From 90a08b0c52fbe20ea3324f7315c04c48c95a8e61 Mon Sep 17 00:00:00 2001
From: Simon Hausmann <simon.hausmann@qt.io>
Date: Fri, 22 Mar 2019 09:43:16 +0100
Subject: Fix memory "leaks" in qmlcachegen

The CompilationUnit class owns the unit data. An exception was made in
bootstrap builds, where it was up to the caller to free the memory. This
lead to cases in qmlcachegen where we didn't free the memory. This is
best fixed by unifying the behavior.

This fixes the build when using an ASAN enabled build, as the runtime
aborts after calling qmlcachegen due to "leaks".

Change-Id: I8b55b4e302a9569a1d4e09eeb488c479368b50f0
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
---
 src/qml/compiler/qv4compileddata.cpp | 10 +++++++++-
 src/qml/compiler/qv4compileddata_p.h |  4 ----
 tools/qmlcachegen/qmlcachegen.cpp    |  4 ----
 3 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/src/qml/compiler/qv4compileddata.cpp b/src/qml/compiler/qv4compileddata.cpp
index 7906b3572c..9ffcb81fa2 100644
--- a/src/qml/compiler/qv4compileddata.cpp
+++ b/src/qml/compiler/qv4compileddata.cpp
@@ -98,18 +98,25 @@ CompilationUnit::CompilationUnit(const Unit *unitData, const QString &fileName,
     setUnitData(unitData, nullptr, fileName, finalUrlString);
 }
 
-#ifndef V4_BOOTSTRAP
 CompilationUnit::~CompilationUnit()
 {
+#ifndef V4_BOOTSTRAP
     unlink();
+#endif
 
     if (data) {
         if (data->qmlUnit() != qmlData)
             free(const_cast<QmlUnit *>(qmlData));
         qmlData = nullptr;
 
+#ifndef V4_BOOTSTRAP
         if (!(data->flags & QV4::CompiledData::Unit::StaticData))
             free(const_cast<Unit *>(data));
+#else
+        // Unconditionally free the memory. In the dev tools we create units that have
+        // the flag set and will be saved to disk, so intended to persist later.
+        free(const_cast<Unit *>(data));
+#endif
     }
     data = nullptr;
 #if Q_BYTE_ORDER == Q_BIG_ENDIAN
@@ -120,6 +127,7 @@ CompilationUnit::~CompilationUnit()
     delete [] imports;
     imports = nullptr;
 }
+#ifndef V4_BOOTSTRAP
 
 QString CompilationUnit::localCacheFilePath(const QUrl &url)
 {
diff --git a/src/qml/compiler/qv4compileddata_p.h b/src/qml/compiler/qv4compileddata_p.h
index 1341c91e97..3fd9fdf74b 100644
--- a/src/qml/compiler/qv4compileddata_p.h
+++ b/src/qml/compiler/qv4compileddata_p.h
@@ -1079,11 +1079,7 @@ struct Q_QML_PRIVATE_EXPORT CompilationUnit final : public CompilationUnitBase
     const QmlUnit *qmlData = nullptr;
 public:
     CompilationUnit(const Unit *unitData = nullptr, const QString &fileName = QString(), const QString &finalUrlString = QString());
-#ifdef V4_BOOTSTRAP
-    ~CompilationUnit() {}
-#else
     ~CompilationUnit();
-#endif
 
     void addref()
     {
diff --git a/tools/qmlcachegen/qmlcachegen.cpp b/tools/qmlcachegen/qmlcachegen.cpp
index e8583996bf..2b84a6babe 100644
--- a/tools/qmlcachegen/qmlcachegen.cpp
+++ b/tools/qmlcachegen/qmlcachegen.cpp
@@ -232,8 +232,6 @@ static bool compileQmlFile(const QString &inputFileName, SaveFunction saveFuncti
 
         if (!saveFunction(irDocument.javaScriptCompilationUnit, &error->message))
             return false;
-
-        free(unit);
     }
     return true;
 }
@@ -241,7 +239,6 @@ static bool compileQmlFile(const QString &inputFileName, SaveFunction saveFuncti
 static bool compileJSFile(const QString &inputFileName, const QString &inputFileUrl, SaveFunction saveFunction, Error *error)
 {
     QQmlRefPointer<QV4::CompiledData::CompilationUnit> unit;
-    QScopedPointer<QV4::CompiledData::Unit, QScopedPointerPodDeleter> unitDataToFree;
 
     QString sourceCode;
     {
@@ -323,7 +320,6 @@ static bool compileJSFile(const QString &inputFileName, const QString &inputFile
             generator.generate(irDocument);
             QV4::CompiledData::Unit *unitData = const_cast<QV4::CompiledData::Unit*>(irDocument.javaScriptCompilationUnit->data);
             unitData->flags |= QV4::CompiledData::Unit::StaticData;
-            unitDataToFree.reset(unitData);
             unit = irDocument.javaScriptCompilationUnit;
         }
     }
-- 
cgit v1.2.3