tidy - bugprone-string-literal-with-embedded-nul — Extra Clang Tools 22.0.0git documentation (original) (raw)

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.

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 achar* (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.

std::string str("abc\0def"); // "def" is truncated str += "\0"; // This statement is doing nothing if (str == "\0abc") return; // This expression is always true