Stefano Lattarini skrev 2012-02-05 14:16: > On 02/02/2012 11:41 PM, Peter Rosin wrote: >> Stefano Lattarini skrev 2012-02-02 22:45: >>> Reference: >>> <http://debbugs.gnu.org/cgi/bugreport.cgi?bug=10434> >>> >>> OK, the attached patch fixes the two spurious failures of GCC forced into >>> Tru64 mode. About time I'd say. >>> >>> But I'm not sure whether we should apply this without first testing it >>> on a real Tru64 compiler, lest we cause a real regression just to fix a >>> spurious failure. Thoughts? >> >> I just had a look at that test, and it seems like a very crappy test >> to me. I had some failures with cl, but figured it was the same as >> these Tru64 failures that I had seen flying past, and put it all on >> the back burner. But the test is destined to cause troubles if IIUC. >> >> It's just dead wrong to assume that feeding -M or -xM to the compiler >> (or whatever other random stuff depcomp might do) and not get an error >> is the same as dependencies magically appearing. Or do I read the >> test wrong? Please tell me that I do! >> > Unfortunately you read the test right. And in hindsight I must agree > with you: its approach is fundamentally flawed. > > So, what about the attached patch, that overhauls (and hopefully improve) > the coverage for automatic dependency tracking support? It is probably > possible to improve the patch even more (esp. w.r.t. optimizations for > speed), but that can be left for follow-up changes IMHO. > > I will push (to master) in 72 hours if there is no objection by then.
Hi Stefano, This looks promising! Appart from the below inline nitpicking, your method to force a depmode doesn't really seem to work, possibly only when you also force another compiler, as shown by the below grep (after a non-libtool run with CC="cl- nologo"). $ grep "checking dependency style" tests/depcomp-*.log tests/depcomp-auto.log:checking dependency style of cl -nologo... msvc7msys tests/depcomp-auto.log:checking dependency style of cl -nologo... msvc7msys tests/depcomp-auto.log:checking dependency style of cl -nologo... msvc7msys tests/depcomp-auto.log:checking dependency style of cl -nologo... msvc7msys tests/depcomp-cpp.log:checking dependency style of gcc... gcc3 tests/depcomp-cpp.log:checking dependency style of gcc... gcc3 tests/depcomp-cpp.log:checking dependency style of gcc... gcc3 tests/depcomp-cpp.log:checking dependency style of gcc... gcc3 tests/depcomp-dashXmstdout.log:checking dependency style of gcc... gcc3 tests/depcomp-dashXmstdout.log:checking dependency style of gcc... gcc3 tests/depcomp-dashXmstdout.log:checking dependency style of gcc... gcc3 tests/depcomp-dashXmstdout.log:checking dependency style of gcc... gcc3 tests/depcomp-dashmstdout.log:checking dependency style of gcc... gcc3 tests/depcomp-dashmstdout.log:checking dependency style of gcc... gcc3 tests/depcomp-dashmstdout.log:checking dependency style of gcc... gcc3 tests/depcomp-dashmstdout.log:checking dependency style of gcc... gcc3 tests/depcomp-disabled.log:checking dependency style of cl -nologo... none tests/depcomp-disabled.log:checking dependency style of cl -nologo... none tests/depcomp-disabled.log:checking dependency style of cl -nologo... none tests/depcomp-disabled.log:checking dependency style of cl -nologo... none tests/depcomp-gcc.log:checking dependency style of gcc... gcc3 tests/depcomp-gcc.log:checking dependency style of gcc... gcc3 tests/depcomp-gcc.log:checking dependency style of gcc... gcc3 tests/depcomp-gcc.log:checking dependency style of gcc... gcc3 Over to the nitpicking part... > From 2008b6bd27bba6194856cb5a58eb8c5e700e35c8 Mon Sep 17 00:00:00 2001 > Message-Id: > <2008b6bd27bba6194856cb5a58eb8c5e700e35c8.1328447619.git.stefano.lattar...@gmail.com> > From: Stefano Lattarini <stefano.lattar...@gmail.com> > Date: Fri, 3 Feb 2012 15:05:48 +0100 > Subject: [PATCH] tests: improve and rework tests on dependency tracking > > Fixes automake bug#10434. Suggestion by Peter Rosin. > > The 'depcomp.tap' test case worked by trying to unconditionally > force the compiler in use by the testsuite to use, one by one, *all* > the dependency modes known by the 'depcomp' script, and, for each > such forced mode that was compatible enough with said compiler not > to cause breakage in the basic compilation rules, checking that it > was *also* good enough not to break remake rules in VPATH builds. > > This seemed a good approach when this test was first introduced, as > it apparently increased coverage for the less used and less tested > dependency-tracking modes. But in the log run it turned out the > approach was actually in part to brittle, causing some annoying too (but I later saw that Jim said the same) > spurious failures (as with the Tru64 depmode forced on GCC, see > automake bug#10434), and partly too forgiving, since, for some of > the more corner-case dependency modes, the 'depcomp' script simply > reverts to silently disabling dependency tracking when an error is > encountered (this happened e.g., with the Tru64 depmode forced on > the Sun C compiler 5.9), so that a passing test means nothing, and > only gives a false sense of security. > > As Peter Rosin put it, "it's just dead wrong to assume that feeding > -M or -xM to the compiler (or whatever other random stuff 'depcomp' > might do) and not get an error is the same as dependencies magically > appearing". > > So we get rid of this wrong approach, and in the process proceed to > a complete overhaul of many of the tests on automatic dependency > tracking, extending the offered coverage and rationalizing their > organization. > > * tests/decomp.sh: New helper script, used by several new depcomp.sh > autogenerated tests. > * tests/gen-testsuite-part: Generate several tests based on the > new 'decomp.sh' script. Emit makefile code that declares their depcomp.sh again > dependency on that script, and that extends EXTRA_DIST in order > to distribute it. > * tests/depmod.tap: Remove. *snip* > diff --git a/.gitignore b/.gitignore > index 46607dc..c95a193 100644 > --- a/.gitignore > +++ b/.gitignore > @@ -53,6 +53,7 @@ Makefile > /tests/testsuite-part.am > /tests/*-w.tap > /tests/*-w.test > +/tests/depcomp-*.tap > /tests/*.dir > /tests/*.log > /tests/*.trs > diff --git a/tests/depcomp.sh b/tests/depcomp.sh > new file mode 100755 > index 0000000..147e8ca > --- /dev/null > +++ b/tests/depcomp.sh > @@ -0,0 +1,378 @@ *snip* > + $FGREP 'unknown directive' output && return 1 > + rm -f output > + # Checks for stray files possible left around by less common possibly > + # depmodes. > + find . -name '*.[ud]' | grep . && return 1 > + return 0 *snip* > + skip_row_ 2 -r "automatic dependency tracking couldn't be activated" > + else > + command_ok_ "$pfx generated $po files look correct" $MAKE grep-test > + r=ok \ > + && : "Some checks in the subdir." \ > + && $sleep \ > + && : "Ensure rebuild rules do really kick in." \ "Ensure rebuild rules really do kick in." > + && rewrite "$srcdir"/src/sub2/sub2foo.h echo 'choke me' \ > + && cd src \ > + && not $MAKE \ *snip* Cheers, Peter (still with a *very* sketchy Internet connection...)
