1//===-- ClangFormatPackages.cs - VSPackage for clang-format ------*- C# -*-===//
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// This class contains a VS extension package that runs clang-format over a
11// selection in a VS text editor.
12//
13//===----------------------------------------------------------------------===//
14
15using Microsoft.VisualStudio.Editor;
16using Microsoft.VisualStudio.Shell;
17using Microsoft.VisualStudio.Shell.Interop;
18using Microsoft.VisualStudio.Text;
19using Microsoft.VisualStudio.Text.Editor;
20using Microsoft.VisualStudio.TextManager.Interop;
21using System;
22using System.ComponentModel;
23using System.ComponentModel.Design;
24using System.IO;
25using System.Reflection;
26using System.Runtime.InteropServices;
27using System.Xml.Linq;
28
29namespace LLVM.ClangFormat
30{
31    [ClassInterface(ClassInterfaceType.AutoDual)]
32    [CLSCompliant(false), ComVisible(true)]
33    public class OptionPageGrid : DialogPage
34    {
35        private string style = "File";
36
37        [Category("LLVM/Clang")]
38        [DisplayName("Style")]
39        [Description("Coding style, currently supports:\n" +
40                     "  - Predefined styles ('LLVM', 'Google', 'Chromium', 'Mozilla').\n" +
41                     "  - 'File' to search for a YAML .clang-format or _clang-format\n" +
42                     "    configuration file.\n" +
43                     "  - A YAML configuration snippet.\n\n" +
44                     "'File':\n" +
45                     "  Searches for a .clang-format or _clang-format configuration file\n" +
46                     "  in the source file's directory and its parents.\n\n" +
47                     "YAML configuration snippet:\n" +
48                     "  The content of a .clang-format configuration file, as string.\n" +
49                     "  Example: '{BasedOnStyle: \"LLVM\", IndentWidth: 8}'\n\n" +
50                     "See also: http://clang.llvm.org/docs/ClangFormatStyleOptions.html.")]
51        public string Style
52        {
53            get { return style; }
54            set { style = value; }
55        }
56    }
57
58    [PackageRegistration(UseManagedResourcesOnly = true)]
59    [InstalledProductRegistration("#110", "#112", "1.0", IconResourceID = 400)]
60    [ProvideMenuResource("Menus.ctmenu", 1)]
61    [Guid(GuidList.guidClangFormatPkgString)]
62    [ProvideOptionPage(typeof(OptionPageGrid), "LLVM/Clang", "ClangFormat", 0, 0, true)]
63    public sealed class ClangFormatPackage : Package
64    {
65        #region Package Members
66        protected override void Initialize()
67        {
68            base.Initialize();
69
70            var commandService = GetService(typeof(IMenuCommandService)) as OleMenuCommandService;
71            if (commandService != null)
72            {
73                var menuCommandID = new CommandID(GuidList.guidClangFormatCmdSet, (int)PkgCmdIDList.cmdidClangFormat);
74                var menuItem = new MenuCommand(MenuItemCallback, menuCommandID);
75                commandService.AddCommand(menuItem);
76            }
77        }
78        #endregion
79
80        private void MenuItemCallback(object sender, EventArgs args)
81        {
82            IWpfTextView view = GetCurrentView();
83            if (view == null)
84                // We're not in a text view.
85                return;
86            string text = view.TextBuffer.CurrentSnapshot.GetText();
87            int start = view.Selection.Start.Position.GetContainingLine().Start.Position;
88            int end = view.Selection.End.Position.GetContainingLine().End.Position;
89            int length = end - start;
90            // clang-format doesn't support formatting a range that starts at the end
91            // of the file.
92            if (start >= text.Length && text.Length > 0)
93                start = text.Length - 1;
94            string path = GetDocumentParent(view);
95            try
96            {
97                var root = XElement.Parse(RunClangFormat(text, start, length, path));
98                var edit = view.TextBuffer.CreateEdit();
99                foreach (XElement replacement in root.Descendants("replacement"))
100                {
101                    var span = new Span(
102                        int.Parse(replacement.Attribute("offset").Value),
103                        int.Parse(replacement.Attribute("length").Value));
104                    edit.Replace(span, replacement.Value);
105                }
106                edit.Apply();
107            }
108            catch (Exception e)
109            {
110                var uiShell = (IVsUIShell)GetService(typeof(SVsUIShell));
111                var id = Guid.Empty;
112                int result;
113                uiShell.ShowMessageBox(
114                        0, ref id,
115                        "Error while running clang-format:",
116                        e.Message,
117                        string.Empty, 0,
118                        OLEMSGBUTTON.OLEMSGBUTTON_OK,
119                        OLEMSGDEFBUTTON.OLEMSGDEFBUTTON_FIRST,
120                        OLEMSGICON.OLEMSGICON_INFO,
121                        0, out result);
122            }
123        }
124
125        /// <summary>
126        /// Runs the given text through clang-format and returns the replacements as XML.
127        ///
128        /// Formats the text range starting at offset of the given length.
129        /// </summary>
130        private string RunClangFormat(string text, int offset, int length, string path)
131        {
132            string vsixPath = Path.GetDirectoryName(
133                typeof(ClangFormatPackage).Assembly.Location);
134
135            System.Diagnostics.Process process = new System.Diagnostics.Process();
136            process.StartInfo.UseShellExecute = false;
137            process.StartInfo.FileName = vsixPath + "\\clang-format.exe";
138            // Poor man's escaping - this will not work when quotes are already escaped
139            // in the input (but we don't need more).
140            string style = GetStyle().Replace("\"", "\\\"");
141            process.StartInfo.Arguments = " -offset " + offset +
142                                          " -length " + length +
143                                          " -output-replacements-xml " +
144                                          " -style \"" + style + "\"";
145            process.StartInfo.CreateNoWindow = true;
146            process.StartInfo.RedirectStandardInput = true;
147            process.StartInfo.RedirectStandardOutput = true;
148            process.StartInfo.RedirectStandardError = true;
149            if (path != null)
150                process.StartInfo.WorkingDirectory = path;
151            // We have to be careful when communicating via standard input / output,
152            // as writes to the buffers will block until they are read from the other side.
153            // Thus, we:
154            // 1. Start the process - clang-format.exe will start to read the input from the
155            //    standard input.
156            try
157            {
158                process.Start();
159            }
160            catch (Exception e)
161            {
162                throw new Exception(
163                    "Cannot execute " + process.StartInfo.FileName + ".\n\"" +
164                    e.Message + "\".\nPlease make sure it is on the PATH.");
165            }
166            // 2. We write everything to the standard output - this cannot block, as clang-format
167            //    reads the full standard input before analyzing it without writing anything to the
168            //    standard output.
169            process.StandardInput.Write(text);
170            // 3. We notify clang-format that the input is done - after this point clang-format
171            //    will start analyzing the input and eventually write the output.
172            process.StandardInput.Close();
173            // 4. We must read clang-format's output before waiting for it to exit; clang-format
174            //    will close the channel by exiting.
175            string output = process.StandardOutput.ReadToEnd();
176            // 5. clang-format is done, wait until it is fully shut down.
177            process.WaitForExit();
178            if (process.ExitCode != 0)
179            {
180                // FIXME: If clang-format writes enough to the standard error stream to block,
181                // we will never reach this point; instead, read the standard error asynchronously.
182                throw new Exception(process.StandardError.ReadToEnd());
183            }
184            return output;
185        }
186
187        /// <summary>
188        /// Returns the currently active view if it is a IWpfTextView.
189        /// </summary>
190        private IWpfTextView GetCurrentView()
191        {
192            // The SVsTextManager is a service through which we can get the active view.
193            var textManager = (IVsTextManager)Package.GetGlobalService(typeof(SVsTextManager));
194            IVsTextView textView;
195            textManager.GetActiveView(1, null, out textView);
196
197            // Now we have the active view as IVsTextView, but the text interfaces we need
198            // are in the IWpfTextView.
199            var userData = (IVsUserData)textView;
200            if (userData == null)
201                return null;
202            Guid guidWpfViewHost = DefGuidList.guidIWpfTextViewHost;
203            object host;
204            userData.GetData(ref guidWpfViewHost, out host);
205            return ((IWpfTextViewHost)host).TextView;
206        }
207
208        private string GetStyle()
209        {
210            var page = (OptionPageGrid)GetDialogPage(typeof(OptionPageGrid));
211            return page.Style;
212        }
213
214        private string GetDocumentParent(IWpfTextView view)
215        {
216            ITextDocument document;
217            if (view.TextBuffer.Properties.TryGetProperty(typeof(ITextDocument), out document))
218            {
219                return Directory.GetParent(document.FilePath).ToString();
220            }
221            return null;
222        }
223    }
224}
225