MFV r323111: 8569 problem with inline functions in abd.h

illumos/illumos-gate@37e84ab74e939caf52150fc3352081786ecc0c29
https://github.com/illumos/illumos-gate/commit/37e84ab74e939caf52150fc3352081786ecc0c29

https://www.illumos.org/issues/8569
  C [C99] has peculiar rules for inline functions that are different from the
  C++ rules.  Unlike C++ where inline is "fire and forget", in C a programmer
  must pay attention to the function's storage class / visibility.  The main
  problem is with the case where a compiler decides to not inline a call to the
  function declared as inline.
  Some relevant links:
  - http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.faqs/ka15831.html
  - http://www.drdobbs.com/the-new-c-inline-functions/184401540
  The summary is that either the inline functions should be declared 'static
  inline' or one of the compilation units (.c files) must provide a callable
  externally visible function definition.  In the former case, the compiler would
  automatically create a local non-inlined function instance in every compilation
  unit where it's needed.  In the latter case the single external definition is
  used to satisfy any non-inlined calls in all compilation units.  As things
  stand right now, we can get an undefined reference error under certain
  combinations of compilers and compiler options.  For example, this is what I
  get on FreeBSD when compiling with clang 4.0.0 and -O1:
    In function `abd_free': /usr/src/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/abd.c:385:
    undefined reference to `abd_is_linear'

Reviewed by: Matt Ahrens <mahrens@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Author: Andriy Gapon <avg@FreeBSD.org>

MFC after:	1 week

0 files changed, 0 insertions, 0 deletions