xref: /llvm-project/clang/tools/clang-format/ClangFormat.cpp (revision 006b5c89cec1ae5de19bcbef71c04c74754594fb)
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 
81 static cl::list<std::string> FileNames(cl::Positional, cl::desc("[<file> ...]"),
82                                        cl::cat(ClangFormatCategory));
83 
84 namespace clang {
85 namespace format {
86 
87 static FileID createInMemoryFile(StringRef FileName, const MemoryBuffer *Source,
88                                  SourceManager &Sources, FileManager &Files) {
89   const FileEntry *Entry = Files.getVirtualFile(FileName == "-" ? "<stdin>" :
90                                                     FileName,
91                                                 Source->getBufferSize(), 0);
92   Sources.overrideFileContents(Entry, Source, true);
93   return Sources.createFileID(Entry, SourceLocation(), SrcMgr::C_User);
94 }
95 
96 FormatStyle getStyle(StringRef StyleName, StringRef FileName) {
97   FormatStyle Style;
98   getPredefinedStyle(DefaultStyle, &Style);
99 
100   if (StyleName.startswith("{")) {
101     // Parse YAML/JSON style from the command line.
102     if (error_code ec = parseConfiguration(StyleName, &Style)) {
103       llvm::errs() << "Error parsing -style: " << ec.message()
104                    << ", using " << DefaultStyle << " style\n";
105     }
106     return Style;
107   }
108 
109   if (!StyleName.equals_lower("file")) {
110     if (!getPredefinedStyle(StyleName, &Style))
111       llvm::errs() << "Invalid value for -style, using " << DefaultStyle
112                    << " style\n";
113     return Style;
114   }
115 
116   SmallString<128> Path(FileName);
117   llvm::sys::fs::make_absolute(Path);
118   for (StringRef Directory = llvm::sys::path::parent_path(Path);
119        !Directory.empty();
120        Directory = llvm::sys::path::parent_path(Directory)) {
121     SmallString<128> ConfigFile(Directory);
122     llvm::sys::path::append(ConfigFile, ".clang-format");
123     DEBUG(llvm::dbgs() << "Trying " << ConfigFile << "...\n");
124     bool IsFile = false;
125     // Ignore errors from is_regular_file: we only need to know if we can read
126     // the file or not.
127     llvm::sys::fs::is_regular_file(Twine(ConfigFile), IsFile);
128     if (IsFile) {
129       OwningPtr<MemoryBuffer> Text;
130       if (error_code ec = MemoryBuffer::getFile(ConfigFile, Text)) {
131         llvm::errs() << ec.message() << "\n";
132         continue;
133       }
134       if (error_code ec = parseConfiguration(Text->getBuffer(), &Style)) {
135         llvm::errs() << "Error reading " << ConfigFile << ": " << ec.message()
136                      << "\n";
137         continue;
138       }
139       DEBUG(llvm::dbgs() << "Using configuration file " << ConfigFile << "\n");
140       return Style;
141     }
142   }
143   llvm::errs() << "Can't find usable .clang-format, using " << DefaultStyle
144                << " style\n";
145   return Style;
146 }
147 
148 // Returns true on error.
149 static bool format(std::string FileName) {
150   FileManager Files((FileSystemOptions()));
151   DiagnosticsEngine Diagnostics(
152       IntrusiveRefCntPtr<DiagnosticIDs>(new DiagnosticIDs),
153       new DiagnosticOptions);
154   SourceManager Sources(Diagnostics, Files);
155   OwningPtr<MemoryBuffer> Code;
156   if (error_code ec = MemoryBuffer::getFileOrSTDIN(FileName, Code)) {
157     llvm::errs() << ec.message() << "\n";
158     return true;
159   }
160   FileID ID = createInMemoryFile(FileName, Code.get(), Sources, Files);
161   Lexer Lex(ID, Sources.getBuffer(ID), Sources, getFormattingLangOpts());
162   if (Offsets.empty())
163     Offsets.push_back(0);
164   if (Offsets.size() != Lengths.size() &&
165       !(Offsets.size() == 1 && Lengths.empty())) {
166     llvm::errs()
167         << "error: number of -offset and -length arguments must match.\n";
168     return true;
169   }
170   std::vector<CharSourceRange> Ranges;
171   for (unsigned i = 0, e = Offsets.size(); i != e; ++i) {
172     if (Offsets[i] >= Code->getBufferSize()) {
173       llvm::errs() << "error: offset " << Offsets[i]
174                    << " is outside the file\n";
175       return true;
176     }
177     SourceLocation Start =
178         Sources.getLocForStartOfFile(ID).getLocWithOffset(Offsets[i]);
179     SourceLocation End;
180     if (i < Lengths.size()) {
181       if (Offsets[i] + Lengths[i] > Code->getBufferSize()) {
182         llvm::errs() << "error: invalid length " << Lengths[i]
183                      << ", offset + length (" << Offsets[i] + Lengths[i]
184                      << ") is outside the file.\n";
185         return true;
186       }
187       End = Start.getLocWithOffset(Lengths[i]);
188     } else {
189       End = Sources.getLocForEndOfFile(ID);
190     }
191     Ranges.push_back(CharSourceRange::getCharRange(Start, End));
192   }
193   tooling::Replacements Replaces =
194       reformat(getStyle(Style, FileName), Lex, Sources, Ranges);
195   if (OutputXML) {
196     llvm::outs()
197         << "<?xml version='1.0'?>\n<replacements xml:space='preserve'>\n";
198     for (tooling::Replacements::const_iterator I = Replaces.begin(),
199                                                E = Replaces.end();
200          I != E; ++I) {
201       llvm::outs() << "<replacement "
202                    << "offset='" << I->getOffset() << "' "
203                    << "length='" << I->getLength() << "'>"
204                    << I->getReplacementText() << "</replacement>\n";
205     }
206     llvm::outs() << "</replacements>\n";
207   } else {
208     Rewriter Rewrite(Sources, LangOptions());
209     tooling::applyAllReplacements(Replaces, Rewrite);
210     if (Inplace) {
211       if (Replaces.size() == 0)
212         return false; // Nothing changed, don't touch the file.
213 
214       std::string ErrorInfo;
215       llvm::raw_fd_ostream FileStream(FileName.c_str(), ErrorInfo,
216                                       llvm::raw_fd_ostream::F_Binary);
217       if (!ErrorInfo.empty()) {
218         llvm::errs() << "Error while writing file: " << ErrorInfo << "\n";
219         return true;
220       }
221       Rewrite.getEditBuffer(ID).write(FileStream);
222       FileStream.flush();
223     } else {
224       Rewrite.getEditBuffer(ID).write(outs());
225     }
226   }
227   return false;
228 }
229 
230 }  // namespace format
231 }  // namespace clang
232 
233 int main(int argc, const char **argv) {
234   llvm::sys::PrintStackTraceOnErrorSignal();
235 
236   // Hide unrelated options.
237   StringMap<cl::Option*> Options;
238   cl::getRegisteredOptions(Options);
239   for (StringMap<cl::Option *>::iterator I = Options.begin(), E = Options.end();
240        I != E; ++I) {
241     if (I->second->Category != &ClangFormatCategory && I->first() != "help" &&
242         I->first() != "version")
243       I->second->setHiddenFlag(cl::ReallyHidden);
244   }
245 
246   cl::ParseCommandLineOptions(
247       argc, argv,
248       "A tool to format C/C++/Obj-C code.\n\n"
249       "If no arguments are specified, it formats the code from standard input\n"
250       "and writes the result to the standard output.\n"
251       "If <file>s are given, it reformats the files. If -i is specified \n"
252       "together with <file>s, the files are edited in-place. Otherwise, the \n"
253       "result is written to the standard output.\n");
254 
255   if (Help)
256     cl::PrintHelpMessage();
257 
258   if (DumpConfig) {
259     std::string Config = clang::format::configurationAsText(
260         clang::format::getStyle(Style, FileNames.empty() ? "-" : FileNames[0]));
261     llvm::outs() << Config << "\n";
262     return 0;
263   }
264 
265   bool Error = false;
266   switch (FileNames.size()) {
267   case 0:
268     Error = clang::format::format("-");
269     break;
270   case 1:
271     Error = clang::format::format(FileNames[0]);
272     break;
273   default:
274     if (!Offsets.empty() || !Lengths.empty()) {
275       llvm::errs() << "error: \"-offset\" and \"-length\" can only be used for "
276                       "single file.\n";
277       return 1;
278     }
279     for (unsigned i = 0; i < FileNames.size(); ++i)
280       Error |= clang::format::format(FileNames[i]);
281     break;
282   }
283   return Error ? 1 : 0;
284 }
285