From 60245e55d7551f525c951d8d866aab081be88a69 Mon Sep 17 00:00:00 2001
From: Oswald Buddenhagen <oswald.buddenhagen@qt.io>
Date: Mon, 14 Aug 2017 18:30:29 +0200
Subject: qmake: Change source identifier type in ProString

The strings remember in which file they were created/assigned.

However, this used a non-counting reference to a ProFile, which could
become dangling. If a subsequent ProFile re-used the exact same address,
a string's source would be mis-identified, which would be fatal in
conjunction with discard_from().

Since we actually need only a unique id for comparison, let's use an
integer for that.

comment on cherry-pick: this is actually a lot more than a cherry-pick,
because the file ids need to be aware of the dual VFS which was
concurrently introduced on the qtc side.

Started-by: Simon Hausmann <simon.hausmann@qt.io>
Change-Id: I395153afaf7c835d0119690ee7f4b915e6f90d4a
(cherry picked from qtbase/190aa94be7f5e146bef44862b974d733755cec85)
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>
---
 src/shared/proparser/qmakevfs.h | 55 ++++++++++++++++++++++++++++++-----------
 1 file changed, 40 insertions(+), 15 deletions(-)

(limited to 'src/shared/proparser/qmakevfs.h')

diff --git a/src/shared/proparser/qmakevfs.h b/src/shared/proparser/qmakevfs.h
index b6b93fb5dd..da0d0626d8 100644
--- a/src/shared/proparser/qmakevfs.h
+++ b/src/shared/proparser/qmakevfs.h
@@ -27,13 +27,11 @@
 
 #include "qmake_global.h"
 
-# include <qiodevice.h>
-#ifndef PROEVALUATOR_FULL
-# include <qhash.h>
-# include <qstring.h>
-# ifdef PROEVALUATOR_THREAD_SAFE
-#  include <qmutex.h>
-# endif
+#include <qiodevice.h>
+#include <qhash.h>
+#include <qstring.h>
+#ifdef PROEVALUATOR_THREAD_SAFE
+# include <qmutex.h>
 #endif
 
 #ifndef QT_NO_TEXTCODEC
@@ -62,23 +60,27 @@ public:
         VfsExact = 0,
 #ifdef PROEVALUATOR_DUAL_VFS
         VfsCumulative = 2,
-        VfsNoVirtual = 4
+        VfsCreate = 4,
+        VfsCreatedOnly = 8,
 #else
         VfsCumulative = 0,
-        VfsNoVirtual = 0
+        VfsCreate = 0,
+        VfsCreatedOnly = 0,
 #endif
+        VfsAccessedOnly = 16
     };
     Q_DECLARE_FLAGS(VfsFlags, VfsFlag)
 
     QMakeVfs();
 
-    bool writeFile(const QString &fn, QIODevice::OpenMode mode, VfsFlags flags, const QString &contents, QString *errStr);
-    ReadResult readFile(const QString &fn, VfsFlags flags, QString *contents, QString *errStr);
-    bool exists(const QString &fn, VfsFlags flags);
+    int idForFileName(const QString &fn, VfsFlags flags);
+    QString fileNameForId(int id);
+    static void clearIds();
+    bool writeFile(int id, QIODevice::OpenMode mode, VfsFlags flags, const QString &contents, QString *errStr);
+    ReadResult readFile(int id, QString *contents, QString *errStr);
+    bool exists(const QString &fn, QMakeVfs::VfsFlags flags);
 
 #ifndef PROEVALUATOR_FULL
-    bool readVirtualFile(const QString &fn, VfsFlags flags, QString *contents);
-
     void invalidateCache();
     void invalidateContents();
 #endif
@@ -88,11 +90,34 @@ public:
 #endif
 
 private:
+#ifdef PROEVALUATOR_THREAD_SAFE
+    static QMutex s_mutex;
+#endif
+    static QAtomicInt s_fileIdCounter;
+    // Qt Creator's ProFile cache is a singleton to maximize its cross-project
+    // effectiveness (shared prf files from QtVersions).
+    // For this to actually work, real files need a global mapping.
+    // This is fine, because the namespace of real files is indeed global.
+    static QHash<QString, int> s_fileIdMap;
+    static QHash<int, QString> s_idFileMap;
+#ifdef PROEVALUATOR_DUAL_VFS
+# ifdef PROEVALUATOR_THREAD_SAFE
+    // The simple way to avoid recursing m_mutex.
+    QMutex m_vmutex;
+# endif
+    // Virtual files are bound to the project context they were created in,
+    // so their ids need to be local as well.
+    // We violate that rule in lupdate (which has a non-dual VFS), but that
+    // does not matter, because it has only one project context anyway.
+    QHash<QString, int> m_virtualFileIdMap[2];  // Exact and cumulative
+    QHash<int, QString> m_virtualIdFileMap;  // Only one map, as ids are unique across realms.
+#endif
+
 #ifndef PROEVALUATOR_FULL
 # ifdef PROEVALUATOR_THREAD_SAFE
     QMutex m_mutex;
 # endif
-    QHash<QString, QString> m_files;
+    QHash<int, QString> m_files;
     QString m_magicMissing;
     QString m_magicExisting;
 #endif
-- 
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