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