compilerplugins/clang/simplifyconstruct.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 #ifndef LO_CLANG_SHARED_PLUGINS
  11
  12 #include <memory>
  13 #include <cassert>
  14 #include <string>
  15 #include <iostream>
  16 #include <fstream>
  17 #include <set>
  18 #include "plugin.hxx"
  19 #include "check.hxx"
  20
  21 namespace
  22 {
  23 class SimplifyConstruct : public loplugin::FilteringPlugin<SimplifyConstruct>
  24 {
  25 public:
  26     explicit SimplifyConstruct(loplugin::InstantiationData const& data)
  27         : FilteringPlugin(data)
  28     {
  29     }
  30
  31     virtual void run() override { TraverseDecl(compiler.getASTContext().getTranslationUnitDecl()); }
  32
  33     bool VisitCXXConstructExpr(CXXConstructExpr const*);
  34     bool VisitVarDecl(VarDecl const*);
  35
  36     // ignore some contexts within which nullptr is fine
  37     bool TraverseReturnStmt(ReturnStmt*) { return true; }
  38     bool TraverseInitListExpr(InitListExpr*) { return true; }
  39     bool TraverseCXXBindTemporaryExpr(CXXBindTemporaryExpr*) { return true; }
  40     // ignore them for the shared visitor too
  41     bool PreTraverseReturnStmt(ReturnStmt*) { return false; }
  42     bool PreTraverseInitListExpr(InitListExpr*) { return false; }
  43     bool PreTraverseCXXBindTemporaryExpr(CXXBindTemporaryExpr*) { return false; }
  44 };
  45
  46 bool SimplifyConstruct::VisitCXXConstructExpr(CXXConstructExpr const* constructExpr)
  47 {
  48     if (ignoreLocation(constructExpr))
  49         return true;
  50     auto tc = loplugin::TypeCheck(constructExpr->getType());
  51     if (!tc.Class("unique_ptr").StdNamespace() && !tc.Class("shared_ptr").StdNamespace()
  52         && !tc.Class("SvRef").Namespace("tools").GlobalNamespace()
  53         && !tc.Class("Reference").Namespace("rtl").GlobalNamespace()
  54         && !tc.Class("Reference")
  55                 .Namespace("uno")
  56                 .Namespace("star")
  57                 .Namespace("sun")
  58                 .Namespace("com")
  59                 .GlobalNamespace())
  60         return true;
  61     if (constructExpr->getNumArgs() == 1
  62         && isa<CXXNullPtrLiteralExpr>(constructExpr->getArg(0)->IgnoreParenImpCasts()))
  63     {
  64         report(DiagnosticsEngine::Warning,
  65                "no need to explicitly init an instance of %0 with nullptr, just use default "
  66                "constructor",
  67                constructExpr->getSourceRange().getBegin())
  68             << constructExpr->getType() << constructExpr->getSourceRange();
  69     }
  70     return true;
  71 }
  72
  73 bool SimplifyConstruct::VisitVarDecl(VarDecl const* varDecl)
  74 {
  75     if (ignoreLocation(varDecl))
  76         return true;
  77     // cannot use OUString s("xxx") style syntax in a parameter
  78     if (isa<ParmVarDecl>(varDecl))
  79         return true;
  80     varDecl = varDecl->getCanonicalDecl();
  81     if (!varDecl->getInit())
  82         return true;
  83     if (varDecl->getInitStyle() != VarDecl::InitializationStyle::CInit)
  84         return true;
  85     if (!varDecl->getType()->isRecordType())
  86         return true;
  87     if (isa<AutoType>(varDecl->getType()))
  88         return true;
  89
  90     auto init = varDecl->getInit();
  91     auto const e1 = init->IgnoreImplicit();
  92     if (!isa<CXXFunctionalCastExpr>(e1) && !isa<CXXTemporaryObjectExpr>(e1))
  93         return true;
  94
  95     // e.g. the LANGUAGE_DONTKNOW defines
  96     if (compiler.getSourceManager().isMacroBodyExpansion(init->getBeginLoc()))
  97         return true;
  98
  99     report(DiagnosticsEngine::Warning, "simplify", varDecl->getLocation())
 100         << varDecl->getSourceRange();
 101
 102     return true;
 103 }
 104
 105 loplugin::Plugin::Registration<SimplifyConstruct> simplifyconstruct("simplifyconstruct", true);
 106 }
 107
 108 #endif // LO_CLANG_SHARED_PLUGINS
 109
 110 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */