Extend loplugin:redundantcast to trivial reinterpret_cast from T to itself

Change-Id: I7c0be7b435d6b5f97bdd40484023584146638d70
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/134506
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

11 files changed, 30 insertions, 14 deletions

diff --git a/basic/source/classes/sbxmod.cxx b/basic/source/classes/sbxmod.cxx
index 67bf03ef9ecb..1e5e7ec36a7f 100644
--- a/basic/source/classes/sbxmod.cxx
+++ b/basic/source/classes/sbxmod.cxx
@@ -1450,7 +1450,7 @@ const sal_uInt8* SbModule::FindNextStmnt( const sal_uInt8* p, sal_uInt16& nLine,
 const sal_uInt8* SbModule::FindNextStmnt( const sal_uInt8* p, sal_uInt16& nLine, sal_uInt16& nCol,
     bool bFollowJumps, const SbiImage* pImg ) const
 {
-    sal_uInt32 nPC = static_cast<sal_uInt32>( p - reinterpret_cast<const sal_uInt8*>(pImage->GetCode()) );
+    sal_uInt32 nPC = static_cast<sal_uInt32>( p - pImage->GetCode() );
     while( nPC < pImage->GetCodeSize() )
     {
         SbiOpcode eOp = static_cast<SbiOpcode>( *p++ );
@@ -1460,7 +1460,7 @@ const sal_uInt8* SbModule::FindNextStmnt( const sal_uInt8* p, sal_uInt16& nLine,
             SAL_WARN_IF( !pImg, "basic", "FindNextStmnt: pImg==NULL with FollowJumps option" );
             sal_uInt32 nOp1 = *p++; nOp1 |= *p++ << 8;
             nOp1 |= *p++ << 16; nOp1 |= *p++ << 24;
-            p = reinterpret_cast<const sal_uInt8*>(pImg->GetCode()) + nOp1;
+            p = pImg->GetCode() + nOp1;
         }
         else if( eOp >= SbiOpcode::SbOP1_START && eOp <= SbiOpcode::SbOP1_END )
         {
@@ -1497,7 +1497,7 @@ bool SbModule::IsBreakable( sal_uInt16 nLine ) const
 {
     if( !pImage )
         return false;
-    const sal_uInt8* p = reinterpret_cast<const sal_uInt8*>(pImage->GetCode());
+    const sal_uInt8* p = pImage->GetCode();
     sal_uInt16 nl, nc;
     while( ( p = FindNextStmnt( p, nl, nc ) ) != nullptr )
         if( nl == nLine )
diff --git a/compilerplugins/clang/redundantcast.cxx b/compilerplugins/clang/redundantcast.cxx
index 1cfe44c9305e..87c4d14458fd 100644
--- a/compilerplugins/clang/redundantcast.cxx
+++ b/compilerplugins/clang/redundantcast.cxx
@@ -577,6 +577,16 @@ bool RedundantCast::VisitCXXReinterpretCastExpr(
     if (ignoreLocation(expr)) {
         return true;
     }
+    if (expr->getTypeAsWritten() == expr->getSubExprAsWritten()->getType())
+        //TODO: instead of exact QualType match, allow some variation?
+    {
+        report(
+            DiagnosticsEngine::Warning, "redundant reinterpret_cast from %0 to %1",
+                expr->getExprLoc())
+                << expr->getSubExprAsWritten()->getType() << expr->getTypeAsWritten()
+                << expr->getSourceRange();
+        return true;
+    }
     if (auto const sub = dyn_cast<ImplicitCastExpr>(expr->getSubExpr())) {
         if (sub->getCastKind() == CK_ArrayToPointerDecay && sub->getType() == expr->getType())
             //TODO: instead of exact QualType match, allow some variation?
diff --git a/compilerplugins/clang/test/redundantcast.cxx b/compilerplugins/clang/test/redundantcast.cxx
index d1803aafbca7..7a102cca5d0a 100644
--- a/compilerplugins/clang/test/redundantcast.cxx
+++ b/compilerplugins/clang/test/redundantcast.cxx
@@ -329,6 +329,11 @@ void testArithmeticTypedefs() {
     (void) static_cast<T1>(c); // expected-error {{redundant}}
 }
 
+void testReinterpretCast() {
+    int * p;
+    (void) reinterpret_cast<int *>(p); // expected-error {{redundant reinterpret_cast from 'int *' to 'int *' [loplugin:redundantcast]}}
+}
+
 void testReinterpretConstCast() {
     int n = 0;
     (void) reinterpret_cast<std::size_t>((const_cast<int const *>(&n))); // expected-error-re {{redundant const_cast from 'int *' to 'const int *' within reinterpret_cast to fundamental type 'std::size_t' (aka 'unsigned {{.+}}') [loplugin:redundantcast]}}
@@ -442,6 +447,7 @@ int main() {
     testFunctionalCast();
     testCStyleCast();
     testCStyleCastOfTemplateMethodResult(nullptr);
+    testReinterpretCast();
     testReinterpretConstCast();
     testDynamicCast();
     testIntermediaryStaticCast();
diff --git a/sal/qa/rtl/textenc/rtl_textcvt.cxx b/sal/qa/rtl/textenc/rtl_textcvt.cxx
index 8fa8b4e8dc96..55804bd32838 100644
--- a/sal/qa/rtl/textenc/rtl_textcvt.cxx
+++ b/sal/qa/rtl/textenc/rtl_textcvt.cxx
@@ -260,7 +260,7 @@ void doComplexCharSetTest(ComplexCharSetTest const & rTest) {
                 sal_Size nConverted;
                 sal_Size nSize = rtl_convertTextToUnicode(
                     aConverter, aContext,
-                    reinterpret_cast< char const * >(rTest.m_pText + nInput),
+                    rTest.m_pText + nInput,
                     nSrcBytes, aUnicode + nOutput, TEST_STRING_SIZE - nOutput,
                     nFlags, &nInfo, &nConverted);
                 nOutput += nSize;
diff --git a/sd/qa/unit/tiledrendering/tiledrendering.cxx b/sd/qa/unit/tiledrendering/tiledrendering.cxx
index 7bfb30a7a544..e9f3f012bc6c 100644
--- a/sd/qa/unit/tiledrendering/tiledrendering.cxx
+++ b/sd/qa/unit/tiledrendering/tiledrendering.cxx
@@ -390,7 +390,7 @@ xmlDocUniquePtr SdTiledRenderingTest::parseXmlDump()
     (void)xmlTextWriterEndDocument(pXmlWriter);
     xmlFreeTextWriter(pXmlWriter);
 
-    auto pCharBuffer = reinterpret_cast<const xmlChar*>(xmlBufferContent(m_pXmlBuffer));
+    auto pCharBuffer = xmlBufferContent(m_pXmlBuffer);
     SAL_INFO("test", "SdTiledRenderingTest::parseXmlDump: pCharBuffer is '" << pCharBuffer << "'");
     return xmlDocUniquePtr(xmlParseDoc(pCharBuffer));
 }
diff --git a/sw/source/core/tox/txmsrt.cxx b/sw/source/core/tox/txmsrt.cxx
index b0195ff8d718..8e2272b1ff8a 100644
--- a/sw/source/core/tox/txmsrt.cxx
+++ b/sw/source/core/tox/txmsrt.cxx
@@ -753,7 +753,7 @@ TextAndReading SwTOXTable::GetText_Impl(SwRootFrame const*const) const
     if( pNd )
     {
         const SwTableNode* pTableNd =
-            reinterpret_cast<const SwTableNode*>(pNd->FindTableNode());
+            pNd->FindTableNode();
         if (pTableNd)
         {
             return TextAndReading(pTableNd->GetTable().GetFrameFormat()->GetName(), OUString());
diff --git a/sw/source/core/txtnode/swfont.cxx b/sw/source/core/txtnode/swfont.cxx
index 30cd44851081..0ed7baf87894 100644
--- a/sw/source/core/txtnode/swfont.cxx
+++ b/sw/source/core/txtnode/swfont.cxx
@@ -975,7 +975,7 @@ Size SwSubFont::GetTextSize_( SwDrawTextInfo& rInf )
 {
     // Robust: the font is supposed to be set already, but better safe than
     // sorry...
-    if ( !pLastFont || pLastFont->GetOwner() != reinterpret_cast<const void*>(m_nFontCacheId) ||
+    if ( !pLastFont || pLastFont->GetOwner() != m_nFontCacheId ||
          !IsSameInstance( rInf.GetpOut()->GetFont() ) )
         ChgFnt( rInf.GetShell(), rInf.GetOut() );
 
@@ -1093,7 +1093,7 @@ void SwSubFont::DrawText_( SwDrawTextInfo &rInf, const bool bGrey )
         pUnderFnt = rInf.GetUnderFnt();
     }
 
-    if( !pLastFont || pLastFont->GetOwner() != reinterpret_cast<const void*>(m_nFontCacheId) )
+    if( !pLastFont || pLastFont->GetOwner() != m_nFontCacheId )
         ChgFnt( rInf.GetShell(), rInf.GetOut() );
 
     SwDigitModeModifier aDigitModeModifier( rInf.GetOut(), rInf.GetFont()->GetLanguage() );
@@ -1218,7 +1218,7 @@ void SwSubFont::DrawStretchText_( SwDrawTextInfo &rInf )
         pUnderFnt = rInf.GetUnderFnt();
     }
 
-    if ( !pLastFont || pLastFont->GetOwner() != reinterpret_cast<const void*>(m_nFontCacheId) )
+    if ( !pLastFont || pLastFont->GetOwner() != m_nFontCacheId )
         ChgFnt( rInf.GetShell(), rInf.GetOut() );
 
     SwDigitModeModifier aDigitModeModifier( rInf.GetOut(), rInf.GetFont()->GetLanguage() );
@@ -1283,7 +1283,7 @@ void SwSubFont::DrawStretchText_( SwDrawTextInfo &rInf )
 
 TextFrameIndex SwSubFont::GetModelPositionForViewPoint_( SwDrawTextInfo& rInf )
 {
-    if ( !pLastFont || pLastFont->GetOwner() != reinterpret_cast<const void*>(m_nFontCacheId) )
+    if ( !pLastFont || pLastFont->GetOwner() != m_nFontCacheId )
         ChgFnt( rInf.GetShell(), rInf.GetOut() );
 
     SwDigitModeModifier aDigitModeModifier( rInf.GetOut(), rInf.GetFont()->GetLanguage() );
diff --git a/unoxml/source/dom/node.cxx b/unoxml/source/dom/node.cxx
index f39aba6bd079..235af0bc5e0d 100644
--- a/unoxml/source/dom/node.cxx
+++ b/unoxml/source/dom/node.cxx
@@ -101,7 +101,7 @@ namespace DOM
     {
         sal_Int32 nNamespaceToken = FastToken::DONTKNOW;
         OString prefix(pPrefix,
-                       strlen(reinterpret_cast<const char*>(pPrefix)));
+                       strlen(pPrefix));
 
         SAL_INFO("unoxml", "getTokenWithPrefix(): prefix " << pPrefix << ", name " << pName);
 
diff --git a/unoxml/source/rdf/librdf_repository.cxx b/unoxml/source/rdf/librdf_repository.cxx
index 63654e09efdd..169f9550f0ea 100644
--- a/unoxml/source/rdf/librdf_repository.cxx
+++ b/unoxml/source/rdf/librdf_repository.cxx
@@ -2426,7 +2426,7 @@ librdf_TypeConverter::convertToXNode(librdf_node* i_pNode) const
         RTL_TEXTENCODING_UTF8) );
     if (lang) {
         const OUString langU( OStringToOUString(
-            std::string_view(reinterpret_cast<const char*>(lang)),
+            std::string_view(lang),
             RTL_TEXTENCODING_UTF8) );
         return rdf::Literal::createWithLanguage(m_xContext, valueU, langU);
     } else if (pType) {
diff --git a/vcl/unx/generic/window/salframe.cxx b/vcl/unx/generic/window/salframe.cxx
index 8c2d67c70565..943aa3d527f7 100644
--- a/vcl/unx/generic/window/salframe.cxx
+++ b/vcl/unx/generic/window/salframe.cxx
@@ -3204,7 +3204,7 @@ bool X11SalFrame::HandleKeyEvent( XKeyEvent *pEvent )
         // convert to single byte text stream
         nSize = rtl_convertTextToUnicode(
                                 aConverter, aContext,
-                                reinterpret_cast<char*>(pPrintable), nLen,
+                                pPrintable, nLen,
                                 pBuffer, nBufferSize,
                                 RTL_TEXTTOUNICODE_FLAGS_UNDEFINED_IGNORE |
                                 RTL_TEXTTOUNICODE_FLAGS_INVALID_IGNORE,
diff --git a/vcl/unx/gtk3/gtkinst.cxx b/vcl/unx/gtk3/gtkinst.cxx
index 12ded5210ef0..86f8bb3af99d 100644
--- a/vcl/unx/gtk3/gtkinst.cxx
+++ b/vcl/unx/gtk3/gtkinst.cxx
@@ -22338,7 +22338,7 @@ private:
         if (!pMouseEnteredAnotherPopup)
             return false;
 
-        return gtk_widget_event(pEventWidget, reinterpret_cast<GdkEvent*>(pEvent));
+        return gtk_widget_event(pEventWidget, pEvent);
     }
 
     static gboolean signalButtonCrossing(GtkWidget*, GdkEvent* pEvent, gpointer widget)