blob: c1c4d3261dfafd9378e7d7b7601b129096c99ebd [file] [log] [blame]
.. title:: clang-tidy - bugprone-string-literal-with-embedded-nul
Finds occurrences of string literal with embedded NUL character and validates
their usage.
Invalid escaping
Special characters can be escaped within a string literal by using their
hexadecimal encoding like ``\x42``. A common mistake is to escape them
like this ``\0x42`` where the ``\0`` stands for the NUL character.
.. code-block:: c++
const char* Example[] = "Invalid character: \0x12 should be \x12";
const char* Bytes[] = "\x03\0x02\0x01\0x00\0xFF\0xFF\0xFF";
Truncated literal
String-like classes can manipulate strings with embedded NUL as they are keeping
track of the bytes and the length. This is not the case for a ``char*``
(NUL-terminated) string.
A common mistake is to pass a string-literal with embedded NUL to a string
constructor expecting a NUL-terminated string. The bytes after the first NUL
character are truncated.
.. code-block:: c++
std::string str("abc\0def"); // "def" is truncated
str += "\0"; // This statement is doing nothing
if (str == "\0abc") return; // This expression is always true