xref: /llvm-project/clang/tools/clang-format/ClangFormat.cpp (revision 5553d0d4cadc35733a910e7af5f8911105ff529d)
1 //===-- clang-format/ClangFormat.cpp - Clang format tool ------------------===//
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 /// \file
11 /// \brief This file implements a clang-format tool that automatically formats
12 /// (fragments of) C++ code.
13 ///
14 //===----------------------------------------------------------------------===//
15 
16 #include "clang/Basic/Diagnostic.h"
17 #include "clang/Basic/DiagnosticOptions.h"
18 #include "clang/Basic/FileManager.h"
19 #include "clang/Basic/SourceManager.h"
20 #include "clang/Format/Format.h"
21 #include "clang/Lex/Lexer.h"
22 #include "clang/Rewrite/Core/Rewriter.h"
23 #include "llvm/ADT/StringMap.h"
24 #include "llvm/Support/Debug.h"
25 #include "llvm/Support/FileSystem.h"
26 #include "llvm/Support/Signals.h"
27 
28 using namespace llvm;
29 
30 static cl::opt<bool> Help("h", cl::desc("Alias for -help"), cl::Hidden);
31 
32 // Mark all our options with this category, everything else (except for -version
33 // and -help) will be hidden.
34 cl::OptionCategory ClangFormatCategory("Clang-format options");
35 
36 static cl::list<unsigned>
37     Offsets("offset",
38             cl::desc("Format a range starting at this byte offset.\n"
39                      "Multiple ranges can be formatted by specifying\n"
40                      "several -offset and -length pairs.\n"
41                      "Can only be used with one input file."),
42             cl::cat(ClangFormatCategory));
43 static cl::list<unsigned>
44     Lengths("length",
45             cl::desc("Format a range of this length (in bytes).\n"
46                      "Multiple ranges can be formatted by specifying\n"
47                      "several -offset and -length pairs.\n"
48                      "When only a single -offset is specified without\n"
49                      "-length, clang-format will format up to the end\n"
50                      "of the file.\n"
51                      "Can only be used with one input file."),
52             cl::cat(ClangFormatCategory));
53 static cl::list<std::string>
54 LineRanges("lines", cl::desc("<start line>:<end line> - format a range of\n"
55                              "lines (both 1-based).\n"
56                              "Multiple ranges can be formatted by specifying\n"
57                              "several -lines arguments.\n"
58                              "Can't be used with -offset and -length.\n"
59                              "Can only be used with one input file."),
60            cl::cat(ClangFormatCategory));
61 static cl::opt<std::string>
62     Style("style",
63           cl::desc(clang::format::StyleOptionHelpDescription),
64           cl::init("file"), cl::cat(ClangFormatCategory));
65 static cl::opt<std::string>
66 FallbackStyle("fallback-style",
67               cl::desc("The name of the predefined style used as a fallback in "
68                        "case clang-format is invoked with -style=file, but can "
69                        "not find the .clang-format file to use."),
70               cl::init("LLVM"), cl::cat(ClangFormatCategory));
71 
72 static cl::opt<std::string>
73 AssumeFilename("assume-filename",
74                cl::desc("When reading from stdin, clang-format assumes this\n"
75                         "filename to look for a style config file (with\n"
76                         "-style=file)."),
77                cl::cat(ClangFormatCategory));
78 
79 static cl::opt<bool> Inplace("i",
80                              cl::desc("Inplace edit <file>s, if specified."),
81                              cl::cat(ClangFormatCategory));
82 
83 static cl::opt<bool> OutputXML("output-replacements-xml",
84                                cl::desc("Output replacements as XML."),
85                                cl::cat(ClangFormatCategory));
86 static cl::opt<bool>
87     DumpConfig("dump-config",
88                cl::desc("Dump configuration options to stdout and exit.\n"
89                         "Can be used with -style option."),
90                cl::cat(ClangFormatCategory));
91 static cl::opt<unsigned>
92     Cursor("cursor",
93            cl::desc("The position of the cursor when invoking\n"
94                     "clang-format from an editor integration"),
95            cl::init(0), cl::cat(ClangFormatCategory));
96 
97 static cl::list<std::string> FileNames(cl::Positional, cl::desc("[<file> ...]"),
98                                        cl::cat(ClangFormatCategory));
99 
100 namespace clang {
101 namespace format {
102 
103 static FileID createInMemoryFile(StringRef FileName, const MemoryBuffer *Source,
104                                  SourceManager &Sources, FileManager &Files) {
105   const FileEntry *Entry = Files.getVirtualFile(FileName == "-" ? "<stdin>" :
106                                                     FileName,
107                                                 Source->getBufferSize(), 0);
108   Sources.overrideFileContents(Entry, Source, true);
109   return Sources.createFileID(Entry, SourceLocation(), SrcMgr::C_User);
110 }
111 
112 // Parses <start line>:<end line> input to a pair of line numbers.
113 // Returns true on error.
114 static bool parseLineRange(StringRef Input, unsigned &FromLine,
115                            unsigned &ToLine) {
116   std::pair<StringRef, StringRef> LineRange = Input.split(':');
117   return LineRange.first.getAsInteger(0, FromLine) ||
118          LineRange.second.getAsInteger(0, ToLine);
119 }
120 
121 static bool fillRanges(SourceManager &Sources, FileID ID,
122                        const MemoryBuffer *Code,
123                        std::vector<CharSourceRange> &Ranges) {
124   if (!LineRanges.empty()) {
125     if (!Offsets.empty() || !Lengths.empty()) {
126       llvm::errs() << "error: cannot use -lines with -offset/-length\n";
127       return true;
128     }
129 
130     for (unsigned i = 0, e = LineRanges.size(); i < e; ++i) {
131       unsigned FromLine, ToLine;
132       if (parseLineRange(LineRanges[i], FromLine, ToLine)) {
133         llvm::errs() << "error: invalid <start line>:<end line> pair\n";
134         return true;
135       }
136       if (FromLine > ToLine) {
137         llvm::errs() << "error: start line should be less than end line\n";
138         return true;
139       }
140       SourceLocation Start = Sources.translateLineCol(ID, FromLine, 1);
141       SourceLocation End = Sources.translateLineCol(ID, ToLine, UINT_MAX);
142       if (Start.isInvalid() || End.isInvalid())
143         return true;
144       Ranges.push_back(CharSourceRange::getCharRange(Start, End));
145     }
146     return false;
147   }
148 
149   if (Offsets.empty())
150     Offsets.push_back(0);
151   if (Offsets.size() != Lengths.size() &&
152       !(Offsets.size() == 1 && Lengths.empty())) {
153     llvm::errs()
154         << "error: number of -offset and -length arguments must match.\n";
155     return true;
156   }
157   for (unsigned i = 0, e = Offsets.size(); i != e; ++i) {
158     if (Offsets[i] >= Code->getBufferSize()) {
159       llvm::errs() << "error: offset " << Offsets[i]
160                    << " is outside the file\n";
161       return true;
162     }
163     SourceLocation Start =
164         Sources.getLocForStartOfFile(ID).getLocWithOffset(Offsets[i]);
165     SourceLocation End;
166     if (i < Lengths.size()) {
167       if (Offsets[i] + Lengths[i] > Code->getBufferSize()) {
168         llvm::errs() << "error: invalid length " << Lengths[i]
169                      << ", offset + length (" << Offsets[i] + Lengths[i]
170                      << ") is outside the file.\n";
171         return true;
172       }
173       End = Start.getLocWithOffset(Lengths[i]);
174     } else {
175       End = Sources.getLocForEndOfFile(ID);
176     }
177     Ranges.push_back(CharSourceRange::getCharRange(Start, End));
178   }
179   return false;
180 }
181 
182 static void outputReplacementXML(StringRef Text) {
183   size_t From = 0;
184   size_t Index;
185   while ((Index = Text.find_first_of("\n\r", From)) != StringRef::npos) {
186     llvm::outs() << Text.substr(From, Index - From);
187     switch (Text[Index]) {
188     case '\n':
189       llvm::outs() << "&#10;";
190       break;
191     case '\r':
192       llvm::outs() << "&#13;";
193       break;
194     default:
195       llvm_unreachable("Unexpected character encountered!");
196     }
197     From = Index + 1;
198   }
199   llvm::outs() << Text.substr(From);
200 }
201 
202 // Returns true on error.
203 static bool format(StringRef FileName) {
204   FileManager Files((FileSystemOptions()));
205   DiagnosticsEngine Diagnostics(
206       IntrusiveRefCntPtr<DiagnosticIDs>(new DiagnosticIDs),
207       new DiagnosticOptions);
208   SourceManager Sources(Diagnostics, Files);
209   OwningPtr<MemoryBuffer> Code;
210   if (error_code ec = MemoryBuffer::getFileOrSTDIN(FileName, Code)) {
211     llvm::errs() << ec.message() << "\n";
212     return true;
213   }
214   if (Code->getBufferSize() == 0)
215     return false; // Empty files are formatted correctly.
216   FileID ID = createInMemoryFile(FileName, Code.get(), Sources, Files);
217   std::vector<CharSourceRange> Ranges;
218   if (fillRanges(Sources, ID, Code.get(), Ranges))
219     return true;
220 
221   FormatStyle FormatStyle = getStyle(
222       Style, (FileName == "-") ? AssumeFilename : FileName, FallbackStyle);
223   Lexer Lex(ID, Sources.getBuffer(ID), Sources,
224             getFormattingLangOpts(FormatStyle.Standard));
225   tooling::Replacements Replaces = reformat(FormatStyle, Lex, Sources, Ranges);
226   if (OutputXML) {
227     llvm::outs()
228         << "<?xml version='1.0'?>\n<replacements xml:space='preserve'>\n";
229     for (tooling::Replacements::const_iterator I = Replaces.begin(),
230                                                E = Replaces.end();
231          I != E; ++I) {
232       llvm::outs() << "<replacement "
233                    << "offset='" << I->getOffset() << "' "
234                    << "length='" << I->getLength() << "'>";
235       outputReplacementXML(I->getReplacementText());
236       llvm::outs() << "</replacement>\n";
237     }
238     llvm::outs() << "</replacements>\n";
239   } else {
240     Rewriter Rewrite(Sources, LangOptions());
241     tooling::applyAllReplacements(Replaces, Rewrite);
242     if (Inplace) {
243       if (Rewrite.overwriteChangedFiles())
244         return true;
245     } else {
246       if (Cursor.getNumOccurrences() != 0)
247         outs() << "{ \"Cursor\": " << tooling::shiftedCodePosition(
248                                           Replaces, Cursor) << " }\n";
249       Rewrite.getEditBuffer(ID).write(outs());
250     }
251   }
252   return false;
253 }
254 
255 }  // namespace format
256 }  // namespace clang
257 
258 int main(int argc, const char **argv) {
259   llvm::sys::PrintStackTraceOnErrorSignal();
260 
261   // Hide unrelated options.
262   StringMap<cl::Option*> Options;
263   cl::getRegisteredOptions(Options);
264   for (StringMap<cl::Option *>::iterator I = Options.begin(), E = Options.end();
265        I != E; ++I) {
266     if (I->second->Category != &ClangFormatCategory && I->first() != "help" &&
267         I->first() != "version")
268       I->second->setHiddenFlag(cl::ReallyHidden);
269   }
270 
271   cl::ParseCommandLineOptions(
272       argc, argv,
273       "A tool to format C/C++/Obj-C code.\n\n"
274       "If no arguments are specified, it formats the code from standard input\n"
275       "and writes the result to the standard output.\n"
276       "If <file>s are given, it reformats the files. If -i is specified\n"
277       "together with <file>s, the files are edited in-place. Otherwise, the\n"
278       "result is written to the standard output.\n");
279 
280   if (Help)
281     cl::PrintHelpMessage();
282 
283   if (DumpConfig) {
284     std::string Config =
285         clang::format::configurationAsText(clang::format::getStyle(
286             Style, FileNames.empty() ? AssumeFilename : FileNames[0],
287             FallbackStyle));
288     llvm::outs() << Config << "\n";
289     return 0;
290   }
291 
292   bool Error = false;
293   switch (FileNames.size()) {
294   case 0:
295     Error = clang::format::format("-");
296     break;
297   case 1:
298     Error = clang::format::format(FileNames[0]);
299     break;
300   default:
301     if (!Offsets.empty() || !Lengths.empty() || !LineRanges.empty()) {
302       llvm::errs() << "error: -offset, -length and -lines can only be used for "
303                       "single file.\n";
304       return 1;
305     }
306     for (unsigned i = 0; i < FileNames.size(); ++i)
307       Error |= clang::format::format(FileNames[i]);
308     break;
309   }
310   return Error ? 1 : 0;
311 }
312