bug#16302: 1.14.1: check-TESTS is not lazy enough

[Akim Demaille]

Hi all,

I have this piece of software with several APIs, organized in clear
layers.  Building the whole package is costly, especially because of
the top-level layers (dozens of binaries), and the whole test suite
is even costlier (because it requires to build the whole set of binaries,
and then it runs all the tests, including the costly top-level tests).

So, « of course », when developing this piece of software, I seldom run
the full test-suite, and run selected bits.  In particular I avoid
« make all », so, of course, I also avoid « make check » since it depends
on the former.  Rather I use check-TESTS and deal with the dependencies
myself, like a grownup.

Alas, for some reason, while it works well to generate individual test logs,
but when generating (the partial) test-suite.log, « make all-am » is
invoked.

Please try to attached tarball.  It features a lazy test suite with two
test scripts.

> AM_TESTS_ENVIRONMENT = export PATH=$(abs_top_builddir):$PATH;
> RECHECK_LOGS =
> TESTS = fast slow

« slow » runs a binary built by the package, so
of course, its log depends on this binary:

> slow.log: foo

but ‘fast’ depends on nothing, so to run it and only it, I have
this piece of syntactic sugar: 

> check-fast:
>       $(MAKE) $(AM_MAKEFLAGS) check-TESTS TESTS='fast'

As expected ‘make check’ is lazy.  However, if I touch
fast and foo.c (the dependency of slow), then observe:

> $ touch ~/src/gnu/test-suite/{foo.c,fast}
> $ make check-fast
> /usr/bin/make  check-TESTS TESTS='fast'
> PASS: fast
> depbase=`echo foo.o | sed 's|[^/]*$|.deps/&|;s|\.o$||'`;\
>       ccache gcc-mp-4.8 -DPACKAGE_NAME=\"test-suite\" 
> -DPACKAGE_TARNAME=\"test-suite\" -DPACKAGE_VERSION=\"1.0\" 
> -DPACKAGE_STRING=\"test-suite\ 1.0\" -DPACKAGE_BUGREPORT=\"\" 
> -DPACKAGE_URL=\"\" -DPACKAGE=\"test-suite\" -DVERSION=\"1.0\" -I. 
> -I/Users/akim/src/gnu/test-suite   -DNDEBUG -isystem /opt/local/include  -O3 
> -MT foo.o -MD -MP -MF $depbase.Tpo -c -o foo.o 
> /Users/akim/src/gnu/test-suite/foo.c &&\
>       mv -f $depbase.Tpo $depbase.Po
> ccache gcc-mp-4.8  -O3  -L/opt/local/lib -o foo foo.o  
> ============================================================================
> Testsuite summary for test-suite 1.0
> ============================================================================
> # TOTAL: 1
> # PASS:  1
> # SKIP:  0
> # XFAIL: 0
> # FAIL:  0
> # XPASS: 0
> # ERROR: 0
> ============================================================================

As you can see, « fast.log » was recreated appropriately, but then,
to build test-suite.log, something fires « all-am » (running make
with -d shows this very well).  It appears to be due to this:

> $(TEST_SUITE_LOG): $(TEST_LOGS)
>       @$(am__set_TESTS_bases); \
>       am__f_ok () { test -f "$$1" && test -r "$$1"; }; \
>       redo_bases=`for i in $$bases; do \
>                     am__f_ok $$i.trs && am__f_ok $$i.log || echo $$i; \
>                   done`; \
>       if test -n "$$redo_bases"; then \
>         redo_logs=`for i in $$redo_bases; do echo $$i.log; done`; \
>         redo_results=`for i in $$redo_bases; do echo $$i.trs; done`; \
>         if $(am__make_dryrun); then :; else \
>           rm -f $$redo_logs && rm -f $$redo_results || exit 1; \
>         fi; \
>       fi; \
>       if test -n "$$am__remaking_logs"; then \
>         echo "fatal: making $(TEST_SUITE_LOG): possible infinite" \
>              "recursion detected" >&2; \
>       else \
>         am__remaking_logs=yes $(MAKE) $(AM_MAKEFLAGS) $$redo_logs; \
>       fi; \

in this last bit, « $$redo_logs » is empty, so, blam, a full cost
make all.  What was the point of this piece of code?  At first sight
it seems that it should be guarder by ‘test -n $$redo_log’.

This is *really* costly, I’d be happy to have nice workarounds.

Thanks, and happy new year!