compilerplugins/clang/cppunitassertequals.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 #ifndef LO_CLANG_SHARED_PLUGINS
  10
  11 #include "plugin.hxx"
  12 #include "check.hxx"
  13 #include "compat.hxx"
  14 #include <iostream>
  15
  16 /**
  17   Check for
  18    (*) calls to CPPUNIT_ASSERT when it should be using CPPUNIT_ASSERT_EQUALS
  19    (*) calls to CPPUNIT_ASSERT_EQUALS where the constant is the second param
  20 */
  21
  22 namespace {
  23
  24 class CppunitAssertEquals:
  25     public loplugin::FilteringPlugin<CppunitAssertEquals>
  26 {
  27 public:
  28     explicit CppunitAssertEquals(loplugin::InstantiationData const & data):
  29         FilteringPlugin(data) {}
  30
  31     virtual bool preRun() override
  32     {
  33         return compiler.getLangOpts().CPlusPlus;
  34     }
  35
  36     virtual void run() override
  37     {
  38         if (preRun()) {
  39             TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
  40         }
  41     }
  42
  43     bool VisitCallExpr(const CallExpr*);
  44
  45 private:
  46     void checkExpr(
  47         SourceRange range, StringRef name, Expr const * expr, bool negated);
  48
  49     void reportEquals(
  50         SourceRange range, StringRef name, bool negative, Expr const * lhs, Expr const * rhs);
  51
  52     bool isCompileTimeConstant(Expr const * expr);
  53 };
  54
  55 bool CppunitAssertEquals::VisitCallExpr(const CallExpr* callExpr)
  56 {
  57     auto const decl = callExpr->getDirectCallee();
  58     if (!decl)
  59         return true;
  60     /*
  61        calls to CPPUNIT_ASSERT when it should be using CPPUNIT_ASSERT_EQUALS
  62     */
  63     if (loplugin::DeclCheck(decl).Function("failIf").Struct("Asserter")
  64              .Namespace("CppUnit").GlobalNamespace())
  65     {
  66         // Don't use callExpr->getLocStart() or callExpr->getExprLoc(), as those
  67         // fall into a nested use of the CPPUNIT_NS macro; CallExpr::getRParenLoc
  68         // happens to be readily available and cause good results:
  69         auto loc = callExpr->getRParenLoc();
  70         while (compiler.getSourceManager().isMacroArgExpansion(loc)) {
  71             loc = compiler.getSourceManager().getImmediateMacroCallerLoc(loc);
  72         }
  73         if (!compiler.getSourceManager().isMacroBodyExpansion(loc)
  74             || ignoreLocation(
  75                 compiler.getSourceManager().getImmediateMacroCallerLoc(loc)))
  76         {
  77             return true;
  78         }
  79         auto name = Lexer::getImmediateMacroName(
  80             loc, compiler.getSourceManager(), compiler.getLangOpts());
  81         if (name != "CPPUNIT_ASSERT" && name != "CPPUNIT_ASSERT_MESSAGE") {
  82             return true;
  83         }
  84         if (decl->getNumParams() != 3) {
  85             report(
  86                 DiagnosticsEngine::Warning,
  87                 ("TODO: suspicious CppUnit::Asserter::failIf call with %0"
  88                  " parameters"),
  89                 callExpr->getExprLoc())
  90                 << decl->getNumParams() << callExpr->getSourceRange();
  91             return true;
  92         }
  93         auto const e1 = callExpr->getArg(0)->IgnoreParenImpCasts();
  94         Expr const * e2 = nullptr;
  95         if (auto const e3 = dyn_cast<UnaryOperator>(e1)) {
  96             if (e3->getOpcode() == UO_LNot) {
  97                 e2 = e3->getSubExpr();
  98             }
  99         } else if (auto const e4 = dyn_cast<CXXOperatorCallExpr>(e1)) {
 100             if (e4->getOperator() == OO_Exclaim) {
 101                 e2 = e4->getArg(0);
 102             }
 103         }
 104         if (e2 == nullptr) {
 105             report(
 106                 DiagnosticsEngine::Warning,
 107                 ("TODO: suspicious CppUnit::Asserter::failIf call not wrapping"
 108                  " !(...)"),
 109                 callExpr->getExprLoc())
 110                 << callExpr->getSourceRange();
 111             return true;
 112         }
 113         auto range = compat::getImmediateExpansionRange(compiler.getSourceManager(), loc);
 114         checkExpr(
 115             SourceRange(range.first, range.second), name,
 116             e2->IgnoreParenImpCasts(), false);
 117     }
 118
 119     /**
 120       Check for calls to CPPUNIT_ASSERT_EQUALS where the constant is the second param
 121     */
 122     if (loplugin::DeclCheck(decl).Function("assertEquals").
 123              Namespace("CppUnit").GlobalNamespace())
 124     {
 125         // can happen in template test code that both params are compile time constants
 126         if (isCompileTimeConstant(callExpr->getArg(0)))
 127             return true;
 128         if (isCompileTimeConstant(callExpr->getArg(1)))
 129             report(
 130                 DiagnosticsEngine::Warning,
 131                 "CPPUNIT_ASSERT_EQUALS parameters look switched, expected value should be first param",
 132                 callExpr->getExprLoc())
 133                 << callExpr->getSourceRange();
 134     }
 135     return true;
 136 }
 137
 138 // copied from stringconcat.cxx
 139 Expr const * stripConstructor(Expr const * expr) {
 140     auto e0 = expr;
 141     auto const e1 = dyn_cast<CXXFunctionalCastExpr>(e0);
 142     if (e1 != nullptr) {
 143         e0 = e1->getSubExpr()->IgnoreParenImpCasts();
 144     }
 145     auto const e2 = dyn_cast<CXXBindTemporaryExpr>(e0);
 146     if (e2 == nullptr) {
 147         return expr;
 148     }
 149     auto const e3 = dyn_cast<CXXConstructExpr>(
 150         e2->getSubExpr()->IgnoreParenImpCasts());
 151     if (e3 == nullptr) {
 152         return expr;
 153     }
 154     auto qt = loplugin::DeclCheck(e3->getConstructor());
 155     if (!((qt.MemberFunction().Class("OString").Namespace("rtl")
 156            .GlobalNamespace())
 157           || (qt.MemberFunction().Class("OUString").Namespace("rtl")
 158               .GlobalNamespace())))
 159     {
 160         return expr;
 161     }
 162     if (e3->getNumArgs() != 2) {
 163         return expr;
 164     }
 165     return e3->getArg(0)->IgnoreParenImpCasts();
 166 }
 167
 168 bool CppunitAssertEquals::isCompileTimeConstant(Expr const * expr)
 169 {
 170     if (expr->isIntegerConstantExpr(compiler.getASTContext()))
 171         return true;
 172     // is string literal ?
 173     expr = expr->IgnoreParenImpCasts();
 174     expr = stripConstructor(expr);
 175     return isa<clang::StringLiteral>(expr);
 176 }
 177
 178 void CppunitAssertEquals::checkExpr(
 179     SourceRange range, StringRef name, Expr const * expr, bool negated)
 180 {
 181     if (auto const e = dyn_cast<UnaryOperator>(expr)) {
 182         if (e->getOpcode() == UO_LNot) {
 183             checkExpr(
 184                 range, name, e->getSubExpr()->IgnoreParenImpCasts(), !negated);
 185         }
 186         return;
 187     }
 188     if (auto const e = dyn_cast<BinaryOperator>(expr)) {
 189         auto const op = e->getOpcode();
 190         if ((!negated && op == BO_EQ) || (negated && op == BO_NE)) {
 191             reportEquals(range, name, op == BO_NE, e->getLHS(), e->getRHS());
 192             return;
 193         }
 194 #if 0 // TODO: enable later
 195         if ((!negated && op == BO_LAnd) || (negated && op == BO_LOr)) {
 196             report(
 197                 DiagnosticsEngine::Warning,
 198                 "rather split into two %0", e->getExprLoc())
 199                 << name << range;
 200             return;
 201         }
 202 #endif
 203         return;
 204     }
 205     if (auto const e = dyn_cast<CXXOperatorCallExpr>(expr)) {
 206         auto const op = e->getOperator();
 207         if ((!negated && op == OO_EqualEqual)
 208             || (negated && op == OO_ExclaimEqual))
 209         {
 210             reportEquals(range, name, op == OO_ExclaimEqual, e->getArg(0), e->getArg(1));
 211             return;
 212         }
 213         return;
 214     }
 215 }
 216
 217 void CppunitAssertEquals::reportEquals(
 218     SourceRange range, StringRef name, bool negative, Expr const * lhs, Expr const * rhs)
 219 {
 220     if (lhs->IgnoreImpCasts()->getType()->isNullPtrType()
 221         != rhs->IgnoreImpCasts()->getType()->isNullPtrType())
 222     {
 223         return;
 224     }
 225     report(
 226         DiagnosticsEngine::Warning,
 227         ("rather call"
 228          " %select{CPPUNIT_ASSERT_EQUAL|CPPUNIT_ASSERT_EQUAL_MESSAGE}0 (or"
 229          " rewrite as an explicit operator %select{==|!=}1 call when the"
 230          " operator itself is the topic)"),
 231         range.getBegin())
 232         << (name == "CPPUNIT_ASSERT_MESSAGE") << negative << range;
 233 }
 234
 235 loplugin::Plugin::Registration< CppunitAssertEquals > cppunitassertequals("cppunitassertequals");
 236
 237 } // namespace
 238
 239 #endif // LO_CLANG_SHARED_PLUGINS
 240
 241 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */