void (@NotNull PsiFile file) { super.visitFile(file); if (InjectedLanguageManager.getInstance(file.getProject()).isInjectedFragment(file) || !file.isPhysical()) { return; } final Document document = PsiDocumentManager.getInstance(file.getProject()).getDocument(file); if (document == null) { return; } final VirtualFile virtualFile = file.getVirtualFile(); final String text = file.getText(); final Charset charset = LoadTextUtil.extractCharsetFromFileContent(file.getProject(), virtualFile, text); final CharsetEncoder encoder = charset.newEncoder().onUnmappableCharacter(CodingErrorAction.REPORT); final CharBuffer charBuffer = CharBuffer.allocate(1); final ByteBuffer byteBuffer = ByteBuffer.allocate(10); final int length = text.length(); for (int i = 0; i < length; i++) { final char c = text.charAt(i); if (c != '\\') { continue; } boolean isEscape = true; int previousChar = i - 1; while (previousChar >= 0 && text.charAt(previousChar) == '\\') { isEscape = !isEscape; previousChar--; } if (!isEscape) { continue; } int nextChar = i + 1; while (nextChar < length && text.charAt(nextChar) == 'u') { nextChar++; // \uuuuFFFD is a legal Unicode escape } if (nextChar == i + 1 || nextChar + 3 >= length) { continue; } if (StringUtil.isHexDigit(text.charAt(nextChar)) && StringUtil.isHexDigit(text.charAt(nextChar + 1)) && StringUtil.isHexDigit(text.charAt(nextChar + 2)) && StringUtil.isHexDigit(text.charAt(nextChar + 3))) { final int escapeEnd = nextChar + 4; final char d = (char)Integer.parseInt(text.substring(nextChar, escapeEnd), 16); if (d == '\uFFFD') { // this character is used as a replacement when a unicode character can't be displayed // replacing the escape with the character may cause confusion, so ignore it. continue; } final int type = Character.getType(d); if (type == Character.CONTROL && d != '\n' && d != '\t') { continue; } else if (type == Character.FORMAT || type == Character.PRIVATE_USE || type == Character.SURROGATE || type == Character.UNASSIGNED || type == Character.LINE_SEPARATOR || type == Character.PARAGRAPH_SEPARATOR) { continue; } if (type == Character.SPACE_SEPARATOR && d != ' ') { continue; } byteBuffer.clear(); charBuffer.clear(); charBuffer.put(d).rewind(); final CoderResult coderResult = encoder.encode(charBuffer, byteBuffer, true); if (coderResult.isError()) { continue; } PsiElement element = file.findElementAt(i); if (element == null) { return; } final RangeMarker rangeMarker = document.createRangeMarker(i, escapeEnd); TextRange range = element.getTextRange(); while (escapeEnd > range.getEndOffset()) { element = element.getParent(); range = element.getTextRange(); } registerErrorAtOffset(element, i - range.getStartOffset(), escapeEnd - i, Character.valueOf(d), rangeMarker); } } }