[gcc r12-2436] c++tools, configury: Configure with C++; test checking status [PR98821].

[gcc r12-2436] c++tools, configury: Configure with C++; test checking status [PR98821].

[Iain D Sandoe]

https://gcc.gnu.org/g:e4d306cf706eef83f99d510c308eda1539d05875

commit r12-2436-ge4d306cf706eef83f99d510c308eda1539d05875
Author: Iain Sandoe <iain@sandoe.co.uk>
Date:   Tue Jul 20 14:00:38 2021 +0100

    c++tools, configury: Configure with C++; test checking status [PR98821].
    
    The c++tools configure fragments need to be built with a C++ compiler.
    
    In addition, the stand-alone server uses diagnostic mechanisms in common
    with GCC, but needs to define implementations for gcc_assert and
    supporting output functions.
    
    Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>
    
    PR c++/98821 - modules : c++tools configures with CC but code fragments assume CXX.
    
            PR c++/98821
    
    c++tools/ChangeLog:
    
            * config.h.in: Regenerate.
            * configure: Regenerate.
            * configure.ac: Configure using C++.  Pull logic to
            detect enabled checking modes; default to release
            checking.
            * server.cc (AI_NUMERICSERV): Define a fallback value.
            (gcc_assert): New.
            (gcc_unreachable): New.
            (fancy_abort): Only build when checking is enabled.
    
    Co-authored-by: Jakub Jelinek <jakub@redhat.com>

Diff:
---
 c++tools/config.h.in  |   3 +
 c++tools/configure    | 761 +++++++-------------------------------------------
 c++tools/configure.ac |  31 ++
 c++tools/server.cc    |  28 ++
 4 files changed, 170 insertions(+), 653 deletions(-)

diff --git a/c++tools/config.h.in b/c++tools/config.h.in
index bfb49582357..410b2f7dab8 100644
--- a/c++tools/config.h.in
+++ b/c++tools/config.h.in
@@ -1,5 +1,8 @@
 /* config.h.in.  Generated from configure.ac by autoheader.  */
 
+/* Define if you want assertions enabled. This is a cheap check. */
+#undef ENABLE_ASSERT_CHECKING
+
 /* Define if accept4 provided. */
 #undef HAVE_ACCEPT4
 
diff --git a/c++tools/configure b/c++tools/configure
index a288f7abe5d..742816e4253 100755
--- a/c++tools/configure
+++ b/c++tools/configure
@@ -626,10 +626,7 @@ NETLIBS
 get_gcc_base_ver
 EGREP
 GREP
-CPP
-ac_ct_CC
-CFLAGS
-CC
+CXXCPP
 PIEFLAG
 MAINTAINER
 CXX_AUX_TOOLS
@@ -701,6 +698,7 @@ ac_user_opts='
 enable_option_checking
 enable_c___tools
 enable_maintainer_mode
+enable_checking
 enable_default_pie
 with_gcc_major_version_only
 '
@@ -713,9 +711,7 @@ LDFLAGS
 LIBS
 CPPFLAGS
 CCC
-CC
-CFLAGS
-CPP'
+CXXCPP'
 
 
 # Initialize some variables set by options.
@@ -1332,6 +1328,10 @@ Optional Features:
   --enable-maintainer-mode
                           enable maintainer mode. Add rules to rebuild
                           configurey bits
+  --enable-checking[=LIST]
+                          enable expensive run-time checks. With LIST, enable
+                          only specific categories of checks. Categories are:
+                          yes,no,all,none,release.
   --enable-default-pie    enable Position Independent Executable as default
 
 Optional Packages:
@@ -1348,9 +1348,7 @@ Some influential environment variables:
   LIBS        libraries to pass to the linker, e.g. -l<library>
   CPPFLAGS    (Objective) C/C++ preprocessor flags, e.g. -I<include dir> if
               you have headers in a nonstandard directory <include dir>
-  CC          C compiler command
-  CFLAGS      C compiler flags
-  CPP         C preprocessor
+  CXXCPP      C++ preprocessor
 
 Use these variables to override the choices made by `configure' or to help
 it to find libraries and programs with nonstandard names/locations.
@@ -1470,48 +1468,10 @@ fi
 
 } # ac_fn_cxx_try_compile
 
-# ac_fn_c_try_compile LINENO
-# --------------------------
-# Try to compile conftest.$ac_ext, and return whether this succeeded.
-ac_fn_c_try_compile ()
-{
-  as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
-  rm -f conftest.$ac_objext
-  if { { ac_try="$ac_compile"
-case "(($ac_try" in
-  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
-  *) ac_try_echo=$ac_try;;
-esac
-eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
-$as_echo "$ac_try_echo"; } >&5
-  (eval "$ac_compile") 2>conftest.err
-  ac_status=$?
-  if test -s conftest.err; then
-    grep -v '^ *+' conftest.err >conftest.er1
-    cat conftest.er1 >&5
-    mv -f conftest.er1 conftest.err
-  fi
-  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
-  test $ac_status = 0; } && {
-	 test -z "$ac_c_werror_flag" ||
-	 test ! -s conftest.err
-       } && test -s conftest.$ac_objext; then :
-  ac_retval=0
-else
-  $as_echo "$as_me: failed program was:" >&5
-sed 's/^/| /' conftest.$ac_ext >&5
-
-	ac_retval=1
-fi
-  eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
-  as_fn_set_status $ac_retval
-
-} # ac_fn_c_try_compile
-
-# ac_fn_c_try_cpp LINENO
-# ----------------------
+# ac_fn_cxx_try_cpp LINENO
+# ------------------------
 # Try to preprocess conftest.$ac_ext, and return whether this succeeded.
-ac_fn_c_try_cpp ()
+ac_fn_cxx_try_cpp ()
 {
   as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
   if { { ac_try="$ac_cpp conftest.$ac_ext"
@@ -1530,7 +1490,7 @@ $as_echo "$ac_try_echo"; } >&5
   fi
   $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
   test $ac_status = 0; } > conftest.i && {
-	 test -z "$ac_c_preproc_warn_flag$ac_c_werror_flag" ||
+	 test -z "$ac_cxx_preproc_warn_flag$ac_cxx_werror_flag" ||
 	 test ! -s conftest.err
        }; then :
   ac_retval=0
@@ -1543,14 +1503,14 @@ fi
   eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
   as_fn_set_status $ac_retval
 
-} # ac_fn_c_try_cpp
+} # ac_fn_cxx_try_cpp
 
-# ac_fn_c_check_header_mongrel LINENO HEADER VAR INCLUDES
-# -------------------------------------------------------
+# ac_fn_cxx_check_header_mongrel LINENO HEADER VAR INCLUDES
+# ---------------------------------------------------------
 # Tests whether HEADER exists, giving a warning if it cannot be compiled using
 # the include files in INCLUDES and setting the cache variable VAR
 # accordingly.
-ac_fn_c_check_header_mongrel ()
+ac_fn_cxx_check_header_mongrel ()
 {
   as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
   if eval \${$3+:} false; then :
@@ -1571,7 +1531,7 @@ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 $4
 #include <$2>
 _ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"; then :
   ac_header_compiler=yes
 else
   ac_header_compiler=no
@@ -1587,7 +1547,7 @@ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 #include <$2>
 _ACEOF
-if ac_fn_c_try_cpp "$LINENO"; then :
+if ac_fn_cxx_try_cpp "$LINENO"; then :
   ac_header_preproc=yes
 else
   ac_header_preproc=no
@@ -1597,7 +1557,7 @@ rm -f conftest.err conftest.i conftest.$ac_ext
 $as_echo "$ac_header_preproc" >&6; }
 
 # So?  What about this header?
-case $ac_header_compiler:$ac_header_preproc:$ac_c_preproc_warn_flag in #((
+case $ac_header_compiler:$ac_header_preproc:$ac_cxx_preproc_warn_flag in #((
   yes:no: )
     { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: $2: accepted by the compiler, rejected by the preprocessor!" >&5
 $as_echo "$as_me: WARNING: $2: accepted by the compiler, rejected by the preprocessor!" >&2;}
@@ -1630,13 +1590,13 @@ $as_echo "$ac_res" >&6; }
 fi
   eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
 
-} # ac_fn_c_check_header_mongrel
+} # ac_fn_cxx_check_header_mongrel
 
-# ac_fn_c_try_run LINENO
-# ----------------------
+# ac_fn_cxx_try_run LINENO
+# ------------------------
 # Try to link conftest.$ac_ext, and return whether this succeeded. Assumes
 # that executables *can* be run.
-ac_fn_c_try_run ()
+ac_fn_cxx_try_run ()
 {
   as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
   if { { ac_try="$ac_link"
@@ -1672,13 +1632,13 @@ fi
   eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
   as_fn_set_status $ac_retval
 
-} # ac_fn_c_try_run
+} # ac_fn_cxx_try_run
 
-# ac_fn_c_check_header_compile LINENO HEADER VAR INCLUDES
-# -------------------------------------------------------
+# ac_fn_cxx_check_header_compile LINENO HEADER VAR INCLUDES
+# ---------------------------------------------------------
 # Tests whether HEADER exists and can be compiled using the include files in
 # INCLUDES, setting the cache variable VAR accordingly.
-ac_fn_c_check_header_compile ()
+ac_fn_cxx_check_header_compile ()
 {
   as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
   { $as_echo "$as_me:${as_lineno-$LINENO}: checking for $2" >&5
@@ -1691,7 +1651,7 @@ else
 $4
 #include <$2>
 _ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"; then :
   eval "$3=yes"
 else
   eval "$3=no"
@@ -1703,12 +1663,12 @@ eval ac_res=\$$3
 $as_echo "$ac_res" >&6; }
   eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
 
-} # ac_fn_c_check_header_compile
+} # ac_fn_cxx_check_header_compile
 
-# ac_fn_c_try_link LINENO
-# -----------------------
+# ac_fn_cxx_try_link LINENO
+# -------------------------
 # Try to link conftest.$ac_ext, and return whether this succeeded.
-ac_fn_c_try_link ()
+ac_fn_cxx_try_link ()
 {
   as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
   rm -f conftest.$ac_objext conftest$ac_exeext
@@ -1728,7 +1688,7 @@ $as_echo "$ac_try_echo"; } >&5
   fi
   $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
   test $ac_status = 0; } && {
-	 test -z "$ac_c_werror_flag" ||
+	 test -z "$ac_cxx_werror_flag" ||
 	 test ! -s conftest.err
        } && test -s conftest$ac_exeext && {
 	 test "$cross_compiling" = yes ||
@@ -1749,7 +1709,7 @@ fi
   eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
   as_fn_set_status $ac_retval
 
-} # ac_fn_c_try_link
+} # ac_fn_cxx_try_link
 cat >config.log <<_ACEOF
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
@@ -2955,6 +2915,13 @@ done
 test -n "$AUTOHEADER" || AUTOHEADER="$MISSING autoheader"
 
 
+ac_ext=cpp
+ac_cpp='$CXXCPP $CPPFLAGS'
+ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
+
+
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether to build C++ tools" >&5
 $as_echo_n "checking whether to build C++ tools... " >&6; }
   # Check whether --enable-c++-tools was given.
@@ -2989,556 +2956,48 @@ $as_echo "$maintainer_mode" >&6; }
 test "$maintainer_mode" = yes && MAINTAINER=yes
 
 
-# Check whether --enable-default-pie was given.
-# Check whether --enable-default-pie was given.
-if test "${enable_default_pie+set}" = set; then :
-  enableval=$enable_default_pie; PIEFLAG=-fPIE
-else
-  PIEFLAG=
-fi
-
-
-
-# Check if O_CLOEXEC is defined by fcntl
-ac_ext=c
-ac_cpp='$CPP $CPPFLAGS'
-ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
-ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
-ac_compiler_gnu=$ac_cv_c_compiler_gnu
-if test -n "$ac_tool_prefix"; then
-  # Extract the first word of "${ac_tool_prefix}gcc", so it can be a program name with args.
-set dummy ${ac_tool_prefix}gcc; ac_word=$2
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
-$as_echo_n "checking for $ac_word... " >&6; }
-if ${ac_cv_prog_CC+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  if test -n "$CC"; then
-  ac_cv_prog_CC="$CC" # Let the user override the test.
-else
-as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
-for as_dir in $PATH
-do
-  IFS=$as_save_IFS
-  test -z "$as_dir" && as_dir=.
-    for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
-    ac_cv_prog_CC="${ac_tool_prefix}gcc"
-    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
-    break 2
-  fi
-done
-  done
-IFS=$as_save_IFS
-
-fi
-fi
-CC=$ac_cv_prog_CC
-if test -n "$CC"; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $CC" >&5
-$as_echo "$CC" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-fi
-
-
-fi
-if test -z "$ac_cv_prog_CC"; then
-  ac_ct_CC=$CC
-  # Extract the first word of "gcc", so it can be a program name with args.
-set dummy gcc; ac_word=$2
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
-$as_echo_n "checking for $ac_word... " >&6; }
-if ${ac_cv_prog_ac_ct_CC+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  if test -n "$ac_ct_CC"; then
-  ac_cv_prog_ac_ct_CC="$ac_ct_CC" # Let the user override the test.
-else
-as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
-for as_dir in $PATH
-do
-  IFS=$as_save_IFS
-  test -z "$as_dir" && as_dir=.
-    for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
-    ac_cv_prog_ac_ct_CC="gcc"
-    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
-    break 2
-  fi
-done
-  done
-IFS=$as_save_IFS
-
-fi
-fi
-ac_ct_CC=$ac_cv_prog_ac_ct_CC
-if test -n "$ac_ct_CC"; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_ct_CC" >&5
-$as_echo "$ac_ct_CC" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-fi
-
-  if test "x$ac_ct_CC" = x; then
-    CC=""
-  else
-    case $cross_compiling:$ac_tool_warned in
-yes:)
-{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
-$as_echo "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
-ac_tool_warned=yes ;;
-esac
-    CC=$ac_ct_CC
-  fi
-else
-  CC="$ac_cv_prog_CC"
-fi
+# Handle configuration of checking; for the tools in this directory we
+# default to release checking and stricter checks do not change this.
 
-if test -z "$CC"; then
-          if test -n "$ac_tool_prefix"; then
-    # Extract the first word of "${ac_tool_prefix}cc", so it can be a program name with args.
-set dummy ${ac_tool_prefix}cc; ac_word=$2
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
-$as_echo_n "checking for $ac_word... " >&6; }
-if ${ac_cv_prog_CC+:} false; then :
-  $as_echo_n "(cached) " >&6
+# Check whether --enable-checking was given.
+if test "${enable_checking+set}" = set; then :
+  enableval=$enable_checking; ac_checking_flags="${enableval}"
 else
-  if test -n "$CC"; then
-  ac_cv_prog_CC="$CC" # Let the user override the test.
-else
-as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
-for as_dir in $PATH
-do
-  IFS=$as_save_IFS
-  test -z "$as_dir" && as_dir=.
-    for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
-    ac_cv_prog_CC="${ac_tool_prefix}cc"
-    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
-    break 2
-  fi
-done
-  done
-IFS=$as_save_IFS
-
-fi
-fi
-CC=$ac_cv_prog_CC
-if test -n "$CC"; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $CC" >&5
-$as_echo "$CC" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-fi
 
+# Default to checking.
+ac_checking_flags=yes
 
-  fi
-fi
-if test -z "$CC"; then
-  # Extract the first word of "cc", so it can be a program name with args.
-set dummy cc; ac_word=$2
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
-$as_echo_n "checking for $ac_word... " >&6; }
-if ${ac_cv_prog_CC+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  if test -n "$CC"; then
-  ac_cv_prog_CC="$CC" # Let the user override the test.
-else
-  ac_prog_rejected=no
-as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
-for as_dir in $PATH
-do
-  IFS=$as_save_IFS
-  test -z "$as_dir" && as_dir=.
-    for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
-    if test "$as_dir/$ac_word$ac_exec_ext" = "/usr/ucb/cc"; then
-       ac_prog_rejected=yes
-       continue
-     fi
-    ac_cv_prog_CC="cc"
-    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
-    break 2
-  fi
-done
-  done
-IFS=$as_save_IFS
-
-if test $ac_prog_rejected = yes; then
-  # We found a bogon in the path, so make sure we never use it.
-  set dummy $ac_cv_prog_CC
-  shift
-  if test $# != 0; then
-    # We chose a different compiler from the bogus one.
-    # However, it has the same basename, so the bogon will be chosen
-    # first if we set CC to just the basename; use the full file name.
-    shift
-    ac_cv_prog_CC="$as_dir/$ac_word${1+' '}$@"
-  fi
-fi
-fi
-fi
-CC=$ac_cv_prog_CC
-if test -n "$CC"; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $CC" >&5
-$as_echo "$CC" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-fi
-
-
-fi
-if test -z "$CC"; then
-  if test -n "$ac_tool_prefix"; then
-  for ac_prog in cl.exe
-  do
-    # Extract the first word of "$ac_tool_prefix$ac_prog", so it can be a program name with args.
-set dummy $ac_tool_prefix$ac_prog; ac_word=$2
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
-$as_echo_n "checking for $ac_word... " >&6; }
-if ${ac_cv_prog_CC+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  if test -n "$CC"; then
-  ac_cv_prog_CC="$CC" # Let the user override the test.
-else
-as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
-for as_dir in $PATH
-do
-  IFS=$as_save_IFS
-  test -z "$as_dir" && as_dir=.
-    for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
-    ac_cv_prog_CC="$ac_tool_prefix$ac_prog"
-    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
-    break 2
-  fi
-done
-  done
-IFS=$as_save_IFS
-
-fi
-fi
-CC=$ac_cv_prog_CC
-if test -n "$CC"; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $CC" >&5
-$as_echo "$CC" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
 fi
 
-
-    test -n "$CC" && break
-  done
-fi
-if test -z "$CC"; then
-  ac_ct_CC=$CC
-  for ac_prog in cl.exe
-do
-  # Extract the first word of "$ac_prog", so it can be a program name with args.
-set dummy $ac_prog; ac_word=$2
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
-$as_echo_n "checking for $ac_word... " >&6; }
-if ${ac_cv_prog_ac_ct_CC+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  if test -n "$ac_ct_CC"; then
-  ac_cv_prog_ac_ct_CC="$ac_ct_CC" # Let the user override the test.
-else
-as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
-for as_dir in $PATH
+IFS="${IFS= 	}"; ac_save_IFS="$IFS"; IFS="$IFS,"
+for check in release $ac_checking_flags
 do
-  IFS=$as_save_IFS
-  test -z "$as_dir" && as_dir=.
-    for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
-    ac_cv_prog_ac_ct_CC="$ac_prog"
-    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
-    break 2
-  fi
-done
-  done
-IFS=$as_save_IFS
-
-fi
-fi
-ac_ct_CC=$ac_cv_prog_ac_ct_CC
-if test -n "$ac_ct_CC"; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_ct_CC" >&5
-$as_echo "$ac_ct_CC" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-fi
-
-
-  test -n "$ac_ct_CC" && break
-done
-
-  if test "x$ac_ct_CC" = x; then
-    CC=""
-  else
-    case $cross_compiling:$ac_tool_warned in
-yes:)
-{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
-$as_echo "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
-ac_tool_warned=yes ;;
-esac
-    CC=$ac_ct_CC
-  fi
-fi
-
-fi
-
-
-test -z "$CC" && { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
-$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
-as_fn_error $? "no acceptable C compiler found in \$PATH
-See \`config.log' for more details" "$LINENO" 5; }
-
-# Provide some information about the compiler.
-$as_echo "$as_me:${as_lineno-$LINENO}: checking for C compiler version" >&5
-set X $ac_compile
-ac_compiler=$2
-for ac_option in --version -v -V -qversion; do
-  { { ac_try="$ac_compiler $ac_option >&5"
-case "(($ac_try" in
-  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
-  *) ac_try_echo=$ac_try;;
-esac
-eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
-$as_echo "$ac_try_echo"; } >&5
-  (eval "$ac_compiler $ac_option >&5") 2>conftest.err
-  ac_status=$?
-  if test -s conftest.err; then
-    sed '10a\
-... rest of stderr output deleted ...
-         10q' conftest.err >conftest.er1
-    cat conftest.er1 >&5
-  fi
-  rm -f conftest.er1 conftest.err
-  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
-  test $ac_status = 0; }
+	case $check in
+	# these set all the flags to specific states
+	yes|all|release|assert) ac_assert_checking=1 ; ;;
+	no|none) ac_assert_checking= ; ;;
+	*) ;;
+	esac
 done
+IFS="$ac_save_IFS"
 
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether we are using the GNU C compiler" >&5
-$as_echo_n "checking whether we are using the GNU C compiler... " >&6; }
-if ${ac_cv_c_compiler_gnu+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-int
-main ()
-{
-#ifndef __GNUC__
-       choke me
-#endif
+if test x$ac_assert_checking != x ; then
 
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
-  ac_compiler_gnu=yes
-else
-  ac_compiler_gnu=no
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-ac_cv_c_compiler_gnu=$ac_compiler_gnu
+$as_echo "#define ENABLE_ASSERT_CHECKING 1" >>confdefs.h
 
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_c_compiler_gnu" >&5
-$as_echo "$ac_cv_c_compiler_gnu" >&6; }
-if test $ac_compiler_gnu = yes; then
-  GCC=yes
-else
-  GCC=
-fi
-ac_test_CFLAGS=${CFLAGS+set}
-ac_save_CFLAGS=$CFLAGS
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CC accepts -g" >&5
-$as_echo_n "checking whether $CC accepts -g... " >&6; }
-if ${ac_cv_prog_cc_g+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_save_c_werror_flag=$ac_c_werror_flag
-   ac_c_werror_flag=yes
-   ac_cv_prog_cc_g=no
-   CFLAGS="-g"
-   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-int
-main ()
-{
-
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
-  ac_cv_prog_cc_g=yes
-else
-  CFLAGS=""
-      cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
 
-int
-main ()
-{
-
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
-
-else
-  ac_c_werror_flag=$ac_save_c_werror_flag
-	 CFLAGS="-g"
-	 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-int
-main ()
-{
-
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
-  ac_cv_prog_cc_g=yes
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-   ac_c_werror_flag=$ac_save_c_werror_flag
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_prog_cc_g" >&5
-$as_echo "$ac_cv_prog_cc_g" >&6; }
-if test "$ac_test_CFLAGS" = set; then
-  CFLAGS=$ac_save_CFLAGS
-elif test $ac_cv_prog_cc_g = yes; then
-  if test "$GCC" = yes; then
-    CFLAGS="-g -O2"
-  else
-    CFLAGS="-g"
-  fi
-else
-  if test "$GCC" = yes; then
-    CFLAGS="-O2"
-  else
-    CFLAGS=
-  fi
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $CC option to accept ISO C89" >&5
-$as_echo_n "checking for $CC option to accept ISO C89... " >&6; }
-if ${ac_cv_prog_cc_c89+:} false; then :
-  $as_echo_n "(cached) " >&6
+# Check whether --enable-default-pie was given.
+# Check whether --enable-default-pie was given.
+if test "${enable_default_pie+set}" = set; then :
+  enableval=$enable_default_pie; PIEFLAG=-fPIE
 else
-  ac_cv_prog_cc_c89=no
-ac_save_CC=$CC
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#include <stdarg.h>
-#include <stdio.h>
-struct stat;
-/* Most of the following tests are stolen from RCS 5.7's src/conf.sh.  */
-struct buf { int x; };
-FILE * (*rcsopen) (struct buf *, struct stat *, int);
-static char *e (p, i)
-     char **p;
-     int i;
-{
-  return p[i];
-}
-static char *f (char * (*g) (char **, int), char **p, ...)
-{
-  char *s;
-  va_list v;
-  va_start (v,p);
-  s = g (p, va_arg (v,int));
-  va_end (v);
-  return s;
-}
-
-/* OSF 4.0 Compaq cc is some sort of almost-ANSI by default.  It has
-   function prototypes and stuff, but not '\xHH' hex character constants.
-   These don't provoke an error unfortunately, instead are silently treated
-   as 'x'.  The following induces an error, until -std is added to get
-   proper ANSI mode.  Curiously '\x00'!='x' always comes out true, for an
-   array size at least.  It's necessary to write '\x00'==0 to get something
-   that's true only with -std.  */
-int osf4_cc_array ['\x00' == 0 ? 1 : -1];
-
-/* IBM C 6 for AIX is almost-ANSI by default, but it replaces macro parameters
-   inside strings and character constants.  */
-#define FOO(x) 'x'
-int xlc6_cc_array[FOO(a) == 'x' ? 1 : -1];
-
-int test (int i, double x);
-struct s1 {int (*f) (int a);};
-struct s2 {int (*f) (double a);};
-int pairnames (int, char **, FILE *(*)(struct buf *, struct stat *, int), int, int);
-int argc;
-char **argv;
-int
-main ()
-{
-return f (e, argv, 0) != argv[0]  ||  f (e, argv, 1) != argv[1];
-  ;
-  return 0;
-}
-_ACEOF
-for ac_arg in '' -qlanglvl=extc89 -qlanglvl=ansi -std \
-	-Ae "-Aa -D_HPUX_SOURCE" "-Xc -D__EXTENSIONS__"
-do
-  CC="$ac_save_CC $ac_arg"
-  if ac_fn_c_try_compile "$LINENO"; then :
-  ac_cv_prog_cc_c89=$ac_arg
-fi
-rm -f core conftest.err conftest.$ac_objext
-  test "x$ac_cv_prog_cc_c89" != "xno" && break
-done
-rm -f conftest.$ac_ext
-CC=$ac_save_CC
-
+  PIEFLAG=
 fi
-# AC_CACHE_VAL
-case "x$ac_cv_prog_cc_c89" in
-  x)
-    { $as_echo "$as_me:${as_lineno-$LINENO}: result: none needed" >&5
-$as_echo "none needed" >&6; } ;;
-  xno)
-    { $as_echo "$as_me:${as_lineno-$LINENO}: result: unsupported" >&5
-$as_echo "unsupported" >&6; } ;;
-  *)
-    CC="$CC $ac_cv_prog_cc_c89"
-    { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_prog_cc_c89" >&5
-$as_echo "$ac_cv_prog_cc_c89" >&6; } ;;
-esac
-if test "x$ac_cv_prog_cc_c89" != xno; then :
 
-fi
 
-ac_ext=c
-ac_cpp='$CPP $CPPFLAGS'
-ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
-ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
-ac_compiler_gnu=$ac_cv_c_compiler_gnu
 
+# Check if O_CLOEXEC is defined by fcntl
 
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for O_CLOEXEC" >&5
 $as_echo_n "checking for O_CLOEXEC... " >&6; }
@@ -3559,7 +3018,7 @@ return open ("/dev/null", O_RDONLY | O_CLOEXEC);
   return 0;
 }
 _ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"; then :
   ac_cv_o_cloexec=yes
 else
   ac_cv_o_cloexec=no
@@ -3574,26 +3033,22 @@ $as_echo "#define HOST_HAS_O_CLOEXEC 1" >>confdefs.h
 
 fi
 
-ac_ext=c
-ac_cpp='$CPP $CPPFLAGS'
-ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
-ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
-ac_compiler_gnu=$ac_cv_c_compiler_gnu
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking how to run the C preprocessor" >&5
-$as_echo_n "checking how to run the C preprocessor... " >&6; }
-# On Suns, sometimes $CPP names a directory.
-if test -n "$CPP" && test -d "$CPP"; then
-  CPP=
-fi
-if test -z "$CPP"; then
-  if ${ac_cv_prog_CPP+:} false; then :
+ac_ext=cpp
+ac_cpp='$CXXCPP $CPPFLAGS'
+ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking how to run the C++ preprocessor" >&5
+$as_echo_n "checking how to run the C++ preprocessor... " >&6; }
+if test -z "$CXXCPP"; then
+  if ${ac_cv_prog_CXXCPP+:} false; then :
   $as_echo_n "(cached) " >&6
 else
-      # Double quotes because CPP needs to be expanded
-    for CPP in "$CC -E" "$CC -E -traditional-cpp" "/lib/cpp"
+      # Double quotes because CXXCPP needs to be expanded
+    for CXXCPP in "$CXX -E" "/lib/cpp"
     do
       ac_preproc_ok=false
-for ac_c_preproc_warn_flag in '' yes
+for ac_cxx_preproc_warn_flag in '' yes
 do
   # Use a header file that comes with gcc, so configuring glibc
   # with a fresh cross-compiler works.
@@ -3610,7 +3065,7 @@ do
 #endif
 		     Syntax error
 _ACEOF
-if ac_fn_c_try_cpp "$LINENO"; then :
+if ac_fn_cxx_try_cpp "$LINENO"; then :
 
 else
   # Broken: fails on valid input.
@@ -3624,7 +3079,7 @@ rm -f conftest.err conftest.i conftest.$ac_ext
 /* end confdefs.h.  */
 #include <ac_nonexistent.h>
 _ACEOF
-if ac_fn_c_try_cpp "$LINENO"; then :
+if ac_fn_cxx_try_cpp "$LINENO"; then :
   # Broken: success on invalid input.
 continue
 else
@@ -3642,17 +3097,17 @@ if $ac_preproc_ok; then :
 fi
 
     done
-    ac_cv_prog_CPP=$CPP
+    ac_cv_prog_CXXCPP=$CXXCPP
 
 fi
-  CPP=$ac_cv_prog_CPP
+  CXXCPP=$ac_cv_prog_CXXCPP
 else
-  ac_cv_prog_CPP=$CPP
+  ac_cv_prog_CXXCPP=$CXXCPP
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $CPP" >&5
-$as_echo "$CPP" >&6; }
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $CXXCPP" >&5
+$as_echo "$CXXCPP" >&6; }
 ac_preproc_ok=false
-for ac_c_preproc_warn_flag in '' yes
+for ac_cxx_preproc_warn_flag in '' yes
 do
   # Use a header file that comes with gcc, so configuring glibc
   # with a fresh cross-compiler works.
@@ -3669,7 +3124,7 @@ do
 #endif
 		     Syntax error
 _ACEOF
-if ac_fn_c_try_cpp "$LINENO"; then :
+if ac_fn_cxx_try_cpp "$LINENO"; then :
 
 else
   # Broken: fails on valid input.
@@ -3683,7 +3138,7 @@ rm -f conftest.err conftest.i conftest.$ac_ext
 /* end confdefs.h.  */
 #include <ac_nonexistent.h>
 _ACEOF
-if ac_fn_c_try_cpp "$LINENO"; then :
+if ac_fn_cxx_try_cpp "$LINENO"; then :
   # Broken: success on invalid input.
 continue
 else
@@ -3701,15 +3156,15 @@ if $ac_preproc_ok; then :
 else
   { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
 $as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
-as_fn_error $? "C preprocessor \"$CPP\" fails sanity check
+as_fn_error $? "C++ preprocessor \"$CXXCPP\" fails sanity check
 See \`config.log' for more details" "$LINENO" 5; }
 fi
 
-ac_ext=c
-ac_cpp='$CPP $CPPFLAGS'
-ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
-ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
-ac_compiler_gnu=$ac_cv_c_compiler_gnu
+ac_ext=cpp
+ac_cpp='$CXXCPP $CPPFLAGS'
+ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
 
 
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for grep that handles long lines and -e" >&5
@@ -3862,7 +3317,7 @@ main ()
   return 0;
 }
 _ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"; then :
   ac_cv_header_stdc=yes
 else
   ac_cv_header_stdc=no
@@ -3935,7 +3390,7 @@ main ()
   return 0;
 }
 _ACEOF
-if ac_fn_c_try_run "$LINENO"; then :
+if ac_fn_cxx_try_run "$LINENO"; then :
 
 else
   ac_cv_header_stdc=no
@@ -3959,7 +3414,7 @@ for ac_header in sys/types.h sys/stat.h stdlib.h string.h memory.h strings.h \
 		  inttypes.h stdint.h unistd.h
 do :
   as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
-ac_fn_c_check_header_compile "$LINENO" "$ac_header" "$as_ac_Header" "$ac_includes_default
+ac_fn_cxx_check_header_compile "$LINENO" "$ac_header" "$as_ac_Header" "$ac_includes_default
 "
 if eval test \"x\$"$as_ac_Header"\" = x"yes"; then :
   cat >>confdefs.h <<_ACEOF
@@ -3973,7 +3428,7 @@ done
 
 for ac_header in sys/mman.h
 do :
-  ac_fn_c_check_header_mongrel "$LINENO" "sys/mman.h" "ac_cv_header_sys_mman_h" "$ac_includes_default"
+  ac_fn_cxx_check_header_mongrel "$LINENO" "sys/mman.h" "ac_cv_header_sys_mman_h" "$ac_includes_default"
 if test "x$ac_cv_header_sys_mman_h" = xyes; then :
   cat >>confdefs.h <<_ACEOF
 #define HAVE_SYS_MMAN_H 1
@@ -4016,7 +3471,7 @@ connect (fd, (sockaddr *)&un, sizeof (un));
   return 0;
 }
 _ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"; then :
   ac_cv_af_unix=yes
 else
   ac_cv_af_unix=no
@@ -4070,7 +3525,7 @@ connect (fd, (sockaddr *)&in6, sizeof (in6));
   return 0;
 }
 _ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"; then :
   ac_cv_af_inet6=yes
 else
   ac_cv_af_inet6=no
@@ -4111,7 +3566,7 @@ epoll_pwait (fd, 0, 0, -1, 0);
   return 0;
 }
 _ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"; then :
   ac_cv_epoll=yes
 else
   ac_cv_epoll=no
@@ -4147,7 +3602,7 @@ pselect (0, 0, 0, 0, 0, 0);
   return 0;
 }
 _ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"; then :
   ac_cv_pselect=yes
 else
   ac_cv_pselect=no
@@ -4184,7 +3639,7 @@ select (0, 0, 0, 0, 0);
   return 0;
 }
 _ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"; then :
   ac_cv_select=yes
 else
   ac_cv_select=no
@@ -4220,7 +3675,7 @@ int err = accept4 (1, 0, 0, SOCK_NONBLOCK);
   return 0;
 }
 _ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"; then :
   ac_cv_accept4=yes
 else
   ac_cv_accept4=no
@@ -4259,7 +3714,7 @@ const char *str = inet_ntop (AF_INET6, &in6, buf, sizeof (buf));
   return 0;
 }
 _ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
+if ac_fn_cxx_try_compile "$LINENO"; then :
   ac_cv_inet_ntop=yes
 else
   ac_cv_inet_ntop=no
@@ -4325,7 +3780,7 @@ for ac_lib in '' nsl; do
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_c_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"; then :
   ac_cv_search_gethostbyname=$ac_res
 fi
 rm -f core conftest.err conftest.$ac_objext \
@@ -4381,7 +3836,7 @@ for ac_lib in '' socket; do
     ac_res=-l$ac_lib
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
-  if ac_fn_c_try_link "$LINENO"; then :
+  if ac_fn_cxx_try_link "$LINENO"; then :
   ac_cv_search_socket=$ac_res
 fi
 rm -f core conftest.err conftest.$ac_objext \
@@ -4431,7 +3886,7 @@ return socket ();
   return 0;
 }
 _ACEOF
-if ac_fn_c_try_link "$LINENO"; then :
+if ac_fn_cxx_try_link "$LINENO"; then :
   ac_cv_lib_socket_socket=yes
 else
   ac_cv_lib_socket_socket=no
diff --git a/c++tools/configure.ac b/c++tools/configure.ac
index 70fcb641db9..f991f63077f 100644
--- a/c++tools/configure.ac
+++ b/c++tools/configure.ac
@@ -41,6 +41,8 @@ MISSING=`cd $ac_aux_dir && ${PWDCMD-pwd}`/missing
 AC_CHECK_PROGS([AUTOCONF], [autoconf], [$MISSING autoconf])
 AC_CHECK_PROGS([AUTOHEADER], [autoheader], [$MISSING autoheader])
 
+AC_LANG(C++)
+
 dnl Enabled by default
 AC_MSG_CHECKING([whether to build C++ tools])
   AC_ARG_ENABLE(c++-tools, 
@@ -67,6 +69,35 @@ AC_MSG_RESULT([$maintainer_mode])
 test "$maintainer_mode" = yes && MAINTAINER=yes
 AC_SUBST(MAINTAINER)
 
+# Handle configuration of checking; for the tools in this directory we
+# default to release checking and stricter checks do not change this.
+
+AC_ARG_ENABLE(checking,
+[AS_HELP_STRING([[--enable-checking[=LIST]]],
+		[enable expensive run-time checks.  With LIST,
+		 enable only specific categories of checks.
+		 Categories are: yes,no,all,none,release.])],
+[ac_checking_flags="${enableval}"],[
+# Default to checking.
+ac_checking_flags=yes
+])
+IFS="${IFS= 	}"; ac_save_IFS="$IFS"; IFS="$IFS,"
+for check in release $ac_checking_flags
+do
+	case $check in
+	# these set all the flags to specific states
+	yes|all|release|assert) ac_assert_checking=1 ; ;;
+	no|none) ac_assert_checking= ; ;;
+	*) ;;
+	esac
+done
+IFS="$ac_save_IFS"
+
+if test x$ac_assert_checking != x ; then
+  AC_DEFINE(ENABLE_ASSERT_CHECKING, 1,
+[Define if you want assertions enabled.  This is a cheap check.])
+fi
+
 # Check whether --enable-default-pie was given.
 AC_ARG_ENABLE(default-pie,
 [AS_HELP_STRING([--enable-default-pie],
diff --git a/c++tools/server.cc b/c++tools/server.cc
index fae3e78dc5d..a60eefe63b0 100644
--- a/c++tools/server.cc
+++ b/c++tools/server.cc
@@ -61,6 +61,10 @@ along with GCC; see the file COPYING3.  If not see
 # define gai_strerror(X) ""
 #endif
 
+#ifndef AI_NUMERICSERV
+#define AI_NUMERICSERV 0
+#endif
+
 #include <getopt.h>
 
 // Select or epoll
@@ -92,6 +96,28 @@ along with GCC; see the file COPYING3.  If not see
 #define DIR_SEPARATOR '/'
 #endif
 
+/* Imported from libcpp/system.h
+   Use gcc_assert(EXPR) to test invariants.  */
+#if ENABLE_ASSERT_CHECKING
+#define gcc_assert(EXPR)                                                \
+   ((void)(!(EXPR) ? fancy_abort (__FILE__, __LINE__, __FUNCTION__), 0 : 0))
+#elif (GCC_VERSION >= 4005)
+#define gcc_assert(EXPR)                                                \
+  ((void)(__builtin_expect (!(EXPR), 0) ? __builtin_unreachable (), 0 : 0))
+#else
+/* Include EXPR, so that unused variable warnings do not occur.  */
+#define gcc_assert(EXPR) ((void)(0 && (EXPR)))
+#endif
+
+/* Use gcc_unreachable() to mark unreachable locations (like an
+   unreachable default case of a switch.  Do not use gcc_assert(0).  */
+#if (GCC_VERSION >= 4005) && !ENABLE_ASSERT_CHECKING
+#define gcc_unreachable() __builtin_unreachable ()
+#else
+#define gcc_unreachable() (fancy_abort (__FILE__, __LINE__, __FUNCTION__))
+#endif
+
+
 #if NETWORKING
 struct netmask {
   in6_addr addr;
@@ -202,11 +228,13 @@ internal_error (const char *fmt, ...)
 
 /* Hooked to from gcc_assert & gcc_unreachable.  */
 
+#if ENABLE_ASSERT_CHECKING
 void ATTRIBUTE_NORETURN ATTRIBUTE_COLD
 fancy_abort (const char *file, int line, const char *func)
 {
   internal_error ("in %s, at %s:%d", func, trim_src_file (file), line);
 }
+#endif
 
 /* Exploded on a signal.  */