compilerplugins/clang/unusedenumvalues.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 <cassert>
  11 #include <string>
  12 #include <iostream>
  13 #include <fstream>
  14 #include <set>
  15 #include "plugin.hxx"
  16 #include "compat.hxx"
  17
  18 /**
  19 Looks for enums with unused constants.
  20
  21 Be warned that it produces around 5G of log file.
  22
  23 The process goes something like this:
  24   $ make check
  25   $ make FORCE_COMPILE_ALL=1 COMPILER_PLUGIN_TOOL='unusedenumconstants' check
  26   $ ./compilerplugins/clang/unusedenumconstants.py
  27
  28 Note that the actual process may involve a fair amount of undoing, hand editing, and general messing around
  29 to get it to work :-)
  30
  31 TODO ignore constants when we are only testing for them, not actually storing them somewhere
  32
  33 */
  34
  35 namespace {
  36
  37 struct MyEnumValueInfo
  38 {
  39     std::string parentClass;
  40     std::string constantName;
  41     std::string sourceLocation;
  42 };
  43 bool operator < (const MyEnumValueInfo &lhs, const MyEnumValueInfo &rhs)
  44 {
  45     return std::tie(lhs.parentClass, lhs.constantName)
  46          < std::tie(rhs.parentClass, rhs.constantName);
  47 }
  48
  49
  50 // try to limit the voluminous output a little
  51 static std::set<MyEnumValueInfo> touchedSet;
  52 static std::set<MyEnumValueInfo> definitionSet;
  53
  54
  55 class UnusedEnumValues:
  56     public RecursiveASTVisitor<UnusedEnumValues>, public loplugin::Plugin
  57 {
  58 public:
  59     explicit UnusedEnumValues(InstantiationData const & data): Plugin(data) {}
  60
  61     virtual void run() override
  62     {
  63         TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
  64
  65         // dump all our output in one write call - this is to try and limit IO "crosstalk" between multiple processes
  66         // writing to the same logfile
  67         std::string output;
  68         for (const MyEnumValueInfo & s : touchedSet)
  69             output += "touch:\t" + s.parentClass + "\t" + s.constantName + "\n";
  70         for (const MyEnumValueInfo & s : definitionSet)
  71         {
  72             output += "definition:\t" + s.parentClass + "\t" + s.constantName + "\t" + s.sourceLocation + "\n";
  73         }
  74         ofstream myfile;
  75         myfile.open( SRCDIR "/loplugin.unusedenumvalues.log", ios::app | ios::out);
  76         myfile << output;
  77         myfile.close();
  78     }
  79
  80     bool shouldVisitTemplateInstantiations () const { return true; }
  81     bool shouldVisitImplicitCode() const { return true; }
  82
  83     bool VisitEnumDecl( const EnumDecl* );
  84     bool VisitDeclRefExpr( const DeclRefExpr* );
  85 private:
  86     MyEnumValueInfo niceName(const EnumConstantDecl*);
  87 };
  88
  89 MyEnumValueInfo UnusedEnumValues::niceName(const EnumConstantDecl* enumDecl)
  90 {
  91     MyEnumValueInfo aInfo;
  92     const EnumType* enumType = dyn_cast<EnumType>(enumDecl->getType());
  93     if (enumType && enumType->getDecl())
  94     {
  95         aInfo.parentClass = enumType->getDecl()->getNameAsString();
  96     } else {
  97         aInfo.parentClass = "unknown";
  98     }
  99     aInfo.constantName = enumDecl->getNameAsString();
 100
 101     SourceLocation expansionLoc = compiler.getSourceManager().getExpansionLoc( enumDecl->getLocation() );
 102     StringRef name = compiler.getSourceManager().getFilename(expansionLoc);
 103     aInfo.sourceLocation = std::string(name.substr(strlen(SRCDIR)+1)) + ":" + std::to_string(compiler.getSourceManager().getSpellingLineNumber(expansionLoc));
 104     normalizeDotDotInFilePath(aInfo.sourceLocation);
 105
 106     return aInfo;
 107 }
 108
 109 bool UnusedEnumValues::VisitEnumDecl( const EnumDecl* enumDecl )
 110 {
 111     enumDecl = enumDecl->getCanonicalDecl();
 112
 113     if( ignoreLocation( enumDecl ))
 114         return true;
 115
 116     for (auto it = enumDecl->enumerator_begin(); it != enumDecl->enumerator_end(); ++it)
 117         definitionSet.insert(niceName(*it));
 118     return true;
 119 }
 120
 121 bool UnusedEnumValues::VisitDeclRefExpr( const DeclRefExpr* declRefExpr )
 122 {
 123     const Decl* decl = declRefExpr->getDecl();
 124     if (!isa<EnumConstantDecl>(decl)) {
 125         return true;
 126     }
 127     touchedSet.insert(niceName(dyn_cast<EnumConstantDecl>(decl)));
 128     return true;
 129 }
 130
 131 loplugin::Plugin::Registration< UnusedEnumValues > X("unusedenumvalues", false);
 132
 133 }
 134
 135 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */