Use clang-format for auto-format (replaces libastyle)

.gitignore

@@ -29,6 +29,7 @@ build/windows/launch4j-*.zip
 build/windows/launcher/launch4j
 build/windows/WinAVR-*.zip
 build/macosx/arduino-*.zip
+build/macosx/clang*.zip
 build/macosx/dist/*.tar.gz
 build/macosx/dist/*.tar.bz2
 build/macosx/*.tar.bz2

app/src/cc/arduino/packages/formatter/clangformat/ClangFormat.java

@@ -0,0 +1,186 @@
+/*
+ * This file is part of Arduino.
+ *
+ * Arduino is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * As a special exception, you may use this file as part of a free software
+ * library without restriction.  Specifically, if other files instantiate
+ * templates or use macros or inline functions from this file, or you compile
+ * this file and link it with other files to produce an executable, this
+ * file does not by itself cause the resulting executable to be covered by
+ * the GNU General Public License.  This exception does not however
+ * invalidate any other reasons why the executable file might be covered by
+ * the GNU General Public License.
+ *
+ * Copyright 2021 Arduino LLC (http://www.arduino.cc/)
+ */
+
+package cc.arduino.packages.formatter.clangformat;
+
+import static processing.app.I18n.tr;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+import org.apache.commons.compress.utils.IOUtils;
+
+import com.fasterxml.jackson.databind.DeserializationFeature;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import processing.app.Base;
+import processing.app.BaseNoGui;
+import processing.app.Editor;
+import processing.app.syntax.SketchTextArea;
+
+public class ClangFormat implements Runnable {
+
+  private final String clangExecutable = Base.getContentFile("clang-format")
+      .getAbsolutePath();
+  private Editor editor;
+
+  public ClangFormat(Editor editor) {
+    this.editor = editor;
+  }
+
+  @Override
+  public void run() {
+    SketchTextArea tab = editor.getCurrentTab().getTextArea();
+    String originalText = tab.getText();
+    int cursorOffset = tab.getCaretPosition();
+    try {
+      FormatResult result = runClangFormatOn(originalText, cursorOffset);
+      if (result.FormattedText.equals(originalText)) {
+        editor.statusNotice(tr("No changes necessary for Auto Format."));
+        return;
+      }
+
+      // To keep cursor position after UNDO we produce a bogus edit (insertion
+      // and removal of a " " at cursor position) and we compound this change
+      // with the full auto-format update.
+      tab.beginAtomicEdit();
+      tab.insert(" ", cursorOffset);
+      tab.replaceRange("", cursorOffset, cursorOffset + 1);
+      tab.setText(result.FormattedText);
+      tab.endAtomicEdit();
+
+      tab.setCaretPosition(result.Cursor);
+
+      editor.statusNotice(tr("Auto Format finished."));
+    } catch (IOException | InterruptedException e) {
+      editor.statusError("Auto format error: " + e.getMessage());
+      e.printStackTrace();
+    } catch (ClangException e) {
+      editor.statusError("Auto format error: " + e.getMessage());
+    }
+  }
+
+  private Thread copyAndClose(InputStream input, OutputStream output) {
+    Thread t = new Thread(() -> {
+      try {
+        IOUtils.copy(input, output);
+      } catch (IOException e) {
+        e.printStackTrace();
+      }
+      try {
+        input.close();
+      } catch (IOException e) {
+        e.printStackTrace();
+      }
+      try {
+        output.close();
+      } catch (IOException e) {
+        e.printStackTrace();
+      }
+    });
+    t.start();
+    return t;
+  }
+
+  private File findConfigFile() {
+    // check if sketch has a config file
+    File sketchDir = editor.getSketch().getFolder();
+    if (new File(sketchDir, ".clang-format").isFile()) {
+      return sketchDir;
+    }
+
+    // check if a global config file exists
+    if (BaseNoGui.getSettingsFile(".clang-format").isFile()) {
+      return BaseNoGui.getSettingsFolder();
+    }
+
+    // otherwise: no custom configs, return Arduino IDE app dir.
+    return new File(clangExecutable).getParentFile();
+  }
+
+  FormatResult runClangFormatOn(String source, int cursorOffset)
+      throws IOException, InterruptedException, ClangException {
+    String cmd[] = new String[] { clangExecutable, "--cursor=" + cursorOffset };
+
+    Process process = Runtime.getRuntime().exec(cmd, null, findConfigFile());
+    ByteArrayOutputStream clangOutput = new ByteArrayOutputStream();
+    ByteArrayOutputStream clangError = new ByteArrayOutputStream();
+    ByteArrayInputStream dataOut = new ByteArrayInputStream(source.getBytes());
+
+    Thread in = copyAndClose(dataOut, process.getOutputStream());
+    Thread err = copyAndClose(process.getErrorStream(), clangError);
+    Thread out = copyAndClose(process.getInputStream(), clangOutput);
+
+    int r = process.waitFor();
+    in.join();
+    out.join();
+    err.join();
+
+    if (r != 0) {
+      throw new ClangException(clangError.toString());
+    }
+
+    // clang-format will output first a JSON object with:
+    // - the resulting cursor position and
+    // - a flag teling if the conversion was successful
+    // for example:
+    //
+    // { "Cursor": 34, "IncompleteFormat": false }
+    ObjectMapper mapper = new ObjectMapper();
+    mapper.configure(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY, true);
+    mapper.configure(DeserializationFeature.EAGER_DESERIALIZER_FETCH, true);
+    mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
+    FormatResult res = mapper.readValue(clangOutput.toByteArray(),
+                                        FormatResult.class);
+
+    // After the JSON object above clang-format will output the formatted source
+    // code in plain text
+    String formattedText = clangOutput.toString();
+    formattedText = formattedText.substring(formattedText.indexOf('}') + 1);
+    // handle different line endings
+    res.FormattedText = formattedText.replaceFirst("\\R", "");
+    return res;
+  }
+}
+
+class ClangException extends Exception {
+  public ClangException(String string) {
+    super(string);
+  }
+}
+
+class FormatResult {
+  public String FormattedText;
+  public int Cursor;
+  public boolean IncompleteFormat;
+}