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
/* -*- 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/.
 */

#if !defined _WIN32 //TODO, #include <sys/mman.h>

#include <cassert>
#include <string>
#include <iostream>
#include "plugin.hxx"
#include "check.hxx"
#include <sys/mman.h>
#include <sys/types.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/stat.h>
#include <assert.h>
#include <cstring>

/**
  This is intended to be run as the second stage of the "constfields" clang plugin.
*/

namespace
{
class ConstFieldsRewrite : public RecursiveASTVisitor<ConstFieldsRewrite>,
                           public loplugin::RewritePlugin
{
public:
    explicit ConstFieldsRewrite(loplugin::InstantiationData const& data);
    ~ConstFieldsRewrite();

    virtual void run() override
    {
        if (rewriter)
        {
            TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
        }
    }

    bool VisitFieldDecl(const FieldDecl* var);

private:
    // I use a brute-force approach - mmap the results file and do a linear search on it
    // It works surprisingly well, because the file is small enough to fit into L2 cache on modern CPU's
    size_t mmapFilesize;
    int mmapFD;
    char* mmappedData;
};

size_t getFilesize(const char* filename)
{
    struct stat st;
    stat(filename, &st);
    return st.st_size;
}

ConstFieldsRewrite::ConstFieldsRewrite(loplugin::InstantiationData const& data)
    : RewritePlugin(data)
{
    static const char sInputFile[] = SRCDIR "/compilerplugins/clang/constfields.results";
    mmapFilesize = getFilesize(sInputFile);
    //Open file
    mmapFD = open(sInputFile, O_RDONLY, 0);
    assert(mmapFD != -1);
    //Execute mmap
    mmappedData = static_cast<char*>(mmap(NULL, mmapFilesize, PROT_READ, MAP_PRIVATE, mmapFD, 0));
    assert(mmappedData != NULL);
}

ConstFieldsRewrite::~ConstFieldsRewrite()
{
    //Cleanup
    int rc = munmap(mmappedData, mmapFilesize);
    assert(rc == 0);
    close(mmapFD);
}

bool ConstFieldsRewrite::VisitFieldDecl(const FieldDecl* fieldDecl)
{
    if (ignoreLocation(fieldDecl))
        return true;
    // ignore stuff that forms part of the stable URE interface
    if (isInUnoIncludeFile(compiler.getSourceManager().getSpellingLoc(
            fieldDecl->getCanonicalDecl()->getLocation())))
        return true;
    // in case we've already processed this field
    if (fieldDecl->getType().isConstQualified())<--- First condition
        return true;
    // in case we've already processed this field
    if (fieldDecl->getType().isConstQualified())<--- Second condition
        return true;
    // TODO rewriting T& is a bit trickier
    if (loplugin::TypeCheck(fieldDecl->getType()).LvalueReference())
        return true;

    const RecordDecl* recordDecl = fieldDecl->getParent();
    std::string parentClassName;
    if (const CXXRecordDecl* cxxRecordDecl = dyn_cast<CXXRecordDecl>(recordDecl))
    {
        if (cxxRecordDecl->getTemplateInstantiationPattern())
            cxxRecordDecl = cxxRecordDecl->getTemplateInstantiationPattern();
        parentClassName = cxxRecordDecl->getQualifiedNameAsString();
    }
    else
    {
        parentClassName = recordDecl->getQualifiedNameAsString();
    }
    // the extra spaces match the formatting in the results file, and help avoid false+
    std::string aNiceName = "    " + parentClassName + " " + fieldDecl->getNameAsString() + " "
                            + fieldDecl->getType().getAsString() + "\n";

    // search mmap'ed file for field
    const char* aNiceNameStr = aNiceName.c_str();
    char* found = std::search(mmappedData, mmappedData + mmapFilesize, aNiceNameStr,
                              aNiceNameStr + aNiceName.size());
    if (!(found < mmappedData + mmapFilesize))
        return true;

    SourceManager& SM = compiler.getSourceManager();
    auto endLoc = fieldDecl->getTypeSourceInfo()->getTypeLoc().getEndLoc();
    endLoc = endLoc.getLocWithOffset(Lexer::MeasureTokenLength(endLoc, SM, compiler.getLangOpts()));

    // Calculate how much space is available after the type declaration that we can use to
    // overwrite with the " const". This reduces the amount of formatting fixups I need to do.
    char const* p1 = SM.getCharacterData(endLoc);
    bool success = false;
    if (*p1 != ' ')
    {
        // Sometimes there is no space at all e.g. in
        //     FastTokenHandlerBase *mpTokenHandler;
        // between the "*" and the "mpTokenHandler", so add an extra space.
        success = insertText(endLoc, " const ");
    }
    else
    {
        int spaceAvailable = 1;
        ++p1;
        for (; spaceAvailable < 6; ++spaceAvailable)
        {
            if (*p1 != ' ')
                break;
            ++p1;
        }
        if (spaceAvailable < 6)
            success = replaceText(endLoc, spaceAvailable - 1, " const");
        else
            success = replaceText(endLoc, spaceAvailable, " const");
    }

    if (!success)
    {
        report(DiagnosticsEngine::Warning, "Could not mark field as const",
               compat::getBeginLoc(fieldDecl))
            << fieldDecl->getSourceRange();
    }
    return true;
}

loplugin::Plugin::Registration<ConstFieldsRewrite> X("constfieldsrewrite", false);
}

#endif

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