configure: Default to CPP="$CC -E" unless overridden.

3 files changed, 28 insertions, 167 deletions

diff --git a/ChangeLog b/ChangeLog
index 1c1011eeb5..7e32beedef 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2013-01-25  Thomas Schwinge  <thomas@codesourcery.com>
+
+	* configure.in (AC_PROG_CPP): New definition.
+	* configure: Regenerate.
+
 2013-01-23  Joseph Myers  <joseph@codesourcery.com>
 
 	* debug/tst-backtrace.h: New file.
diff --git a/configure b/configure
index c2fdc151e9..10d4d82c1f 100755
--- a/configure
+++ b/configure
@@ -1573,43 +1573,6 @@ fi
 
 } # ac_fn_c_try_compile
 
-# ac_fn_c_try_cpp LINENO
-# ----------------------
-# Try to preprocess conftest.$ac_ext, and return whether this succeeded.
-ac_fn_c_try_cpp ()
-{
-  as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
-  if { { ac_try="$ac_cpp conftest.$ac_ext"
-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_cpp conftest.$ac_ext") 2>conftest.err
-  ac_status=$?
-  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 $ac_status = 0; } > conftest.i && {
-	 test -z "$ac_c_preproc_warn_flag$ac_c_werror_flag" ||
-	 test ! -s conftest.err
-       }; 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 $ac_retval
-
-} # ac_fn_c_try_cpp
-
 # ac_fn_cxx_try_compile LINENO
 # ----------------------------
 # Try to compile conftest.$ac_ext, and return whether this succeeded.
@@ -2359,6 +2322,11 @@ _ACEOF
 # Glibc should not depend on any header files
 
 
+# We require GCC, and by default use its preprocessor.  Override AC_PROG_CPP
+# here to work around the Autoconf issue discussed in
+# <http://sourceware.org/ml/libc-alpha/2013-01/msg00721.html>.
+# AC_PROG_CPP
+
 
 
 subdirs="$subdirs "
@@ -3073,143 +3041,14 @@ done
 
 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 :
-  $as_echo_n "(cached) " >&6
-else
-      # Double quotes because CPP needs to be expanded
-    for CPP in "$CC -E" "$CC -E -traditional-cpp" "/lib/cpp"
-    do
-      ac_preproc_ok=false
-for ac_c_preproc_warn_flag in '' yes
-do
-  # Use a header file that comes with gcc, so configuring glibc
-  # with a fresh cross-compiler works.
-  # Prefer <limits.h> to <assert.h> if __STDC__ is defined, since
-  # <limits.h> exists even on freestanding compilers.
-  # On the NeXT, cc -E runs the code through the compiler's parser,
-  # not just through cpp. "Syntax error" is here to catch this case.
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#ifdef __STDC__
-# include <limits.h>
-#else
-# include <assert.h>
-#endif
-		     Syntax error
-_ACEOF
-if ac_fn_c_try_cpp "$LINENO"; then :
-
-else
-  # Broken: fails on valid input.
-continue
-fi
-rm -f conftest.err conftest.i conftest.$ac_ext
-
-  # OK, works on sane cases.  Now check whether nonexistent headers
-  # can be detected and how.
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#include <ac_nonexistent.h>
-_ACEOF
-if ac_fn_c_try_cpp "$LINENO"; then :
-  # Broken: success on invalid input.
-continue
-else
-  # Passes both tests.
-ac_preproc_ok=:
-break
-fi
-rm -f conftest.err conftest.i conftest.$ac_ext
-
-done
-# Because of `break', _AC_PREPROC_IFELSE's cleaning code was skipped.
-rm -f conftest.i conftest.err conftest.$ac_ext
-if $ac_preproc_ok; then :
-  break
-fi
-
-    done
-    ac_cv_prog_CPP=$CPP
-
-fi
-  CPP=$ac_cv_prog_CPP
-else
-  ac_cv_prog_CPP=$CPP
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $CPP" >&5
-$as_echo "$CPP" >&6; }
-ac_preproc_ok=false
-for ac_c_preproc_warn_flag in '' yes
-do
-  # Use a header file that comes with gcc, so configuring glibc
-  # with a fresh cross-compiler works.
-  # Prefer <limits.h> to <assert.h> if __STDC__ is defined, since
-  # <limits.h> exists even on freestanding compilers.
-  # On the NeXT, cc -E runs the code through the compiler's parser,
-  # not just through cpp. "Syntax error" is here to catch this case.
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#ifdef __STDC__
-# include <limits.h>
-#else
-# include <assert.h>
-#endif
-		     Syntax error
-_ACEOF
-if ac_fn_c_try_cpp "$LINENO"; then :
-
-else
-  # Broken: fails on valid input.
-continue
-fi
-rm -f conftest.err conftest.i conftest.$ac_ext
-
-  # OK, works on sane cases.  Now check whether nonexistent headers
-  # can be detected and how.
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#include <ac_nonexistent.h>
-_ACEOF
-if ac_fn_c_try_cpp "$LINENO"; then :
-  # Broken: success on invalid input.
-continue
-else
-  # Passes both tests.
-ac_preproc_ok=:
-break
-fi
-rm -f conftest.err conftest.i conftest.$ac_ext
-
-done
-# Because of `break', _AC_PREPROC_IFELSE's cleaning code was skipped.
-rm -f conftest.i conftest.err conftest.$ac_ext
-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
-See \`config.log' for more details" "$LINENO" 5; }
+  CPP="$CC -E"
 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
-
 # We need the C++ compiler only for testing.
 ac_ext=cpp
 ac_cpp='$CXXCPP $CPPFLAGS'
diff --git a/configure.in b/configure.in
index 4cfa36db00..2c50d0940f 100644
--- a/configure.in
+++ b/configure.in
@@ -17,6 +17,23 @@ AC_DEFUN([_AC_INCLUDES_DEFAULT_REQUIREMENTS],
   [m4_divert_text([DEFAULTS],
     [ac_includes_default='/* none */'])])
 
+# We require GCC, and by default use its preprocessor.  Override AC_PROG_CPP
+# here to work around the Autoconf issue discussed in
+# <http://sourceware.org/ml/libc-alpha/2013-01/msg00721.html>.
+AC_DEFUN([AC_PROG_CPP],
+[AC_REQUIRE([AC_PROG_CC])dnl
+AC_ARG_VAR([CPP],      [C preprocessor])dnl
+_AC_ARG_VAR_CPPFLAGS()dnl
+# On Suns, sometimes $CPP names a directory.
+if test -n "$CPP" && test -d "$CPP"; then
+  CPP=
+fi
+if test -z "$CPP"; then
+  CPP="$CC -E"
+fi
+AC_SUBST(CPP)dnl
+])# AC_PROG_CPP
+
 dnl This is here so we can set $subdirs directly based on configure fragments.
 AC_CONFIG_SUBDIRS()