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 #ifndef LO_CLANG_SHARED_PLUGINS
10 
11 #include "check.hxx"
12 #include "compat.hxx"
13 #include "plugin.hxx"
14 
15 // For std::array or std::vector x, replace &x[0] with x.data().
16 
17 namespace
18 {
19 class Data final : public loplugin::FilteringPlugin<Data>
20 {
21 public:
Data(loplugin::InstantiationData const & data)22     explicit Data(loplugin::InstantiationData const& data)
23         : FilteringPlugin(data)
24     {
25     }
26 
VisitUnaryOperator(UnaryOperator const * expr)27     bool VisitUnaryOperator(UnaryOperator const* expr)
28     {
29         if (ignoreLocation(expr))
30         {
31             return true;
32         }
33         if (expr->getOpcode() != UO_AddrOf)
34         {
35             return true;
36         }
37         auto const e1 = dyn_cast<CXXOperatorCallExpr>(expr->getSubExpr()->IgnoreParenImpCasts());
38         if (e1 == nullptr)
39         {
40             return true;
41         }
42         if (e1->getOperator() != OO_Subscript)
43         {
44             return true;
45         }
46         auto const t = e1->getArg(0)->getType();
47         auto const chk = loplugin::TypeCheck(t);
48         if (!(chk.Class("array").StdNamespace() || chk.Class("vector").StdNamespace()))
49         {
50             return true;
51         }
52         auto const e2 = e1->getArg(1);
53         if (e2->isValueDependent())
54         {
55             return true;
56         }
57         APSInt v;
58         if (!compat::EvaluateAsInt(e2, v, compiler.getASTContext()))
59         {
60             return true;
61         }
62         if (v != 0)
63         {
64             return true;
65         }
66         report(DiagnosticsEngine::Warning,
67                "use 'data' member function to access first element of %0", expr->getExprLoc())
68             << t << expr->getSourceRange();
69         return true;
70     }
71 
preRun()72     bool preRun() override { return compiler.getLangOpts().CPlusPlus; }
73 
run()74     void run() override
75     {
76         if (preRun())
77         {
78             TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
79         }
80     }
81 };
82 
83 static loplugin::Plugin::Registration<Data> data("data");
84 
85 } // namespace
86 
87 #endif // LO_CLANG_SHARED_PLUGINS
88 
89 /* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */
90