xref: /llvm-project/clang/tools/clang-format/ClangFormat.cpp (revision b00d66e6ac9bd12b6988fcbc1c287b0490ec97c5)
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/Basic/Version.h"
21 #include "clang/Format/Format.h"
22 #include "clang/Lex/Lexer.h"
23 #include "clang/Rewrite/Core/Rewriter.h"
24 #include "llvm/ADT/StringMap.h"
25 #include "llvm/Support/Debug.h"
26 #include "llvm/Support/FileSystem.h"
27 #include "llvm/Support/Signals.h"
28 
29 using namespace llvm;
30 
31 static cl::opt<bool> Help("h", cl::desc("Alias for -help"), cl::Hidden);
32 
33 // Mark all our options with this category, everything else (except for -version
34 // and -help) will be hidden.
35 cl::OptionCategory ClangFormatCategory("Clang-format options");
36 
37 static cl::list<unsigned>
38     Offsets("offset",
39             cl::desc("Format a range starting at this byte offset.\n"
40                      "Multiple ranges can be formatted by specifying\n"
41                      "several -offset and -length pairs.\n"
42                      "Can only be used with one input file."),
43             cl::cat(ClangFormatCategory));
44 static cl::list<unsigned>
45     Lengths("length",
46             cl::desc("Format a range of this length (in bytes).\n"
47                      "Multiple ranges can be formatted by specifying\n"
48                      "several -offset and -length pairs.\n"
49                      "When only a single -offset is specified without\n"
50                      "-length, clang-format will format up to the end\n"
51                      "of the file.\n"
52                      "Can only be used with one input file."),
53             cl::cat(ClangFormatCategory));
54 static cl::list<std::string>
55 LineRanges("lines", cl::desc("<start line>:<end line> - format a range of\n"
56                              "lines (both 1-based).\n"
57                              "Multiple ranges can be formatted by specifying\n"
58                              "several -lines arguments.\n"
59                              "Can't be used with -offset and -length.\n"
60                              "Can only be used with one input file."),
61            cl::cat(ClangFormatCategory));
62 static cl::opt<std::string>
63     Style("style",
64           cl::desc(clang::format::StyleOptionHelpDescription),
65           cl::init("file"), cl::cat(ClangFormatCategory));
66 static cl::opt<std::string>
67 FallbackStyle("fallback-style",
68               cl::desc("The name of the predefined style used as a fallback in "
69                        "case clang-format is invoked with -style=file, but can "
70                        "not find the .clang-format file to use."),
71               cl::init("LLVM"), cl::cat(ClangFormatCategory));
72 
73 static cl::opt<std::string>
74 AssumeFilename("assume-filename",
75                cl::desc("When reading from stdin, clang-format assumes this\n"
76                         "filename to look for a style config file (with\n"
77                         "-style=file)."),
78                cl::cat(ClangFormatCategory));
79 
80 static cl::opt<bool> Inplace("i",
81                              cl::desc("Inplace edit <file>s, if specified."),
82                              cl::cat(ClangFormatCategory));
83 
84 static cl::opt<bool> OutputXML("output-replacements-xml",
85                                cl::desc("Output replacements as XML."),
86                                cl::cat(ClangFormatCategory));
87 static cl::opt<bool>
88     DumpConfig("dump-config",
89                cl::desc("Dump configuration options to stdout and exit.\n"
90                         "Can be used with -style option."),
91                cl::cat(ClangFormatCategory));
92 static cl::opt<unsigned>
93     Cursor("cursor",
94            cl::desc("The position of the cursor when invoking\n"
95                     "clang-format from an editor integration"),
96            cl::init(0), cl::cat(ClangFormatCategory));
97 
98 static cl::list<std::string> FileNames(cl::Positional, cl::desc("[<file> ...]"),
99                                        cl::cat(ClangFormatCategory));
100 
101 namespace clang {
102 namespace format {
103 
104 static FileID createInMemoryFile(StringRef FileName, const MemoryBuffer *Source,
105                                  SourceManager &Sources, FileManager &Files) {
106   const FileEntry *Entry = Files.getVirtualFile(FileName == "-" ? "<stdin>" :
107                                                     FileName,
108                                                 Source->getBufferSize(), 0);
109   Sources.overrideFileContents(Entry, Source, true);
110   return Sources.createFileID(Entry, SourceLocation(), SrcMgr::C_User);
111 }
112 
113 // Parses <start line>:<end line> input to a pair of line numbers.
114 // Returns true on error.
115 static bool parseLineRange(StringRef Input, unsigned &FromLine,
116                            unsigned &ToLine) {
117   std::pair<StringRef, StringRef> LineRange = Input.split(':');
118   return LineRange.first.getAsInteger(0, FromLine) ||
119          LineRange.second.getAsInteger(0, ToLine);
120 }
121 
122 static bool fillRanges(SourceManager &Sources, FileID ID,
123                        const MemoryBuffer *Code,
124                        std::vector<CharSourceRange> &Ranges) {
125   if (!LineRanges.empty()) {
126     if (!Offsets.empty() || !Lengths.empty()) {
127       llvm::errs() << "error: cannot use -lines with -offset/-length\n";
128       return true;
129     }
130 
131     for (unsigned i = 0, e = LineRanges.size(); i < e; ++i) {
132       unsigned FromLine, ToLine;
133       if (parseLineRange(LineRanges[i], FromLine, ToLine)) {
134         llvm::errs() << "error: invalid <start line>:<end line> pair\n";
135         return true;
136       }
137       if (FromLine > ToLine) {
138         llvm::errs() << "error: start line should be less than end line\n";
139         return true;
140       }
141       SourceLocation Start = Sources.translateLineCol(ID, FromLine, 1);
142       SourceLocation End = Sources.translateLineCol(ID, ToLine, UINT_MAX);
143       if (Start.isInvalid() || End.isInvalid())
144         return true;
145       Ranges.push_back(CharSourceRange::getCharRange(Start, End));
146     }
147     return false;
148   }
149 
150   if (Offsets.empty())
151     Offsets.push_back(0);
152   if (Offsets.size() != Lengths.size() &&
153       !(Offsets.size() == 1 && Lengths.empty())) {
154     llvm::errs()
155         << "error: number of -offset and -length arguments must match.\n";
156     return true;
157   }
158   for (unsigned i = 0, e = Offsets.size(); i != e; ++i) {
159     if (Offsets[i] >= Code->getBufferSize()) {
160       llvm::errs() << "error: offset " << Offsets[i]
161                    << " is outside the file\n";
162       return true;
163     }
164     SourceLocation Start =
165         Sources.getLocForStartOfFile(ID).getLocWithOffset(Offsets[i]);
166     SourceLocation End;
167     if (i < Lengths.size()) {
168       if (Offsets[i] + Lengths[i] > Code->getBufferSize()) {
169         llvm::errs() << "error: invalid length " << Lengths[i]
170                      << ", offset + length (" << Offsets[i] + Lengths[i]
171                      << ") is outside the file.\n";
172         return true;
173       }
174       End = Start.getLocWithOffset(Lengths[i]);
175     } else {
176       End = Sources.getLocForEndOfFile(ID);
177     }
178     Ranges.push_back(CharSourceRange::getCharRange(Start, End));
179   }
180   return false;
181 }
182 
183 static void outputReplacementXML(StringRef Text) {
184   size_t From = 0;
185   size_t Index;
186   while ((Index = Text.find_first_of("\n\r", From)) != StringRef::npos) {
187     llvm::outs() << Text.substr(From, Index - From);
188     switch (Text[Index]) {
189     case '\n':
190       llvm::outs() << "&#10;";
191       break;
192     case '\r':
193       llvm::outs() << "&#13;";
194       break;
195     default:
196       llvm_unreachable("Unexpected character encountered!");
197     }
198     From = Index + 1;
199   }
200   llvm::outs() << Text.substr(From);
201 }
202 
203 // Returns true on error.
204 static bool format(StringRef FileName) {
205   FileManager Files((FileSystemOptions()));
206   DiagnosticsEngine Diagnostics(
207       IntrusiveRefCntPtr<DiagnosticIDs>(new DiagnosticIDs),
208       new DiagnosticOptions);
209   SourceManager Sources(Diagnostics, Files);
210   OwningPtr<MemoryBuffer> Code;
211   if (error_code ec = MemoryBuffer::getFileOrSTDIN(FileName, Code)) {
212     llvm::errs() << ec.message() << "\n";
213     return true;
214   }
215   if (Code->getBufferSize() == 0)
216     return false; // Empty files are formatted correctly.
217   FileID ID = createInMemoryFile(FileName, Code.get(), Sources, Files);
218   std::vector<CharSourceRange> Ranges;
219   if (fillRanges(Sources, ID, Code.get(), Ranges))
220     return true;
221 
222   FormatStyle FormatStyle = getStyle(
223       Style, (FileName == "-") ? AssumeFilename : FileName, FallbackStyle);
224   Lexer Lex(ID, Sources.getBuffer(ID), Sources,
225             getFormattingLangOpts(FormatStyle.Standard));
226   tooling::Replacements Replaces = reformat(FormatStyle, Lex, Sources, Ranges);
227   if (OutputXML) {
228     llvm::outs()
229         << "<?xml version='1.0'?>\n<replacements xml:space='preserve'>\n";
230     for (tooling::Replacements::const_iterator I = Replaces.begin(),
231                                                E = Replaces.end();
232          I != E; ++I) {
233       llvm::outs() << "<replacement "
234                    << "offset='" << I->getOffset() << "' "
235                    << "length='" << I->getLength() << "'>";
236       outputReplacementXML(I->getReplacementText());
237       llvm::outs() << "</replacement>\n";
238     }
239     llvm::outs() << "</replacements>\n";
240   } else {
241     Rewriter Rewrite(Sources, LangOptions());
242     tooling::applyAllReplacements(Replaces, Rewrite);
243     if (Inplace) {
244       if (Rewrite.overwriteChangedFiles())
245         return true;
246     } else {
247       if (Cursor.getNumOccurrences() != 0)
248         outs() << "{ \"Cursor\": " << tooling::shiftedCodePosition(
249                                           Replaces, Cursor) << " }\n";
250       Rewrite.getEditBuffer(ID).write(outs());
251     }
252   }
253   return false;
254 }
255 
256 }  // namespace format
257 }  // namespace clang
258 
259 static void PrintVersion() {
260   raw_ostream &OS = outs();
261   OS << clang::getClangToolFullVersion("clang-format") << '\n';
262 }
263 
264 int main(int argc, const char **argv) {
265   llvm::sys::PrintStackTraceOnErrorSignal();
266 
267   // Hide unrelated options.
268   StringMap<cl::Option*> Options;
269   cl::getRegisteredOptions(Options);
270   for (StringMap<cl::Option *>::iterator I = Options.begin(), E = Options.end();
271        I != E; ++I) {
272     if (I->second->Category != &ClangFormatCategory && I->first() != "help" &&
273         I->first() != "version")
274       I->second->setHiddenFlag(cl::ReallyHidden);
275   }
276 
277   cl::SetVersionPrinter(PrintVersion);
278   cl::ParseCommandLineOptions(
279       argc, argv,
280       "A tool to format C/C++/Obj-C code.\n\n"
281       "If no arguments are specified, it formats the code from standard input\n"
282       "and writes the result to the standard output.\n"
283       "If <file>s are given, it reformats the files. If -i is specified\n"
284       "together with <file>s, the files are edited in-place. Otherwise, the\n"
285       "result is written to the standard output.\n");
286 
287   if (Help)
288     cl::PrintHelpMessage();
289 
290   if (DumpConfig) {
291     std::string Config =
292         clang::format::configurationAsText(clang::format::getStyle(
293             Style, FileNames.empty() ? AssumeFilename : FileNames[0],
294             FallbackStyle));
295     llvm::outs() << Config << "\n";
296     return 0;
297   }
298 
299   bool Error = false;
300   switch (FileNames.size()) {
301   case 0:
302     Error = clang::format::format("-");
303     break;
304   case 1:
305     Error = clang::format::format(FileNames[0]);
306     break;
307   default:
308     if (!Offsets.empty() || !Lengths.empty() || !LineRanges.empty()) {
309       llvm::errs() << "error: -offset, -length and -lines can only be used for "
310                       "single file.\n";
311       return 1;
312     }
313     for (unsigned i = 0; i < FileNames.size(); ++i)
314       Error |= clang::format::format(FileNames[i]);
315     break;
316   }
317   return Error ? 1 : 0;
318 }
319