tests: enable -Wsign-compare and fix corresponding warnings

[bison.git] / configure.ac

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# better to avoid a typo in the 'configure --help' entry for the YACC
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AC_PREREQ([2.68])
m4_pattern_forbid([^gl_[A-Z]])

AC_INIT([GNU Bison],
        m4_esyscmd([build-aux/git-version-gen .tarball-version]),
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AC_SUBST([PACKAGE_COPYRIGHT_YEAR], [2013])
AC_DEFINE_UNQUOTED([PACKAGE_COPYRIGHT_YEAR], [$PACKAGE_COPYRIGHT_YEAR],
                   [The copyright year for this package])

AC_CONFIG_AUX_DIR([build-aux])
AC_CONFIG_MACRO_DIR([m4])

# Automake 1.10.3 and 1.11.1 fix a security flaw discussed here:
#
#   http://thread.gmane.org/gmane.comp.sysutils.autotools.announce/131
#
# To avoid 1.11, we make 1.11.1 the minimum version.
#
# We want gnits strictness only when rolling a stable release.  For
# release candidates, we use version strings like 2.4.3_rc1, but gnits
# doesn't like that, so we let the underscore disable gnits.  Between
# releases, we want to be able run make dist without being required to
# add a bogus NEWS entry.  In that case, the version string
# automatically contains a dash, which we also let disable gnits.
AM_INIT_AUTOMAKE([1.11.1 dist-xz nostdinc
                 color-tests parallel-tests
                 silent-rules]
                 m4_bmatch(m4_defn([AC_PACKAGE_VERSION]), [[-_]],
                           [gnu], [gnits]))
AM_SILENT_RULES([yes])
AC_CONFIG_HEADERS([lib/config.h:lib/config.in.h])

# Checks for the compiler.
AC_PROG_CC_STDC
AC_PROG_CXX

# Gnulib (early checks).
gl_EARLY

# Gnulib uses '#pragma GCC diagnostic push' to silence some
# warnings, but older gcc doesn't support this.
AC_CACHE_CHECK([whether pragma GCC diagnostic push works],
  [lv_cv_gcc_pragma_push_works], [
  save_CFLAGS=$CFLAGS
  CFLAGS='-Wunknown-pragmas -Werror'
  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
    #pragma GCC diagnostic push
    #pragma GCC diagnostic pop
  ]])],
  [lv_cv_gcc_pragma_push_works=yes],
  [lv_cv_gcc_pragma_push_works=no])
  CFLAGS=$save_CFLAGS])

AC_ARG_ENABLE([gcc-warnings],
[  --enable-gcc-warnings   turn on lots of GCC warnings (not recommended)],
[case $enable_gcc_warnings in
   yes|no) ;;
   *)  AC_MSG_ERROR([invalid value for --gcc-warnings: $enable_gcc_warnings]);;
 esac],
              [enable_gcc_warnings=no])
if test "$enable_gcc_warnings" = yes; then
  warn_common='-Wall -Wextra -Wno-sign-compare -Wcast-align
    -Wformat -Wpointer-arith -Wwrite-strings'
  warn_c='-Wbad-function-cast -Wshadow -Wstrict-prototypes'
  warn_cxx='-Wnoexcept'
  # Warnings for the test suite only.
  #
  # -fno-color-diagnostics: Clang's use of colors in the error
  # messages is confusing the tests looking at the compiler's output
  # (e.g., synclines.at).
  warn_tests='-Wundef -pedantic -Wsign-compare -fno-color-diagnostics'

  AC_LANG_PUSH([C])
  # Clang supports many of GCC's -W options, but only issues warnings
  # on the ones it does not recognize.  In that case, gl_WARN_ADD
  # thinks the option is supported, and unknown options are then added
  # to CFLAGS.  But then, when -Werror is added in the test suite for
  # instance, the warning about the unknown option turns into an
  # error.
  #
  # This should be addressed by gnulib's gl_WARN_ADD, but in the
  # meanwhile, turn warnings about unknown options into errors in
  # CFLAGS, and restore CFLAGS after the tests.
  save_CFLAGS=$CFLAGS
  gl_WARN_ADD([-Werror=unknown-warning-option], [CFLAGS])
  for i in $warn_common $warn_c;
  do
    gl_WARN_ADD([$i], [WARN_CFLAGS])
  done
  gl_WARN_ADD([-Werror], [WERROR_CFLAGS])

  # Warnings for the test suite, and maybe for bison if GCC is modern
  # enough.
  gl_WARN_ADD([-Wmissing-declarations], [WARN_CFLAGS_TEST])
  gl_WARN_ADD([-Wmissing-prototypes], [WARN_CFLAGS_TEST])
  test $lv_cv_gcc_pragma_push_works = yes &&
    AS_VAR_APPEND([WARN_CFLAGS], [" $WARN_CFLAGS_TEST"])

  # Warnings for the test suite only.
  for i in $warn_tests;
  do
    gl_WARN_ADD([$i], [WARN_CFLAGS_TEST])
  done
  CFLAGS=$save_CFLAGS
  AC_LANG_POP([C])

  AC_LANG_PUSH([C++])
  save_CXXFLAGS=$CXXFLAGS
  gl_WARN_ADD([-Werror=unknown-warning-option], [CXXFLAGS])
  for i in $warn_common $warn_cxx;
  do
    gl_WARN_ADD([$i], [WARN_CXXFLAGS])
  done
  gl_WARN_ADD([-Wzero-as-null-pointer-constant], [WARN_CXXFLAGS],
              [AC_LANG_PROGRAM([], [nullptr])])
  gl_WARN_ADD([-Werror], [WERROR_CXXFLAGS])
  # Warnings for the test suite only.
  for i in $warn_tests;
  do
    gl_WARN_ADD([$i], [WARN_CXXFLAGS_TEST])
  done
  # Clang++ 3.2+ reject C code generated by Flex.
  gl_WARN_ADD([-Wno-null-conversion], [FLEX_SCANNER_CXXFLAGS])
  # So does G++ 4.8 in std=c++11 mode.
  gl_WARN_ADD([-Wno-zero-as-null-pointer-constant], [FLEX_SCANNER_CXXFLAGS])
  CXXFLAGS=$save_CXXFLAGS
  AC_LANG_POP([C++])
fi

BISON_TEST_FOR_WORKING_C_COMPILER
BISON_C_COMPILER_POSIXLY_CORRECT
BISON_TEST_FOR_WORKING_CXX_COMPILER
BISON_CXX_COMPILER_POSIXLY_CORRECT

AC_ARG_ENABLE([yacc],
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     [do not build a yacc command or an -ly library])],
  , [enable_yacc=yes])
case $enable_yacc in
yes)
  YACC_SCRIPT=src/yacc
  YACC_LIBRARY=lib/liby.a;;
*)
  YACC_SCRIPT=
  YACC_LIBRARY=;;
esac
AC_SUBST([YACC_SCRIPT])
AC_SUBST([YACC_LIBRARY])

# Checks for programs.
AM_MISSING_PROG([DOT], [dot])
AC_PROG_LEX
$LEX_IS_FLEX || AC_MSG_ERROR([Flex is required])
AC_PROG_YACC
AC_PROG_RANLIB
AC_PROG_GNU_M4
AC_DEFINE_UNQUOTED([M4], ["$M4"], [Define to the GNU M4 executable name.])
AC_DEFINE_UNQUOTED([M4_GNU_OPTION], ["$M4_GNU"], [Define to "-g" if GNU M4
supports -g, otherwise to "".])
AC_PATH_PROG([PERL], [perl])
if test -z "$PERL"; then
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fi
AM_MISSING_PROG([HELP2MAN], [help2man])
AC_PATH_PROG([XSLTPROC], [xsltproc])
AC_SUBST([XSLTPROC])

# Checks for header files.
AC_CHECK_HEADERS_ONCE([locale.h])

# Checks for compiler characteristics.
AC_C_INLINE

# Gnulib (later checks).  Putting them here rather than right after
# gl_EARLY avoids some redundant checks.
gl_INIT

# Checks for library functions.
AC_CHECK_FUNCS_ONCE([setlocale])
AM_WITH_DMALLOC
BISON_PREREQ_TIMEVAR

# Gettext.
# We use gnulib, which is only guaranteed to work properly with the
# latest Gettext.
AM_GNU_GETTEXT([external], [need-ngettext])
AM_GNU_GETTEXT_VERSION([0.18])
BISON_I18N

# Internationalized parsers.
AC_CONFIG_FILES([runtime-po/Makefile.in])
# Autoconf macros for packages using internationalized parsers.
aclocaldir='${datadir}/aclocal'
AC_SUBST([aclocaldir])

# Create the benchmark script.
AC_CONFIG_FILES([etc/bench.pl], [chmod +x etc/bench.pl])

# Initialize the test suite.
AC_CONFIG_TESTDIR(tests)
AC_CONFIG_FILES([tests/atlocal])
AC_CONFIG_FILES([tests/bison], [chmod +x tests/bison])
AC_CHECK_PROGS([VALGRIND], [valgrind])
case $VALGRIND:$host_os in
  '':*) ;;
  *:darwin*)
    # See README-hacking.
    # VALGRIND+=' --suppressions=$(abs_top_srcdir)/build-aux/darwin11.4.0.valgrind'
    VALGRIND=;;
  *:*)
    AC_SUBST([VALGRIND_PREBISON], ["$VALGRIND -q"]);;
esac

AM_MISSING_PROG([AUTOM4TE], [autom4te])
# Needed by tests/atlocal.in.
AC_SUBST([GCC])

gt_JAVACOMP([1.3], [1.4])
gt_JAVAEXEC

AC_CONFIG_FILES([Makefile
                 po/Makefile.in
                 doc/yacc.1])
AC_OUTPUT