xref: /llvm-project/clang/tools/clang-format/ClangFormat.cpp (revision 3fbee010c6b55fda1e34b424e331e418c96e917f)
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/FileSystem.h"
24 #include "llvm/Support/Signals.h"
25 
26 using namespace llvm;
27 
28 static cl::opt<bool> Help("h", cl::desc("Alias for -help"), cl::Hidden);
29 
30 static cl::list<unsigned>
31 Offsets("offset", cl::desc("Format a range starting at this file offset. Can "
32                            "only be used with one input file."));
33 static cl::list<unsigned>
34 Lengths("length", cl::desc("Format a range of this length. "
35                            "When it's not specified, end of file is used. "
36                            "Can only be used with one input file."));
37 static cl::opt<std::string> Style(
38     "style",
39     cl::desc("Coding style, currently supports: LLVM, Google, Chromium."),
40     cl::init("LLVM"));
41 static cl::opt<bool> Inplace("i",
42                              cl::desc("Inplace edit <file>s, if specified."));
43 
44 static cl::opt<bool> OutputXML(
45     "output-replacements-xml", cl::desc("Output replacements as XML."));
46 
47 static cl::list<std::string> FileNames(cl::Positional,
48                                        cl::desc("[<file> ...]"));
49 
50 namespace clang {
51 namespace format {
52 
53 static FileID createInMemoryFile(StringRef FileName, const MemoryBuffer *Source,
54                                  SourceManager &Sources, FileManager &Files) {
55   const FileEntry *Entry = Files.getVirtualFile(FileName == "-" ? "<stdin>" :
56                                                     FileName,
57                                                 Source->getBufferSize(), 0);
58   Sources.overrideFileContents(Entry, Source, true);
59   return Sources.createFileID(Entry, SourceLocation(), SrcMgr::C_User);
60 }
61 
62 static FormatStyle getStyle() {
63   FormatStyle TheStyle = getGoogleStyle();
64   if (Style == "LLVM")
65     TheStyle = getLLVMStyle();
66   if (Style == "Chromium")
67     TheStyle = getChromiumStyle();
68   return TheStyle;
69 }
70 
71 // Returns true on error.
72 static bool format(std::string FileName) {
73   FileManager Files((FileSystemOptions()));
74   DiagnosticsEngine Diagnostics(
75       IntrusiveRefCntPtr<DiagnosticIDs>(new DiagnosticIDs),
76       new DiagnosticOptions);
77   SourceManager Sources(Diagnostics, Files);
78   OwningPtr<MemoryBuffer> Code;
79   if (error_code ec = MemoryBuffer::getFileOrSTDIN(FileName, Code)) {
80     llvm::errs() << ec.message() << "\n";
81     return true;
82   }
83   FileID ID = createInMemoryFile(FileName, Code.get(), Sources, Files);
84   Lexer Lex(ID, Sources.getBuffer(ID), Sources, getFormattingLangOpts());
85   if (Offsets.empty())
86     Offsets.push_back(0);
87   if (Offsets.size() != Lengths.size() &&
88       !(Offsets.size() == 1 && Lengths.empty())) {
89     llvm::errs()
90         << "error: number of -offset and -length arguments must match.\n";
91     return true;
92   }
93   std::vector<CharSourceRange> Ranges;
94   for (unsigned i = 0, e = Offsets.size(); i != e; ++i) {
95     if (Offsets[i] >= Code->getBufferSize()) {
96       llvm::errs() << "error: offset " << Offsets[i]
97                    << " is outside the file\n";
98       return true;
99     }
100     SourceLocation Start =
101         Sources.getLocForStartOfFile(ID).getLocWithOffset(Offsets[i]);
102     SourceLocation End;
103     if (i < Lengths.size()) {
104       if (Offsets[i] + Lengths[i] > Code->getBufferSize()) {
105         llvm::errs() << "error: invalid length " << Lengths[i]
106                      << ", offset + length (" << Offsets[i] + Lengths[i]
107                      << ") is outside the file.\n";
108         return true;
109       }
110       End = Start.getLocWithOffset(Lengths[i]);
111     } else {
112       End = Sources.getLocForEndOfFile(ID);
113     }
114     Ranges.push_back(CharSourceRange::getCharRange(Start, End));
115   }
116   tooling::Replacements Replaces = reformat(getStyle(), Lex, Sources, Ranges);
117   if (OutputXML) {
118     llvm::outs()
119         << "<?xml version='1.0'?>\n<replacements xml:space='preserve'>\n";
120     for (tooling::Replacements::const_iterator I = Replaces.begin(),
121                                                E = Replaces.end();
122          I != E; ++I) {
123       llvm::outs() << "<replacement "
124                    << "offset='" << I->getOffset() << "' "
125                    << "length='" << I->getLength() << "'>"
126                    << I->getReplacementText() << "</replacement>\n";
127     }
128     llvm::outs() << "</replacements>\n";
129   } else {
130     Rewriter Rewrite(Sources, LangOptions());
131     tooling::applyAllReplacements(Replaces, Rewrite);
132     if (Inplace) {
133       if (Replaces.size() == 0)
134         return false; // Nothing changed, don't touch the file.
135 
136       std::string ErrorInfo;
137       llvm::raw_fd_ostream FileStream(FileName.c_str(), ErrorInfo,
138                                       llvm::raw_fd_ostream::F_Binary);
139       if (!ErrorInfo.empty()) {
140         llvm::errs() << "Error while writing file: " << ErrorInfo << "\n";
141         return true;
142       }
143       Rewrite.getEditBuffer(ID).write(FileStream);
144       FileStream.flush();
145     } else {
146       Rewrite.getEditBuffer(ID).write(outs());
147     }
148   }
149   return false;
150 }
151 
152 }  // namespace format
153 }  // namespace clang
154 
155 int main(int argc, const char **argv) {
156   llvm::sys::PrintStackTraceOnErrorSignal();
157   cl::ParseCommandLineOptions(
158       argc, argv,
159       "A tool to format C/C++/Obj-C code.\n\n"
160       "If no arguments are specified, it formats the code from standard input\n"
161       "and writes the result to the standard output.\n"
162       "If <file>s are given, it reformats the files. If -i is specified \n"
163       "together with <file>s, the files are edited in-place. Otherwise, the \n"
164       "result is written to the standard output.\n");
165 
166   if (Help)
167     cl::PrintHelpMessage();
168 
169   bool Error = false;
170   switch (FileNames.size()) {
171   case 0:
172     Error = clang::format::format("-");
173     break;
174   case 1:
175     Error = clang::format::format(FileNames[0]);
176     break;
177   default:
178     if (!Offsets.empty() || !Lengths.empty()) {
179       llvm::errs() << "error: \"-offset\" and \"-length\" can only be used for "
180                       "single file.\n";
181       return 1;
182     }
183     for (unsigned i = 0; i < FileNames.size(); ++i)
184       Error |= clang::format::format(FileNames[i]);
185     break;
186   }
187   return Error ? 1 : 0;
188 }
189