compilerplugins/clang/pointerbool.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
  16 #include <clang/AST/CXXInheritance.h>
  17 #include "plugin.hxx"
  18 #include "check.hxx"
  19
  20 /**
  21   Look for calls where the param is bool but the call-site-arg is pointer.
  22 */
  23 #ifndef LO_CLANG_SHARED_PLUGINS
  24
  25 namespace
  26 {
  27 class PointerBool : public loplugin::FilteringPlugin<PointerBool>
  28 {
  29 public:
  30     explicit PointerBool(loplugin::InstantiationData const& data)
  31         : FilteringPlugin(data)
  32     {
  33     }
  34
  35     virtual void run() override
  36     {
  37         if (preRun())
  38             TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
  39     }
  40
  41     bool VisitCallExpr(CallExpr const*);
  42
  43 private:
  44     llvm::Optional<APSInt> getCallValue(const Expr* arg);
  45 };
  46
  47 bool PointerBool::VisitCallExpr(CallExpr const* callExpr)
  48 {
  49     if (ignoreLocation(callExpr))
  50         return true;
  51     // TODO this doesn't currently work, the args and the params don't seem to line up
  52     if (isa<CXXOperatorCallExpr>(callExpr))
  53         return true;
  54     const FunctionDecl* functionDecl;
  55     if (isa<CXXMemberCallExpr>(callExpr))
  56     {
  57         functionDecl = dyn_cast<CXXMemberCallExpr>(callExpr)->getMethodDecl();
  58     }
  59     else
  60     {
  61         functionDecl = callExpr->getDirectCallee();
  62     }
  63     if (!functionDecl)
  64         return true;
  65
  66     unsigned len = std::min(callExpr->getNumArgs(), functionDecl->getNumParams());
  67     for (unsigned i = 0; i < len; ++i)
  68     {
  69         auto param = functionDecl->getParamDecl(i);
  70         auto paramTC = loplugin::TypeCheck(param->getType());
  71         if (!paramTC.AnyBoolean())
  72             continue;
  73         auto arg = callExpr->getArg(i)->IgnoreImpCasts();
  74         auto argTC = loplugin::TypeCheck(arg->getType());
  75         if (argTC.AnyBoolean())
  76             continue;
  77         // sal_Bool is sometimes disguised
  78         if (isa<SubstTemplateTypeParmType>(arg->getType()))
  79             if (arg->getType()->getUnqualifiedDesugaredType()->isSpecificBuiltinType(
  80                     clang::BuiltinType::UChar))
  81                 continue;
  82         if (arg->getType()->isDependentType())
  83             continue;
  84         if (arg->getType()->isIntegerType())
  85         {
  86             auto ret = getCallValue(arg);
  87             if (ret.hasValue() && (ret.getValue() == 1 || ret.getValue() == 0))
  88                 continue;
  89             // something like: priv->m_nLOKFeatures & LOK_FEATURE_DOCUMENT_PASSWORD
  90             if (isa<BinaryOperator>(arg->IgnoreParenImpCasts()))
  91                 continue;
  92             // something like: pbEmbolden ? FcTrue : FcFalse
  93             if (isa<ConditionalOperator>(arg->IgnoreParenImpCasts()))
  94                 continue;
  95         }
  96         report(DiagnosticsEngine::Warning,
  97                "possibly unwanted implicit conversion when calling bool param", arg->getExprLoc())
  98             << arg->getSourceRange();
  99         report(DiagnosticsEngine::Note, "method here", param->getLocation())
 100             << param->getSourceRange();
 101     }
 102     return true;
 103 }
 104
 105 llvm::Optional<APSInt> PointerBool::getCallValue(const Expr* arg)
 106 {
 107     arg = arg->IgnoreParenCasts();
 108     if (auto defArg = dyn_cast<CXXDefaultArgExpr>(arg))
 109     {
 110         arg = defArg->getExpr()->IgnoreParenCasts();
 111     }
 112     // ignore this, it seems to trigger an infinite recursion
 113     if (isa<UnaryExprOrTypeTraitExpr>(arg))
 114     {
 115         return llvm::Optional<APSInt>();
 116     }
 117     APSInt x1;
 118     if (compat::EvaluateAsInt(arg, x1, compiler.getASTContext()))
 119     {
 120         return x1;
 121     }
 122     return llvm::Optional<APSInt>();
 123 }
 124
 125 loplugin::Plugin::Registration<PointerBool> pointerbool("pointerbool");
 126
 127 } // namespace
 128
 129 #endif // LO_CLANG_SHARED_PLUGINS
 130
 131 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */