compilerplugins/clang/check.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
  12 #include <clang/AST/DeclCXX.h>
  13
  14 #include "check.hxx"
  15
  16 namespace loplugin {
  17
  18 TypeCheck TypeCheck::NonConst() const {
  19     return !type_.isNull() && !type_.isConstQualified()
  20         ? *this : TypeCheck();
  21         // returning TypeCheck(type_.getUnqualifiedType()) instead of *this
  22         // may look tempting, but could remove sugar we might be interested in
  23         // checking for
  24 }
  25
  26 TypeCheck TypeCheck::NonConstVolatile() const {
  27     return
  28         (!type_.isNull() && !type_.isConstQualified()
  29          && !type_.isVolatileQualified())
  30         ? *this : TypeCheck();
  31         // returning TypeCheck(type_.getUnqualifiedType()) instead of *this
  32         // may look tempting, but could remove sugar we might be interested in
  33         // checking for
  34 }
  35
  36 TypeCheck TypeCheck::Const() const {
  37     return
  38         (!type_.isNull() && type_.isConstQualified()
  39          && !type_.isVolatileQualified())
  40         ? *this : TypeCheck();
  41         // returning TypeCheck(type_.getUnqualifiedType()) instead of *this
  42         // may look tempting, but could remove sugar we might be interested in
  43         // checking for
  44 }
  45
  46 TypeCheck TypeCheck::Volatile() const {
  47     return
  48         (!type_.isNull() && !type_.isConstQualified()
  49          && type_.isVolatileQualified())
  50         ? *this : TypeCheck();
  51         // returning TypeCheck(type_.getUnqualifiedType()) instead of *this
  52         // may look tempting, but could remove sugar we might be interested in
  53         // checking for
  54 }
  55
  56 TypeCheck TypeCheck::ConstVolatile() const {
  57     return
  58         (!type_.isNull() && type_.isConstQualified()
  59          && type_.isVolatileQualified())
  60         ? *this : TypeCheck();
  61         // returning TypeCheck(type_.getUnqualifiedType()) instead of *this
  62         // may look tempting, but could remove sugar we might be interested in
  63         // checking for
  64 }
  65
  66 TerminalCheck TypeCheck::Void() const {
  67     return TerminalCheck(
  68         !type_.isNull()
  69         && type_->isSpecificBuiltinType(clang::BuiltinType::Void));
  70 }
  71
  72 TerminalCheck TypeCheck::Char() const {
  73     return TerminalCheck(
  74         !type_.isNull()
  75         && (type_->isSpecificBuiltinType(clang::BuiltinType::Char_S)
  76             || type_->isSpecificBuiltinType(clang::BuiltinType::Char_U)));
  77 }
  78
  79 TerminalCheck TypeCheck::AnyBoolean() const {
  80     if (type_->isBooleanType()) {
  81         return TerminalCheck(true);
  82     }
  83     auto t = type_->getAs<clang::TypedefType>();
  84     if (t == nullptr) {
  85         return TerminalCheck(false);
  86     }
  87     auto n =t->getDecl()->getName();
  88     return TerminalCheck(
  89         n == "sal_Bool" || n == "BOOL" || n == "Boolean" || n == "FT_Bool"
  90         || n == "FcBool" || n == "GLboolean" || n == "NPBool" || n == "TW_BOOL"
  91         || n == "UBool" || n == "boolean" || n == "dbus_bool_t"
  92         || n == "gboolean" || n == "hb_bool_t" || n == "jboolean");
  93 }
  94
  95 TypeCheck TypeCheck::LvalueReference() const {
  96     if (!type_.isNull()) {
  97         auto const t = type_->getAs<clang::LValueReferenceType>();
  98         if (t != nullptr) {
  99             return TypeCheck(t->getPointeeType());
 100         }
 101     }
 102     return TypeCheck();
 103 }
 104
 105 TypeCheck TypeCheck::Pointer() const {
 106     if (!type_.isNull()) {
 107         auto const t = type_->getAs<clang::PointerType>();
 108         if (t != nullptr) {
 109             return TypeCheck(t->getPointeeType());
 110         }
 111     }
 112     return TypeCheck();
 113 }
 114
 115 TerminalCheck TypeCheck::Enum() const {
 116     if (!type_.isNull()) {
 117         auto const t = type_->getAs<clang::EnumType>();
 118         if (t != nullptr) {
 119             return TerminalCheck(true);
 120         }
 121     }
 122     return TerminalCheck(false);
 123 }
 124
 125 TypeCheck TypeCheck::Typedef() const {
 126     if (!type_.isNull()) {
 127         if (auto const t = type_->getAs<clang::TypedefType>()) {
 128             return TypeCheck(t->desugar());
 129         }
 130     }
 131     return TypeCheck();
 132 }
 133
 134 TypeCheck TypeCheck::NotSubstTemplateTypeParmType() const {
 135     return
 136         (!type_.isNull()
 137          && type_->getAs<clang::SubstTemplateTypeParmType>() == nullptr)
 138         ? *this : TypeCheck();
 139 }
 140
 141 ContextCheck DeclCheck::Operator(clang::OverloadedOperatorKind op) const {
 142     assert(op != clang::OO_None);
 143     auto f = llvm::dyn_cast_or_null<clang::FunctionDecl>(decl_);
 144     return ContextCheck(
 145         f != nullptr && f->getOverloadedOperator() == op
 146         ? f->getDeclContext() : nullptr);
 147 }
 148
 149 ContextCheck DeclCheck::MemberFunction() const {
 150     auto m = llvm::dyn_cast_or_null<clang::CXXMethodDecl>(decl_);
 151     return ContextCheck(m == nullptr ? nullptr : m->getParent());
 152 }
 153
 154 TerminalCheck ContextCheck::GlobalNamespace() const {
 155     return TerminalCheck(
 156         context_ != nullptr
 157         && ((context_->isLookupContext()
 158              ? context_ : context_->getLookupParent())
 159             ->isTranslationUnit()));
 160 }
 161
 162 TerminalCheck ContextCheck::StdNamespace() const {
 163     return TerminalCheck(
 164         context_ != nullptr && context_->isStdNamespace());
 165 }
 166
 167 ContextCheck ContextCheck::AnonymousNamespace() const {
 168     auto n = llvm::dyn_cast_or_null<clang::NamespaceDecl>(context_);
 169     return ContextCheck(
 170         n != nullptr && n->isAnonymousNamespace() ? n->getParent() : nullptr);
 171 }
 172
 173 namespace {
 174
 175 bool BaseCheckNotSomethingInterestingSubclass(const clang::CXXRecordDecl *BaseDefinition) {
 176     if (BaseDefinition) {
 177         auto tc = TypeCheck(BaseDefinition);
 178         if (tc.Class("Dialog").GlobalNamespace() || tc.Class("SfxPoolItem").GlobalNamespace()) {
 179             return false;
 180         }
 181     }
 182     return true;
 183 }
 184
 185 bool isDerivedFromSomethingInteresting(const clang::CXXRecordDecl *decl) {
 186     if (!decl)
 187         return false;
 188     auto tc = TypeCheck(decl);
 189     if (tc.Class("Dialog"))
 190         return true;
 191     if (tc.Class("SfxPoolItem"))
 192         return true;
 193     if (!decl->hasDefinition()) {
 194         return false;
 195     }
 196     if (// not sure what hasAnyDependentBases() does,
 197         // but it avoids classes we don't want, e.g. WeakAggComponentImplHelper1
 198         !decl->hasAnyDependentBases() &&
 199         !decl->forallBases(BaseCheckNotSomethingInterestingSubclass, true)) {
 200         return true;
 201     }
 202     return false;
 203 }
 204
 205 }
 206
 207 bool isExtraWarnUnusedType(clang::QualType type) {
 208     auto const rec = type->getAsCXXRecordDecl();
 209     if (rec == nullptr) {
 210         return false;
 211     }
 212     auto const tc = TypeCheck(rec);
 213     // Check some common non-LO types:
 214     if (tc.Class("basic_string").StdNamespace()
 215         || tc.Class("deque").StdNamespace()
 216         || tc.Class("list").StdNamespace()
 217         || tc.Class("map").StdNamespace()
 218         || tc.Class("pair").StdNamespace()
 219         || tc.Class("queue").StdNamespace()
 220         || tc.Class("set").StdNamespace()
 221         || tc.Class("stack").StdNamespace()
 222         || tc.Class("unordered_map").StdNamespace()
 223         || tc.Class("unordered_set").StdNamespace()
 224         || tc.Class("vector").StdNamespace())
 225     {
 226         return true;
 227     }
 228     return isDerivedFromSomethingInteresting(rec);
 229 }
 230
 231 namespace {
 232
 233 bool isArithmeticOp(clang::Expr const * expr) {
 234     expr = expr->IgnoreParenImpCasts();
 235     if (auto const e = llvm::dyn_cast<clang::BinaryOperator>(expr)) {
 236         switch (e->getOpcode()) {
 237         case clang::BO_Mul:
 238         case clang::BO_Div:
 239         case clang::BO_Rem:
 240         case clang::BO_Add:
 241         case clang::BO_Sub:
 242         case clang::BO_Shl:
 243         case clang::BO_Shr:
 244         case clang::BO_And:
 245         case clang::BO_Xor:
 246         case clang::BO_Or:
 247             return true;
 248         case clang::BO_Comma:
 249             return isArithmeticOp(e->getRHS());
 250         default:
 251             return false;
 252         }
 253     }
 254     return llvm::isa<clang::UnaryOperator>(expr)
 255         || llvm::isa<clang::AbstractConditionalOperator>(expr);
 256 }
 257
 258 }
 259
 260 bool isOkToRemoveArithmeticCast(
 261     clang::ASTContext & context, clang::QualType t1, clang::QualType t2, const clang::Expr* subExpr)
 262 {
 263     // Don't warn if the types are arithmetic (in the C++ meaning), and: either
 264     // at least one is a typedef (and if both are typedefs,they're different),
 265     // or the sub-expression involves some operation that is likely to change
 266     // types through promotion, or the sub-expression is an integer literal (so
 267     // its type generally depends on its value and suffix if any---even with a
 268     // suffix like L it could still be either long or long long):
 269     if ((t1->isIntegralType(context)
 270          || t1->isRealFloatingType())
 271         && ((t1 != t2
 272              && (loplugin::TypeCheck(t1).Typedef()
 273                  || loplugin::TypeCheck(t2).Typedef()))
 274             || isArithmeticOp(subExpr)
 275             || llvm::isa<clang::IntegerLiteral>(subExpr->IgnoreParenImpCasts())))
 276     {
 277         return false;
 278     }
 279     return true;
 280 }
 281
 282 }
 283
 284 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */