Re: [PATCH] {yacc-work} coverage: test mixed C/C++ yacc-generated parsers in the same dir

[Stefano Lattarini]

On Sunday 10 April 2011, Ralf Wildenhues wrote:
> * Stefano Lattarini wrote on Sun, Apr 10, 2011 at 02:50:28PM CEST:
> > On Sunday 10 April 2011, Ralf Wildenhues wrote:
> > > I think it would make sense to also do parallel build tests here
> > >
> > Agreed (and BTW this uncovered a bug in the testcase: I had forgotten
> > to add `p.h' and `parse.hh' to BUILT_SOURCES in the Makefile.am; it's
> > fixed now).
> 
> Hehe.
> 
> > Here is what we could do IMHO: first try a VPATH serial build, then
> > an in-tree parallel build.  See the attached squash-in.
> > 
> > Tested with GNU make (3.80, 3.81, 3.82), FreeBSD and NetBSD make
> > (Debian ports), Heirloom make, Solaris XPG4 and CCS make, and
> > Solaris dmake.  OK?
> 
> OK.
> 
> > > (only if make is GNU make, of course)
> > >
> > Why?  I've never found a make implementation rejecting the `-j' option.
> 
> HP-UX make has -P but not -j.  The semantics of -P are sufficiently
> different so that it is not worth trying to support that, however.
> 
> $ make -j; echo $?
> Make: Unknown flag argument j.  Stop.
> 1
> 
> Several other makes accept -j only when given a number, not without,
>
I have no intention to use `-j' without a number.  Too risky IMHO (it
wouldn't be the first time that my machine gets freezed by that).

> e.g., OpenBSD make:
> 
> $ make  -j
> make: option requires an argument -- j
> usage: make [-BeiknPqrSst] [-D variable] [-d flags] [-f makefile]
>             [-I directory] [-j max_jobs] [-m directory] [-V variable]
>             [NAME=value] [target ...]
> 
> 
> And I think for portability to all GNU make versions, the number should
> follow immediately, i.e., without intervening space, but I'm going from
> memory here.
>
The space is fine from at least GNU make 3.78.  I don't know about
earlier versions.

> It's fine to try out first if make groks -j, and use that, that gives
> more coverage then.  But you should try it out in a way to not expose
> the issues you just spotted.  For example, you could use
>   make -j2 clean || Exit 77
>
Or, since we are doing both VPATH an in-tree builds, just continue
with serial make if `-j' doesn't work.  See the attached squash-in
(which goes on the top of the previous squash-in).  OK?

> (or Exit 0, if you don't consider that part of the test important
> enough).
> 
> > +# Try a VPATH and by default serial build first, and then an in-tree
> > +# and by default parallel build.
> > +
> > +for try in 0 1; do
> > +
> > +  if test $try -eq 0; then
> > +    mkdir build
> > +    cd build
> > +    srcdir=..
> > +    debug_info="ls -l . $srcdir"
> > +    run_make=$MAKE
> > +  elif test $try -eq 1; then
> > +    srcdir=.
> > +    debug_info="ls -l"
> > +    case $MAKE in
> > +      *\ -j*) run_make=$MAKE;;
> > +      *) run_make="$MAKE -j 3";;
> 
> See above for spacing.
>
See attached squash-in.

> Also, note that $MAKE might already include -jN.
>
The `case' statement should take care of that: in fact, it's there
only for this purpose ...  I've added a clarifying comment now.

> Thanks,
> Ralf
>

Thanks, and sorry for all this churn,
  Stefano

diff --git a/tests/yacc-mix-c-cxx.test b/tests/yacc-mix-c-cxx.test
index 0901ac8..8b7c1a5 100755
--- a/tests/yacc-mix-c-cxx.test
+++ b/tests/yacc-mix-c-cxx.test
@@ -141,17 +141,32 @@ $AUTOMAKE -a
 for try in 0 1; do
 
   if test $try -eq 0; then
+    # VPATH serial build.
     mkdir build
     cd build
     srcdir=..
     debug_info="ls -l . $srcdir"
     run_make=$MAKE
   elif test $try -eq 1; then
+    # In-tree parallel build.
     srcdir=.
     debug_info="ls -l"
     case $MAKE in
-      *\ -j*) run_make=$MAKE;;
-      *) run_make="$MAKE -j 3";;
+      *\ -j*)
+        # Degree of parallelism already specified by the user do
+        # not override it.
+        run_make=$MAKE;;
+      *)
+        # Some make implementations (e.g., HP-UX) don't grok `-j',
+        # some require no space between `-j' and the number of jobs
+        # (e.g., older GNU make versions), and some *do* require a
+        # space between `-j' and the number of jobs (e.g., Solaris
+        # dmake).  We need a runtime test to see what works.
+        echo 'all:' > Makefile
+        for run_make in "$MAKE -j3" "$MAKE -j 3" "$MAKE"; do
+          $run_make && break
+        done
+        rm -f Makefile
     esac
   else
     echo "$me: invalid value of \$try '$try'" >&2