On Sun, 27 Oct 2024, 07:59 Johannes Krottmayer via Gcc-help, < gcc-help@xxxxxxxxxxx> wrote: > Hi! > > Exists there a soft limit (warning when the limit is exceeded) when an > identifier is longer than 63 (intern) or 31 (extern) characters, when > at least the -std=c99 is set? > No, see https://gcc.gnu.org/onlinedocs/cpp/Implementation-limits.html "The preprocessor treats all characters as significant. The C standard requires only that the first 63 be significant." > Extract from C99 specification in section 5.2.4.1: > > - 63 significant initial characters in an internal identifier or a macro > name (each universal character name or extended source character is > considered a single character) > - 31 significant initial characters in an external identifier (each > universal character name specifying a short identifier of 0000FFFF or > less is considered 6 characters, each universal character name > specifying a short identifier of 00010000 or more is considered 10 > characters, and each extended source character is considered the same > number of characters as the corresponding universal character name, if any) > > Source: http://port70.net/%7Ensz/c/c99/n1256.html#5.2.4.1 > > Kind regards, > > Johannes >
