loplugin:passstuffbyref even more return improvements

Change-Id: I2a752025cd429e4d271626402dce5d8a8b0c76d2
Reviewed-on: https://gerrit.libreoffice.org/47021Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

basegfx/source/polygon/b2dpolygon.cxx

@@ -1175,7 +1175,7 @@ namespace basegfx
         return mpPolygon->count();
     }
 
-    B2DPoint B2DPolygon::getB2DPoint(sal_uInt32 nIndex) const
+    B2DPoint const & B2DPolygon::getB2DPoint(sal_uInt32 nIndex) const
     {
         OSL_ENSURE(nIndex < mpPolygon->count(), "B2DPolygon access outside range (!)");
 
@@ -1399,12 +1399,12 @@ namespace basegfx
         }
     }
 
-    B2DPolygon B2DPolygon::getDefaultAdaptiveSubdivision() const
+    B2DPolygon const & B2DPolygon::getDefaultAdaptiveSubdivision() const
     {
         return mpPolygon->getDefaultAdaptiveSubdivision(*this);
     }
 
-    B2DRange B2DPolygon::getB2DRange() const
+    B2DRange const & B2DPolygon::getB2DRange() const
     {
         return mpPolygon->getB2DRange(*this);
     }

basegfx/source/polygon/b2dpolypolygon.cxx

@@ -230,7 +230,7 @@ namespace basegfx
         return mpPolyPolygon->count();
     }
 
-    B2DPolygon B2DPolyPolygon::getB2DPolygon(sal_uInt32 nIndex) const
+    B2DPolygon const & B2DPolyPolygon::getB2DPolygon(sal_uInt32 nIndex) const
     {
         OSL_ENSURE(nIndex < mpPolyPolygon->count(), "B2DPolyPolygon access outside range (!)");
 

basegfx/source/tools/b2dclipstate.cxx

@@ -482,7 +482,7 @@ namespace utils
         mpImpl->xorPolyPolygon(rPolyPoly);
     }
 
-    B2DPolyPolygon B2DClipState::getClipPoly() const
+    B2DPolyPolygon const & B2DClipState::getClipPoly() const
     {
         return mpImpl->getClipPoly();
     }

compilerplugins/clang/passstuffbyref.cxx

@@ -229,6 +229,10 @@ void PassStuffByRef::checkReturnValue(const FunctionDecl * functionDecl, const C
         return;
     }
 
+    // not sure if it's possible to modify these
+    if (isa<CXXConversionDecl>(functionDecl))
+        return;
+
     // ignore stuff that forms part of the stable URE interface
     if (isInUnoIncludeFile(functionDecl)) {
         return;
@@ -267,6 +271,9 @@ void PassStuffByRef::checkReturnValue(const FunctionDecl * functionDecl, const C
     if (startswith(type.getAsString(), "struct o3tl::strong_int")) {
         return;
     }
+
+    //functionDecl->dump();
+
     mbInsideFunctionDecl = true;
     mbFoundReturnValueDisqualifier = false;
     TraverseStmt(functionDecl->getBody());
@@ -395,7 +402,9 @@ bool PassStuffByRef::isReturnExprDisqualified(const Expr* expr)
             FunctionDecl const * calleeFunctionDecl = callExpr->getDirectCallee();
             if (!calleeFunctionDecl)
                 return true;
-            return !loplugin::TypeCheck(calleeFunctionDecl->getReturnType()).LvalueReference();
+            auto tc = loplugin::TypeCheck(calleeFunctionDecl->getReturnType());
+            if (!tc.LvalueReference() && !tc.Pointer())
+                return true;
         }
         return false;
     }

compilerplugins/clang/test/passstuffbyref.cxx

@@ -9,6 +9,7 @@
 
 #include <rtl/ustring.hxx>
 #include <sys/time.h>
+#include <o3tl/cow_wrapper.hxx>
 #include <vector>
 
 struct S1 {
@@ -21,6 +22,7 @@ struct S2 {
     OUString mv3[2];
     S1 child;
     static OUString gs1;
+    o3tl::cow_wrapper<S1> mxCow;
 
     // make sure we ignore cases where the passed in parameter is std::move'd