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     if (loplugin::DeclCheck(decl).Function("assertDoubleEquals").
 136              Namespace("CppUnit").GlobalNamespace())
 137     {
 138         // can happen in template test code that both params are compile time constants
 139         if (isCompileTimeConstant(callExpr->getArg(0)))
 140             return true;
 141         if (isCompileTimeConstant(callExpr->getArg(1)))
 142             report(
 143                 DiagnosticsEngine::Warning,
 144                 "CPPUNIT_ASSERT_DOUBLES_EQUALS parameters look switched, expected value should be first param",
 145                 callExpr->getExprLoc())
 146                 << callExpr->getSourceRange();
 147     }
 148     if (loplugin::DeclCheck(decl).Function("assertLess").
 149              Namespace("CppUnit").GlobalNamespace())
 150     {
 151         // can happen in template test code that both params are compile time constants
 152         if (isCompileTimeConstant(callExpr->getArg(0)))
 153             return true;
 154         if (isCompileTimeConstant(callExpr->getArg(1)))
 155             report(
 156                 DiagnosticsEngine::Warning,
 157                 "CPPUNIT_ASSERT_LESS parameters look switched, expected value should be first param",
 158                 callExpr->getExprLoc())
 159                 << callExpr->getSourceRange();
 160     }
 161     if (loplugin::DeclCheck(decl).Function("assertLessEqual").
 162              Namespace("CppUnit").GlobalNamespace())
 163     {
 164         // can happen in template test code that both params are compile time constants
 165         if (isCompileTimeConstant(callExpr->getArg(0)))
 166             return true;
 167         if (isCompileTimeConstant(callExpr->getArg(1)))
 168             report(
 169                 DiagnosticsEngine::Warning,
 170                 "CPPUNIT_ASSERT_LESSEQUAL parameters look switched, expected value should be first param",
 171                 callExpr->getExprLoc())
 172                 << callExpr->getSourceRange();
 173     }
 174     if (loplugin::DeclCheck(decl).Function("assertGreater").
 175              Namespace("CppUnit").GlobalNamespace())
 176     {
 177         // can happen in template test code that both params are compile time constants
 178         if (isCompileTimeConstant(callExpr->getArg(0)))
 179             return true;
 180         if (isCompileTimeConstant(callExpr->getArg(1)))
 181             report(
 182                 DiagnosticsEngine::Warning,
 183                 "CPPUNIT_ASSERT_GREATER parameters look switched, expected value should be first param",
 184                 callExpr->getExprLoc())
 185                 << callExpr->getSourceRange();
 186     }
 187     if (loplugin::DeclCheck(decl).Function("assertGreaterEqual").
 188              Namespace("CppUnit").GlobalNamespace())
 189     {
 190         // can happen in template test code that both params are compile time constants
 191         if (isCompileTimeConstant(callExpr->getArg(0)))
 192             return true;
 193         if (isCompileTimeConstant(callExpr->getArg(1)))
 194             report(
 195                 DiagnosticsEngine::Warning,
 196                 "CPPUNIT_ASSERT_GREATEREQUAL parameters look switched, expected value should be first param",
 197                 callExpr->getExprLoc())
 198                 << callExpr->getSourceRange();
 199     }
 200     return true;
 201 }
 202
 203 // copied from stringconcat.cxx
 204 Expr const * stripConstructor(Expr const * expr) {
 205     auto e0 = expr;
 206     auto const e1 = dyn_cast<CXXFunctionalCastExpr>(e0);
 207     if (e1 != nullptr) {
 208         e0 = e1->getSubExpr()->IgnoreParenImpCasts();
 209     }
 210     auto const e2 = dyn_cast<CXXBindTemporaryExpr>(e0);
 211     if (e2 == nullptr) {
 212         return expr;
 213     }
 214     auto const e3 = dyn_cast<CXXConstructExpr>(
 215         e2->getSubExpr()->IgnoreParenImpCasts());
 216     if (e3 == nullptr) {
 217         return expr;
 218     }
 219     auto qt = loplugin::DeclCheck(e3->getConstructor());
 220     if (!((qt.MemberFunction().Class("OString").Namespace("rtl")
 221            .GlobalNamespace())
 222           || (qt.MemberFunction().Class("OUString").Namespace("rtl")
 223               .GlobalNamespace())))
 224     {
 225         return expr;
 226     }
 227     if (e3->getNumArgs() != 2) {
 228         return expr;
 229     }
 230     return e3->getArg(0)->IgnoreParenImpCasts();
 231 }
 232
 233 bool CppunitAssertEquals::isCompileTimeConstant(Expr const * expr)
 234 {
 235     if (expr->isCXX11ConstantExpr(compiler.getASTContext()))
 236         return true;
 237     // is string literal ?
 238     expr = expr->IgnoreParenImpCasts();
 239     expr = stripConstructor(expr);
 240     return isa<clang::StringLiteral>(expr);
 241 }
 242
 243 void CppunitAssertEquals::checkExpr(
 244     SourceRange range, StringRef name, Expr const * expr, bool negated)
 245 {
 246     if (auto const e = dyn_cast<UnaryOperator>(expr)) {
 247         if (e->getOpcode() == UO_LNot) {
 248             checkExpr(
 249                 range, name, e->getSubExpr()->IgnoreParenImpCasts(), !negated);
 250         }
 251         return;
 252     }
 253     if (auto const e = dyn_cast<BinaryOperator>(expr)) {
 254         auto const op = e->getOpcode();
 255         if ((!negated && op == BO_EQ) || (negated && op == BO_NE)) {
 256             reportEquals(range, name, op == BO_NE, e->getLHS(), e->getRHS());
 257             return;
 258         }
 259         if ((!negated && op == BO_LAnd) || (negated && op == BO_LOr)) {
 260             report(
 261                 DiagnosticsEngine::Warning,
 262                 "rather split into two %0", e->getExprLoc())
 263                 << name << range;
 264             return;
 265         }
 266         return;
 267     }
 268     if (auto const e = dyn_cast<CXXOperatorCallExpr>(expr)) {
 269         auto const op = e->getOperator();
 270         if ((!negated && op == OO_EqualEqual)
 271             || (negated && op == OO_ExclaimEqual))
 272         {
 273             reportEquals(range, name, op == OO_ExclaimEqual, e->getArg(0), e->getArg(1));
 274             return;
 275         }
 276         return;
 277     }
 278 }
 279
 280 void CppunitAssertEquals::reportEquals(
 281     SourceRange range, StringRef name, bool negative, Expr const * lhs, Expr const * rhs)
 282 {
 283     if (lhs->IgnoreImpCasts()->getType()->isNullPtrType()
 284         != rhs->IgnoreImpCasts()->getType()->isNullPtrType())
 285     {
 286         return;
 287     }
 288     report(
 289         DiagnosticsEngine::Warning,
 290         ("rather call"
 291          " %select{CPPUNIT_ASSERT_EQUAL|CPPUNIT_ASSERT_EQUAL_MESSAGE}0 when comparing %1 and %2 (or"
 292          " rewrite as an explicit operator %select{==|!=}3 call when the"
 293          " operator itself is the topic)"),
 294         range.getBegin())
 295         << (name == "CPPUNIT_ASSERT_MESSAGE") << lhs->IgnoreImpCasts()->getType()
 296         << rhs->IgnoreImpCasts()->getType() << negative << range;
 297 }
 298
 299 loplugin::Plugin::Registration< CppunitAssertEquals > cppunitassertequals("cppunitassertequals");
 300
 301 } // namespace
 302
 303 #endif // LO_CLANG_SHARED_PLUGINS
 304
 305 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */