+2021-05-24 Bruno Haible <bruno@clisp.org>
+
+ c-stack: Document another restriction.
+ Triggered by a discussion with Paul Eggert.
+ * lib/c-stack.h: Mention that ACTION should not use nested functions.
+
2021-05-22 Bruno Haible <bruno@clisp.org>
stdio: Fix compilation error on DragonFly BSD.
A null ACTION acts like an action that does nothing.
- ACTION must be async-signal-safe. ACTION together with its callees
- must not require more than 64 KiB of stack space. Also,
- ACTION should not call longjmp, because this implementation does
- not guarantee that it is safe to return to the original stack.
+ Restrictions:
+ - ACTION must be async-signal-safe.
+ - ACTION together with its callees must not require more than 64 KiB of
+ stack space.
+ - ACTION must not create and then invoke nested functions
+ <https://gcc.gnu.org/onlinedocs/gcc/Nested-Functions.html>, because
+ this implementation does not guarantee an executable stack.
+ - ACTION should not call longjmp, because this implementation does not
+ guarantee that it is safe to return to the original stack.
This function may install a handler for the SIGSEGV signal or for the SIGBUS
signal or exercise other system dependent exception handling APIs. */