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