summaryrefslogtreecommitdiff
path: root/compilerplugins/clang/shouldreturnbool.cxx
blob: 03cc0c856a6f74275b366f0a076f9cb137aac70e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * This file is part of the LibreOffice project.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */

#include <string>
#include <set>
#include <iostream>

#include "check.hxx"
#include "plugin.hxx"
#include "functionaddress.hxx"

/*
 Look for functions that only return 1 and/or 0, which sometimes indicates that the
 function should be returning bool.

 Note that is partly a question of taste and code style, which is why this plugin is off by default.
*/

namespace
{
class ShouldReturnBool : public loplugin::FunctionAddress<ShouldReturnBool>
{
public:
    explicit ShouldReturnBool(loplugin::InstantiationData const& data)
        : loplugin::FunctionAddress<ShouldReturnBool>(data)
    {
    }

    virtual void run() override
    {
        if (!compiler.getLangOpts().CPlusPlus)
            return;
        StringRef fn(handler.getMainFileName());
        // functions used as function pointers
        if (loplugin::isSamePathname(fn, SRCDIR "/sal/rtl/alloc_cache.cxx"))
            return;
        // false +, slightly odd usage, but not wrong
        if (loplugin::isSamePathname(fn, SRCDIR "/libreofficekit/qa/tilebench/tilebench.cxx")
            || loplugin::isSamePathname(fn, SRCDIR "/smoketest/libtest.cxx"))
            return;
        // uses the Unix convention of "non-zero return indicates error"
        if (loplugin::isSamePathname(fn, SRCDIR "/idlc/source/idlcproduce.cxx"))
            return;
        // template magic
        if (loplugin::isSamePathname(fn, SRCDIR "/vcl/source/gdi/bmpfast.cxx"))
            return;
        // fine
        if (loplugin::isSamePathname(fn, SRCDIR "/svl/unx/source/svdde/ddedummy.cxx"))
            return;
        if (loplugin::isSamePathname(fn, SRCDIR "/vcl/source/opengl/OpenGLHelper.cxx"))
            return;
        if (loplugin::isSamePathname(fn, SRCDIR "/svtools/source/misc/imap2.cxx"))
            return;
        if (loplugin::isSamePathname(fn, SRCDIR "/svx/source/dialog/docrecovery.cxx"))
            return;
        if (loplugin::isSamePathname(fn, SRCDIR "/hwpfilter/source/lexer.cxx"))
            return;
        if (loplugin::isSamePathname(fn, SRCDIR "/hwpfilter/source/grammar.cxx"))
            return;
        if (loplugin::isSamePathname(
                fn, SRCDIR "/connectivity/source/drivers/odbc/ODatabaseMetaDataResultSet.cxx"))
            return;
        if (loplugin::isSamePathname(fn, SRCDIR "/dbaccess/source/ui/browser/dsEntriesNoExp.cxx"))
            return;
        if (loplugin::isSamePathname(fn, SRCDIR "/lotuswordpro/source/filter/explode.cxx"))
            return;
        if (loplugin::isSamePathname(fn, SRCDIR "/filter/source/graphicfilter/ipict/ipict.cxx"))
            return;
        if (loplugin::isSamePathname(fn, SRCDIR "/sc/source/core/data/dptabsrc.cxx"))
            return;
        if (loplugin::isSamePathname(fn, SRCDIR "/sc/source/ui/docshell/docsh3.cxx"))
            return;
        if (loplugin::isSamePathname(fn, SRCDIR "/sd/source/ui/dlg/masterlayoutdlg.cxx"))
            return;
        if (loplugin::isSamePathname(fn, SRCDIR "/sd/source/filter/ppt/pptinanimations.cxx"))
            return;
        if (loplugin::isSamePathname(fn, SRCDIR "/vcl/unx/generic/app/i18n_im.cxx"))
            return;

        // callback
        if (loplugin::isSamePathname(fn, SRCDIR "/sax/source/expatwrap/sax_expat.cxx"))
            return;
        if (loplugin::isSamePathname(fn, SRCDIR "/xmlsecurity/source/xmlsec/xmlstreamio.cxx"))
            return;
        if (loplugin::isSamePathname(fn, SRCDIR "/sw/source/filter/ww8/ww8par.cxx"))
            return;
        if (loplugin::isSamePathname(fn, SRCDIR "/sw/source/filter/ww8/ww8par2.cxx"))
            return;
        if (loplugin::isSamePathname(fn, SRCDIR "/sw/source/filter/ww8/ww8par5.cxx"))
            return;
        // SaxWriterHelper::writeSequence a little weird
        if (loplugin::isSamePathname(fn, SRCDIR "/sax/source/expatwrap/saxwriter.cxx"))
            return;
        // main function
        if (loplugin::isSamePathname(fn, SRCDIR "/xmlsecurity/workben/pdfverify.cxx"))
            return;

        TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());

        for (auto functionDecl : problemFunctions)
        {
            auto canonicalDecl = functionDecl->getCanonicalDecl();
            if (getFunctionsWithAddressTaken().find(canonicalDecl)
                != getFunctionsWithAddressTaken().end())
                continue;
            report(DiagnosticsEngine::Warning,
                   "only returning one or zero is an indication you want to return bool",
                   compat::getBeginLoc(functionDecl))
                << functionDecl->getSourceRange();
            if (canonicalDecl->getLocation() != functionDecl->getLocation())
            {
                report(DiagnosticsEngine::Note, "canonical function declaration here",
                       compat::getBeginLoc(canonicalDecl))
                    << canonicalDecl->getSourceRange();
            }
        }
    }

    bool TraverseFunctionDecl(FunctionDecl*);
    bool TraverseCXXMethodDecl(CXXMethodDecl*);
    bool VisitReturnStmt(ReturnStmt const*);

private:
    bool mbInsideFunction = false;
    bool mbFunctionOnlyReturningOneOrZero = false;
    std::unordered_set<FunctionDecl const*> problemFunctions;

    bool IsInteresting(FunctionDecl const*);
    void Report(FunctionDecl const*) const;
    bool isExprOneOrZero(Expr const*) const;
};

bool ShouldReturnBool::TraverseFunctionDecl(FunctionDecl* functionDecl)
{
    bool ret;
    if (IsInteresting(functionDecl))
    {
        mbInsideFunction = true;
        mbFunctionOnlyReturningOneOrZero = true;
        ret = loplugin::FunctionAddress<ShouldReturnBool>::TraverseFunctionDecl(functionDecl);
        mbInsideFunction = false;
        if (mbFunctionOnlyReturningOneOrZero)
            problemFunctions.insert(functionDecl);
    }
    else
        ret = loplugin::FunctionAddress<ShouldReturnBool>::TraverseFunctionDecl(functionDecl);
    return ret;
}

bool ShouldReturnBool::TraverseCXXMethodDecl(CXXMethodDecl* methodDecl)
{
    bool ret;
    if (IsInteresting(methodDecl))
    {
        mbInsideFunction = true;
        mbFunctionOnlyReturningOneOrZero = true;
        ret = loplugin::FunctionAddress<ShouldReturnBool>::TraverseCXXMethodDecl(methodDecl);
        mbInsideFunction = false;
        if (mbFunctionOnlyReturningOneOrZero)
            problemFunctions.insert(methodDecl);
    }
    else
        ret = loplugin::FunctionAddress<ShouldReturnBool>::TraverseCXXMethodDecl(methodDecl);
    return ret;
}

bool ShouldReturnBool::IsInteresting(FunctionDecl const* functionDecl)
{
    if (ignoreLocation(functionDecl))
        return false;
    // ignore stuff that forms part of the stable URE interface
    if (isInUnoIncludeFile(functionDecl))
        return false;
    if (functionDecl->getTemplatedKind() != FunctionDecl::TK_NonTemplate)
        return false;
    if (!functionDecl->isThisDeclarationADefinition())
        return false;
    if (functionDecl->isMain())
        return false;
    if (functionDecl->isExternC() || functionDecl->isInExternCContext())
        return false;
    auto methodDecl = dyn_cast<CXXMethodDecl>(functionDecl);
    if (methodDecl && methodDecl->isVirtual())
        return false;
    auto tc = loplugin::TypeCheck(functionDecl->getReturnType());
    if (tc.AnyBoolean() || tc.Void())
        return false;
    auto returnType = functionDecl->getReturnType();
    if (returnType->isEnumeralType() || !returnType->getUnqualifiedDesugaredType()->isIntegerType())
        return false;
    // Ignore functions that contains #ifdef-ery
    if (containsPreprocessingConditionalInclusion(functionDecl->getSourceRange()))
        return false;

    // not sure what basegfx is doing here
    StringRef fileName{ compiler.getSourceManager().getFilename(functionDecl->getLocation()) };
    if (loplugin::isSamePathname(fileName, SRCDIR "/include/basegfx/range/basicrange.hxx"))
        return false;
    // false +
    if (loplugin::isSamePathname(fileName, SRCDIR "/include/svl/macitem.hxx"))
        return false;
    if (loplugin::isSamePathname(fileName, SRCDIR "/lotuswordpro/source/filter/lwpcharsetmgr.hxx"))
        return false;
    if (loplugin::isSamePathname(fileName, SRCDIR "/sc/inc/dptabsrc.hxx"))
        return false;

    return true;
}

bool ShouldReturnBool::VisitReturnStmt(const ReturnStmt* returnStmt)
{
    if (!mbInsideFunction)
        return true;
    if (!returnStmt->getRetValue())
        return true;
    if (loplugin::TypeCheck(returnStmt->getRetValue()->getType()).AnyBoolean())
        return true;
    if (!isExprOneOrZero(returnStmt->getRetValue()))
        mbFunctionOnlyReturningOneOrZero = false;
    return true;
}

bool ShouldReturnBool::isExprOneOrZero(const Expr* arg) const
{
    arg = arg->IgnoreParenCasts();
    // ignore this, it seems to trigger an infinite recursion
    if (isa<UnaryExprOrTypeTraitExpr>(arg))
    {
        return false;
    }
    APSInt x1;
    if (compat::EvaluateAsInt(arg, x1, compiler.getASTContext()))
    {
        return x1 == 1 || x1 == 0;
    }
    return false;
}

loplugin::Plugin::Registration<ShouldReturnBool> X("shouldreturnbool", false);
}

/* vim:set shiftwidth=4 softtabstop=4 expandtab: */