8.170 --signed_chars, --unsigned_chars

Makes the char type signed or unsigned.

When char is signed, the macro __FEATURE_SIGNED_CHAR is also defined by the compiler.


  • Care must be taken when mixing translation units that have been compiled with and without this option, and that share interfaces or data structures.

  • The ARM ABI defines char as an unsigned byte, and this is the interpretation used by the C++ libraries.


The default is --unsigned_chars.

Related reference
10.155 Predefined macros
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