entry.filePath == filePath;
+    });
+    QTC_ASSERT(toRemove != range.second, return);
+    m_set.erase(toRemove);
+}
+
+QStringList FileIterationOrder::toStringList() const
+{
+    QStringList result;
+
+    for (const auto &entry : m_set)
+        result.append(entry.filePath);
+
+    return result;
+}
+
+} // namespace CppTools
diff --git a/src/plugins/cpptools/cppfileiterationorder.h b/src/plugins/cpptools/cppfileiterationorder.h
new file mode 100644
index 0000000000..aecd17d036
--- /dev/null
+++ b/src/plugins/cpptools/cppfileiterationorder.h
@@ -0,0 +1,84 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing
+**
+** 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 The Qt Company.  For licensing terms and
+** conditions see http://www.qt.io/terms-conditions.  For further information
+** use the contact form at http://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 2.1 or version 3 as published by the Free
+** Software Foundation and appearing in the file LICENSE.LGPLv21 and
+** LICENSE.LGPLv3 included in the packaging of this file.  Please review the
+** following information to ensure the GNU Lesser General Public License
+** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, The Qt Company gives you certain additional
+** rights.  These rights are described in The Qt Company LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+****************************************************************************/
+
+#ifndef FILEITERATIONORDER_H
+#define FILEITERATIONORDER_H
+
+#include "cpptools_global.h"
+
+#include <QStringList>
+
+#include <set>
+
+namespace CppTools {
+
+class CPPTOOLS_EXPORT FileIterationOrder {
+public:
+    struct Entry {
+        Entry(const QString &filePath,
+              const QString &projectPartId = QString(),
+              int commonFilePathPrefixLength = 0,
+              int commonProjectPartPrefixLength = 0);
+
+        friend CPPTOOLS_EXPORT bool operator<(const Entry &first, const Entry &second);
+
+        const QString filePath;
+        const QString projectPartId;
+        int commonFilePathPrefixLength = 0;
+        int commonProjectPartPrefixLength = 0;
+    };
+
+    FileIterationOrder();
+    FileIterationOrder(const QString &referenceFilePath,
+                       const QString &referenceProjectPartId);
+
+    void setReference(const QString &filePath, const QString &projectPartId);
+    bool isValid() const;
+
+    void insert(const QString &filePath, const QString &projectPartId = QString());
+    void remove(const QString &filePath, const QString &projectPartId);
+    QStringList toStringList() const;
+
+private:
+    Entry createEntryFromFilePath(const QString &filePath,
+                                  const QString &projectPartId) const;
+
+private:
+    QString m_referenceFilePath;
+    QString m_referenceProjectPartId;
+    std::multiset<Entry> m_set;
+};
+
+CPPTOOLS_EXPORT bool operator<(const FileIterationOrder::Entry &first,
+                               const FileIterationOrder::Entry &second);
+
+} // namespace CppTools
+
+#endif // FILEITERATIONORDER_H
diff --git a/src/plugins/cpptools/cppmodelmanager.cpp b/src/plugins/cpptools/cppmodelmanager.cpp
index 5cd9c98689..0b8ccc8fe6 100644
--- a/src/plugins/cpptools/cppmodelmanager.cpp
+++ b/src/plugins/cpptools/cppmodelmanager.cpp
@@ -796,6 +796,8 @@ void CppModelManager::recalculateProjectPartMappings()
 
         }
     }
+
+    d->m_symbolFinder.clearCache();
 }
 
 void CppModelManager::updateCppEditorDocuments() const
diff --git a/src/plugins/cpptools/cpptools.pro b/src/plugins/cpptools/cpptools.pro
index 61a249026e..b543389456 100644
--- a/src/plugins/cpptools/cpptools.pro
+++ b/src/plugins/cpptools/cpptools.pro
@@ -27,6 +27,7 @@ HEADERS += \
     cppcurrentdocumentfilter.h \
     cppeditoroutline.h \
     cppdoxygen.h \
+    cppfileiterationorder.h \
     cppfilesettingspage.h \
     cppfindreferences.h \
     cppfunctionsfilter.h \
@@ -92,6 +93,7 @@ SOURCES += \
     cppcurrentdocumentfilter.cpp \
     cppeditoroutline.cpp \
     cppdoxygen.cpp \
+    cppfileiterationorder.cpp \
     cppfilesettingspage.cpp \
     cppfindreferences.cpp \
     cppfunctionsfilter.cpp \
diff --git a/src/plugins/cpptools/cpptools.qbs b/src/plugins/cpptools/cpptools.qbs
index 065ea0e4c1..611316c4d9 100644
--- a/src/plugins/cpptools/cpptools.qbs
+++ b/src/plugins/cpptools/cpptools.qbs
@@ -49,6 +49,7 @@ QtcPlugin {
         "cppcurrentdocumentfilter.cpp", "cppcurrentdocumentfilter.h",
         "cppdoxygen.cpp", "cppdoxygen.h",
         "cppeditoroutline.cpp", "cppeditoroutline.h",
+        "cppfileiterationorder.cpp", "cppfileiterationorder.h",
         "cppfilesettingspage.cpp", "cppfilesettingspage.h", "cppfilesettingspage.ui",
         "cppfindreferences.cpp", "cppfindreferences.h",
         "cppfunctionsfilter.cpp", "cppfunctionsfilter.h",
diff --git a/src/plugins/cpptools/symbolfinder.cpp b/src/plugins/cpptools/symbolfinder.cpp
index 26df91bc04..3bc72c00b5 100644
--- a/src/plugins/cpptools/symbolfinder.cpp
+++ b/src/plugins/cpptools/symbolfinder.cpp
@@ -34,6 +34,8 @@
 
 #include "symbolfinder.h"
 
+#include "cppmodelmanager.h"
+
 #include <cplusplus/LookupContext.h>
 
 #include <utils/qtcassert.h>
@@ -357,13 +359,20 @@ QStringList SymbolFinder::fileIterationOrder(const QString &referenceFile, const
             insertCache(referenceFile, doc->fileName());
     }
 
-    QStringList files = m_filePriorityCache.value(referenceFile).values();
+    QStringList files = m_filePriorityCache.value(referenceFile).toStringList();
 
     trackCacheUse(referenceFile);
 
     return files;
 }
 
+void SymbolFinder::clearCache()
+{
+    m_filePriorityCache.clear();
+    m_fileMetaCache.clear();
+    m_recent.clear();
+}
+
 void SymbolFinder::checkCacheConsistency(const QString &referenceFile, const Snapshot &snapshot)
 {
     // We only check for "new" files, which which are in the snapshot but not in the cache.
@@ -376,18 +385,29 @@ void SymbolFinder::checkCacheConsistency(const QString &referenceFile, const Sna
     }
 }
 
+const QString projectPartIdForFile(const QString &filePath)
+{
+    const QList<ProjectPart::Ptr> parts = CppModelManager::instance()->projectPart(filePath);
+    if (!parts.isEmpty())
+        return parts.first()->id();
+    return QString();
+}
+
 void SymbolFinder::clearCache(const QString &referenceFile, const QString &comparingFile)
 {
-    m_filePriorityCache[referenceFile].remove(computeKey(referenceFile, comparingFile),
-                                              comparingFile);
+    m_filePriorityCache[referenceFile].remove(comparingFile, projectPartIdForFile(comparingFile));
     m_fileMetaCache[referenceFile].remove(comparingFile);
 }
 
 void SymbolFinder::insertCache(const QString &referenceFile, const QString &comparingFile)
 {
-    // We want an ordering such that the documents with the most common path appear first.
-    m_filePriorityCache[referenceFile].insert(computeKey(referenceFile, comparingFile),
-                                              comparingFile);
+    FileIterationOrder &order = m_filePriorityCache[referenceFile];
+    if (!order.isValid()) {
+        const auto projectPartId = projectPartIdForFile(referenceFile);
+        order.setReference(referenceFile, projectPartId);
+    }
+    order.insert(comparingFile, projectPartIdForFile(comparingFile));
+
     m_fileMetaCache[referenceFile].insert(comparingFile);
 }
 
@@ -408,14 +428,3 @@ void SymbolFinder::trackCacheUse(const QString &referenceFile)
         m_fileMetaCache.remove(oldest);
     }
 }
-
-int SymbolFinder::computeKey(const QString &referenceFile, const QString &comparingFile)
-{
-    // As similar the path from the comparing file is to the path from the reference file,
-    // the smaller the key is, which is then used for sorting the map.
-    std::pair<QString::const_iterator,
-              QString::const_iterator> r = std::mismatch(referenceFile.begin(),
-                                                         referenceFile.end(),
-                                                         comparingFile.begin());
-    return referenceFile.length() - (r.first - referenceFile.begin());
-}
diff --git a/src/plugins/cpptools/symbolfinder.h b/src/plugins/cpptools/symbolfinder.h
index a71d9ed4d2..45236eb1ad 100644
--- a/src/plugins/cpptools/symbolfinder.h
+++ b/src/plugins/cpptools/symbolfinder.h
@@ -33,10 +33,12 @@
 
 #include "cpptools_global.h"
 
+#include "cppfileiterationorder.h"
+
 #include <QHash>
 #include <QStringList>
-#include <QMultiMap>
-#include <QSet>
+
+#include <set>
 
 namespace CPlusPlus {
 class Class;
@@ -71,19 +73,18 @@ public:
     QList<CPlusPlus::Declaration *> findMatchingDeclaration(const CPlusPlus::LookupContext &context,
                                                             CPlusPlus::Function *functionType);
 
+    void clearCache();
+
 private:
     QStringList fileIterationOrder(const QString &referenceFile,
                                    const CPlusPlus::Snapshot &snapshot);
-
     void checkCacheConsistency(const QString &referenceFile, const CPlusPlus::Snapshot &snapshot);
     void clearCache(const QString &referenceFile, const QString &comparingFile);
     void insertCache(const QString &referenceFile, const QString &comparingFile);
 
     void trackCacheUse(const QString &referenceFile);
 
-    static int computeKey(const QString &referenceFile, const QString &comparingFile);
-
-    QHash<QString, QMultiMap<int, QString> > m_filePriorityCache;
+    QHash<QString, FileIterationOrder> m_filePriorityCache;
     QHash<QString, QSet<QString> > m_fileMetaCache;
     QStringList m_recent;
 };