compilerplugins/clang/overrideparam.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  */
   9
  10 #include <string>
  11 #include <set>
  12
  13 #include "plugin.hxx"
  14 #include "compat.hxx"
  15 #include "check.hxx"
  16
  17 /*
  18   Find overridden methods that :
  19   (a) declare default params in different palces to their super-method(s)
  20
  21   Still TODO
  22   (b) Find places where the values of the default parameters are different
  23   (c) Find places where the names of the parameters differ
  24 */
  25
  26 namespace {
  27
  28 class OverrideParam:
  29     public RecursiveASTVisitor<OverrideParam>, public loplugin::Plugin
  30 {
  31 public:
  32     explicit OverrideParam(loplugin::InstantiationData const & data):
  33         Plugin(data) {}
  34
  35     virtual void run() override;
  36
  37     bool VisitCXXMethodDecl(const CXXMethodDecl *);
  38
  39 private:
  40     bool hasSameDefaultParams(const ParmVarDecl * parmVarDecl, const ParmVarDecl * superParmVarDecl);
  41 };
  42
  43 void OverrideParam::run()
  44 {
  45     /*
  46     StringRef fn( compiler.getSourceManager().getFileEntryForID(
  47                       compiler.getSourceManager().getMainFileID())->getName() );
  48     if (fn == SRCDIR "/include/svx/checklbx.hxx")
  49          return;
  50 */
  51     TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
  52 }
  53
  54 bool OverrideParam::VisitCXXMethodDecl(const CXXMethodDecl * methodDecl) {
  55     if (ignoreLocation(methodDecl)) {
  56         return true;
  57     }
  58     if (methodDecl->isThisDeclarationADefinition() || methodDecl->size_overridden_methods() == 0) {
  59         return true;
  60     }
  61     loplugin::DeclCheck dc(methodDecl);
  62     // there is an InsertEntry override here which causes trouble if I modify it
  63     if (dc.Function("InsertEntry").Class("SvxCheckListBox").GlobalNamespace()) {
  64         return true;
  65     }
  66     // This class is overriding ShowCursor(bool) AND declaring a ShowCursor() method.
  67     // Adding a default param causes 'ambiguous override'.
  68     if (dc.Function("ShowCursor").Class("ScTabViewShell").GlobalNamespace()) {
  69         return true;
  70     }
  71
  72     for(auto superMethodIt = methodDecl->begin_overridden_methods();
  73         superMethodIt != methodDecl->end_overridden_methods(); ++superMethodIt)
  74     {
  75         const CXXMethodDecl * superMethodDecl = *superMethodIt;
  76         if (ignoreLocation(superMethodDecl)) {
  77             continue;
  78         }
  79         int i = 0;
  80         for (const ParmVarDecl *superParmVarDecl : compat::parameters(*superMethodDecl)) {
  81             const ParmVarDecl *parmVarDecl = methodDecl->getParamDecl(i);
  82             if (parmVarDecl->hasDefaultArg() && !superParmVarDecl->hasDefaultArg()) {
  83                 report(
  84                     DiagnosticsEngine::Warning,
  85                     "overridden method declaration has default arg, but super-method does not",
  86                     parmVarDecl->getSourceRange().getBegin())
  87                     << parmVarDecl->getSourceRange();
  88                 report(
  89                     DiagnosticsEngine::Note,
  90                     "original param here",
  91                     superParmVarDecl->getSourceRange().getBegin())
  92                     << superParmVarDecl->getSourceRange();
  93             }
  94             else if (!parmVarDecl->hasDefaultArg() && superParmVarDecl->hasDefaultArg()) {
  95                 report(
  96                     DiagnosticsEngine::Warning,
  97                     "overridden method declaration has no default arg, but super-method does",
  98                     parmVarDecl->getSourceRange().getBegin())
  99                     << parmVarDecl->getSourceRange();
 100                 report(
 101                     DiagnosticsEngine::Note,
 102                     "original param here",
 103                     superParmVarDecl->getSourceRange().getBegin())
 104                     << superParmVarDecl->getSourceRange();
 105             }
 106             else if (parmVarDecl->hasDefaultArg() && superParmVarDecl->hasDefaultArg()
 107                 && !hasSameDefaultParams(parmVarDecl, superParmVarDecl)) {
 108                 report(
 109                     DiagnosticsEngine::Warning,
 110                     "overridden method declaration has different default param to super-method",
 111                     parmVarDecl->getSourceRange().getBegin())
 112                     << parmVarDecl->getSourceRange();
 113                 report(
 114                     DiagnosticsEngine::Note,
 115                     "original param here",
 116                     superParmVarDecl->getSourceRange().getBegin())
 117                     << superParmVarDecl->getSourceRange();
 118             }
 119             /* do nothing for now, will enable this in a later commit
 120             if (methodDecl->isThisDeclarationADefinition() && parmVarDecl->getName().empty()) {
 121                 // ignore this - means the param is unused
 122             }
 123             else if (superParmVarDecl->getName().empty()) {
 124                 // ignore, nothing reasonable I can do
 125             }
 126             else if (superParmVarDecl->getName() != parmVarDecl->getName()) {
 127                 report(
 128                     DiagnosticsEngine::Warning,
 129                     "overridden method declaration uses different name for parameter",
 130                     parmVarDecl->getSourceRange().getBegin())
 131                     << parmVarDecl->getSourceRange();
 132                 report(
 133                     DiagnosticsEngine::Note,
 134                     "original param here",
 135                     superParmVarDecl->getSourceRange().getBegin())
 136                     << superParmVarDecl->getSourceRange();
 137             }*/
 138             ++i;
 139         }
 140     }
 141     return true;
 142 }
 143
 144 bool OverrideParam::hasSameDefaultParams(const ParmVarDecl * parmVarDecl, const ParmVarDecl * superParmVarDecl)
 145 {
 146     // don't know what this means, but it prevents a clang crash
 147     if (parmVarDecl->hasUninstantiatedDefaultArg() || superParmVarDecl->hasUninstantiatedDefaultArg()) {
 148         return true;
 149     }
 150     return
 151         checkIdenticalDefaultArguments(
 152             parmVarDecl->getDefaultArg(), superParmVarDecl->getDefaultArg())
 153         != IdenticalDefaultArgumentsResult::No;
 154         // for one, Clang 3.8 doesn't have EvaluateAsFloat; for another, since
 155         // <http://llvm.org/viewvc/llvm-project?view=revision&revision=291318>
 156         // "PR23135: Don't instantiate constexpr functions referenced in
 157         // unevaluated operands where possible", default args are not
 158         // necessarily evaluated, so the above calls to EvaluateAsInt etc. may
 159         // fail (as they do e.g. for SfxViewShell::SetPrinter and derived
 160         // classes' 'SfxPrinterChangeFlags nDiffFlags = SFX_PRINTER_ALL' arg,
 161         // include/sfx2/viewsh.hxx; what appears would help is to call
 162         // 'compiler.getSema().MarkDeclarationsReferencedInExpr()' on
 163         // defaultArgExpr and superDefaultArgExpr before any of the calls to
 164         // EvaluateAsInt etc., cf. the implementation of
 165         // Sema::CheckCXXDefaultArgExpr in Clang's lib/Sema/SemaExpr.cpp, but
 166         // that would probably have unwanted side-effects)
 167 }
 168
 169 loplugin::Plugin::Registration< OverrideParam > X("overrideparam");
 170
 171 }
 172
 173 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */