On 2022-12-12 2:07 AM, Frederic Berat wrote:
This patch is mainly a proposal. While the macro can simply be removed as explained below, another possibility it to add a flex option "--never-interactive" to prevent flex to make use of "isatty". This is related to an effort to prepare Automake for future GCC/Clang versions which set c99 as default standard to be used. Future version of flex make the "NO_UNISTD" flag a no-op, and include unistd.h by default. In current version of flex, not having this header leads to implicit function declarations that are not compatible with c99 standard. On top of that, while flex dedicated test were having this macro set, the yacc ones didn't have it despise their use of Flex. Thus, if this macro was ever useful, it looks like nobody actually cared.
I'm guessing that the idea here was to avoid using unistd.h on platforms that don't supply that header at all. I suggest that we should apply your patch *and* consistently test flex with "--never-interactive".
zw
