xref: /llvm-project/clang/tools/clang-format/ClangFormat.cpp (revision 1e80887d6314e3d34b0f1c4aa6ffef9999fba8ec)
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/Support/Debug.h"
24 #include "llvm/Support/FileSystem.h"
25 #include "llvm/Support/Signals.h"
26 #include "llvm/ADT/StringMap.h"
27 
28 using namespace llvm;
29 
30 // Default style to use when no style specified or specified style not found.
31 static const char *DefaultStyle = "LLVM";
32 
33 static cl::opt<bool> Help("h", cl::desc("Alias for -help"), cl::Hidden);
34 
35 // Mark all our options with this category, everything else (except for -version
36 // and -help) will be hidden.
37 cl::OptionCategory ClangFormatCategory("Clang-format options");
38 
39 static cl::list<unsigned>
40     Offsets("offset",
41             cl::desc("Format a range starting at this byte offset.\n"
42                      "Multiple ranges can be formatted by specifying\n"
43                      "several -offset and -length pairs.\n"
44                      "Can only be used with one input file."),
45             cl::cat(ClangFormatCategory));
46 static cl::list<unsigned>
47     Lengths("length",
48             cl::desc("Format a range of this length (in bytes).\n"
49                      "Multiple ranges can be formatted by specifying\n"
50                      "several -offset and -length pairs.\n"
51                      "When only a single -offset is specified without\n"
52                      "-length, clang-format will format up to the end\n"
53                      "of the file.\n"
54                      "Can only be used with one input file."),
55             cl::cat(ClangFormatCategory));
56 static cl::opt<std::string>
57     Style("style",
58           cl::desc("Coding style, currently supports:\n"
59                    "  LLVM, Google, Chromium, Mozilla.\n"
60                    "Use -style=file to load style configuration from\n"
61                    ".clang-format file located in one of the parent\n"
62                    "directories of the source file (or current\n"
63                    "directory for stdin).\n"
64                    "Use -style=\"{key: value, ...}\" to set specific\n"
65                    "parameters, e.g.:\n"
66                    "  -style=\"{BasedOnStyle: llvm, IndentWidth: 8}\""),
67           cl::init(DefaultStyle), cl::cat(ClangFormatCategory));
68 static cl::opt<bool> Inplace("i",
69                              cl::desc("Inplace edit <file>s, if specified."),
70                              cl::cat(ClangFormatCategory));
71 
72 static cl::opt<bool> OutputXML("output-replacements-xml",
73                                cl::desc("Output replacements as XML."),
74                                cl::cat(ClangFormatCategory));
75 static cl::opt<bool>
76     DumpConfig("dump-config",
77                cl::desc("Dump configuration options to stdout and exit.\n"
78                         "Can be used with -style option."),
79                cl::cat(ClangFormatCategory));
80 static cl::opt<unsigned>
81     Cursor("cursor",
82            cl::desc("The position of the cursor when invoking clang-format from"
83                     " an editor integration"),
84            cl::init(0), cl::cat(ClangFormatCategory));
85 
86 static cl::list<std::string> FileNames(cl::Positional, cl::desc("[<file> ...]"),
87                                        cl::cat(ClangFormatCategory));
88 
89 namespace clang {
90 namespace format {
91 
92 static FileID createInMemoryFile(StringRef FileName, const MemoryBuffer *Source,
93                                  SourceManager &Sources, FileManager &Files) {
94   const FileEntry *Entry = Files.getVirtualFile(FileName == "-" ? "<stdin>" :
95                                                     FileName,
96                                                 Source->getBufferSize(), 0);
97   Sources.overrideFileContents(Entry, Source, true);
98   return Sources.createFileID(Entry, SourceLocation(), SrcMgr::C_User);
99 }
100 
101 FormatStyle getStyle(StringRef StyleName, StringRef FileName) {
102   FormatStyle Style;
103   getPredefinedStyle(DefaultStyle, &Style);
104 
105   if (StyleName.startswith("{")) {
106     // Parse YAML/JSON style from the command line.
107     if (error_code ec = parseConfiguration(StyleName, &Style)) {
108       llvm::errs() << "Error parsing -style: " << ec.message()
109                    << ", using " << DefaultStyle << " style\n";
110     }
111     return Style;
112   }
113 
114   if (!StyleName.equals_lower("file")) {
115     if (!getPredefinedStyle(StyleName, &Style))
116       llvm::errs() << "Invalid value for -style, using " << DefaultStyle
117                    << " style\n";
118     return Style;
119   }
120 
121   SmallString<128> Path(FileName);
122   llvm::sys::fs::make_absolute(Path);
123   for (StringRef Directory = llvm::sys::path::parent_path(Path);
124        !Directory.empty();
125        Directory = llvm::sys::path::parent_path(Directory)) {
126     SmallString<128> ConfigFile(Directory);
127     llvm::sys::path::append(ConfigFile, ".clang-format");
128     DEBUG(llvm::dbgs() << "Trying " << ConfigFile << "...\n");
129     bool IsFile = false;
130     // Ignore errors from is_regular_file: we only need to know if we can read
131     // the file or not.
132     llvm::sys::fs::is_regular_file(Twine(ConfigFile), IsFile);
133     if (IsFile) {
134       OwningPtr<MemoryBuffer> Text;
135       if (error_code ec = MemoryBuffer::getFile(ConfigFile, Text)) {
136         llvm::errs() << ec.message() << "\n";
137         continue;
138       }
139       if (error_code ec = parseConfiguration(Text->getBuffer(), &Style)) {
140         llvm::errs() << "Error reading " << ConfigFile << ": " << ec.message()
141                      << "\n";
142         continue;
143       }
144       DEBUG(llvm::dbgs() << "Using configuration file " << ConfigFile << "\n");
145       return Style;
146     }
147   }
148   llvm::errs() << "Can't find usable .clang-format, using " << DefaultStyle
149                << " style\n";
150   return Style;
151 }
152 
153 // Returns true on error.
154 static bool format(std::string FileName) {
155   FileManager Files((FileSystemOptions()));
156   DiagnosticsEngine Diagnostics(
157       IntrusiveRefCntPtr<DiagnosticIDs>(new DiagnosticIDs),
158       new DiagnosticOptions);
159   SourceManager Sources(Diagnostics, Files);
160   OwningPtr<MemoryBuffer> Code;
161   if (error_code ec = MemoryBuffer::getFileOrSTDIN(FileName, Code)) {
162     llvm::errs() << ec.message() << "\n";
163     return true;
164   }
165   FileID ID = createInMemoryFile(FileName, Code.get(), Sources, Files);
166   if (Offsets.empty())
167     Offsets.push_back(0);
168   if (Offsets.size() != Lengths.size() &&
169       !(Offsets.size() == 1 && Lengths.empty())) {
170     llvm::errs()
171         << "error: number of -offset and -length arguments must match.\n";
172     return true;
173   }
174   std::vector<CharSourceRange> Ranges;
175   for (unsigned i = 0, e = Offsets.size(); i != e; ++i) {
176     if (Offsets[i] >= Code->getBufferSize()) {
177       llvm::errs() << "error: offset " << Offsets[i]
178                    << " is outside the file\n";
179       return true;
180     }
181     SourceLocation Start =
182         Sources.getLocForStartOfFile(ID).getLocWithOffset(Offsets[i]);
183     SourceLocation End;
184     if (i < Lengths.size()) {
185       if (Offsets[i] + Lengths[i] > Code->getBufferSize()) {
186         llvm::errs() << "error: invalid length " << Lengths[i]
187                      << ", offset + length (" << Offsets[i] + Lengths[i]
188                      << ") is outside the file.\n";
189         return true;
190       }
191       End = Start.getLocWithOffset(Lengths[i]);
192     } else {
193       End = Sources.getLocForEndOfFile(ID);
194     }
195     Ranges.push_back(CharSourceRange::getCharRange(Start, End));
196   }
197   FormatStyle FormatStyle = getStyle(Style, FileName);
198   Lexer Lex(ID, Sources.getBuffer(ID), Sources,
199             getFormattingLangOpts(FormatStyle.Standard));
200   tooling::Replacements Replaces = reformat(FormatStyle, Lex, Sources, Ranges);
201   if (OutputXML) {
202     llvm::outs()
203         << "<?xml version='1.0'?>\n<replacements xml:space='preserve'>\n";
204     for (tooling::Replacements::const_iterator I = Replaces.begin(),
205                                                E = Replaces.end();
206          I != E; ++I) {
207       llvm::outs() << "<replacement "
208                    << "offset='" << I->getOffset() << "' "
209                    << "length='" << I->getLength() << "'>"
210                    << I->getReplacementText() << "</replacement>\n";
211     }
212     llvm::outs() << "</replacements>\n";
213   } else {
214     Rewriter Rewrite(Sources, LangOptions());
215     tooling::applyAllReplacements(Replaces, Rewrite);
216     if (Inplace) {
217       if (Replaces.size() == 0)
218         return false; // Nothing changed, don't touch the file.
219 
220       std::string ErrorInfo;
221       llvm::raw_fd_ostream FileStream(FileName.c_str(), ErrorInfo,
222                                       llvm::raw_fd_ostream::F_Binary);
223       if (!ErrorInfo.empty()) {
224         llvm::errs() << "Error while writing file: " << ErrorInfo << "\n";
225         return true;
226       }
227       Rewrite.getEditBuffer(ID).write(FileStream);
228       FileStream.flush();
229     } else {
230       if (Cursor.getNumOccurrences() != 0)
231         outs() << "{ \"Cursor\": " << tooling::shiftedCodePosition(
232                                           Replaces, Cursor) << " }\n";
233       Rewrite.getEditBuffer(ID).write(outs());
234     }
235   }
236   return false;
237 }
238 
239 }  // namespace format
240 }  // namespace clang
241 
242 int main(int argc, const char **argv) {
243   llvm::sys::PrintStackTraceOnErrorSignal();
244 
245   // Hide unrelated options.
246   StringMap<cl::Option*> Options;
247   cl::getRegisteredOptions(Options);
248   for (StringMap<cl::Option *>::iterator I = Options.begin(), E = Options.end();
249        I != E; ++I) {
250     if (I->second->Category != &ClangFormatCategory && I->first() != "help" &&
251         I->first() != "version")
252       I->second->setHiddenFlag(cl::ReallyHidden);
253   }
254 
255   cl::ParseCommandLineOptions(
256       argc, argv,
257       "A tool to format C/C++/Obj-C code.\n\n"
258       "If no arguments are specified, it formats the code from standard input\n"
259       "and writes the result to the standard output.\n"
260       "If <file>s are given, it reformats the files. If -i is specified \n"
261       "together with <file>s, the files are edited in-place. Otherwise, the \n"
262       "result is written to the standard output.\n");
263 
264   if (Help)
265     cl::PrintHelpMessage();
266 
267   if (DumpConfig) {
268     std::string Config = clang::format::configurationAsText(
269         clang::format::getStyle(Style, FileNames.empty() ? "-" : FileNames[0]));
270     llvm::outs() << Config << "\n";
271     return 0;
272   }
273 
274   bool Error = false;
275   switch (FileNames.size()) {
276   case 0:
277     Error = clang::format::format("-");
278     break;
279   case 1:
280     Error = clang::format::format(FileNames[0]);
281     break;
282   default:
283     if (!Offsets.empty() || !Lengths.empty()) {
284       llvm::errs() << "error: \"-offset\" and \"-length\" can only be used for "
285                       "single file.\n";
286       return 1;
287     }
288     for (unsigned i = 0; i < FileNames.size(); ++i)
289       Error |= clang::format::format(FileNames[i]);
290     break;
291   }
292   return Error ? 1 : 0;
293 }
294