qml: Make ownership of CompiledUnit more clear

The coverity scan utility didn't understand the code flow and assumed
the compiledData would be leaked. Use a QScopedPointer and have the
::backendCompileStep() forward the ownership. From what I see the code
has not leaked memory.

Fixes: CID 10605, CID 10607

Change-Id: I7759f681871bbe12e2aa320a5f39c47c70f4e4e0
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>

2 files changed, 4 insertions, 5 deletions

diff --git a/src/qml/compiler/qv4isel_moth.cpp b/src/qml/compiler/qv4isel_moth.cpp
index c684aa3e79..7c67ae2301 100644
--- a/src/qml/compiler/qv4isel_moth.cpp
+++ b/src/qml/compiler/qv4isel_moth.cpp
@@ -328,9 +328,8 @@ InstructionSelection::InstructionSelection(QQmlEnginePrivate *qmlEngine, QV4::Ex
     , _codeNext(0)
     , _codeEnd(0)
     , _currentStatement(0)
-{
-    compilationUnit = new CompilationUnit;
-}
+    , compilationUnit(new CompilationUnit)
+{}
 
 InstructionSelection::~InstructionSelection()
 {
@@ -459,7 +458,7 @@ QV4::CompiledData::CompilationUnit *InstructionSelection::backendCompileStep()
     int i = 0;
     foreach (IR::Function *irFunction, irModule->functions)
         compilationUnit->codeRefs[i++] = codeRefs[irFunction];
-    return compilationUnit;
+    return compilationUnit.take();
 }
 
 void InstructionSelection::callValue(IR::Expr *value, IR::ExprList *args, IR::Expr *result)
diff --git a/src/qml/compiler/qv4isel_moth_p.h b/src/qml/compiler/qv4isel_moth_p.h
index 6f9f001f28..2fdb7c007c 100644
--- a/src/qml/compiler/qv4isel_moth_p.h
+++ b/src/qml/compiler/qv4isel_moth_p.h
@@ -184,7 +184,7 @@ private:
     QSet<IR::Jump *> _removableJumps;
     IR::Stmt *_currentStatement;
 
-    CompilationUnit *compilationUnit;
+    QScopedPointer<CompilationUnit> compilationUnit;
     QHash<IR::Function *, QByteArray> codeRefs;
 };