Re: [PATCH] {master} Extend, fix and improve tests on Lex and Yacc support.

[Ralf Wildenhues]

* Stefano Lattarini wrote on Mon, Dec 13, 2010 at 07:54:05PM CET:
> OK to apply to a temporary branch off of maint, and merge to master?

The patch is ok with nits addressed.

> BTW, notice that I'm planning to further extend the Lex/Yacc tests
> and make them more "semantic", but that should be better done in a
> follow-up patch IMVHO.

If there is any way I can get you to not do any more of such
conversions: Please don't work even more on *these* tests.  They are
Good Enough[tm].  The incremental gain from more change is not worth
the additional work from you nor review from me.


Actually, lex and yacc support has *several* *real* issues, with maybe
more than a dozen reported bugs in the last few years, many of them
unfixed.  See the list archives.  It would be really nice if somebody
who knows their ways around bison/yacc and flex/lex well (or is willing
to learn) could look into some of the issues.  I should warn that it's
not easy though to come up with coherent/consistent and portable
improvements.


> Subject: [PATCH] Extend, fix and improve tests on Lex and Yacc support.
> 
> * tests/lexcpp.test: New test script, on support for Lex + C++.
> * tests/lexvpath.test: New test script, test build and rebuild
> rules for lexers in VPATH setup.
> * tests/yacc-basic.test: New test script, run simple "semantic"
> checks on basic Yacc support (similarly to what lex3.test does
> for Lex support).
> * tests/lex.test: Don't create useless dummy source file joe.l.
> Remove extra blank lines.
> (Makefile.am): Remove useless definition of $(LDADD).
> * tests/lex4.test: Add trailing `:' command.  Do not create dummy
> useless lex source file.
> * tests/lex2.test: Likewise.  Call automake with the `-a' option,
> so that it doesn't fail for the absence of `ylwrap' script.  Make
> grepping of automake stderr stricter.
> * tests/yacc7.test: Add trailing `:' command.  Enable `errexit'
> shell flag earlier (just after having sourced ./defs).
> * tests/yacc4.test: Likewise.  Also ...
> (configure.in): Use pre-populated skeleton set up by ./defs,
> instead of writing one from scratch.
> Other minor cosmetic changes.
> * tests/yacc5.test: Likewise.
> * tests/yaccvpath.test: Likewise. Also ...
> ($distdir): New variable.
> Use it throughout.
> * tests/lex5.test: Likewise.
> * tests/lex3.test: Likewise.  Check the distdir, rather than
> grepping the distribution tarball.  Extend the test on the
> created binary, and be sure to avoid hangs.  Add some comments.
> * tests/yacc.test: Use stricter grepping.  Add trailing `:'.
> * tests/yacc6.test: Likewise.
> * tests/yacc3.test: Likewise.  Prefer `cp -f' over plain `cp'.
> Do not create unused file `Makefile.sed'.  Remove useless rules
> from Makefile.am.  Other minor cosmetic changes.
> * tests/yacc2.test: Make grepping of generated `Makefile.in' and
> of automake error messages stricter.  Do not redirect output of
> grep to /dev/null.  Prefer `cp -f' over plain `cp'.  Move call to
> aclocal earlier.  Reduce the number of empty blank lines.  Fix a
> typo in comments.
> * tests/yacc8.test: Fixed bugs that reduced the completeness of
> the tests.  Added trailing `:' command.
> (configure.in): Use pre-populated skeleton set up by ./defs,
> instead of writing one from scratch.
> * tests/yaccpp.test: Test also extensions `.y++', `.ypp', and
> `.yxx', rather than only `.yy'.
> * tests/defs.in ($required): Better recognition of requirement
> "flex".
> * tests/Makefile.am (TESTS): Update.


> --- a/tests/defs.in
> +++ b/tests/defs.in
> @@ -113,6 +113,13 @@ do
>        echo "$me: running etags --version -o /dev/null"
>        ( etags --version -o /dev/null ) || exit 77
>        ;;
> +    flex)
> +      # Since flex is required, we pick LEX for ./configure.
> +      LEX=flex
> +      export LEX
> +      echo "$me: running flex --version"
> +      ( flex --version ) || exit 77
> +      ;;

I don't understand why the new 'required=flex' entry should be needed in
defs.in.  Any tests that fail without the defs.in change?

> +++ b/tests/lex.test
> @@ -26,22 +26,16 @@ END
>  cat > Makefile.am << 'END'
>  bin_PROGRAMS = zot
>  zot_SOURCES = joe.l
> -LDADD = @LEXLIB@

Please don't remove that.  It is documented to be required.

>  END


> --- a/tests/lex3.test
> +++ b/tests/lex3.test

> +# Basic semantic checks on Lex support.
>  # Test associated with PR 19.
>  # From Matthew D. Langston.

>  cat > Makefile.am << 'END'
> @@ -46,38 +44,44 @@ END
>  
>  cat > foo.l << 'END'
>  %%
> -"END"   return EOF;
> +"GOOD"   return EOF;
>  .
>  %%
>  int
>  main ()
>  {
> -  while (yylex () != EOF)
> -    ;
> -
> -  return 0;
> +  if (yylex () == EOF)
> +    return 0;
> +  else
> +    return 1;

That's not "semantic" either.  One wouldn't write a lexer like that.

>  }
>  END

> +# Program should build and run.
>  $MAKE
> -echo 'This is the END' | ./foo
> -$MAKE distcheck
> +echo GOOD | ./foo
> +echo BAD | ./foo && Exit 1

> --- a/tests/lex5.test
> +++ b/tests/lex5.test

> @@ -33,10 +29,9 @@ AC_OUTPUT
>  END
>  
>  cat > Makefile.am << 'END'
> -AUTOMAKE_OPTIONS  = subdir-objects
> -LDADD             = @LEXLIB@
> -
> -bin_PROGRAMS    = foo/foo
> +AUTOMAKE_OPTIONS = subdir-objects
> +LDADD = @LEXLIB@
> +bin_PROGRAMS = foo/foo
>  foo_foo_SOURCES = foo/foo.l

Please.  Such changes cost you time, me time, clutter up the history,
and gain nobody anything.  We've been there before.

>  END
>  

> --- /dev/null
> +++ b/tests/lexcpp.test
> @@ -0,0 +1,46 @@
> +#! /bin/sh

> +# Test to make sure Lex + C++ is supported.
> +# Please keep this is sync with sister test yaccpp.test.
> +
> +. ./defs || Exit 1
> +
> +set -e
> +
> +cat >> configure.in << 'END'
> +AC_PROG_CXX
> +AC_PROG_LEX
> +END
> +
> +cat > Makefile.am << 'END'
> +bin_PROGRAMS = foo bar baz qux
> +foo_SOURCES = foo.l++
> +bar_SOURCES = bar.lpp
> +baz_SOURCES = baz.ll
> +qux_SOURCES = qux.lxx
> +END
> +
> +$ACLOCAL
> +$AUTOMAKE -a
> +
> +sed -e 's/^/ /' -e 's/$/ /' Makefile.in >mk
> +$FGREP ' foo.c++ ' mk
> +$FGREP ' bar.cpp ' mk
> +$FGREP ' baz.cc '  mk
> +$FGREP ' qux.cxx ' mk
> +
> +:

> --- /dev/null
> +++ b/tests/lexvpath.test
> @@ -0,0 +1,117 @@

> +# This test checks that dependent files are updated before including
> +# in the distribution. `lexer.c' depends on `lexer.l'. The later is

s/\. /.  /  (several instances)
latter

> +# updated so that `lexer.c' should be rebuild. Then we are running

rebuilt

> +# `make' and `make distdir' and check whether the version of `lexer.c'
> +# to be distributed is up to date.
> +
> +# Please keep this in sync with sister test `yaccvapth.test'.
> +
> +required='gcc flex'
> +. ./defs || Exit 1
> +
> +set -e
> +
> +distdir=$me-1.0
> +
> +cat > lexoutroot.in << 'END'
> +LEX_OUTPUT_ROOT='@LEX_OUTPUT_ROOT@'
> +END
> +
> +cat >> configure.in << 'END'
> +AC_CONFIG_FILES([lexoutroot])
> +AC_PROG_CC
> +AC_PROG_LEX
> +AC_OUTPUT
> +END
> +
> +cat > Makefile.am << 'END'
> +bin_PROGRAMS = foo
> +foo_SOURCES = lexer.l foo.c
> +LDADD = $(LEXLIB)
> +END
> +
> +# Original lexer, with a "foobar" comment
> +cat > lexer.l << 'END'
> +%%
> +"END" return EOF;
> +.
> +%%
> +/*foobar*/
> +END
> +
> +cat > foo.c << 'END'
> +int main () { return 0; }
> +END
> +
> +$ACLOCAL
> +$AUTOCONF
> +$AUTOMAKE -a
> +
> +mkdir sub
> +
> +# We must run configure early, to find out whay $LEX_OUTPUT_ROOT is.
> +cd sub
> +../configure
> +. ./lexoutroot
> +test -n "$LEX_OUTPUT_ROOT" # sanity check
> +cd ..
> +
> +$LEX lexer.l
> +mv "$LEX_OUTPUT_ROOT".c lexer.c
> +
> +cd sub
> +
> +# A delay is needed to make sure that the new lexer.l is indeed newer
> +# than lexer.c, i.e. the they don't have the same timestamp.
> +$sleep
> +
> +# New lexer, with `fubar' comment.
> +cat > ../lexer.l << 'END'
> +%%
> +"END" return EOF;
> +.
> +%%
> +/*fubar*/
> +END
> +
> +$MAKE
> +$MAKE distdir
> +$FGREP '/*fubar*/' $distdir/lexer.c
> +
> +#
> +# Now check to make sure that `make dist' will rebuild the parser.
> +#
> +
> +# A delay is needed to make sure that the new parse.y is indeed newer
> +# than parse.c, i.e. the they don't have the same timestamp.

The comment was already too verbose before you copy and pasted it.  ;-)

> +$sleep
> +
> +# New lexer, with `maude' comment.
> +cat > ../lexer.l << 'END'
> +%%
> +"END" return EOF;
> +.
> +%%
> +/*maude*/
> +END
> +
> +$MAKE distdir
> +$FGREP '/*maude*/' $distdir/lexer.c
> +
> +:

> --- /dev/null
> +++ b/tests/yacc-basic.test
> @@ -0,0 +1,78 @@

> +# Basic semantic checks on Yacc support.
> +
> +required=bison
> +. ./defs || Exit 1
> +
> +set -e
> +
> +distdir=$me-1.0
> +
> +cat >> configure.in << 'END'
> +AC_PROG_CC
> +AC_PROG_YACC
> +AC_OUTPUT
> +END
> +
> +cat > Makefile.am << 'END'
> +bin_PROGRAMS = foo
> +foo_SOURCES = parse.y foo.c
> +END
> +
> +cat > parse.y << 'END'
> +%{
> +#include <stdio.h>
> +#include <stdlib.h>
> +int yylex () { return (getchar()); }

space before open paren (after getchar).

> +void yyerror (char *s) {}
> +%}
> +%%
> +a : 'a' { exit(0); };
> +END
> +
> +cat > foo.c << 'END'
> +int main () { yyparse(); return 1; }

see above

> +END
> +
> +$ACLOCAL
> +$AUTOCONF
> +$AUTOMAKE -a
> +
> +./configure
> +$MAKE
> +
> +echo a | ./foo
> +echo b | ./foo && Exit 1
> +
> +# The generated file `parse.c' must be shipped.
> +$MAKE distdir
> +test -f $distdir/parse.c
> +
> +# Sanity check on distribution.
> +$MAKE distcheck
> +
> +# While we are at it, make sure that parse.c is erased by
> +# maintainer-clean, and not by distclean.
> +test -f parse.c
> +$MAKE distclean
> +test -f parse.c
> +./configure # we must re-create `Makefile'
> +$MAKE maintainer-clean
> +test ! -f parse.c
> +
> +:

> --- a/tests/yacc2.test
> +++ b/tests/yacc2.test
> @@ -1,5 +1,6 @@
>  #! /bin/sh
> -# Copyright (C) 1999, 2001, 2002, 2003, 2006  Free Software Foundation, Inc.
> +# Copyright (C) 1999, 2001, 2002, 2003, 2006, 2010 Free Software
> +# Foundation, Inc.
>  #
>  # This program is free software; you can redistribute it and/or modify
>  # it under the terms of the GNU General Public License as published by
> @@ -26,61 +27,48 @@ AC_PROG_CC
>  AC_PROG_YACC
>  END
>  
> +# Run it here once and for all, since we are not going to modify
> +# configure.in anymore.
> +$ACLOCAL
> +
>  cat > Makefile.am <<'END'
>  bin_PROGRAMS = zardoz
>  zardoz_SOURCES = zardoz.y
>  END
>  
>  # Don't redefine several times the same variable.
> -cp Makefile.am Makefile.src
> +cp -f Makefile.am Makefile.src

Why should you need this change?  Generally, I don't see why you ever
need 'cp -f'.  Please undo.  (several instances)

>  
> -$ACLOCAL
>  $AUTOMAKE -a
> -
>  # If zardoz.h IS mentioned, fail
> -grep 'zardoz.h' Makefile.in > /dev/null && Exit 1
> -
> +$FGREP 'zardoz.h' Makefile.in && Exit 1
>  
> -
> -cp Makefile.src Makefile.am
> +cp -f Makefile.src Makefile.am
>  echo 'AM_YFLAGS = -d' >> Makefile.am
> -
>  $AUTOMAKE
> -
>  # If zardoz.h is NOT mentioned, fail
> -grep 'zardoz.h' Makefile.in > /dev/null
> -
> -
> +$FGREP 'zardoz.h' Makefile.in
>  
> -cp Makefile.src Makefile.am
> +cp -f Makefile.src Makefile.am
>  echo 'AM_YFLAGS = ' >> Makefile.am
> -
>  $AUTOMAKE
> -
>  # If zardoz.h IS mentioned, fail
> -grep 'zardoz.h' Makefile.in > /dev/null && Exit 1
> -
> +$FGREP 'zardoz.h' Makefile.in && Exit 1
>  
> -
> -cp Makefile.src Makefile.am
> +cp -f Makefile.src Makefile.am
>  echo 'YFLAGS = -d' >> Makefile.am
> -
> -# YFLAGS is a use variable.
> +# YFLAGS is a user variable.
>  AUTOMAKE_fails
> -grep 'YFLAGS' stderr
> +grep 'YFLAGS.* user variable' stderr
> +grep 'AM_YFLAGS.* instead' stderr
>  $AUTOMAKE -Wno-gnu
> -
>  # If zardoz.h is NOT mentioned, fail
> -grep 'zardoz.h' Makefile.in > /dev/null
> -
> -
> +$FGREP 'zardoz.h' Makefile.in
>  
> -cp Makefile.src Makefile.am
> +cp -f Makefile.src Makefile.am
>  echo 'YFLAGS = ' >> Makefile.am
> -
>  $AUTOMAKE -Wno-gnu
> -
>  # If zardoz.h IS mentioned, fail
> -grep 'zardoz.h' Makefile.in > /dev/null && Exit 1
> +$FGREP 'zardoz.h' Makefile.in && Exit 1
>  
>  :

> --- a/tests/yacc3.test
> +++ b/tests/yacc3.test

> @@ -30,24 +31,22 @@ cat > Makefile.am <<'END'
>  AUTOMAKE_OPTIONS = no-dependencies
>  bin_PROGRAMS = zardoz
>  zardoz_SOURCES = zardoz.y
> -magic:
> -     @echo $(DIST_COMMON)
>  END
>  
>  $ACLOCAL
>  $AUTOMAKE -a
>  
> -$FGREP -v @SET_MAKE@ Makefile.in > Makefile.sed
>  # It should not be disted here
> -grep 'zardoz.h' Makefile.in && Exit 1
> +$FGREP 'zardoz.h' Makefile.in && Exit 1
>  
> -cp Makefile.am Save
> +cp -f Makefile.am Makefile.sav
>  # Test all available flags to make sure header is distributed with
>  # `-d'.
>  for flag in YFLAGS AM_YFLAGS zardoz_YFLAGS; do
> -   cp Save Makefile.am
> +   cp -f Makefile.sav Makefile.am
>     echo "$flag = -d" >> Makefile.am
> -
>     $AUTOMAKE -Wno-gnu
> -   grep 'zardoz.h' Makefile.in
> +   $FGREP 'zardoz.h' Makefile.in
>  done
> +
> +:
> diff --git a/tests/yacc4.test b/tests/yacc4.test
> index 0435ec0..bb25290 100755
> --- a/tests/yacc4.test
> +++ b/tests/yacc4.test
> @@ -1,5 +1,5 @@
>  #! /bin/sh
> -# Copyright (C) 2001, 2002  Free Software Foundation, Inc.
> +# Copyright (C) 2001, 2002, 2010 Free Software Foundation, Inc.
>  #
>  # This program is free software; you can redistribute it and/or modify
>  # it under the terms of the GNU General Public License as published by
> @@ -19,15 +19,12 @@
>  required='bison gcc'
>  . ./defs || Exit 1
>  
> -cat > configure.in << 'END'
> -AC_INIT
> -AC_CONFIG_AUX_DIR([.])
> -AM_INIT_AUTOMAKE(foo, 0.1)
> -PACKAGE=foo
> -VERSION=0.1
> +set -e
> +
> +cat >> configure.in << 'END'
>  AC_PROG_CC
>  AC_PROG_YACC
> -AC_OUTPUT(Makefile)
> +AC_OUTPUT
>  END
>  
>  cat > Makefile.am << 'END'
> @@ -60,8 +57,6 @@ cat > foo.c << 'END'
>  int main () { return 0; }
>  END
>  
> -set -e
> -
>  $ACLOCAL
>  $AUTOCONF
>  $AUTOMAKE -a
> @@ -86,6 +81,5 @@ test -f parse.c
>  $MAKE maintainer-clean
>  test ! -f bar.c
>  test ! -f parse.c
> -:
>  
> -Exit 0
> +:
> diff --git a/tests/yacc5.test b/tests/yacc5.test
> index 8b00ed8..77de2e9 100755
> --- a/tests/yacc5.test
> +++ b/tests/yacc5.test
> @@ -1,5 +1,5 @@
>  #! /bin/sh
> -# Copyright (C) 2001, 2002, 2003  Free Software Foundation, Inc.
> +# Copyright (C) 2001, 2002, 2003, 2010 Free Software Foundation, Inc.
>  #
>  # This program is free software; you can redistribute it and/or modify
>  # it under the terms of the GNU General Public License as published by
> @@ -21,13 +21,10 @@
>  
>  set -e
>  
> -cat > configure.in << 'END'
> -AC_INIT
> -AM_INIT_AUTOMAKE(nonesuch, nonesuch)
> +cat >> configure.in << 'END'
>  AC_PROG_CC
>  AM_PROG_CC_C_O
>  AC_PROG_YACC
> -AC_OUTPUT(Makefile)
>  END
>  
>  cat > Makefile.am << 'END'
> @@ -69,8 +66,8 @@ maude_SOURCES = sub/maude.y
>  maude_YFLAGS = -d
>  END
>  
> -$ACLOCAL || Exit 1
> -$AUTOMAKE -a || Exit 1
> +$ACLOCAL
> +$AUTOMAKE -a
>  
>  # Rule should use maude_YFLAGS.
>  grep 'AM_YFLAGS.*maude' Makefile.in && Exit 1
> @@ -80,3 +77,5 @@ grep 'maudec' Makefile.in && Exit 1
>  
>  # Make sure the .o file is required.
>  grep '^am_maude_OBJECTS.*maude' Makefile.in
> +
> +:
> diff --git a/tests/yacc6.test b/tests/yacc6.test
> index f10effd..b9b259b 100755
> --- a/tests/yacc6.test
> +++ b/tests/yacc6.test
> @@ -1,5 +1,5 @@
>  #! /bin/sh
> -# Copyright (C) 2001, 2002, 2003, 2004, 2006, 2007  Free Software
> +# Copyright (C) 2001, 2002, 2003, 2004, 2006, 2007, 2010 Free Software
>  # Foundation, Inc.
>  #
>  # This program is free software; you can redistribute it and/or modify
> @@ -27,13 +27,13 @@ set -e
>  
>  cat > configure.in << 'END'
>  AC_INIT([yacc6], [1.0])
> +# `aux' is not an acceptable file/directory name on Windows systems
>  AC_CONFIG_AUX_DIR([aux1])
>  AM_INIT_AUTOMAKE
> -AC_CONFIG_FILES([Makefile])
> +AC_CONFIG_FILES([Makefile sub/Makefile])
>  AC_PROG_CC
>  AM_PROG_CC_C_O
>  AC_PROG_YACC
> -AC_CONFIG_FILES([sub/Makefile])
>  AC_OUTPUT
>  END
>  
> @@ -89,11 +89,11 @@ $AUTOMAKE -a
>  test -f aux1/ylwrap
>  test ! -f ylwrap
>  test ! -f sub/ylwrap
> -$FGREP '(top_srcdir)/aux1/ylwrap' sub/Makefile.in
> +$FGREP '$(top_srcdir)/aux1/ylwrap' sub/Makefile.in
>  ./configure
>  $MAKE
> -grep '#.*line.*foo.y' sub/foo.c
> -grep '#.*line.*bar.y' sub/bar.c
> +grep '#.*line.*foo\.y' sub/foo.c
> +grep '#.*line.*bar\.y' sub/bar.c
>  
>  $sleep
>  : > z
> @@ -106,3 +106,5 @@ sed s/TOKEN/TEKON/g sub/bar.y >sub/bar.yt
>  mv -f sub/bar.yt sub/bar.y
>  $MAKE
>  $MAKE test-time-changed
> +
> +:
> diff --git a/tests/yacc7.test b/tests/yacc7.test
> index 2edd15c..2b866bc 100755
> --- a/tests/yacc7.test
> +++ b/tests/yacc7.test
> @@ -1,5 +1,6 @@
>  #! /bin/sh
> -# Copyright (C) 2001, 2002, 2003, 2004  Free Software Foundation, Inc.
> +# Copyright (C) 2001, 2002, 2003, 2004, 2010 Free Software Foundation,
> +# Inc.
>  #
>  # This program is free software; you can redistribute it and/or modify
>  # it under the terms of the GNU General Public License as published by
> @@ -23,6 +24,8 @@
>  required=bison
>  . ./defs || Exit 1
>  
> +set -e
> +
>  cat >> configure.in << 'END'
>  AC_PROG_CC
>  AC_PROG_YACC
> @@ -52,8 +55,6 @@ WORD: "up";
>  %%
>  END
>  
> -set -e
> -
>  $ACLOCAL
>  $AUTOMAKE -a
>  $AUTOCONF
> @@ -83,8 +84,9 @@ $MAKE distclean
>  test -f foo.h
>  test -f foo.c
>  # ... but maintainer-clean should.
> -./configure
> +./configure # we must re-create `Makefile'
>  $MAKE maintainer-clean
>  test ! -f foo.h
>  test ! -f foo.c
> +
>  :
> diff --git a/tests/yacc8.test b/tests/yacc8.test
> index 979415c..797f4e7 100755
> --- a/tests/yacc8.test
> +++ b/tests/yacc8.test
> @@ -1,5 +1,6 @@
>  #! /bin/sh
> -# Copyright (C) 2002, 2003, 2004, 2006  Free Software Foundation, Inc.
> +# Copyright (C) 2002, 2003, 2004, 2006, 2010 Free Software Foundation,
> +# Inc.
>  #
>  # This program is free software; you can redistribute it and/or modify
>  # it under the terms of the GNU General Public License as published by
> @@ -22,11 +23,7 @@ required="gcc bison"
>  
>  set -e
>  
> -cat > configure.in << 'END'
> -AC_INIT([yacc8], [1.0])
> -AC_CONFIG_AUX_DIR([.])
> -AM_INIT_AUTOMAKE
> -AC_CONFIG_FILES([Makefile])
> +cat >> configure.in << 'END'
>  AC_PROG_CC
>  AM_PROG_CC_C_O
>  AC_PROG_YACC
> @@ -39,15 +36,16 @@ bin_PROGRAMS = foo/foo
>  foo_foo_SOURCES = foo/parse.y
>  AM_YFLAGS = -d
>  
> +.PHONY: obj
>  obj: foo/parse.$(OBJEXT)
>  
> -test1: obj
> -     test -f foo/parse.c
> -     test -f foo/parse.$(OBJEXT)
> -
> -test2: obj
> +.PHONY: test1 test2
> +test1: foo/parse.$(OBJEXT)
>       test -f foo/parse.c
>       test -f foo/parse.$(OBJEXT)
> +test2: foo/parse2.$(OBJEXT)
> +     test -f foo/parse2.c
> +     test -f foo/parse2.$(OBJEXT)
>  END
>  
>  mkdir foo
> @@ -104,9 +102,11 @@ EXTRA_foo_foo_SOURCES = foo/parse2.y
>  END
>  
>  $AUTOMAKE -a
> -test -f ./ylwrap || Exit 1
> +test -f ./ylwrap
>  
>  cd sub
>  # Regenerate Makefile (automatic in GNU Make, but not in other Makes)
>  ./config.status
>  $MAKE test2

Thanks,
Ralf