compilerplugins/clang/redundantinline.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
   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 <cassert>
  11
  12 #include "plugin.hxx"
  13
  14 namespace {
  15
  16 class RedundantInline:
  17     public RecursiveASTVisitor<RedundantInline>, public loplugin::RewritePlugin
  18 {
  19 public:
  20     explicit RedundantInline(loplugin::InstantiationData const & data):
  21         RewritePlugin(data) {}
  22
  23     void run() override {
  24         if (compiler.getLangOpts().CPlusPlus) {
  25             TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
  26         }
  27     }
  28
  29     bool VisitFunctionDecl(FunctionDecl const * decl) {
  30         if (ignoreLocation(decl) || !decl->isInlineSpecified()
  31             || !(decl->doesThisDeclarationHaveABody()
  32                  || decl->isExplicitlyDefaulted())
  33             || !(decl->getLexicalDeclContext()->isRecord()
  34                  || decl->isConstexpr()))
  35         {
  36             return true;
  37         }
  38         auto l1 = unwindToQObject(decl->getLocStart());
  39         if (l1.isValid() && l1 == unwindToQObject(decl->getLocEnd())) {
  40             return true;
  41         }
  42         SourceLocation inlineLoc;
  43         unsigned n;
  44         auto end = Lexer::getLocForEndOfToken(
  45             compiler.getSourceManager().getExpansionLoc(decl->getLocEnd()), 0,
  46             compiler.getSourceManager(), compiler.getLangOpts());
  47         assert(end.isValid());
  48         for (auto loc = compiler.getSourceManager().getExpansionLoc(
  49                  decl->getLocStart());
  50              loc != end; loc = loc.getLocWithOffset(std::max<unsigned>(n, 1)))
  51         {
  52             n = Lexer::MeasureTokenLength(
  53                 loc, compiler.getSourceManager(), compiler.getLangOpts());
  54             StringRef s(compiler.getSourceManager().getCharacterData(loc), n);
  55             //TODO: see compilerplugins/clang/override.cxx:
  56             if (s.startswith("\\\n")) {
  57                 s = s.drop_front(2);
  58             }
  59             if (s == "inline") {
  60                 if (!compiler.getSourceManager().isMacroArgExpansion(loc)) {
  61                     inlineLoc = loc;
  62                 }
  63                 break;
  64             } else if (s == "#") {
  65                 // Hard to pick the right 'inline' in code like
  66                 //
  67                 //   #if 1
  68                 //     static
  69                 //   #else
  70                 //     inline
  71                 //   #endif
  72                 //   inline void f() {}
  73                 //
  74                 // so just give up once a preprocessing directive is seen:
  75                 break;
  76             }
  77         }
  78         if (rewriter != nullptr && inlineLoc.isValid()) {
  79             for (auto loc = inlineLoc.getLocWithOffset(
  80                      std::max<unsigned>(n, 1));;)
  81             {
  82                 assert(loc != end);
  83                 unsigned n2 = Lexer::MeasureTokenLength(
  84                     loc, compiler.getSourceManager(), compiler.getLangOpts());
  85                 StringRef s(
  86                     compiler.getSourceManager().getCharacterData(loc), n2);
  87                 //TODO: see compilerplugins/clang/override.cxx:
  88                 if (s.startswith("\\\n")) {
  89                     s = s.drop_front(2);
  90                 }
  91                 if (!s.empty()) {
  92                     break;
  93                 }
  94                 n2 = std::max<unsigned>(n2, 1);
  95                 n += n2;
  96                 loc = loc.getLocWithOffset(n2);
  97             }
  98             if (removeText(inlineLoc, n, RewriteOptions(RemoveLineIfEmpty))) {
  99                 return true;
 100             }
 101         }
 102         report(
 103             DiagnosticsEngine::Warning,
 104             "function definition redundantly declared 'inline'",
 105             inlineLoc.isValid() ? inlineLoc : decl->getLocStart())
 106             << decl->getSourceRange();
 107         return true;
 108     }
 109
 110 private:
 111     SourceLocation unwindToQObject(SourceLocation const & loc) {
 112         if (!loc.isMacroID()) {
 113             return SourceLocation();
 114         }
 115         auto l = compiler.getSourceManager().getImmediateMacroCallerLoc(loc);
 116         return
 117             (Lexer::getImmediateMacroName(
 118                 loc, compiler.getSourceManager(), compiler.getLangOpts())
 119              == "Q_OBJECT")
 120             ? l : unwindToQObject(l);
 121     }
 122 };
 123
 124 loplugin::Plugin::Registration<RedundantInline> reg("redundantinline", true);
 125
 126 }
 127
 128 /* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */