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