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