compilerplugins/clang/unicodetochar.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
   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 #ifndef LO_CLANG_SHARED_PLUGINS
  11
  12 #include <stack>
  13
  14 #include "check.hxx"
  15 #include "plugin.hxx"
  16
  17 // In C++, find implicit conversions from char16_t (aka sal_Unicode) to char.
  18 // Such places are probably meant to properly work on char16_t instead.
  19
  20 namespace {
  21
  22 class UnicodeToChar final:
  23     public loplugin::FilteringPlugin<UnicodeToChar>
  24 {
  25 public:
  26     explicit UnicodeToChar(loplugin::InstantiationData const & data):
  27         FilteringPlugin(data) {}
  28
  29     bool PreTraverseCStyleCastExpr(CStyleCastExpr * expr) {
  30         subExprs_.push(expr->getSubExpr());
  31         return true;
  32     }
  33     bool PostTraverseCStyleCastExpr(CStyleCastExpr *, bool ) {
  34         subExprs_.pop();
  35         return true;
  36     }
  37     bool TraverseCStyleCastExpr(CStyleCastExpr * expr) {
  38         PreTraverseCStyleCastExpr(expr);
  39         bool ret = RecursiveASTVisitor::TraverseCStyleCastExpr(expr);
  40         PostTraverseCStyleCastExpr(expr, ret);
  41         return ret;
  42     }
  43
  44     bool PreTraverseCXXStaticCastExpr(CXXStaticCastExpr * expr) {
  45         subExprs_.push(expr->getSubExpr());
  46         return true;
  47     }
  48     bool PostTraverseCXXStaticCastExpr(CXXStaticCastExpr *, bool) {
  49         subExprs_.pop();
  50         return true;
  51     }
  52     bool TraverseCXXStaticCastExpr(CXXStaticCastExpr * expr) {
  53         PreTraverseCXXStaticCastExpr(expr);
  54         bool ret = RecursiveASTVisitor::TraverseCXXStaticCastExpr(expr);
  55         PostTraverseCXXStaticCastExpr(expr, ret);
  56         return ret;
  57     }
  58
  59     bool PreTraverseCXXFunctionalCastExpr(CXXFunctionalCastExpr * expr) {
  60         subExprs_.push(expr->getSubExpr());
  61         return true;
  62     }
  63     bool PostTraverseCXXFunctionalCastExpr(CXXFunctionalCastExpr *, bool) {
  64         subExprs_.pop();
  65         return true;
  66     }
  67     bool TraverseCXXFunctionalCastExpr(CXXFunctionalCastExpr * expr) {
  68         PreTraverseCXXFunctionalCastExpr(expr);
  69         bool ret = RecursiveASTVisitor::TraverseCXXFunctionalCastExpr(expr);
  70         PostTraverseCXXFunctionalCastExpr(expr, ret);
  71         return ret;
  72     }
  73
  74     bool VisitImplicitCastExpr(ImplicitCastExpr const * expr) {
  75         if ((!subExprs_.empty() && expr == subExprs_.top())
  76             || ignoreLocation(expr))
  77         {
  78             return true;
  79         }
  80         if (!(loplugin::TypeCheck(expr->getType()).Char()
  81               && expr->getSubExpr()->getType()->isSpecificBuiltinType(
  82                   clang::BuiltinType::Char16)))
  83         {
  84             return true;
  85         }
  86         APSInt res;
  87         if (compat::EvaluateAsInt(expr->getSubExpr(), res, compiler.getASTContext())
  88             && res >= 0 && res <= 0x7F)
  89         {
  90             return true;
  91         }
  92         report(
  93             DiagnosticsEngine::Warning,
  94             "suspicious implicit cast from %0 to %1",
  95             expr->getExprLoc())
  96             << expr->getSubExpr()->getType() << expr->getType()
  97             << expr->getSourceRange();
  98         return true;
  99     }
 100
 101     bool preRun() override {
 102         return compiler.getLangOpts().CPlusPlus;
 103     }
 104
 105     void run() override {
 106         if (preRun()) {
 107             TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
 108         }
 109     }
 110
 111 private:
 112     std::stack<Expr const *> subExprs_;
 113 };
 114
 115 static loplugin::Plugin::Registration<UnicodeToChar> unicodetochar("unicodetochar");
 116
 117 } // namespace
 118
 119 #endif // LO_CLANG_SHARED_PLUGINS
 120
 121 /* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */