compilerplugins/clang/store/changefunctioncalls.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  * Based on LLVM/Clang.
   6  *
   7  * This file is distributed under the University of Illinois Open Source
   8  * License. See LICENSE.TXT for details.
   9  *
  10  */
  11
  12 /*
  13 This is a rewriter.
  14
  15 Changes all calls to a specific function (after it's been renamed or its
  16 arguments have changed).
  17
  18 This specific example checks for calls to function 'void bar(unsigned int)'
  19 and adds '+ 10' to the argument (as plain text, so if the argument is a more
  20 complex expression, operator precedence may mean the result is actually different).
  21
  22 This can be easily adjusted for different modifications to a function:
  23 - replace CallExpr with CXXOperatorCallExpr or CXXMemberCallExpr
  24 - check different names or arguments
  25 - change getDirectCallee() to getCallee()
  26 - etc.
  27 */
  28
  29 #include "plugin.hxx"
  30 #include "check.hxx"
  31
  32 namespace loplugin
  33 {
  34
  35 class ChangeFunctionCalls
  36     : public loplugin::FilteringRewritePlugin< ChangeFunctionCalls >
  37     {
  38     public:
  39         explicit ChangeFunctionCalls( CompilerInstance& compiler, Rewriter& rewriter );
  40         virtual void run() override;
  41         bool VisitCallExpr( const CallExpr* call );
  42     };
  43
  44 ChangeFunctionCalls::ChangeFunctionCalls( CompilerInstance& compiler, Rewriter& rewriter )
  45     : FilteringRewritePlugin( compiler, rewriter )
  46     {
  47     }
  48
  49 void ChangeFunctionCalls::run()
  50     {
  51     TraverseDecl( compiler.getASTContext().getTranslationUnitDecl());
  52     }
  53
  54 bool ChangeFunctionCalls::VisitCallExpr( const CallExpr* call )
  55     {
  56     if( ignoreLocation( call ))
  57         return true;
  58     // Using getDirectCallee() here means that we find only calls
  59     // that call the function directly (i.e. not using a pointer, for example).
  60     // Use getCallee() to include also those :
  61     //    if( const FunctionDecl* func = dyn_cast_or_null< FunctionDecl >( call->getCalleeDecl()))
  62     if( const FunctionDecl* func = call->getDirectCallee())
  63         {
  64         // so first check fast details like number of arguments or the (unqualified)
  65         // name before checking the fully qualified name.
  66         // See FunctionDecl for all the API about the function.
  67         if( func->getNumParams() == 1 && func->getIdentifier() != NULL
  68             && ( func->getName() == "bar" ))
  69             {
  70             auto qt = loplugin::DeclCheck(func);
  71             if( qt.Function("bar").GlobalNamespace() )
  72                 {
  73                 // Further checks about arguments. Check mainly ParmVarDecl, VarDecl,
  74                 // ValueDecl and QualType for Clang API details.
  75                 string arg0 = func->getParamDecl( 0 )->getType().getAsString();
  76                 if( arg0 == "unsigned int" )
  77                     {
  78                     insertTextAfterToken( call->getArg( 0 )->getLocEnd(), " + 10" );
  79                     report( DiagnosticsEngine::Warning, "found", call->getLocStart());
  80                     }
  81                 }
  82             }
  83         }
  84     return true;
  85     }
  86
  87 static Plugin::Registration< ChangeFunctionCalls > X( "changefunctioncalls" );
  88
  89 } // namespace
  90
  91 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */