MFC r285119,r292502,r295380:

r285119 (by jmmv):

Add support for TEST_METADATA

Allow Makefiles to define generic metadata settings that apply to all test
programs defined by a Makefile. The generic TEST_METADATA variable extends
the per-test program settings already supported via TEST_METADATA.<program>.

This feature will be useful to easily apply some settings to all programs
in a directory. In particular, Kyua 0.12 will support parallel execution
of test programs and a bunch of them will need to be tagged as is_exclusive
to indicate that they cannot be run in parallel with anything else due to
their side-effects. It will be reasonable to set this setting on whole
directories.

r292502:

Always expose LOCALBASE, not just when CROSS_TOOLCHAIN is defined

Instead of using which(1) to look for doxygen, look for it in <LOCALBASE>/bin .
$PATH gets mangled by make buildenv, etc so it's better to just be explicit
about the path if someone uses that for instance.

r295380:

Simplify running the FreeBSD test suite

Replace `make regress` (legacy test make target) and `make test` (incomplete
test make target added with the FreeBSD test suite) with make check as it's
consistent with other open source projects.

`make check` defaults to running tests from `.OBJDIR`, but can be overridden
with the `CHECKDIR` variable.

Add `make checkworld` target to simplify running the FreeBSD test suite from
`TESTSBASE` (i.e. the top-level tests directory), similar to buildworld.

Document `make check` and `make checkworld` in build(7).

Other minor changes:

- Rename intermediate file (`Kyuafile.auto`) to `Kyuafile` to simplify
`make check`.
- Remove terse warnings attached to `beforetest`/`aftertest`.
- Add kyua binary check to check target in suite.test.mk; error out if it's
not found

The MFC is [partly] contingent on other build related changes being MFCed.

X-MFC to: stable/10
Relnotes: yes

MFC r288241:

r288241 (by bdrewery):

Remove 'set -e' that are no longer needed as it is already default.

When bmake was initially imported at r241298 shell commands were no longer
ran with 'set -e' as they were before. This was fixed in r254980 so they
again always use 'set -e'.

MFC r289360,r289361,r289378,r289430,r289605,r289676:

r289360:
Add temporary workaround for .MAKE being applied to _worldtmp, since
r251750.
r289361:
Consider top-level targets to be .PHONY as bmake won't build them otherwise
if a file with the same name is found in the directory.
r289378:
Mark sub-make targets as .MAKE and .PHONY to handle -n and always-build
properly.
r289430:
Remove .MAKE from targets that do more than just run sub-makes, such as
calling rm or mtree.
r289605:
Add missing .PHONY for parallel subdir target.
r289676:
Add some missing '+', .MAKE, and .PHONY modifiers.

MFC r266473,267331,267511:

Use an intermediate target to associate with _SUBDIR which is marked .MAKE
this allows make -n to do tree walks as expected without
doing anything else (as intended).
Use prefix _sub. to help avoid conflict with any real target.

Put the test suite in its own tests.txz distribution file.
Force all the contents of /usr/tests to go into a separate distribution
file so that users of binary releases can easily choose to not install

Create a mechanism for providing fine-grained build order dependencies
during SUBDIR_PARALLEL builds. This augments the coarse .WAIT mechanism,
which is still useful if you've got a situation such as "almost everything
depends on A and B".

MFC r264822: Allow .WAIT to appear in SUBDIR= lists

MFC r263778:

Add a SUBDIR_PARALLEL option to bsd.subdir.mk, to allow make to process
all the SUBDIR entries in parallel, instead of serially. Apply this
option to a selected number of Makefiles, which can greatly speed up the
build on multi-core machines, when using make -j.

This can be extended to more Makefiles later on, whenever they are
verified to work correctly with parallel building.

I tested this on a 24-core machine, with make -j48 buildworld (N = 6):

before stddev after stddev
======= ====== ======= ======
real time 1741.1 16.5 959.8 2.7
user time 12468.7 16.4 14393.0 16.8
sys time 1825.0 54.8 2110.6 22.8

(user+sys)/real 8.2 17.1

E.g. the build was approximately 45% faster in real time. On machines
with less cores, or with lower -j settings, the speedup will not be as
impressive. But at least you can now almost max out a machine with
buildworld!

Submitted by: jilles

MFC r263833:

Enable parallel building for gnu/usr.bin and usr.bin/clang too.

MFC r266473,267331,267511:

Use an intermediate target to associate with _SUBDIR which is marked .MAKE
this allows make -n to do tree walks as expected without
doing anything else (as intended).
Use prefix _sub. to help avoid conflict with any real target.

Put the test suite in its own tests.txz distribution file.
Force all the contents of /usr/tests to go into a separate distribution
file so that users of binary releases can easily choose to not install

Create a mechanism for providing fine-grained build order dependencies
during SUBDIR_PARALLEL builds. This augments the coarse .WAIT mechanism,
which is still useful if you've got a situation such as "almost everything
depends on A and B".

MFC r264822: Allow .WAIT to appear in SUBDIR= lists

MFC r263778:

Add a SUBDIR_PARALLEL option to bsd.subdir.mk, to allow make to process
all the SUBDIR entries in parallel, instead of serially. Apply this
option to a selected number of Makefiles, which can greatly speed up the
build on multi-core machines, when using make -j.

This can be extended to more Makefiles later on, whenever they are
verified to work correctly with parallel building.

I tested this on a 24-core machine, with make -j48 buildworld (N = 6):

before stddev after stddev
======= ====== ======= ======
real time 1741.1 16.5 959.8 2.7
user time 12468.7 16.4 14393.0 16.8
sys time 1825.0 54.8 2110.6 22.8

(user+sys)/real 8.2 17.1

E.g. the build was approximately 45% faster in real time. On machines
with less cores, or with lower -j settings, the speedup will not be as
impressive. But at least you can now almost max out a machine with
buildworld!

Submitted by: jilles

MFC r263833:

Enable parallel building for gnu/usr.bin and usr.bin/clang too.