// Find and unescape a string.
private String readString() {
StringBuilder sb = new StringBuilder();
char c = next();
if (c != '"') throw new RuntimeException("expecting start of string");
while (true)
switch (c = next()) {
case '"':
return sb.toString();
case '\\':
sb.append(readEscaped());
continue;
default:
if (Character.isISOControl(c)) throw new RuntimeException("illegal character in string");
sb.append(c);
}
}
@Override
public void visitFile(PsiFile file) {
super.visitFile(file);
if (InjectedLanguageManager.getInstance(file.getProject()).isInjectedFragment(file)
|| !file.isPhysical()) {
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;
do {
nextChar++;
if (nextChar >= length) {
break;
}
} while (text.charAt(nextChar) == 'u'); // \uuuu0061 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 (Character.isISOControl(d)) {
continue;
}
byteBuffer.clear();
charBuffer.clear();
charBuffer.put(d).rewind();
final CoderResult coderResult = encoder.encode(charBuffer, byteBuffer, true);
if (!coderResult.isUnmappable()) {
final PsiElement element = file.findElementAt(i);
if (element != null && isSuppressedFor(element)) {
return;
}
registerErrorAtOffset(file, i, escapeEnd - i, Character.valueOf(d));
}
}
}
}
