Avoid C++ tests when the C++ cannot be linked.

1 files changed, 174 insertions, 84 deletions

diff --git a/configure b/configure
index 7337823652..71cc6bb0b2 100755
--- a/configure
+++ b/configure
@@ -677,10 +677,10 @@ hardcoded_path_in_tests
 use_default_link
 sysheaders
 with_fp
-READELF
 ac_ct_CXX
 CXXFLAGS
 CXX
+READELF
 CPP
 cross_compiling
 BUILD_CC
@@ -1627,6 +1627,52 @@ fi
 
 } # ac_fn_cxx_try_compile
 
+# ac_fn_cxx_try_link LINENO
+# -------------------------
+# Try to link conftest.$ac_ext, and return whether this succeeded.
+ac_fn_cxx_try_link ()
+{
+  as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
+  rm -f conftest.$ac_objext conftest$ac_exeext
+  if { { ac_try="$ac_link"
+case "(($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_link") 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_cxx_werror_flag" ||
+	 test ! -s conftest.err
+       } && test -s conftest$ac_exeext && {
+	 test "$cross_compiling" = yes ||
+	 test -x conftest$ac_exeext
+       }; then :
+  ac_retval=0
+else
+  $as_echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+	ac_retval=1
+fi
+  # Delete the IPA/IPO (Inter Procedural Analysis/Optimization) information
+  # created by the PGI compiler (conftest_ipa8_conftest.oo), as it would
+  # interfere with the next link command; also delete a directory that is
+  # left behind by Apple's compiler.  We do this before executing the actions.
+  rm -rf conftest.dSYM conftest_ipa8_conftest.oo
+  eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
+  as_fn_set_status $ac_retval
+
+} # ac_fn_cxx_try_link
+
 # ac_fn_c_try_link LINENO
 # -----------------------
 # Try to link conftest.$ac_ext, and return whether this succeeded.
@@ -2985,6 +3031,99 @@ if test -z "$CPP"; then
   CPP="$CC -E"
 fi
 
+if test -n "$ac_tool_prefix"; then
+  # Extract the first word of "${ac_tool_prefix}readelf", so it can be a program name with args.
+set dummy ${ac_tool_prefix}readelf; 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_READELF+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test -n "$READELF"; then
+  ac_cv_prog_READELF="$READELF" # Let the user override the test.
+else
+as_save_IFS=$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_READELF="${ac_tool_prefix}readelf"
+    $as_echo "$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
+READELF=$ac_cv_prog_READELF
+if test -n "$READELF"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $READELF" >&5
+$as_echo "$READELF" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+fi
+if test -z "$ac_cv_prog_READELF"; then
+  ac_ct_READELF=$READELF
+  # Extract the first word of "readelf", so it can be a program name with args.
+set dummy readelf; 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_READELF+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test -n "$ac_ct_READELF"; then
+  ac_cv_prog_ac_ct_READELF="$ac_ct_READELF" # Let the user override the test.
+else
+as_save_IFS=$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_READELF="readelf"
+    $as_echo "$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_READELF=$ac_cv_prog_ac_ct_READELF
+if test -n "$ac_ct_READELF"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_ct_READELF" >&5
+$as_echo "$ac_ct_READELF" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+  if test "x$ac_ct_READELF" = x; then
+    READELF="false"
+  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
+    READELF=$ac_ct_READELF
+  fi
+else
+  READELF="$ac_cv_prog_READELF"
+fi
+
+
 # We need the C++ compiler only for testing.
 ac_ext=cpp
 ac_cpp='$CXXCPP $CPPFLAGS'
@@ -3243,98 +3382,49 @@ ac_compile='$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}readelf", so it can be a program name with args.
-set dummy ${ac_tool_prefix}readelf; 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_READELF+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  if test -n "$READELF"; then
-  ac_cv_prog_READELF="$READELF" # Let the user override the test.
-else
-as_save_IFS=$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_READELF="${ac_tool_prefix}readelf"
-    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
-    break 2
-  fi
-done
-  done
-IFS=$as_save_IFS
+# It's useless to us if it can't link programs (e.g. missing -lstdc++).
 
-fi
-fi
-READELF=$ac_cv_prog_READELF
-if test -n "$READELF"; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $READELF" >&5
-$as_echo "$READELF" >&6; }
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX can link programs" >&5
+$as_echo_n "checking whether $CXX can link programs... " >&6; }
+if ${libc_cv_cxx_link_ok+:} false; then :
+  $as_echo_n "(cached) " >&6
 else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-fi
+  ac_ext=cpp
+ac_cpp='$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
 
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
 
-fi
-if test -z "$ac_cv_prog_READELF"; then
-  ac_ct_READELF=$READELF
-  # Extract the first word of "readelf", so it can be a program name with args.
-set dummy readelf; 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_READELF+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  if test -n "$ac_ct_READELF"; then
-  ac_cv_prog_ac_ct_READELF="$ac_ct_READELF" # Let the user override the test.
-else
-as_save_IFS=$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_READELF="readelf"
-    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
-    break 2
-  fi
-done
-  done
-IFS=$as_save_IFS
+int
+main ()
+{
 
-fi
-fi
-ac_ct_READELF=$ac_cv_prog_ac_ct_READELF
-if test -n "$ac_ct_READELF"; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_ct_READELF" >&5
-$as_echo "$ac_ct_READELF" >&6; }
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_link "$LINENO"; then :
+  libc_cv_cxx_link_ok=yes
 else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
+  libc_cv_cxx_link_ok=no
 fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+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 "x$ac_ct_READELF" = x; then
-    READELF="false"
-  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
-    READELF=$ac_ct_READELF
-  fi
-else
-  READELF="$ac_cv_prog_READELF"
 fi
-
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_cxx_link_ok" >&5
+$as_echo "$libc_cv_cxx_link_ok" >&6; }
+if test $libc_cv_cxx_link_ok != yes; then :
+  CXX=
+fi
 
 if test "`cd $srcdir; /bin/pwd`" = "`/bin/pwd`"; then
   as_fn_error $? "you must configure in a separate build directory" "$LINENO" 5