xref: /llvm-project/clang/tools/clang-format/ClangFormat.cpp (revision 4b14f4f9e6dc5af3e3529bf6d0335aebf14b4455)
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<int> Offsets(
31     "offset", cl::desc("Format a range starting at this file offset."));
32 static cl::list<int> Lengths(
33     "length", cl::desc("Format a range of this length, -1 for end of file."));
34 static cl::opt<std::string> Style(
35     "style",
36     cl::desc("Coding style, currently supports: LLVM, Google, Chromium."),
37     cl::init("LLVM"));
38 static cl::opt<bool> Inplace("i",
39                              cl::desc("Inplace edit <file>, if specified."));
40 
41 static cl::opt<bool> OutputXML(
42     "output-replacements-xml", cl::desc("Output replacements as XML."));
43 
44 static cl::opt<std::string> FileName(cl::Positional, cl::desc("[<file>]"),
45                                      cl::init("-"));
46 
47 namespace clang {
48 namespace format {
49 
50 static FileID createInMemoryFile(StringRef FileName, const MemoryBuffer *Source,
51                                  SourceManager &Sources, FileManager &Files) {
52   const FileEntry *Entry = Files.getVirtualFile(FileName == "-" ? "<stdin>" :
53                                                     FileName,
54                                                 Source->getBufferSize(), 0);
55   Sources.overrideFileContents(Entry, Source, true);
56   return Sources.createFileID(Entry, SourceLocation(), SrcMgr::C_User);
57 }
58 
59 static FormatStyle getStyle() {
60   FormatStyle TheStyle = getGoogleStyle();
61   if (Style == "LLVM")
62     TheStyle = getLLVMStyle();
63   if (Style == "Chromium")
64     TheStyle = getChromiumStyle();
65   return TheStyle;
66 }
67 
68 static void format() {
69   FileManager Files((FileSystemOptions()));
70   DiagnosticsEngine Diagnostics(
71       IntrusiveRefCntPtr<DiagnosticIDs>(new DiagnosticIDs),
72       new DiagnosticOptions);
73   SourceManager Sources(Diagnostics, Files);
74   OwningPtr<MemoryBuffer> Code;
75   if (error_code ec = MemoryBuffer::getFileOrSTDIN(FileName, Code)) {
76     llvm::errs() << ec.message() << "\n";
77     return;
78   }
79   FileID ID = createInMemoryFile(FileName, Code.get(), Sources, Files);
80   Lexer Lex(ID, Sources.getBuffer(ID), Sources, getFormattingLangOpts());
81   if (Offsets.empty())
82     Offsets.push_back(0);
83   if (Offsets.size() != Lengths.size() &&
84       !(Offsets.size() == 1 && Lengths.empty())) {
85     llvm::errs() << "Number of -offset and -length arguments must match.\n";
86     return;
87   }
88   std::vector<CharSourceRange> Ranges;
89   for (cl::list<int>::size_type i = 0, e = Offsets.size(); i != e; ++i) {
90     SourceLocation Start =
91         Sources.getLocForStartOfFile(ID).getLocWithOffset(Offsets[i]);
92     SourceLocation End;
93     if (i < Lengths.size()) {
94       End = Start.getLocWithOffset(Lengths[i]);
95     } else {
96       End = Sources.getLocForEndOfFile(ID);
97     }
98     Ranges.push_back(CharSourceRange::getCharRange(Start, End));
99   }
100   tooling::Replacements Replaces = reformat(getStyle(), Lex, Sources, Ranges);
101   if (OutputXML) {
102     llvm::outs() << "<?xml version='1.0'?>\n<replacements xml:space='preserve'>\n";
103     for (tooling::Replacements::const_iterator I = Replaces.begin(),
104                                                E = Replaces.end();
105          I != E; ++I) {
106       llvm::outs() << "<replacement "
107                    << "offset='" << I->getOffset() << "' "
108                    << "length='" << I->getLength() << "'>"
109                    << I->getReplacementText() << "</replacement>\n";
110     }
111     llvm::outs() << "</replacements>\n";
112   } else {
113     Rewriter Rewrite(Sources, LangOptions());
114     tooling::applyAllReplacements(Replaces, Rewrite);
115     if (Inplace) {
116       if (Replaces.size() == 0)
117         return; // Nothing changed, don't touch the file.
118 
119       std::string ErrorInfo;
120       llvm::raw_fd_ostream FileStream(FileName.c_str(), ErrorInfo,
121                                       llvm::raw_fd_ostream::F_Binary);
122       if (!ErrorInfo.empty()) {
123         llvm::errs() << "Error while writing file: " << ErrorInfo << "\n";
124         return;
125       }
126       Rewrite.getEditBuffer(ID).write(FileStream);
127       FileStream.flush();
128     } else {
129       Rewrite.getEditBuffer(ID).write(outs());
130     }
131   }
132 }
133 
134 }  // namespace format
135 }  // namespace clang
136 
137 int main(int argc, const char **argv) {
138   llvm::sys::PrintStackTraceOnErrorSignal();
139   cl::ParseCommandLineOptions(
140       argc, argv,
141       "A tool to format C/C++/Obj-C code.\n\n"
142       "If no arguments are specified, it formats the code from standard input\n"
143       "and writes the result to the standard output.\n"
144       "If <file> is given, it reformats the file. If -i is specified together\n"
145       "with <file>, the file is edited in-place. Otherwise, the result is\n"
146       "written to the standard output.\n");
147   if (Help)
148     cl::PrintHelpMessage();
149   clang::format::format();
150   return 0;
151 }
152