newlib: update preprocessor configure checks

The nds32 & spu dirs are using compile tests to look for some
preprocessor defines, but we don't need to compile the code,
just preprocess it.  So switch to AC_PREPROC_IFELSE.

The sh dir is using a preprocessor test via grep, but let's
switch it to AC_PREPROC_IFELSE too to be consistent.

This should allow us to drop the uncommon AC_NO_EXECUTABLES call.

3 files changed, 192 insertions, 96 deletions

diff --git a/newlib/libm/machine/nds32/Makefile.in b/newlib/libm/machine/nds32/Makefile.in
index ec448232f..2bd695e46 100644
--- a/newlib/libm/machine/nds32/Makefile.in
+++ b/newlib/libm/machine/nds32/Makefile.in
@@ -193,6 +193,7 @@ CCAS = @CCAS@
 CCASFLAGS = @CCASFLAGS@
 CCDEPMODE = @CCDEPMODE@
 CFLAGS = @CFLAGS@
+CPP = @CPP@
 CPPFLAGS = @CPPFLAGS@
 CYGPATH_W = @CYGPATH_W@
 DEFS = @DEFS@
diff --git a/newlib/libm/machine/nds32/configure b/newlib/libm/machine/nds32/configure
index 7c8bb1775..8f80c485d 100644..100755
--- a/newlib/libm/machine/nds32/configure
+++ b/newlib/libm/machine/nds32/configure
@@ -582,7 +582,6 @@ PACKAGE_BUGREPORT=''
 PACKAGE_URL=''
 
 ac_unique_file="Makefile.am"
-ac_no_link=no
 ac_subst_vars='am__EXEEXT_FALSE
 am__EXEEXT_TRUE
 LTLIBOBJS
@@ -591,6 +590,7 @@ HAS_NDS32_FPU_DP_FALSE
 HAS_NDS32_FPU_DP_TRUE
 HAS_NDS32_FPU_SP_FALSE
 HAS_NDS32_FPU_SP_TRUE
+CPP
 EXEEXT
 ac_ct_CC
 CPPFLAGS
@@ -738,7 +738,8 @@ CC
 CFLAGS
 LDFLAGS
 LIBS
-CPPFLAGS'
+CPPFLAGS
+CPP'
 
 
 # Initialize some variables set by options.
@@ -1385,6 +1386,7 @@ 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>
+  CPP         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.
@@ -1503,6 +1505,43 @@ fi
   as_fn_set_status $ac_retval
 
 } # 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 $ac_retval
+
+} # ac_fn_c_try_cpp
 cat >config.log <<_ACEOF
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
@@ -3631,7 +3670,6 @@ OBJEXT=${oext}
 
 
 
-
 ac_ext=c
 ac_cpp='$CPP $CPPFLAGS'
 ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
@@ -3971,29 +4009,6 @@ main ()
   return 0;
 }
 _ACEOF
-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>&5
-  ac_status=$?
-  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
-  test $ac_status = 0; }; then
-  ac_no_link=no
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-int
-main ()
-{
-
-  ;
-  return 0;
-}
-_ACEOF
 ac_clean_files_save=$ac_clean_files
 ac_clean_files="$ac_clean_files a.out a.out.dSYM a.exe b.out"
 # Try to create an executable without -o first, disregard a.out.
@@ -4182,59 +4197,6 @@ $as_echo "$cross_compiling" >&6; }
 
 rm -f conftest.$ac_ext conftest$ac_cv_exeext conftest.out
 ac_clean_files=$ac_clean_files_save
-
-else
-  rm -f -r a.out a.exe b.out conftest.$ac_ext conftest.o conftest.obj conftest.dSYM
-  ac_no_link=yes
-  # Setting cross_compile will disable run tests; it will
-  # also disable AC_CHECK_FILE but that's generally
-  # correct if we can't link.
-  cross_compiling=yes
-  EXEEXT=
-  # Check that the compiler produces executables we can run.  If not, either
-# the compiler is broken, or we cross compile.
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether we are cross compiling" >&5
-$as_echo_n "checking whether we are cross compiling... " >&6; }
-if test "$cross_compiling" != yes; then
-  { { 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>&5
-  ac_status=$?
-  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
-  test $ac_status = 0; }
-  if { ac_try='./conftest$ac_cv_exeext'
-  { { 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_try") 2>&5
-  ac_status=$?
-  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
-  test $ac_status = 0; }; }; then
-    cross_compiling=no
-  else
-    if test "$cross_compiling" = maybe; then
-	cross_compiling=yes
-    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 $? "cannot run C compiled programs.
-If you meant to cross compile, use \`--host'.
-See \`config.log' for more details" "$LINENO" 5; }
-    fi
-  fi
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $cross_compiling" >&5
-$as_echo "$cross_compiling" >&6; }
-
-fi
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for suffix of object files" >&5
 $as_echo_n "checking for suffix of object files... " >&6; }
 if ${ac_cv_objext+:} false; then :
@@ -4557,10 +4519,148 @@ ac_compiler_gnu=$ac_cv_c_compiler_gnu
 
 
 
+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" "$LINENO" 5; }
+fi
+
+ac_ext=c
+ac_cpp='$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
+
+
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 #if (__NDS32_EXT_FPU_SP__)
-warning: Has nds32 FPU SP extension support
+# error "Has nds32 FPU SP extension support"
 #endif
 
 int
@@ -4571,12 +4671,12 @@ main ()
   return 0;
 }
 _ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
+if ac_fn_c_try_cpp "$LINENO"; then :
   has_nds32_fpu_sp="no"
 else
   has_nds32_fpu_sp="yes"
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f conftest.err conftest.i conftest.$ac_ext
  if test "$has_nds32_fpu_sp" = "yes"; then
   HAS_NDS32_FPU_SP_TRUE=
   HAS_NDS32_FPU_SP_FALSE='#'
@@ -4589,7 +4689,7 @@ fi
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 #if (__NDS32_EXT_FPU_DP__)
-warning: Has nds32 FPU DP extension support
+# error "Has nds32 FPU DP extension support"
 #endif
 
 int
@@ -4600,12 +4700,12 @@ main ()
   return 0;
 }
 _ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
+if ac_fn_c_try_cpp "$LINENO"; then :
   has_nds32_fpu_dp="no"
 else
   has_nds32_fpu_dp="yes"
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f conftest.err conftest.i conftest.$ac_ext
  if test "$has_nds32_fpu_dp" = "yes"; then
   HAS_NDS32_FPU_DP_TRUE=
   HAS_NDS32_FPU_DP_FALSE='#'
diff --git a/newlib/libm/machine/nds32/configure.ac b/newlib/libm/machine/nds32/configure.ac
index 7d49c9ae2..e3589a072 100644
--- a/newlib/libm/machine/nds32/configure.ac
+++ b/newlib/libm/machine/nds32/configure.ac
@@ -11,23 +11,18 @@ NEWLIB_CONFIGURE(../../..)
 
 
 dnl Use builtin macro to detect if FPU extension support is on.
-AC_NO_EXECUTABLES
-AC_COMPILE_IFELSE([AC_LANG_PROGRAM(
+AC_PREPROC_IFELSE([AC_LANG_PROGRAM(
 [[#if (__NDS32_EXT_FPU_SP__)
-warning: Has nds32 FPU SP extension support
+# error "Has nds32 FPU SP extension support"
 #endif
-]])],
-                  [has_nds32_fpu_sp="no"],
-		  [has_nds32_fpu_sp="yes"])
+]])], [has_nds32_fpu_sp="no"], [has_nds32_fpu_sp="yes"])
 AM_CONDITIONAL(HAS_NDS32_FPU_SP, test "$has_nds32_fpu_sp" = "yes")
 
-AC_COMPILE_IFELSE([AC_LANG_PROGRAM(
+AC_PREPROC_IFELSE([AC_LANG_PROGRAM(
 [[#if (__NDS32_EXT_FPU_DP__)
-warning: Has nds32 FPU DP extension support
+# error "Has nds32 FPU DP extension support"
 #endif
-]])],
-                  [has_nds32_fpu_dp="no"],
-		  [has_nds32_fpu_dp="yes"])
+]])], [has_nds32_fpu_dp="no"], [has_nds32_fpu_dp="yes"])
 AM_CONDITIONAL(HAS_NDS32_FPU_DP, test "$has_nds32_fpu_dp" = "yes")
 
 AC_CONFIG_FILES([Makefile])