@c Documentation of gnulib module 'alloca'.

The alloca module provides for a function alloca() which allocates memory
on the stack, where the system allows it. A memory block allocated with alloca()
exists only until the function that calls alloca() returns or exits abruptly.

There are a few systems where this is not possible: HP-UX systems, and some
other platforms when the C++ compiler is used. On these platforms the alloca
module provides a malloc() based emulation. This emulation will not free a
memory block immediately when the calling function returns, but rather will
wait until the next alloca() call from a function with the same or a shorter
stack length. Thus, in some cases, a few memory blocks will be kept although
they are not needed any more.

The user can #include <alloca.h> and use alloca() on all platforms. Note
that the #include <alloca.h> must be the first one after the autoconf-generated
config.h. Thanks to AIX for this nice restriction!

An alternative to this module is the 'alloca-opt' module.