new loplugin:shouldreturnbool

look for methods returning only 1 and/or 0, which (most of the time)
should be returning bool.

Off by default, because some of this is a matter of taste

Change-Id: Ib17782e629888255196e89d4a178618a9612a0de
Reviewed-on: https://gerrit.libreoffice.org/54379
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

44 files changed, 390 insertions, 137 deletions

diff --git a/chart2/source/view/main/OpenGLRender.cxx b/chart2/source/view/main/OpenGLRender.cxx
index 35fbbac1d76f..56e46040ac5e 100644
--- a/chart2/source/view/main/OpenGLRender.cxx
+++ b/chart2/source/view/main/OpenGLRender.cxx
@@ -169,7 +169,7 @@ int OpenGLRender::InitOpenGL()
     return 0;
 }
 
-int OpenGLRender::SetLine2DShapePoint(float x, float y, int listLength)
+void OpenGLRender::SetLine2DShapePoint(float x, float y, int listLength)
 {
     if (m_Line2DPointList.empty())
     {
@@ -184,7 +184,6 @@ int OpenGLRender::SetLine2DShapePoint(float x, float y, int listLength)
         m_Line2DShapePointList.push_back(m_Line2DPointList);
         m_Line2DPointList.clear();
     }
-    return 0;
 }
 
 int OpenGLRender::RenderLine2FBO()
@@ -275,13 +274,12 @@ void OpenGLRender::prepareToRender()
     m_fZStep = 0;
 }
 
-int OpenGLRender::MoveModelf(const PosVecf3& trans, const PosVecf3& angle, const PosVecf3& scale)
+void OpenGLRender::MoveModelf(const PosVecf3& trans, const PosVecf3& angle, const PosVecf3& scale)
 {
     glm::mat4 aTranslationMatrix = glm::translate(glm::vec3(trans.x, trans.y, trans.z));
     glm::mat4 aScaleMatrix = glm::scale(glm::vec3(scale.x, scale.y, scale.z));
     glm::mat4 aRotationMatrix = glm::eulerAngleYXZ(angle.y, angle.x, angle.z);
     m_Model = aTranslationMatrix * aRotationMatrix * aScaleMatrix;
-    return 0;
 }
 
 void OpenGLRender::Release()
@@ -392,7 +390,7 @@ int OpenGLRender::Create2DCircle(int detail)
     return 0;
 }
 
-int OpenGLRender::Bubble2DShapePoint(float x, float y, float directionX, float directionY)
+void OpenGLRender::Bubble2DShapePoint(float x, float y, float directionX, float directionY)
 {
     //check whether to create the circle data
     if (m_Bubble2DCircle.empty())
@@ -407,7 +405,6 @@ int OpenGLRender::Bubble2DShapePoint(float x, float y, float directionX, float d
     aBubble2DPointList.y = y + aBubble2DPointList.yScale / 2;
 
     m_Bubble2DShapePointList.push_back(aBubble2DPointList);
-    return 0;
 }
 
 int OpenGLRender::RenderBubble2FBO()
@@ -487,7 +484,7 @@ int OpenGLRender::RenderBubble2FBO()
     return 0;
 }
 
-int OpenGLRender::RectangleShapePoint(float x, float y, float directionX, float directionY)
+void OpenGLRender::RectangleShapePoint(float x, float y, float directionX, float directionY)
 {
     RectanglePointList aRectangle;
 
@@ -505,10 +502,9 @@ int OpenGLRender::RectangleShapePoint(float x, float y, float directionX, float
     aRectangle.points[11] = m_fZStep;
 
     m_RectangleShapePointList.push_back(aRectangle);
-    return 0;
 }
 
-int OpenGLRender::RenderRectangleShape(bool bBorder, bool bFill)
+void OpenGLRender::RenderRectangleShape(bool bBorder, bool bFill)
 {
     for (auto const& pointList : m_RectangleShapePointList)
     {
@@ -613,7 +609,6 @@ int OpenGLRender::RenderRectangleShape(bool bBorder, bool bFill)
     CHECK_GL_ERROR();
 
     m_fZStep += Z_STEP;
-    return 0;
 }
 
 
@@ -637,11 +632,12 @@ int OpenGLRender::CreateTextTexture(const BitmapEx& rBitmapEx, const awt::Size&
 
     OpenGLHelper::ConvertBitmapExToRGBATextureBuffer(rBitmapEx, bitmapBuf.get());
 
-    return CreateTextTexture(bitmapBuf, rBitmapEx.GetSizePixel(),
+    CreateTextTexture(bitmapBuf, rBitmapEx.GetSizePixel(),
                              aSize, rotation, rTrans);
+    return 0;
 }
 
-int OpenGLRender::CreateTextTexture(const boost::shared_array<sal_uInt8> &rPixels,
+void OpenGLRender::CreateTextTexture(const boost::shared_array<sal_uInt8> &rPixels,
                                     const ::Size &aPixelSize,
                                     const awt::Size& aSize,
                                     long rotation,
@@ -688,10 +684,9 @@ int OpenGLRender::CreateTextTexture(const boost::shared_array<sal_uInt8> &rPixel
     glBindTexture(GL_TEXTURE_2D, 0);
     CHECK_GL_ERROR();
     m_TextInfoVector.push_back(aTextInfo);
-    return 0;
 }
 
-int OpenGLRender::RenderTextShape()
+void OpenGLRender::RenderTextShape()
 {
     CHECK_GL_ERROR();
     for (auto const& textInfo : m_TextInfoVector)
@@ -753,10 +748,9 @@ int OpenGLRender::RenderTextShape()
     m_TextInfoVector.clear();
     CHECK_GL_ERROR();
     m_fZStep += Z_STEP;
-    return 0;
 }
 
-int OpenGLRender::SetArea2DShapePoint(float x, float y, int listLength)
+void OpenGLRender::SetArea2DShapePoint(float x, float y, int listLength)
 {
     if (m_Area2DPointList.empty())
     {
@@ -771,7 +765,6 @@ int OpenGLRender::SetArea2DShapePoint(float x, float y, int listLength)
         m_Area2DShapePointList.push_back(m_Area2DPointList);
         m_Area2DPointList.clear();
     }
-    return 0;
 }
 
 namespace {
@@ -799,7 +792,7 @@ bool checkCCW(const PointList& rPoints)
 
 }
 
-int OpenGLRender::RenderArea2DShape()
+void OpenGLRender::RenderArea2DShape()
 {
     CHECK_GL_ERROR();
 
@@ -847,8 +840,6 @@ int OpenGLRender::RenderArea2DShape()
     m_fZStep += Z_STEP;
 
     CHECK_GL_ERROR();
-
-    return 0;
 }
 
 void OpenGLRender::SetBackGroundColor(::Color color1, ::Color color2, css::drawing::FillStyle fillStyle)
@@ -932,7 +923,7 @@ void OpenGLRender::GeneratePieSegment2D(double fInnerRadius, double fOutterRadiu
     m_PieSegment2DShapePointList.push_back(aPointList);
 }
 
-int OpenGLRender::RenderPieSegment2DShape(float fSize, float fPosX, float fPosY)
+void OpenGLRender::RenderPieSegment2DShape(float fSize, float fPosX, float fPosY)
 {
     int listNum = m_PieSegment2DShapePointList.size();
     PosVecf3 const trans = {fPosX, fPosY, 0.0f};
@@ -975,10 +966,9 @@ int OpenGLRender::RenderPieSegment2DShape(float fSize, float fPosX, float fPosY)
     m_fZStep += Z_STEP;
 
     CHECK_GL_ERROR();
-    return 0;
 }
 
-int OpenGLRender::RenderSymbol2DShape(float x, float y, sal_Int32 nSymbol)
+void OpenGLRender::RenderSymbol2DShape(float x, float y, sal_Int32 nSymbol)
 {
     CHECK_GL_ERROR();
 
@@ -1028,7 +1018,6 @@ int OpenGLRender::RenderSymbol2DShape(float x, float y, sal_Int32 nSymbol)
     m_fZStep += Z_STEP;
 
     CHECK_GL_ERROR();
-    return 0;
 }
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/chart2/source/view/main/OpenGLRender.hxx b/chart2/source/view/main/OpenGLRender.hxx
index b222a40f6647..3b9d8700c3ce 100644
--- a/chart2/source/view/main/OpenGLRender.hxx
+++ b/chart2/source/view/main/OpenGLRender.hxx
@@ -67,24 +67,24 @@ public:
     OpenGLRender();
     ~OpenGLRender();
     int InitOpenGL();
-    int MoveModelf(const PosVecf3& trans, const PosVecf3& angle, const PosVecf3& scale);
+    void MoveModelf(const PosVecf3& trans, const PosVecf3& angle, const PosVecf3& scale);
     void SetSize(int width, int height);
     void SetSizePixel(int width, int height);
     void Release();
     int RenderLine2FBO();
-    int SetLine2DShapePoint(float x, float y, int listLength);
+    void SetLine2DShapePoint(float x, float y, int listLength);
     void SetLine2DColor(sal_uInt8 r, sal_uInt8 g, sal_uInt8 b, sal_uInt8 nAlpha);
     void SetLine2DWidth(int width);
     void SetColor(sal_uInt32 color, sal_uInt8 nAlpha);
-    int Bubble2DShapePoint(float x, float y, float directionX, float directionY);
+    void Bubble2DShapePoint(float x, float y, float directionX, float directionY);
     int RenderBubble2FBO();
 
     void prepareToRender();
 
-    int RenderRectangleShape(bool bBorder, bool bFill);
-    int RectangleShapePoint(float x, float y, float directionX, float directionY);
+    void RenderRectangleShape(bool bBorder, bool bFill);
+    void RectangleShapePoint(float x, float y, float directionX, float directionY);
 
-    int CreateTextTexture(const boost::shared_array<sal_uInt8> &rPixels,
+    void CreateTextTexture(const boost::shared_array<sal_uInt8> &rPixels,
                           const ::Size &aPixelSize,
                           const css::awt::Size& aSize,
                           long rotation,
@@ -92,16 +92,16 @@ public:
     int CreateTextTexture(const BitmapEx& rBitmapEx,
             const css::awt::Size& aSize,
             long rotation, const css::drawing::HomogenMatrix3& rTrans);
-    int RenderTextShape();
+    void RenderTextShape();
 
-    int SetArea2DShapePoint(float x, float y, int listLength);
-    int RenderArea2DShape();
+    void SetArea2DShapePoint(float x, float y, int listLength);
+    void RenderArea2DShape();
     void SetChartTransparencyGradient(long transparencyGradient);
 
     void GeneratePieSegment2D(double, double, double, double);
-    int RenderPieSegment2DShape(float, float, float);
+    void RenderPieSegment2DShape(float, float, float);
 
-    int RenderSymbol2DShape(float, float, sal_Int32);
+    void RenderSymbol2DShape(float, float, sal_Int32);
 #if DEBUG_POSITIONING
     void renderDebug();
 #endif
diff --git a/compilerplugins/clang/shouldreturnbool.cxx b/compilerplugins/clang/shouldreturnbool.cxx
new file mode 100644
index 000000000000..d993bf25f21e
--- /dev/null
+++ b/compilerplugins/clang/shouldreturnbool.cxx
@@ -0,0 +1,250 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <string>
+#include <set>
+#include <iostream>
+
+#include "check.hxx"
+#include "plugin.hxx"
+#include "functionaddress.hxx"
+
+/*
+ Look for functions that only return 1 and/or 0, which sometimes indicates that the
+ function should be returning bool.
+
+ Note that is partly a question of taste and code style, which is why this plugin is off by default.
+*/
+
+namespace
+{
+class ShouldReturnBool : public loplugin::FunctionAddress<ShouldReturnBool>
+{
+public:
+    explicit ShouldReturnBool(loplugin::InstantiationData const& data)
+        : loplugin::FunctionAddress<ShouldReturnBool>(data)
+    {
+    }
+
+    virtual void run() override
+    {
+        if (!compiler.getLangOpts().CPlusPlus)
+            return;
+        StringRef fn(compiler.getSourceManager()
+                         .getFileEntryForID(compiler.getSourceManager().getMainFileID())
+                         ->getName());
+        // functions used as function pointers
+        if (loplugin::isSamePathname(fn, SRCDIR "/sal/rtl/alloc_cache.cxx"))
+            return;
+        // false +, slightly odd usage, but not wrong
+        if (loplugin::isSamePathname(fn, SRCDIR "/libreofficekit/qa/tilebench/tilebench.cxx")
+            || loplugin::isSamePathname(fn, SRCDIR "/smoketest/libtest.cxx"))
+            return;
+        // uses the Unix convention of "non-zero return indicates error"
+        if (loplugin::isSamePathname(fn, SRCDIR "/idlc/source/idlcproduce.cxx"))
+            return;
+        // template magic
+        if (loplugin::isSamePathname(fn, SRCDIR "/vcl/source/gdi/bmpfast.cxx"))
+            return;
+        // fine
+        if (loplugin::isSamePathname(fn, SRCDIR "/svl/unx/source/svdde/ddedummy.cxx"))
+            return;
+        if (loplugin::isSamePathname(fn, SRCDIR "/vcl/source/opengl/OpenGLHelper.cxx"))
+            return;
+        if (loplugin::isSamePathname(fn, SRCDIR "/svtools/source/misc/imap2.cxx"))
+            return;
+        if (loplugin::isSamePathname(fn, SRCDIR "/svx/source/dialog/docrecovery.cxx"))
+            return;
+        if (loplugin::isSamePathname(fn, SRCDIR "/hwpfilter/source/lexer.cxx"))
+            return;
+        if (loplugin::isSamePathname(fn, SRCDIR "/hwpfilter/source/grammar.cxx"))
+            return;
+        if (loplugin::isSamePathname(
+                fn, SRCDIR "/connectivity/source/drivers/odbc/ODatabaseMetaDataResultSet.cxx"))
+            return;
+        if (loplugin::isSamePathname(fn, SRCDIR "/dbaccess/source/ui/browser/dsEntriesNoExp.cxx"))
+            return;
+        if (loplugin::isSamePathname(fn, SRCDIR "/lotuswordpro/source/filter/explode.cxx"))
+            return;
+        if (loplugin::isSamePathname(fn, SRCDIR "/filter/source/graphicfilter/ipict/ipict.cxx"))
+            return;
+        if (loplugin::isSamePathname(fn, SRCDIR "/sc/source/core/data/dptabsrc.cxx"))
+            return;
+        if (loplugin::isSamePathname(fn, SRCDIR "/sc/source/ui/docshell/docsh3.cxx"))
+            return;
+        if (loplugin::isSamePathname(fn, SRCDIR "/sd/source/ui/dlg/masterlayoutdlg.cxx"))
+            return;
+        if (loplugin::isSamePathname(fn, SRCDIR "/sd/source/filter/ppt/pptinanimations.cxx"))
+            return;
+        if (loplugin::isSamePathname(fn, SRCDIR "/vcl/unx/generic/app/i18n_im.cxx"))
+            return;
+
+        // callback
+        if (loplugin::isSamePathname(fn, SRCDIR "/sax/source/expatwrap/sax_expat.cxx"))
+            return;
+        if (loplugin::isSamePathname(fn, SRCDIR "/xmlsecurity/source/xmlsec/xmlstreamio.cxx"))
+            return;
+        if (loplugin::isSamePathname(fn, SRCDIR "/sw/source/filter/ww8/ww8par.cxx"))
+            return;
+        if (loplugin::isSamePathname(fn, SRCDIR "/sw/source/filter/ww8/ww8par2.cxx"))
+            return;
+        if (loplugin::isSamePathname(fn, SRCDIR "/sw/source/filter/ww8/ww8par5.cxx"))
+            return;
+        // SaxWriterHelper::writeSequence a little weird
+        if (loplugin::isSamePathname(fn, SRCDIR "/sax/source/expatwrap/saxwriter.cxx"))
+            return;
+        // main function
+        if (loplugin::isSamePathname(fn, SRCDIR "/xmlsecurity/workben/pdfverify.cxx"))
+            return;
+
+        TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
+
+        for (auto functionDecl : problemFunctions)
+        {
+            auto canonicalDecl = functionDecl->getCanonicalDecl();
+            if (getFunctionsWithAddressTaken().find(canonicalDecl)
+                != getFunctionsWithAddressTaken().end())
+                continue;
+            report(DiagnosticsEngine::Warning,
+                   "only returning one or zero is an indication you want to return bool",
+                   functionDecl->getLocStart())
+                << functionDecl->getSourceRange();
+            if (canonicalDecl->getLocation() != functionDecl->getLocation())
+            {
+                report(DiagnosticsEngine::Note, "canonical function declaration here",
+                       canonicalDecl->getLocStart())
+                    << canonicalDecl->getSourceRange();
+            }
+        }
+    }
+
+    bool TraverseFunctionDecl(FunctionDecl*);
+    bool TraverseCXXMethodDecl(CXXMethodDecl*);
+    bool VisitReturnStmt(ReturnStmt const*);
+
+private:
+    bool mbInsideFunction = false;
+    bool mbFunctionOnlyReturningOneOrZero = false;
+    std::unordered_set<FunctionDecl const*> problemFunctions;
+
+    bool IsInteresting(FunctionDecl const*);
+    void Report(FunctionDecl const*) const;
+    bool isExprOneOrZero(Expr const*) const;
+};
+
+bool ShouldReturnBool::TraverseFunctionDecl(FunctionDecl* functionDecl)
+{
+    bool ret;
+    if (IsInteresting(functionDecl))
+    {
+        mbInsideFunction = true;
+        mbFunctionOnlyReturningOneOrZero = true;
+        ret = loplugin::FunctionAddress<ShouldReturnBool>::TraverseFunctionDecl(functionDecl);
+        mbInsideFunction = false;
+        if (mbFunctionOnlyReturningOneOrZero)
+            problemFunctions.insert(functionDecl);
+    }
+    else
+        ret = loplugin::FunctionAddress<ShouldReturnBool>::TraverseFunctionDecl(functionDecl);
+    return ret;
+}
+
+bool ShouldReturnBool::TraverseCXXMethodDecl(CXXMethodDecl* methodDecl)
+{
+    bool ret;
+    if (IsInteresting(methodDecl))
+    {
+        mbInsideFunction = true;
+        mbFunctionOnlyReturningOneOrZero = true;
+        ret = loplugin::FunctionAddress<ShouldReturnBool>::TraverseCXXMethodDecl(methodDecl);
+        mbInsideFunction = false;
+        if (mbFunctionOnlyReturningOneOrZero)
+            problemFunctions.insert(methodDecl);
+    }
+    else
+        ret = loplugin::FunctionAddress<ShouldReturnBool>::TraverseCXXMethodDecl(methodDecl);
+    return ret;
+}
+
+bool ShouldReturnBool::IsInteresting(FunctionDecl const* functionDecl)
+{
+    if (ignoreLocation(functionDecl))
+        return false;
+    // ignore stuff that forms part of the stable URE interface
+    if (isInUnoIncludeFile(functionDecl))
+        return false;
+    if (functionDecl->getTemplatedKind() != FunctionDecl::TK_NonTemplate)
+        return false;
+    if (!functionDecl->isThisDeclarationADefinition())
+        return false;
+    if (functionDecl->isMain())
+        return false;
+    if (functionDecl->isExternC() || functionDecl->isInExternCContext())
+        return false;
+    auto methodDecl = dyn_cast<CXXMethodDecl>(functionDecl);
+    if (methodDecl && methodDecl->isVirtual())
+        return false;
+    auto tc = loplugin::TypeCheck(functionDecl->getReturnType());
+    if (tc.AnyBoolean() || tc.Void())
+        return false;
+    auto returnType = functionDecl->getReturnType();
+    if (returnType->isEnumeralType() || !returnType->getUnqualifiedDesugaredType()->isIntegerType())
+        return false;
+    // Ignore functions that contains #ifdef-ery
+    if (containsPreprocessingConditionalInclusion(functionDecl->getSourceRange()))
+        return false;
+
+    // not sure what basegfx is doing here
+    StringRef fileName{ compiler.getSourceManager().getFilename(functionDecl->getLocation()) };
+    if (loplugin::isSamePathname(fileName, SRCDIR "/include/basegfx/range/basicrange.hxx"))
+        return false;
+    // false +
+    if (loplugin::isSamePathname(fileName, SRCDIR "/include/svl/macitem.hxx"))
+        return false;
+    if (loplugin::isSamePathname(fileName, SRCDIR "/lotuswordpro/source/filter/lwpcharsetmgr.hxx"))
+        return false;
+    if (loplugin::isSamePathname(fileName, SRCDIR "/sc/inc/dptabsrc.hxx"))
+        return false;
+
+    return true;
+}
+
+bool ShouldReturnBool::VisitReturnStmt(const ReturnStmt* returnStmt)
+{
+    if (!mbInsideFunction)
+        return true;
+    if (!returnStmt->getRetValue())
+        return true;
+    if (loplugin::TypeCheck(returnStmt->getRetValue()->getType()).AnyBoolean())
+        return true;
+    if (!isExprOneOrZero(returnStmt->getRetValue()))
+        mbFunctionOnlyReturningOneOrZero = false;
+    return true;
+}
+
+bool ShouldReturnBool::isExprOneOrZero(const Expr* arg) const
+{
+    arg = arg->IgnoreParenCasts();
+    // ignore this, it seems to trigger an infinite recursion
+    if (isa<UnaryExprOrTypeTraitExpr>(arg))
+    {
+        return false;
+    }
+    APSInt x1;
+    if (arg->EvaluateAsInt(x1, compiler.getASTContext()))
+    {
+        return x1 == 1 || x1 == 0;
+    }
+    return false;
+}
+
+loplugin::Plugin::Registration<ShouldReturnBool> X("shouldreturnbool", false);
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/compilerplugins/clang/test/shouldreturnbool.cxx b/compilerplugins/clang/test/shouldreturnbool.cxx
new file mode 100644
index 000000000000..03a698e30ed4
--- /dev/null
+++ b/compilerplugins/clang/test/shouldreturnbool.cxx
@@ -0,0 +1,31 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+int foo1(char ch)
+{
+    // expected-error@-2 {{only returning one or zero is an indication you want to return bool [loplugin:shouldreturnbool]}}
+    if (ch == 'x')
+        return 1;
+    return 0;
+}
+
+long foo2()
+{
+    // expected-error@-2 {{only returning one or zero is an indication you want to return bool [loplugin:shouldreturnbool]}}
+    return 1;
+}
+
+enum Enum1
+{
+    NONE
+};
+
+Enum1 foo3() { return Enum1::NONE; }
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */
diff --git a/cui/source/customize/macropg.cxx b/cui/source/customize/macropg.cxx
index 345438a23cb3..6d87a95f73a5 100644
--- a/cui/source/customize/macropg.cxx
+++ b/cui/source/customize/macropg.cxx
@@ -564,11 +564,12 @@ IMPL_LINK( SvxMacroTabPage_, AssignDeleteHdl_Impl, Button*, pBtn, void )
 
 IMPL_LINK_NOARG( SvxMacroTabPage_, DoubleClickHdl_Impl, SvTreeListBox*, bool)
 {
-    return GenericHandler_Impl( this, nullptr );
+    GenericHandler_Impl( this, nullptr );
+    return false;
 }
 
 // handler for double click on the listbox, and for the assign/delete buttons
-long SvxMacroTabPage_::GenericHandler_Impl( SvxMacroTabPage_* pThis, PushButton* pBtn )
+void SvxMacroTabPage_::GenericHandler_Impl( SvxMacroTabPage_* pThis, PushButton* pBtn )
 {
     SvxMacroTabPage_Impl*    pImpl = pThis->mpImpl;
     SvHeaderTabListBox& rListBox = pImpl->pEventLB->GetListBox();
@@ -576,7 +577,7 @@ long SvxMacroTabPage_::GenericHandler_Impl( SvxMacroTabPage_* pThis, PushButton*
     if( !pE || LISTBOX_ENTRY_NOTFOUND == rListBox.GetModel()->GetAbsPos( pE ) )
     {
         DBG_ASSERT( pE, "Where does the empty entry come from?" );
-        return 0;
+        return;
     }
 
     const bool bAssEnabled = pBtn != pImpl->pDeletePB && pImpl->pAssignPB->IsEnabled();
@@ -675,7 +676,6 @@ long SvxMacroTabPage_::GenericHandler_Impl( SvxMacroTabPage_* pThis, PushButton*
     rListBox.SetUpdateMode( true );
 
     pThis->EnableButtons();
-    return 0;
 }
 
 // pass in the XNameReplace.
diff --git a/cui/source/inc/macropg.hxx b/cui/source/inc/macropg.hxx
index 2020c3e4f0bf..040fcc7838d2 100644
--- a/cui/source/inc/macropg.hxx
+++ b/cui/source/inc/macropg.hxx
@@ -61,7 +61,7 @@ class SvxMacroTabPage_ : public SfxTabPage
     DECL_LINK( AssignDeleteHdl_Impl, Button *, void );
     DECL_LINK( DoubleClickHdl_Impl, SvTreeListBox*, bool );
 
-    static long GenericHandler_Impl( SvxMacroTabPage_* pThis, PushButton* pBtn );
+    static void GenericHandler_Impl( SvxMacroTabPage_* pThis, PushButton* pBtn );
 
     css::uno::Reference< css::container::XNameReplace > m_xAppEvents;
 protected:
diff --git a/editeng/source/editeng/impedit.hxx b/editeng/source/editeng/impedit.hxx
index 56ff504827b7..741fa77b3da0 100644
--- a/editeng/source/editeng/impedit.hxx
+++ b/editeng/source/editeng/impedit.hxx
@@ -657,7 +657,7 @@ private:
     EditPaM             ReadHTML( SvStream& rInput, const OUString& rBaseURL, EditSelection aSel, SvKeyValueIterator* pHTTPHeaderAttrs );
     ErrCode             WriteText( SvStream& rOutput, EditSelection aSel );
     ErrCode             WriteRTF( SvStream& rOutput, EditSelection aSel );
-    sal_uInt32          WriteXML(SvStream& rOutput, const EditSelection& rSel);
+    void                WriteXML(SvStream& rOutput, const EditSelection& rSel);
 
     void                WriteItemAsRTF( const SfxPoolItem& rItem, SvStream& rOutput, sal_Int32 nPara, sal_Int32 nPos,
                             std::vector<SvxFontItem*>& rFontTable, SvxColorList& rColorList );
diff --git a/editeng/source/editeng/impedit4.cxx b/editeng/source/editeng/impedit4.cxx
index 8fcf39508d33..a19876928bb4 100644
--- a/editeng/source/editeng/impedit4.cxx
+++ b/editeng/source/editeng/impedit4.cxx
@@ -268,13 +268,11 @@ static void lcl_FindValidAttribs( ItemList& rLst, ContentNode* pNode, sal_Int32
     }
 }
 
-sal_uInt32 ImpEditEngine::WriteXML(SvStream& rOutput, const EditSelection& rSel)
+void ImpEditEngine::WriteXML(SvStream& rOutput, const EditSelection& rSel)
 {
     ESelection aESel = CreateESel(rSel);
 
     SvxWriteXML( *GetEditEnginePtr(), rOutput, aESel );
-
-    return 0;
 }
 
 ErrCode ImpEditEngine::WriteRTF( SvStream& rOutput, EditSelection aSel )
diff --git a/editeng/source/outliner/outlvw.cxx b/editeng/source/outliner/outlvw.cxx
index 42222d14119f..82c3da7f4d96 100644
--- a/editeng/source/outliner/outlvw.cxx
+++ b/editeng/source/outliner/outlvw.cxx
@@ -371,7 +371,7 @@ void OutlinerView::ImpToggleExpand( Paragraph const * pPara )
     pEditView->ShowCursor();
 }
 
-sal_Int32 OutlinerView::Select( Paragraph const * pParagraph, bool bSelect )
+void OutlinerView::Select( Paragraph const * pParagraph, bool bSelect )
 {
     sal_Int32 nPara = pOwner->pParaList->GetAbsPos( pParagraph );
     sal_Int32 nEnd = 0;
@@ -380,7 +380,6 @@ sal_Int32 OutlinerView::Select( Paragraph const * pParagraph, bool bSelect )
 
     ESelection aSel( nPara, 0, nPara, nEnd );
     pEditView->SetSelection( aSel );
-    return 1;
 }
 
 
diff --git a/filter/source/xsltfilter/LibXSLTTransformer.cxx b/filter/source/xsltfilter/LibXSLTTransformer.cxx
index b5691b93c38a..b27546e1343f 100644
--- a/filter/source/xsltfilter/LibXSLTTransformer.cxx
+++ b/filter/source/xsltfilter/LibXSLTTransformer.cxx
@@ -102,7 +102,8 @@ namespace XSLT
         on_close(void * context)
         {
             Reader * tmp = static_cast<Reader*> (context);
-            return tmp->closeOutput();
+            tmp->closeOutput();
+            return 0;
         }
     };
     /**
@@ -251,7 +252,7 @@ namespace XSLT
         return len;
     }
 
-    int
+    void
     Reader::closeOutput()
     {
         css::uno::Reference<XOutputStream> xos = m_transformer->getOutputStream();
@@ -261,7 +262,6 @@ namespace XSLT
             xos.get()->closeOutput();
         }
         m_transformer->done();
-        return 0;
     }
 
     void
diff --git a/filter/source/xsltfilter/LibXSLTTransformer.hxx b/filter/source/xsltfilter/LibXSLTTransformer.hxx
index 2e434033f93c..7261978ed6ed 100644
--- a/filter/source/xsltfilter/LibXSLTTransformer.hxx
+++ b/filter/source/xsltfilter/LibXSLTTransformer.hxx
@@ -61,7 +61,7 @@ namespace XSLT
         int read(char * buffer, int len);
         int write(const char * buffer, int len);
         void forceStateStopped();
-        int closeOutput();
+        void closeOutput();
 
     private:
         virtual ~Reader() override;
diff --git a/forms/source/richtext/richtextimplcontrol.cxx b/forms/source/richtext/richtextimplcontrol.cxx
index 9059870ebdd5..52c0a0b6b707 100644
--- a/forms/source/richtext/richtextimplcontrol.cxx
+++ b/forms/source/richtext/richtextimplcontrol.cxx
@@ -552,7 +552,7 @@ namespace frm
         }
     }
 
-    long RichTextControlImpl::HandleCommand( const CommandEvent& _rEvent )
+    bool RichTextControlImpl::HandleCommand( const CommandEvent& _rEvent )
     {
         if (  ( _rEvent.GetCommand() == CommandEventId::Wheel )
            || ( _rEvent.GetCommand() == CommandEventId::StartAutoScroll )
@@ -560,9 +560,9 @@ namespace frm
            )
         {
             m_pAntiImpl->HandleScrollCommand( _rEvent, m_pHScroll, m_pVScroll );
-            return 1;
+            return true;
         }
-        return 0;
+        return false;
     }
 
 
diff --git a/forms/source/richtext/richtextimplcontrol.hxx b/forms/source/richtext/richtextimplcontrol.hxx
index cac441a1ed83..635799baeb40 100644
--- a/forms/source/richtext/richtextimplcontrol.hxx
+++ b/forms/source/richtext/richtextimplcontrol.hxx
@@ -145,7 +145,7 @@ namespace frm
         void    Draw( OutputDevice* _pDev, const Point& _rPos, const Size& _rSize );
 
         /// handles command events arrived at the anti-impl control
-        long    HandleCommand( const CommandEvent& _rEvent );
+        bool    HandleCommand( const CommandEvent& _rEvent );
 
     private:
         // updates the cache with the state provided by the given attribute handler
diff --git a/fpicker/source/office/iodlg.cxx b/fpicker/source/office/iodlg.cxx
index 6ccb634bf73f..ac43ea6ebe5d 100644
--- a/fpicker/source/office/iodlg.cxx
+++ b/fpicker/source/office/iodlg.cxx
@@ -1799,10 +1799,10 @@ void SvtFileDialog::EnableControl( Control* _pControl, bool _bEnable )
 }
 
 
-short SvtFileDialog::PrepareExecute()
+bool SvtFileDialog::PrepareExecute()
 {
     if (comphelper::LibreOfficeKit::isActive())
-        return 0;
+        return false;
 
     OUString aEnvValue;
     if ( getEnvironmentValue( "WorkDirMustContainRemovableMedia", aEnvValue ) && aEnvValue == "1" )
@@ -1839,7 +1839,7 @@ short SvtFileDialog::PrepareExecute()
                                                               VclMessageType::Warning, VclButtonsType::Ok,
                                                               FpsResId(STR_SVT_NOREMOVABLEDEVICE)));
                     xBox->run();
-                    return 0;
+                    return false;
                 }
             }
         }
@@ -1939,7 +1939,7 @@ short SvtFileDialog::PrepareExecute()
     OUString aFilter;
 
     if ( !IsolateFilterFromPath_Impl( _aPath, aFilter ) )
-        return 0;
+        return false;
 
     AdjustFilterFlags nNewFilterFlags = adjustFilter( aFilter );
     if ( nNewFilterFlags & ( AdjustFilterFlags::NonEmpty | AdjustFilterFlags::UserFilter ) )
@@ -1979,7 +1979,7 @@ short SvtFileDialog::PrepareExecute()
     // if applicable read and set size from ini
     InitSize();
 
-    return 1;
+    return true;
 }
 
 
diff --git a/fpicker/source/office/iodlg.hxx b/fpicker/source/office/iodlg.hxx
index 55d7270e09da..3cb4f631e307 100644
--- a/fpicker/source/office/iodlg.hxx
+++ b/fpicker/source/office/iodlg.hxx
@@ -165,7 +165,7 @@ private:
         <member>EnableUI</member> for details.
     */
     void                        EnableControl( Control* _pControl, bool _bEnable );
-    short                       PrepareExecute();
+    bool                        PrepareExecute();
 
 public:
                                 SvtFileDialog( vcl::Window* _pParent, PickerFlags nBits );
diff --git a/framework/source/layoutmanager/toolbarlayoutmanager.cxx b/framework/source/layoutmanager/toolbarlayoutmanager.cxx
index e8925e9de098..a2a1df0c8e90 100644
--- a/framework/source/layoutmanager/toolbarlayoutmanager.cxx
+++ b/framework/source/layoutmanager/toolbarlayoutmanager.cxx
@@ -903,7 +903,7 @@ bool ToolbarLayoutManager::dockAllToolbars()
     return bResult;
 }
 
-long ToolbarLayoutManager::childWindowEvent( VclSimpleEvent const * pEvent )
+void ToolbarLayoutManager::childWindowEvent( VclSimpleEvent const * pEvent )
 {
     // To enable toolbar controllers to change their image when a sub-toolbar function
     // is activated, we need this mechanism. We have NO connection between these toolbars
@@ -982,8 +982,6 @@ long ToolbarLayoutManager::childWindowEvent( VclSimpleEvent const * pEvent )
             }
         }
     }
-
-    return 1;
 }
 
 void ToolbarLayoutManager::resetDockingArea()
diff --git a/framework/source/layoutmanager/toolbarlayoutmanager.hxx b/framework/source/layoutmanager/toolbarlayoutmanager.hxx
index def4ea56fedd..12dfffe46e50 100644
--- a/framework/source/layoutmanager/toolbarlayoutmanager.hxx
+++ b/framework/source/layoutmanager/toolbarlayoutmanager.hxx
@@ -125,7 +125,7 @@ class ToolbarLayoutManager : public ::cppu::WeakImplHelper< css::awt::XDockableW
         css::uno::Sequence< css::uno::Reference< css::ui::XUIElement > > getToolbars();
 
         // child window notifications
-        long childWindowEvent( VclSimpleEvent const * pEvent );
+        void childWindowEvent( VclSimpleEvent const * pEvent );
 
         // XInterface
 
diff --git a/hwpfilter/source/solver.cxx b/hwpfilter/source/solver.cxx
index f297160159f1..d1c76b8cd916 100644
--- a/hwpfilter/source/solver.cxx
+++ b/hwpfilter/source/solver.cxx
@@ -62,18 +62,18 @@ double* mgcLinearSystemD::NewVector (int N)
   return B;
 }
 
-int mgcLinearSystemD::Solve (int n, double** a, double* b)
+bool mgcLinearSystemD::Solve (int n, double** a, double* b)
 {
   std::unique_ptr<int[]> indxc( new int[n] );
   if ( !indxc )
-    return 0;
+    return false;
   std::unique_ptr<int[]> indxr( new int[n] );
   if ( !indxr ) {
-    return 0;
+    return false;
   }
   std::unique_ptr<int[]> ipiv( new int[n] );
   if ( !ipiv ) {
-    return 0;
+    return false;
   }
 
   int i, j, k;
@@ -104,7 +104,7 @@ int mgcLinearSystemD::Solve (int n, double** a, double* b)
           }
           else if ( ipiv[k] > 1 )
           {
-            return 0;
+            return false;
           }
         }
       }
@@ -126,7 +126,7 @@ int mgcLinearSystemD::Solve (int n, double** a, double* b)
     indxc[i] = icol;
     if ( a[icol][icol] == 0 )
     {
-      return 0;
+      return false;
     }
 
     double pivinv = 1/a[icol][icol];
@@ -161,7 +161,7 @@ int mgcLinearSystemD::Solve (int n, double** a, double* b)
     }
   }
 
-  return 1;
+  return true;
 }
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/hwpfilter/source/solver.h b/hwpfilter/source/solver.h
index 54daf1542653..ea3295bad9d4 100644
--- a/hwpfilter/source/solver.h
+++ b/hwpfilter/source/solver.h
@@ -27,7 +27,7 @@ public:
   static void DeleteMatrix (int N, double** A);
   static double* NewVector (int N);
 
-  static int Solve (int N, double** A, double* b);
+  static bool Solve (int N, double** A, double* b);
   // Input:
   //     A[N][N] coefficient matrix, entries are A[row][col]
   //     b[N] vector, entries are b[row]
diff --git a/include/editeng/outliner.hxx b/include/editeng/outliner.hxx
index 6ad87b3385e5..3c0126f3b31b 100644
--- a/include/editeng/outliner.hxx
+++ b/include/editeng/outliner.hxx
@@ -248,8 +248,7 @@ public:
 
     void        CreateSelectionList (std::vector<Paragraph*> &aSelList) ;
 
-    // Returns the number of selected paragraphs
-    sal_Int32   Select( Paragraph const * pParagraph, bool bSelect = true);
+    void        Select( Paragraph const * pParagraph, bool bSelect = true);
 
     OUString    GetSelected() const;
     void        SelectRange( sal_Int32 nFirst, sal_Int32 nCount );
diff --git a/sal/rtl/alloc_arena.cxx b/sal/rtl/alloc_arena.cxx
index 94944c105845..1cd06615d1a3 100644
--- a/sal/rtl/alloc_arena.cxx
+++ b/sal/rtl/alloc_arena.cxx
@@ -73,14 +73,12 @@ void rtl_machdep_free(
 
 sal_Size rtl_machdep_pagesize();
 
-int rtl_arena_segment_constructor(void * obj)
+void rtl_arena_segment_constructor(void * obj)
 {
     rtl_arena_segment_type * segment = static_cast<rtl_arena_segment_type*>(obj);
 
     QUEUE_START_NAMED(segment, s);
     QUEUE_START_NAMED(segment, f);
-
-    return 1;
 }
 
 void rtl_arena_segment_destructor(void * obj)
@@ -425,7 +423,7 @@ dequeue_and_leave:
     @precond arena->m_lock acquired
     @precond (*ppSegment == 0)
 */
-int rtl_arena_segment_create(
+bool rtl_arena_segment_create(
     rtl_arena_type * arena,
     sal_Size size,
     rtl_arena_segment_type ** ppSegment
@@ -463,14 +461,14 @@ int rtl_arena_segment_create(
                     QUEUE_INSERT_HEAD_NAMED(span, (*ppSegment), s);
 
                     /* report success */
-                    return 1;
+                    return true;
                 }
                 rtl_arena_segment_put (arena, &span);
             }
             rtl_arena_segment_put (arena, ppSegment);
         }
     }
-    return 0;
+    return false; // failure
 }
 
 /**
diff --git a/sc/source/core/opencl/formulagroupcl.cxx b/sc/source/core/opencl/formulagroupcl.cxx
index 84ee1cc30798..314a6a8eb696 100644
--- a/sc/source/core/opencl/formulagroupcl.cxx
+++ b/sc/source/core/opencl/formulagroupcl.cxx
@@ -1215,9 +1215,9 @@ public:
 
     size_t GetWindowSize() const { return mpDVR->GetRefRowSize(); }
 
-    size_t GetStartFixed() const { return bIsStartFixed; }
+    bool GetStartFixed() const { return bIsStartFixed; }
 
-    size_t GetEndFixed() const { return bIsEndFixed; }
+    bool GetEndFixed() const { return bIsEndFixed; }
 
 protected:
     bool bIsStartFixed, bIsEndFixed;
diff --git a/solenv/CompilerTest_compilerplugins_clang.mk b/solenv/CompilerTest_compilerplugins_clang.mk
index f97fb9c31f75..db6e7f23a3e2 100644
--- a/solenv/CompilerTest_compilerplugins_clang.mk
+++ b/solenv/CompilerTest_compilerplugins_clang.mk
@@ -45,6 +45,7 @@ $(eval $(call gb_CompilerTest_add_exception_objects,compilerplugins_clang, \
     compilerplugins/clang/test/salcall \
     compilerplugins/clang/test/sallogareas \
     compilerplugins/clang/test/salunicodeliteral \
+    compilerplugins/clang/test/shouldreturnbool \
     compilerplugins/clang/test/simplifybool \
     compilerplugins/clang/test/simplifydynamiccast \
     compilerplugins/clang/test/stringconstant \
diff --git a/store/source/storbios.cxx b/store/source/storbios.cxx
index 1a34da60d420..fad48695797d 100644
--- a/store/source/storbios.cxx
+++ b/store/source/storbios.cxx
@@ -396,13 +396,12 @@ OStorePageBIOS::Ace::~Ace()
   m_prev->m_next = m_next;
 }
 
-int
+void
 SAL_CALL OStorePageBIOS::Ace::constructor (
     void * obj, SAL_UNUSED_PARAMETER void * /* arg */)
 {
   Ace * ace = static_cast<Ace*>(obj);
   ace->m_next = ace->m_prev = ace;
-  return 1;
 }
 
 OStorePageBIOS::Ace *
diff --git a/store/source/storbios.hxx b/store/source/storbios.hxx
index 8c2abd54f5a7..fafb54e79fed 100644
--- a/store/source/storbios.hxx
+++ b/store/source/storbios.hxx
@@ -141,7 +141,7 @@ public:
         Ace();
         ~Ace();
 
-        static int SAL_CALL constructor (void * obj, void * arg);
+        static void SAL_CALL constructor (void * obj, void * arg);
 
         static Ace * find   (Ace * head, sal_uInt32 addr);
         static void  insert (Ace * head, Ace * entry);
diff --git a/sw/inc/editsh.hxx b/sw/inc/editsh.hxx
index 42a542ff3502..07308fa4db3d 100644
--- a/sw/inc/editsh.hxx
+++ b/sw/inc/editsh.hxx
@@ -202,7 +202,7 @@ public:
        Copy all selections to the document. */
     bool CopySelToDoc( SwDoc* pInsDoc );
 
-    long SplitNode( bool bAutoFormat = false, bool bCheckTableStart = true );
+    void SplitNode( bool bAutoFormat = false, bool bCheckTableStart = true );
     bool AppendTextNode();
     void AutoFormatBySplitNode();
 
diff --git a/sw/inc/view.hxx b/sw/inc/view.hxx
index a3eddaedf991..cb32b2180a32 100644
--- a/sw/inc/view.hxx
+++ b/sw/inc/view.hxx
@@ -279,12 +279,12 @@ class SW_DLLPUBLIC SwView: public SfxViewShell
     SAL_DLLPRIVATE bool          GetPageScrollDownOffset(SwTwips& rOff) const;
 
     // scrollbar movements
-    SAL_DLLPRIVATE long          PageUp();
-    SAL_DLLPRIVATE long          PageDown();
+    SAL_DLLPRIVATE bool          PageUp();
+    SAL_DLLPRIVATE bool          PageDown();
     SAL_DLLPRIVATE bool          PageUpCursor(bool bSelect);
     SAL_DLLPRIVATE bool          PageDownCursor(bool bSelect);
-    SAL_DLLPRIVATE long          PhyPageUp();
-    SAL_DLLPRIVATE long          PhyPageDown();
+    SAL_DLLPRIVATE void          PhyPageUp();
+    SAL_DLLPRIVATE void          PhyPageDown();
 
     SAL_DLLPRIVATE void           CreateScrollbar( bool bHori );
     DECL_DLLPRIVATE_LINK(  ScrollHdl, ScrollBar*, void );
@@ -472,10 +472,10 @@ public:
     void            EnableHScrollbar(bool bEnable);
     void            EnableVScrollbar(bool bEnable);
 
-    int             CreateVRuler();
-    int             KillVRuler();
-    int             CreateTab();
-    int             KillTab();
+    void            CreateVRuler();
+    void            KillVRuler();
+    void            CreateTab();
+    void            KillTab();
 
     bool            StatVRuler() const { return m_pVRuler->IsVisible(); }
     void            ChangeVRulerMetric(FieldUnit eUnit);
diff --git a/sw/source/core/edit/editsh.cxx b/sw/source/core/edit/editsh.cxx
index e3f443b25eec..1971989d93eb 100644
--- a/sw/source/core/edit/editsh.cxx
+++ b/sw/source/core/edit/editsh.cxx
@@ -184,7 +184,7 @@ void SwEditShell::Overwrite(const OUString &rStr)
     EndAllAction();
 }
 
-long SwEditShell::SplitNode( bool bAutoFormat, bool bCheckTableStart )
+void SwEditShell::SplitNode( bool bAutoFormat, bool bCheckTableStart )
 {
     StartAllAction();
     GetDoc()->GetIDocumentUndoRedo().StartUndo(SwUndoId::EMPTY, nullptr);
@@ -204,7 +204,6 @@ long SwEditShell::SplitNode( bool bAutoFormat, bool bCheckTableStart )
     ClearTableBoxContent();
 
     EndAllAction();
-    return 1;
 }
 
 bool SwEditShell::AppendTextNode()
diff --git a/sw/source/uibase/dochdl/gloshdl.cxx b/sw/source/uibase/dochdl/gloshdl.cxx
index 8b93fb6545be..12720302f0e5 100644
--- a/sw/source/uibase/dochdl/gloshdl.cxx
+++ b/sw/source/uibase/dochdl/gloshdl.cxx
@@ -691,10 +691,10 @@ bool SwGlossaryHdl::CopyToClipboard(SwWrtShell& rSh, const OUString& rShortName)
 
     rtl::Reference<SwTransferable> pTransfer = new SwTransferable( rSh );
 
-    int nRet = pTransfer->CopyGlossary( *pGlossary, rShortName );
+    bool bRet = pTransfer->CopyGlossary( *pGlossary, rShortName );
     if( !pCurGrp )
         delete pGlossary;
-    return 0 != nRet;
+    return bRet;
 }
 
 bool SwGlossaryHdl::ImportGlossaries( const OUString& rName )
diff --git a/sw/source/uibase/dochdl/swdtflvr.cxx b/sw/source/uibase/dochdl/swdtflvr.cxx
index 996632519910..10ab121d348e 100644
--- a/sw/source/uibase/dochdl/swdtflvr.cxx
+++ b/sw/source/uibase/dochdl/swdtflvr.cxx
@@ -1029,10 +1029,10 @@ void SwTransferable::CalculateAndCopy()
     CopyToClipboard( &m_pWrtShell->GetView().GetEditWin() );
 }
 
-int SwTransferable::CopyGlossary( SwTextBlocks& rGlossary, const OUString& rStr )
+bool SwTransferable::CopyGlossary( SwTextBlocks& rGlossary, const OUString& rStr )
 {
     if(!m_pWrtShell)
-        return 0;
+        return false;
     SwWait aWait( *m_pWrtShell->GetView().GetDocShell(), true );
 
     m_pClpDocFac = new SwDocFac;
@@ -1073,7 +1073,7 @@ int SwTransferable::CopyGlossary( SwTextBlocks& rGlossary, const OUString& rStr
 
     CopyToClipboard( &m_pWrtShell->GetView().GetEditWin() );
 
-    return 1;
+    return true;
 }
 
 static inline uno::Reference < XTransferable > * lcl_getTransferPointer ( uno::Reference < XTransferable > &xRef )
diff --git a/sw/source/uibase/inc/langhelper.hxx b/sw/source/uibase/inc/langhelper.hxx
index 2c7a979fd670..8c93d29d3c36 100644
--- a/sw/source/uibase/inc/langhelper.hxx
+++ b/sw/source/uibase/inc/langhelper.hxx
@@ -35,7 +35,7 @@ enum class SvtScriptType;
 
 namespace SwLangHelper
 {
-    extern sal_uInt16 GetLanguageStatus( OutlinerView* pOLV, SfxItemSet& rSet );
+    extern void GetLanguageStatus( OutlinerView* pOLV, SfxItemSet& rSet );
     extern bool SetLanguageStatus( OutlinerView* pOLV, SfxRequest &rReq, SwView const &rView, SwWrtShell &rSh );
 
     extern void SetLanguage( SwWrtShell &rWrtSh, const OUString &rLangText, bool bIsForSelection, SfxItemSet &rCoreSet );
diff --git a/sw/source/uibase/inc/swdtflvr.hxx b/sw/source/uibase/inc/swdtflvr.hxx
index e15e4a5664c9..58990e80f943 100644
--- a/sw/source/uibase/inc/swdtflvr.hxx
+++ b/sw/source/uibase/inc/swdtflvr.hxx
@@ -166,7 +166,7 @@ public:
     int  Copy( bool bIsCut = false );
     int  PrepareForCopy( bool bIsCut = false );
     void  CalculateAndCopy();                // special for Calculator
-    int  CopyGlossary( SwTextBlocks& rGlossary, const OUString& rStr );
+    bool  CopyGlossary( SwTextBlocks& rGlossary, const OUString& rStr );
 
     // remove the DDE-Link format promise
     void RemoveDDELinkFormat( const vcl::Window& rWin );
diff --git a/sw/source/uibase/inc/wrtsh.hxx b/sw/source/uibase/inc/wrtsh.hxx
index f87d113b80ab..6fbbb38d3d7e 100644
--- a/sw/source/uibase/inc/wrtsh.hxx
+++ b/sw/source/uibase/inc/wrtsh.hxx
@@ -188,7 +188,7 @@ public:
     // #i32329# Enhanced selection
     void    SelSentence (const Point *);
     void    SelPara     (const Point *);
-    long    SelAll();
+    void    SelAll();
 
     // basecursortravelling
 typedef bool (SwWrtShell:: *FNSimpleMove)();
diff --git a/sw/source/uibase/shells/drwtxtex.cxx b/sw/source/uibase/shells/drwtxtex.cxx
index c24d82199a79..ea1810fbc485 100644
--- a/sw/source/uibase/shells/drwtxtex.cxx
+++ b/sw/source/uibase/shells/drwtxtex.cxx
@@ -610,7 +610,8 @@ void SwDrawTextShell::GetState(SfxItemSet& rSet)
         {
             case SID_LANGUAGE_STATUS://20412:
             {
-                nSlotId = SwLangHelper::GetLanguageStatus(pOLV,rSet);
+                SwLangHelper::GetLanguageStatus(pOLV,rSet);
+                nSlotId = 0;
                 break;
             }
 
diff --git a/sw/source/uibase/shells/langhelper.cxx b/sw/source/uibase/shells/langhelper.cxx
index 33bdcce561df..07b626ad5bb5 100644
--- a/sw/source/uibase/shells/langhelper.cxx
+++ b/sw/source/uibase/shells/langhelper.cxx
@@ -57,7 +57,7 @@ using namespace ::com::sun::star;
 namespace SwLangHelper
 {
 
-    sal_uInt16 GetLanguageStatus( OutlinerView* pOLV, SfxItemSet& rSet )
+    void GetLanguageStatus( OutlinerView* pOLV, SfxItemSet& rSet )
     {
         ESelection aSelection = pOLV->GetSelection();
         EditView& rEditView=pOLV->GetEditView();
@@ -95,7 +95,6 @@ namespace SwLangHelper
         SfxStringListItem aItem( SID_LANGUAGE_STATUS );
         aItem.SetStringList( aSeq );
         rSet.Put( aItem );
-        return 0;
     }
 
     bool SetLanguageStatus( OutlinerView* pOLV, SfxRequest &rReq, SwView const &rView, SwWrtShell &rSh )
diff --git a/sw/source/uibase/shells/txtcrsr.cxx b/sw/source/uibase/shells/txtcrsr.cxx
index f64127c45069..3ecf385bd9f3 100644
--- a/sw/source/uibase/shells/txtcrsr.cxx
+++ b/sw/source/uibase/shells/txtcrsr.cxx
@@ -155,7 +155,8 @@ void SwTextShell::ExecMove(SfxRequest &rReq)
             bRet = rSh.SelNearestWrd();
             break;
         case SID_SELECTALL:
-            bRet = 0 != rSh.SelAll();
+            rSh.SelAll();
+            bRet = true;
             break;
         default:
             OSL_FAIL("wrong dispatcher");
diff --git a/sw/source/uibase/uiview/viewmdi.cxx b/sw/source/uibase/uiview/viewmdi.cxx
index 2944568079a1..5038bae46bf8 100644
--- a/sw/source/uibase/uiview/viewmdi.cxx
+++ b/sw/source/uibase/uiview/viewmdi.cxx
@@ -486,20 +486,18 @@ IMPL_LINK( SwView, MoveNavigationHdl, void*, p, void )
     delete pbNext;
 }
 
-int SwView::CreateTab()
+void SwView::CreateTab()
 {
     m_pHRuler->SetActive(GetFrame() && IsActive());
 
     m_pHRuler->Show();
     InvalidateBorder();
-    return 1;
 }
 
-int SwView::KillTab()
+void SwView::KillTab()
 {
     m_pHRuler->Hide();
     InvalidateBorder();
-    return 1;
 }
 
 void SwView::ChangeTabMetric( FieldUnit eUnit )
@@ -530,22 +528,20 @@ void SwView::GetHRulerMetric(FieldUnit& eToFill) const
     eToFill = m_pHRuler->GetUnit();
 }
 
-int SwView::CreateVRuler()
+void SwView::CreateVRuler()
 {
     m_pHRuler->SetBorderPos( m_pVRuler->GetSizePixel().Width()-1 );
 
     m_pVRuler->SetActive(GetFrame() && IsActive());
     m_pVRuler->Show();
     InvalidateBorder();
-    return 1;
 }
 
-int SwView::KillVRuler()
+void SwView::KillVRuler()
 {
     m_pVRuler->Hide();
     m_pHRuler->SetBorderPos();
     InvalidateBorder();
-    return 1;
 }
 
 IMPL_LINK( SwView, ExecRulerClick, Ruler *, pRuler, void )
diff --git a/sw/source/uibase/uiview/viewport.cxx b/sw/source/uibase/uiview/viewport.cxx
index 96ae9c630c60..2896dbd653cd 100644
--- a/sw/source/uibase/uiview/viewport.cxx
+++ b/sw/source/uibase/uiview/viewport.cxx
@@ -576,30 +576,30 @@ bool SwView::GetPageScrollDownOffset( SwTwips &rOff ) const
 }
 
 // Scroll page by page
-long SwView::PageUp()
+bool SwView::PageUp()
 {
     if (!m_aVisArea.GetHeight())
-        return 0;
+        return false;
 
     Point aPos(m_aVisArea.TopLeft());
     aPos.AdjustY( -(m_aVisArea.GetHeight() - (GetYScroll() / 2)) );
     aPos.setY( std::max(0L, aPos.Y()) );
     SetVisArea( aPos );
-    return 1;
+    return true;
 }
 
-long SwView::PageDown()
+bool SwView::PageDown()
 {
     if ( !m_aVisArea.GetHeight() )
-        return 0;
+        return false;
     Point aPos( m_aVisArea.TopLeft() );
     aPos.AdjustY(m_aVisArea.GetHeight() - (GetYScroll() / 2) );
     aPos.setY( SetVScrollMax( aPos.Y() ) );
     SetVisArea( aPos );
-    return 1;
+    return true;
 }
 
-long SwView::PhyPageUp()
+void SwView::PhyPageUp()
 {
     // Check for the currently visible page, do not format
     sal_uInt16 nActPage = m_pWrtShell->GetNextPrevPageNum( false );
@@ -615,10 +615,9 @@ long SwView::PhyPageUp()
             aAlPt.AdjustY(3 * GetEditWin().PixelToLogic( Size( 0, 1 ) ).Height() );
         SetVisArea( aAlPt );
     }
-    return 1;
 }
 
-long SwView::PhyPageDown()
+void SwView::PhyPageDown()
 {
     // Check for the currently visible page, do not format
     sal_uInt16 nActPage = m_pWrtShell->GetNextPrevPageNum();
@@ -634,7 +633,6 @@ long SwView::PhyPageDown()
             aAlPt.AdjustY(3 * GetEditWin().PixelToLogic( Size( 0, 1 ) ).Height() );
         SetVisArea( aAlPt );
     }
-    return 1;
 }
 
 bool SwView::PageUpCursor( bool bSelect )
diff --git a/sw/source/uibase/wrtsh/select.cxx b/sw/source/uibase/wrtsh/select.cxx
index 105e1caf7d67..839a95572d2f 100644
--- a/sw/source/uibase/wrtsh/select.cxx
+++ b/sw/source/uibase/wrtsh/select.cxx
@@ -120,7 +120,7 @@ void SwWrtShell::SelPara(const Point *pPt )
     m_bSelWrd = false;  // disable SelWord, otherwise no SelLine goes on
 }
 
-long SwWrtShell::SelAll()
+void SwWrtShell::SelAll()
 {
     const bool bLockedView = IsViewLocked();
     LockView( true );
@@ -205,7 +205,6 @@ long SwWrtShell::SelAll()
     }
     EndSelect();
     LockView( bLockedView );
-    return 1;
 }
 
 // Description: Text search
diff --git a/vcl/inc/salobj.hxx b/vcl/inc/salobj.hxx
index e4c8b918c09b..3e8dbf152d29 100644
--- a/vcl/inc/salobj.hxx
+++ b/vcl/inc/salobj.hxx
@@ -26,6 +26,8 @@
 
 struct SystemEnvData;
 
+typedef void (*SALOBJECTPROC)( void* pInst, SalObjEvent nEvent );
+
 class VCL_PLUGIN_PUBLIC SalObject
 {
     void*               m_pInst;
diff --git a/vcl/inc/salwtype.hxx b/vcl/inc/salwtype.hxx
index 29cbaf00c3a6..4f7c2f6a186f 100644
--- a/vcl/inc/salwtype.hxx
+++ b/vcl/inc/salwtype.hxx
@@ -221,8 +221,6 @@ enum class SalObjEvent {
     ToTop              = 3
 };
 
-typedef long (*SALOBJECTPROC)( void* pInst, SalObjEvent nEvent );
-
 struct SalFrameState
 {
     WindowStateMask mnMask;
diff --git a/vcl/inc/unx/i18n_ic.hxx b/vcl/inc/unx/i18n_ic.hxx
index 2da9e8bbc072..c07bc6f3a3fb 100644
--- a/vcl/inc/unx/i18n_ic.hxx
+++ b/vcl/inc/unx/i18n_ic.hxx
@@ -52,7 +52,7 @@ private:
 
     bool         SupportInputMethodStyle( XIMStyles const *pIMStyles );
     static unsigned int GetWeightingOfIMStyle(   XIMStyle n_style );
-    Bool         IsSupportedIMStyle(      XIMStyle n_style ) const;
+    bool         IsSupportedIMStyle(      XIMStyle n_style ) const;
 
 public:
 
diff --git a/vcl/source/window/syschild.cxx b/vcl/source/window/syschild.cxx
index 9b36ab44bf43..b96123ddc637 100644
--- a/vcl/source/window/syschild.cxx
+++ b/vcl/source/window/syschild.cxx
@@ -42,7 +42,7 @@
 
 using namespace ::com::sun::star;
 
-long ImplSysChildProc( void* pInst, SalObjEvent nEvent )
+void ImplSysChildProc( void* pInst, SalObjEvent nEvent )
 {
     VclPtr<SystemChildWindow> pWindow = static_cast<SystemChildWindow*>(pInst);
 
@@ -92,8 +92,6 @@ long ImplSysChildProc( void* pInst, SalObjEvent nEvent )
 
         default: break;
     }
-
-    return 0;
 }
 
 void SystemChildWindow::ImplInitSysChild( vcl::Window* pParent, WinBits nStyle, SystemWindowData *pData, bool bShow )
diff --git a/vcl/unx/generic/app/i18n_ic.cxx b/vcl/unx/generic/app/i18n_ic.cxx
index 64ad7fc190ff..5dc4f6c435b3 100644
--- a/vcl/unx/generic/app/i18n_ic.cxx
+++ b/vcl/unx/generic/app/i18n_ic.cxx
@@ -465,15 +465,15 @@ SalI18N_InputContext::GetWeightingOfIMStyle( XIMStyle nStyle )
     return nWeight;
 }
 
-Bool
+bool
 SalI18N_InputContext::IsSupportedIMStyle( XIMStyle nStyle ) const
 {
     if (   (nStyle & mnSupportedPreeditStyle)
            && (nStyle & g_nSupportedStatusStyle) )
     {
-        return True;
+        return true;
     }
-    return False;
+    return false;
 }
 
 bool