1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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 #if !defined _WIN32 //TODO, #include <sys/mman.h>
11 
12 #include <cassert>
13 #include <string>
14 #include <iostream>
15 #include "plugin.hxx"
16 #include "compat.hxx"
17 #include <sys/mman.h>
18 #include <sys/types.h>
19 #include <fcntl.h>
20 #include <unistd.h>
21 #include <sys/stat.h>
22 #include <assert.h>
23 #include <cstring>
24 
25 /**
26   This is intended to be run as the second stage of the "unusedmethods" clang plugin.
27 */
28 
29 namespace {
30 
31 class UnusedMethodsRemove:
32     public loplugin::FilteringRewritePlugin<UnusedMethodsRemove>
33 {
34 public:
35     explicit UnusedMethodsRemove(loplugin::InstantiationData const & data);
36     ~UnusedMethodsRemove();
37 
run()38     virtual void run() override { TraverseDecl(compiler.getASTContext().getTranslationUnitDecl()); }
39 
40     bool VisitCXXMethodDecl( const CXXMethodDecl* var );
41 private:
42     // I use a brute-force approach - mmap the results file and do a linear search on it
43     // It works surprisingly well, because the file is small enough to fit into L2 cache on modern CPU's
44     size_t mmapFilesize;
45     int mmapFD;
46     char* mmappedData;
47 };
48 
getFilesize(const char * filename)49 size_t getFilesize(const char* filename)
50 {
51     struct stat st;
52     stat(filename, &st);
53     return st.st_size;
54 }
55 
UnusedMethodsRemove(loplugin::InstantiationData const & data)56 UnusedMethodsRemove::UnusedMethodsRemove(loplugin::InstantiationData const & data): FilteringRewritePlugin(data)
57 {
58     static const char sInputFile[] = SRCDIR "/result.txt";
59     mmapFilesize = getFilesize(sInputFile);
60     //Open file
61     mmapFD = open(sInputFile, O_RDONLY, 0);
62     assert(mmapFD != -1);
63     //Execute mmap
64     mmappedData = static_cast<char*>(mmap(NULL, mmapFilesize, PROT_READ, MAP_PRIVATE, mmapFD, 0));
65     assert(mmappedData != NULL);
66 }
67 
~UnusedMethodsRemove()68 UnusedMethodsRemove::~UnusedMethodsRemove()
69 {
70     //Cleanup
71     int rc = munmap(mmappedData, mmapFilesize);
72     assert(rc == 0);
73     (void)rc;
74     close(mmapFD);
75 }
76 
niceName(const CXXMethodDecl * functionDecl)77 std::string niceName(const CXXMethodDecl* functionDecl)
78 {
79     std::string s =
80         functionDecl->getReturnType().getCanonicalType().getAsString()
81         + " " + functionDecl->getParent()->getQualifiedNameAsString()
82         + "::" + functionDecl->getNameAsString()
83         + "(";
84     bool bFirst = true;
85     for (const ParmVarDecl *pParmVarDecl : functionDecl->parameters()) {
86         if (bFirst)
87             bFirst = false;
88         else
89             s += ",";
90         s += pParmVarDecl->getType().getCanonicalType().getAsString();
91     }
92     s += ")";
93     if (functionDecl->isConst()) {
94         s += " const";
95     }
96     return s;
97 }
98 
VisitCXXMethodDecl(const CXXMethodDecl * functionDecl)99 bool UnusedMethodsRemove::VisitCXXMethodDecl( const CXXMethodDecl* functionDecl )
100 {
101     if (rewriter == nullptr) {
102         return true;
103     }
104     if (ignoreLocation(functionDecl)) {
105         return true;
106     }
107     // ignore stuff that forms part of the stable URE interface
108     if (isInUnoIncludeFile(functionDecl)) {
109         return true;
110     }
111 
112     // don't mess with templates
113     if (functionDecl->getParent()->getDescribedClassTemplate() != nullptr) {
114         return true;
115     }
116     if (functionDecl->getTemplatedKind() != FunctionDecl::TK_NonTemplate) {
117         return true;
118     }
119 
120     std::string aNiceName = "\n" + niceName(functionDecl) + "\n";
121     const char *aNiceNameStr = aNiceName.c_str();
122     char* found = std::search(mmappedData, mmappedData + mmapFilesize, aNiceNameStr, aNiceNameStr + strlen(aNiceNameStr));
123     if(!(found < mmappedData + mmapFilesize)) {
124         return true;
125     }
126     SourceRange replaceRange(functionDecl->getSourceRange());
127     // sometimes the declaration has a semicolon just after it, and it's much neater to remove that too.
128     if (rewriter->getRewrittenText(SourceRange(replaceRange.getEnd(), replaceRange.getEnd().getLocWithOffset(1))) == ";") {
129         replaceRange.setEnd(replaceRange.getEnd().getLocWithOffset(1));
130     }
131     // remove leading spaces
132     while (rewriter->getRewrittenText(SourceRange(replaceRange.getBegin().getLocWithOffset(-1), replaceRange.getBegin())) == " ")
133     {
134         replaceRange.setBegin(replaceRange.getBegin().getLocWithOffset(-1));
135     }
136     if (!replaceText(replaceRange, "")) {
137         report(
138             DiagnosticsEngine::Warning,
139             "Could not remove unused method (" + niceName(functionDecl) + ")",
140             compat::getBeginLoc(functionDecl))
141           << functionDecl->getSourceRange();
142     }
143     return true;
144 }
145 
146 
147 loplugin::Plugin::Registration< UnusedMethodsRemove > X("unusedmethodsremove", false);
148 
149 }
150 
151 #endif
152 
153 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
154