1 //===--- Refactoring.cpp - Framework for clang refactoring tools ----------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 //  Implements tools to support refactorings.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/Basic/DiagnosticOptions.h"
15 #include "clang/Basic/FileManager.h"
16 #include "clang/Basic/SourceManager.h"
17 #include "clang/Frontend/TextDiagnosticPrinter.h"
18 #include "clang/Lex/Lexer.h"
19 #include "clang/Rewrite/Core/Rewriter.h"
20 #include "clang/Tooling/Refactoring.h"
21 #include "llvm/Support/raw_os_ostream.h"
22 
23 namespace clang {
24 namespace tooling {
25 
26 static const char * const InvalidLocation = "";
27 
28 Replacement::Replacement()
29   : FilePath(InvalidLocation) {}
30 
31 Replacement::Replacement(StringRef FilePath, unsigned Offset, unsigned Length,
32                          StringRef ReplacementText)
33     : FilePath(FilePath), ReplacementRange(Offset, Length),
34       ReplacementText(ReplacementText) {}
35 
36 Replacement::Replacement(SourceManager &Sources, SourceLocation Start,
37                          unsigned Length, StringRef ReplacementText) {
38   setFromSourceLocation(Sources, Start, Length, ReplacementText);
39 }
40 
41 Replacement::Replacement(SourceManager &Sources, const CharSourceRange &Range,
42                          StringRef ReplacementText) {
43   setFromSourceRange(Sources, Range, ReplacementText);
44 }
45 
46 bool Replacement::isApplicable() const {
47   return FilePath != InvalidLocation;
48 }
49 
50 bool Replacement::apply(Rewriter &Rewrite) const {
51   SourceManager &SM = Rewrite.getSourceMgr();
52   const FileEntry *Entry = SM.getFileManager().getFile(FilePath);
53   if (Entry == NULL)
54     return false;
55   FileID ID;
56   // FIXME: Use SM.translateFile directly.
57   SourceLocation Location = SM.translateFileLineCol(Entry, 1, 1);
58   ID = Location.isValid() ?
59     SM.getFileID(Location) :
60     SM.createFileID(Entry, SourceLocation(), SrcMgr::C_User);
61   // FIXME: We cannot check whether Offset + Length is in the file, as
62   // the remapping API is not public in the RewriteBuffer.
63   const SourceLocation Start =
64     SM.getLocForStartOfFile(ID).
65     getLocWithOffset(ReplacementRange.getOffset());
66   // ReplaceText returns false on success.
67   // ReplaceText only fails if the source location is not a file location, in
68   // which case we already returned false earlier.
69   bool RewriteSucceeded = !Rewrite.ReplaceText(
70       Start, ReplacementRange.getLength(), ReplacementText);
71   assert(RewriteSucceeded);
72   return RewriteSucceeded;
73 }
74 
75 std::string Replacement::toString() const {
76   std::string result;
77   llvm::raw_string_ostream stream(result);
78   stream << FilePath << ": " << ReplacementRange.getOffset() << ":+"
79          << ReplacementRange.getLength() << ":\"" << ReplacementText << "\"";
80   return result;
81 }
82 
83 bool Replacement::Less::operator()(const Replacement &R1,
84                                    const Replacement &R2) const {
85   if (R1.FilePath != R2.FilePath) return R1.FilePath < R2.FilePath;
86   if (R1.ReplacementRange.getOffset() != R2.ReplacementRange.getOffset())
87     return R1.ReplacementRange.getOffset() < R2.ReplacementRange.getOffset();
88   if (R1.ReplacementRange.getLength() != R2.ReplacementRange.getLength())
89     return R1.ReplacementRange.getLength() < R2.ReplacementRange.getLength();
90   return R1.ReplacementText < R2.ReplacementText;
91 }
92 
93 bool Replacement::operator==(const Replacement &Other) const {
94   return ReplacementRange.getOffset() == Other.ReplacementRange.getOffset() &&
95          ReplacementRange.getLength() == Other.ReplacementRange.getLength() &&
96          FilePath == Other.FilePath && ReplacementText == Other.ReplacementText;
97 }
98 
99 void Replacement::setFromSourceLocation(SourceManager &Sources,
100                                         SourceLocation Start, unsigned Length,
101                                         StringRef ReplacementText) {
102   const std::pair<FileID, unsigned> DecomposedLocation =
103       Sources.getDecomposedLoc(Start);
104   const FileEntry *Entry = Sources.getFileEntryForID(DecomposedLocation.first);
105   this->FilePath = Entry != NULL ? Entry->getName() : InvalidLocation;
106   this->ReplacementRange = Range(DecomposedLocation.second, Length);
107   this->ReplacementText = ReplacementText;
108 }
109 
110 // FIXME: This should go into the Lexer, but we need to figure out how
111 // to handle ranges for refactoring in general first - there is no obvious
112 // good way how to integrate this into the Lexer yet.
113 static int getRangeSize(SourceManager &Sources, const CharSourceRange &Range) {
114   SourceLocation SpellingBegin = Sources.getSpellingLoc(Range.getBegin());
115   SourceLocation SpellingEnd = Sources.getSpellingLoc(Range.getEnd());
116   std::pair<FileID, unsigned> Start = Sources.getDecomposedLoc(SpellingBegin);
117   std::pair<FileID, unsigned> End = Sources.getDecomposedLoc(SpellingEnd);
118   if (Start.first != End.first) return -1;
119   if (Range.isTokenRange())
120     End.second += Lexer::MeasureTokenLength(SpellingEnd, Sources,
121                                             LangOptions());
122   return End.second - Start.second;
123 }
124 
125 void Replacement::setFromSourceRange(SourceManager &Sources,
126                                      const CharSourceRange &Range,
127                                      StringRef ReplacementText) {
128   setFromSourceLocation(Sources, Sources.getSpellingLoc(Range.getBegin()),
129                         getRangeSize(Sources, Range), ReplacementText);
130 }
131 
132 bool applyAllReplacements(const Replacements &Replaces, Rewriter &Rewrite) {
133   bool Result = true;
134   for (Replacements::const_iterator I = Replaces.begin(),
135                                     E = Replaces.end();
136        I != E; ++I) {
137     if (I->isApplicable()) {
138       Result = I->apply(Rewrite) && Result;
139     } else {
140       Result = false;
141     }
142   }
143   return Result;
144 }
145 
146 std::string applyAllReplacements(StringRef Code, const Replacements &Replaces) {
147   FileManager Files((FileSystemOptions()));
148   DiagnosticsEngine Diagnostics(
149       IntrusiveRefCntPtr<DiagnosticIDs>(new DiagnosticIDs),
150       new DiagnosticOptions);
151   Diagnostics.setClient(new TextDiagnosticPrinter(
152       llvm::outs(), &Diagnostics.getDiagnosticOptions()));
153   SourceManager SourceMgr(Diagnostics, Files);
154   Rewriter Rewrite(SourceMgr, LangOptions());
155   llvm::MemoryBuffer *Buf = llvm::MemoryBuffer::getMemBuffer(Code, "<stdin>");
156   const clang::FileEntry *Entry =
157       Files.getVirtualFile("<stdin>", Buf->getBufferSize(), 0);
158   SourceMgr.overrideFileContents(Entry, Buf);
159   FileID ID =
160       SourceMgr.createFileID(Entry, SourceLocation(), clang::SrcMgr::C_User);
161   for (Replacements::const_iterator I = Replaces.begin(), E = Replaces.end();
162        I != E; ++I) {
163     Replacement Replace("<stdin>", I->getOffset(), I->getLength(),
164                         I->getReplacementText());
165     if (!Replace.apply(Rewrite))
166       return "";
167   }
168   std::string Result;
169   llvm::raw_string_ostream OS(Result);
170   Rewrite.getEditBuffer(ID).write(OS);
171   OS.flush();
172   return Result;
173 }
174 
175 unsigned shiftedCodePosition(const Replacements &Replaces, unsigned Position) {
176   unsigned NewPosition = Position;
177   for (Replacements::iterator I = Replaces.begin(), E = Replaces.end(); I != E;
178        ++I) {
179     if (I->getOffset() >= Position)
180       break;
181     if (I->getOffset() + I->getLength() > Position)
182       NewPosition += I->getOffset() + I->getLength() - Position;
183     NewPosition += I->getReplacementText().size() - I->getLength();
184   }
185   return NewPosition;
186 }
187 
188 void deduplicate(std::vector<Replacement> &Replaces,
189                  std::vector<Range> &Conflicts) {
190   if (Replaces.empty())
191     return;
192 
193   // Deduplicate
194   std::sort(Replaces.begin(), Replaces.end(), Replacement::Less());
195   std::vector<Replacement>::iterator End =
196       std::unique(Replaces.begin(), Replaces.end());
197   Replaces.erase(End, Replaces.end());
198 
199   // Detect conflicts
200   Range ConflictRange(Replaces.front().getOffset(),
201                       Replaces.front().getLength());
202   unsigned ConflictStart = 0;
203   unsigned ConflictLength = 1;
204   for (unsigned i = 1; i < Replaces.size(); ++i) {
205     Range Current(Replaces[i].getOffset(), Replaces[i].getLength());
206     if (ConflictRange.overlapsWith(Current)) {
207       // Extend conflicted range
208       ConflictRange = Range(ConflictRange.getOffset(),
209                             Current.getOffset() + Current.getLength() -
210                                 ConflictRange.getOffset());
211       ++ConflictLength;
212     } else {
213       if (ConflictLength > 1)
214         Conflicts.push_back(Range(ConflictStart, ConflictLength));
215       ConflictRange = Current;
216       ConflictStart = i;
217       ConflictLength = 1;
218     }
219   }
220 
221   if (ConflictLength > 1)
222     Conflicts.push_back(Range(ConflictStart, ConflictLength));
223 }
224 
225 
226 RefactoringTool::RefactoringTool(const CompilationDatabase &Compilations,
227                                  ArrayRef<std::string> SourcePaths)
228   : ClangTool(Compilations, SourcePaths) {}
229 
230 Replacements &RefactoringTool::getReplacements() { return Replace; }
231 
232 int RefactoringTool::runAndSave(FrontendActionFactory *ActionFactory) {
233   if (int Result = run(ActionFactory)) {
234     return Result;
235   }
236 
237   LangOptions DefaultLangOptions;
238   IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
239   TextDiagnosticPrinter DiagnosticPrinter(llvm::errs(), &*DiagOpts);
240   DiagnosticsEngine Diagnostics(
241       IntrusiveRefCntPtr<DiagnosticIDs>(new DiagnosticIDs()),
242       &*DiagOpts, &DiagnosticPrinter, false);
243   SourceManager Sources(Diagnostics, getFiles());
244   Rewriter Rewrite(Sources, DefaultLangOptions);
245 
246   if (!applyAllReplacements(Rewrite)) {
247     llvm::errs() << "Skipped some replacements.\n";
248   }
249 
250   return saveRewrittenFiles(Rewrite);
251 }
252 
253 bool RefactoringTool::applyAllReplacements(Rewriter &Rewrite) {
254   return tooling::applyAllReplacements(Replace, Rewrite);
255 }
256 
257 int RefactoringTool::saveRewrittenFiles(Rewriter &Rewrite) {
258   for (Rewriter::buffer_iterator I = Rewrite.buffer_begin(),
259                                  E = Rewrite.buffer_end();
260        I != E; ++I) {
261     // FIXME: This code is copied from the FixItRewriter.cpp - I think it should
262     // go into directly into Rewriter (there we also have the Diagnostics to
263     // handle the error cases better).
264     const FileEntry *Entry =
265         Rewrite.getSourceMgr().getFileEntryForID(I->first);
266     std::string ErrorInfo;
267     llvm::raw_fd_ostream FileStream(Entry->getName(), ErrorInfo,
268                                     llvm::sys::fs::F_Binary);
269     if (!ErrorInfo.empty())
270       return 1;
271     I->second.write(FileStream);
272     FileStream.flush();
273   }
274   return 0;
275 }
276 
277 } // end namespace tooling
278 } // end namespace clang
279