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1.21 (July 2016)
Yann E. MORIN (yann.morin.1998@free.fr): Buildroot [1] is a build-system
targetting embedded devices. It is able to build toolchains for various
architectures, based on the traditional GNU compiler collection gcc, the GNU
binutils and various C libraries, such as GNU libc (glibc), uClibc [2] [3] or
musl [4].
glibc is a feature-full C library, which has had support for Yellow Pages
(and the rest of the SUN RPC stuff) for a long time. However, circa the 2.14
release, glibc stopped installing the RPC headers [5], on the principle that
providing the RPC implementation would be better served by a third-party
package, namely ti-rpc [6]. That did not happen in time, so installing the
RPC headers from glibc was re-instated circa 2.16.
uClibc (no longer maintained, replaced by a fork, uClibc-ng) is a fully
configurable C library for embedded systems. It entirely lacks a SUN RPC
implementation altogether.
musl is standards-conforming, lightweight C library. It also entirely lacks a
SUN RPC implementation.
TI-RPC is a stand-alone package. It may or may not be available (because the
user may not need SUN RPC stuff on an embedded device, for example). Besides,
it is not yet as feature-full as the implementation in glibc, though for all
practical means, it is totally useable.
So, there are cases where a SUN RPC implementation is not available.
This patch makes it so that the use of Yellow Pages is conditional on the
presence of a SUN RPC implementation, by checking at ./configure whether the
required header is present, and disabling the corresponding code if the
header is missing.
At the same time, the legacy, long unsupported AM_C_PROTOTYPES directive is
also removed, as it makes recent-ish autoconf fail.
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