config/

	* no-executables.m4 (GCC_TRY_COMPILE_OR_LINK): New function.

libstdc++/
	* acinclude.m4 (GLIBCXX_ENABLE_C99): Temporarily add
	-fno-exceptions to CXXFLAGS.  Use GCC_TRY_COMPILE_OR_LINK.
	Make the tests assign results to volatile variables.
	* configure: Regenerate.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@128959 138bc75d-0d04-0410-961f-82ee72b054a4

config/ChangeLog

+2007-10-02  Richard Sandiford  <richard@codesourcery.com>
+
+	* no-executables.m4 (GCC_TRY_COMPILE_OR_LINK): New function.
+
 2007-09-21  Richard Sandiford  <rsandifo@nildram.co.uk>
 
 	* mt-sde (CFLAGS_FOR_TARGET): Replace -fno-optimize-sibling-calls

config/no-executables.m4

@@ -59,3 +59,11 @@ fi)
 
 m4_divert_pop()dnl
 ])# GCC_NO_EXECUTABLES
+
+# Use the strongest available test out of AC_TRY_COMPILE and AC_TRY_LINK.
+AC_DEFUN([GCC_TRY_COMPILE_OR_LINK],
+[if test x$gcc_no_link = xyes; then
+  AC_TRY_COMPILE([$1], [$2], [$3], [$4])
+else
+  AC_TRY_LINK([$1], [$2], [$3], [$4])
+fi])

libstdc++-v3/ChangeLog

+2007-10-02  Richard Sandiford  <richard@codesourcery.com>
+
+	* acinclude.m4 (GLIBCXX_ENABLE_C99): Temporarily add
+	-fno-exceptions to CXXFLAGS.  Use GCC_TRY_COMPILE_OR_LINK.
+	Make the tests assign results to volatile variables.
+	* configure: Regenerate.
+
 2007-10-02  Benjamin Kosnik  <bkoz@redhat.com>
 
 	* testsuite/25_algorithms/binary_search/2.cc: Split into...

libstdc++-v3/acinclude.m4

@@ -763,24 +763,32 @@ AC_DEFUN([GLIBCXX_ENABLE_C99], [
   AC_LANG_SAVE
   AC_LANG_CPLUSPLUS
 
+  # Use -fno-exceptions so that the C driver can link these tests without
+  # hitting undefined references to personality routines.
+  ac_save_CXXFLAGS="$CXXFLAGS"
+  CXXFLAGS="$CXXFLAGS -fno-exceptions"
+
   # Check for the existence of <math.h> functions used if C99 is enabled.
   AC_MSG_CHECKING([for ISO C99 support in <math.h>])
   AC_CACHE_VAL(ac_c99_math, [
-  AC_TRY_COMPILE([#include <math.h>],
-	         [fpclassify(0.0);
-	          isfinite(0.0); 
-		  isinf(0.0);
-	          isnan(0.0);
-		  isnormal(0.0);
-	  	  signbit(0.0);
-	 	  isgreater(0.0,0.0);
-		  isgreaterequal(0.0,0.0);
-		  isless(0.0,0.0);
-		  islessequal(0.0,0.0);
-		  islessgreater(0.0,0.0);
-		  islessgreater(0.0,0.0);
-		  isunordered(0.0,0.0);
-		 ],[ac_c99_math=yes], [ac_c99_math=no])
+  GCC_TRY_COMPILE_OR_LINK(
+     [#include <math.h>
+      volatile double d1, d2;
+      volatile int i;],
+     [i = fpclassify(d1);
+      i = isfinite(d1);
+      i = isinf(d1);
+      i = isnan(d1);
+      i = isnormal(d1);
+      i = signbit(d1);
+      i = isgreater(d1, d2);
+      i = isgreaterequal(d1, d2);
+      i = isless(d1, d2);
+      i = islessequal(d1, d2);
+      i = islessgreater(d1, d2);
+      i = islessgreater(d1, d2);
+      i = isunordered(d1, d2);
+     ],[ac_c99_math=yes], [ac_c99_math=no])
   ])
   AC_MSG_RESULT($ac_c99_math)
   if test x"$ac_c99_math" = x"yes"; then
@@ -798,47 +806,54 @@ AC_DEFUN([GLIBCXX_ENABLE_C99], [
   ac_c99_complex=no;
   if test x"$ac_has_complex_h" = x"yes"; then
     AC_MSG_CHECKING([for ISO C99 support in <complex.h>])
-    AC_TRY_COMPILE([#include <complex.h>],
-	           [typedef __complex__ float float_type; float_type tmpf;
-	            cabsf(tmpf);
-		    cargf(tmpf);
-		    ccosf(tmpf);
-  		    ccoshf(tmpf);
-		    cexpf(tmpf);
-	            clogf(tmpf);
-		    csinf(tmpf);
-		    csinhf(tmpf);
-		    csqrtf(tmpf);
-		    ctanf(tmpf);
-		    ctanhf(tmpf);
-		    cpowf(tmpf, tmpf);
-		    typedef __complex__ double double_type; double_type tmpd;
-	            cabs(tmpd);
-		    carg(tmpd);
-		    ccos(tmpd);
-  		    ccosh(tmpd);
-		    cexp(tmpd);
-	            clog(tmpd);
-		    csin(tmpd);
-		    csinh(tmpd);
-		    csqrt(tmpd);
-		    ctan(tmpd);
-		    ctanh(tmpd);
-		    cpow(tmpd, tmpd);
-		    typedef __complex__ long double ld_type; ld_type tmpld;
-	            cabsl(tmpld);
-		    cargl(tmpld);
-		    ccosl(tmpld);
-  		    ccoshl(tmpld);
-		    cexpl(tmpld);
-	            clogl(tmpld);
-		    csinl(tmpld);
-		    csinhl(tmpld);
-		    csqrtl(tmpld);
-		    ctanl(tmpld);
-		    ctanhl(tmpld);
-		    cpowl(tmpld, tmpld);
-		   ],[ac_c99_complex=yes], [ac_c99_complex=no])
+    GCC_TRY_COMPILE_OR_LINK(
+       [#include <complex.h>
+	typedef __complex__ float float_type;
+	typedef __complex__ double double_type;
+	typedef __complex__ long double ld_type;
+	volatile float_type tmpf;
+	volatile double_type tmpd;
+	volatile ld_type tmpld;
+	volatile float f;
+	volatile double d;
+	volatile long double ld;],
+       [f = cabsf(tmpf);
+	f = cargf(tmpf);
+	tmpf = ccosf(tmpf);
+	tmpf = ccoshf(tmpf);
+	tmpf = cexpf(tmpf);
+	tmpf = clogf(tmpf);
+	tmpf = csinf(tmpf);
+	tmpf = csinhf(tmpf);
+	tmpf = csqrtf(tmpf);
+	tmpf = ctanf(tmpf);
+	tmpf = ctanhf(tmpf);
+	tmpf = cpowf(tmpf, tmpf);
+	d = cabs(tmpd);
+	d = carg(tmpd);
+	tmpd = ccos(tmpd);
+	tmpd = ccosh(tmpd);
+	tmpd = cexp(tmpd);
+	tmpd = clog(tmpd);
+	tmpd = csin(tmpd);
+	tmpd = csinh(tmpd);
+	tmpd = csqrt(tmpd);
+	tmpd = ctan(tmpd);
+	tmpd = ctanh(tmpd);
+	tmpd = cpow(tmpd, tmpd);
+	ld = cabsl(tmpld);
+	ld = cargl(tmpld);
+	tmpld = ccosl(tmpld);
+	tmpld = ccoshl(tmpld);
+	tmpld = cexpl(tmpld);
+	tmpld = clogl(tmpld);
+	tmpld = csinl(tmpld);
+	tmpld = csinhl(tmpld);
+	tmpld = csqrtl(tmpld);
+	tmpld = ctanl(tmpld);
+	tmpld = ctanhl(tmpld);
+	tmpld = cpowl(tmpld, tmpld);
+       ],[ac_c99_complex=yes], [ac_c99_complex=no])
   fi
   AC_MSG_RESULT($ac_c99_complex)
   if test x"$ac_c99_complex" = x"yes"; then
@@ -851,35 +866,43 @@ AC_DEFUN([GLIBCXX_ENABLE_C99], [
   # Check for the existence in <stdio.h> of vscanf, et. al.
   AC_MSG_CHECKING([for ISO C99 support in <stdio.h>])
   AC_CACHE_VAL(ac_c99_stdio, [
-  AC_TRY_COMPILE([#include <stdio.h>
-		  #include <stdarg.h>
-                  void foo(char* fmt, ...)
-                  {
-	            va_list args; va_start(args, fmt);
-                    vfscanf(stderr, "%i", args); 
-		    vscanf("%i", args);
-                    vsnprintf(fmt, 0, "%i", args);
-                    vsscanf(fmt, "%i", args);
-		  }],
-                 [snprintf("12", 0, "%i");],
-		 [ac_c99_stdio=yes], [ac_c99_stdio=no])
+  GCC_TRY_COMPILE_OR_LINK(
+     [#include <stdio.h>
+      #include <stdarg.h>
+      void foo(char* fmt, ...)
+      {
+	va_list args; va_start(args, fmt);
+	vfscanf(stderr, "%i", args); 
+	vscanf("%i", args);
+	vsnprintf(fmt, 0, "%i", args);
+	vsscanf(fmt, "%i", args);
+      }],
+     [snprintf("12", 0, "%i");],
+     [ac_c99_stdio=yes], [ac_c99_stdio=no])
   ])
   AC_MSG_RESULT($ac_c99_stdio)
 
   # Check for the existence in <stdlib.h> of lldiv_t, et. al.
   AC_MSG_CHECKING([for ISO C99 support in <stdlib.h>])
   AC_CACHE_VAL(ac_c99_stdlib, [
-  AC_TRY_COMPILE([#include <stdlib.h>],
-                 [char* tmp;
-	    	  strtof("gnu", &tmp);
-		  strtold("gnu", &tmp);
-	          strtoll("gnu", &tmp, 10);
-	          strtoull("gnu", &tmp, 10);
-	          llabs(10);
-		  lldiv(10,1);
-		  atoll("10");
-		  _Exit(0);
-		  lldiv_t mydivt;],[ac_c99_stdlib=yes], [ac_c99_stdlib=no])
+  GCC_TRY_COMPILE_OR_LINK(
+     [#include <stdlib.h>
+      volatile float f;
+      volatile long double ld;
+      volatile unsigned long long ll;
+      lldiv_t mydivt;],
+     [char* tmp;
+      f = strtof("gnu", &tmp);
+      ld = strtold("gnu", &tmp);
+      ll = strtoll("gnu", &tmp, 10);
+      ll = strtoull("gnu", &tmp, 10);
+      ll = llabs(10);
+      mydivt = lldiv(10,1);
+      ll = mydivt.quot;
+      ll = mydivt.rem;
+      ll = atoll("10");
+      _Exit(0);
+      ],[ac_c99_stdlib=yes], [ac_c99_stdlib=no])
   ])
   AC_MSG_RESULT($ac_c99_stdlib)
 
@@ -940,6 +963,7 @@ AC_DEFUN([GLIBCXX_ENABLE_C99], [
     <complex.h>, <stdio.h>, and <stdlib.h> can be used or exposed.])
   fi
 
+  CXXFLAGS="$ac_save_CXXFLAGS"
   AC_LANG_RESTORE
   fi	
 

libstdc++-v3/configure

@@ -15436,6 +15436,11 @@ ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ex
 ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
+  # Use -fno-exceptions so that the C driver can link these tests without
+  # hitting undefined references to personality routines.
+  ac_save_CXXFLAGS="$CXXFLAGS"
+  CXXFLAGS="$CXXFLAGS -fno-exceptions"
+
   # Check for the existence of <math.h> functions used if C99 is enabled.
   echo "$as_me:$LINENO: checking for ISO C99 support in <math.h>" >&5
 echo $ECHO_N "checking for ISO C99 support in <math.h>... $ECHO_C" >&6
@@ -15443,6 +15448,7 @@ echo $ECHO_N "checking for ISO C99 support in <math.h>... $ECHO_C" >&6
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
+  if test x$gcc_no_link = xyes; then
   cat >conftest.$ac_ext <<_ACEOF
 /* confdefs.h.  */
 _ACEOF
@@ -15450,22 +15456,24 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 #include <math.h>
+      volatile double d1, d2;
+      volatile int i;
 int
 main ()
 {
-fpclassify(0.0);
-	          isfinite(0.0);
-		  isinf(0.0);
-	          isnan(0.0);
-		  isnormal(0.0);
-	  	  signbit(0.0);
-	 	  isgreater(0.0,0.0);
-		  isgreaterequal(0.0,0.0);
-		  isless(0.0,0.0);
-		  islessequal(0.0,0.0);
-		  islessgreater(0.0,0.0);
-		  islessgreater(0.0,0.0);
-		  isunordered(0.0,0.0);
+i = fpclassify(d1);
+      i = isfinite(d1);
+      i = isinf(d1);
+      i = isnan(d1);
+      i = isnormal(d1);
+      i = signbit(d1);
+      i = isgreater(d1, d2);
+      i = isgreaterequal(d1, d2);
+      i = isless(d1, d2);
+      i = islessequal(d1, d2);
+      i = islessgreater(d1, d2);
+      i = islessgreater(d1, d2);
+      i = isunordered(d1, d2);
   ;
   return 0;
@@ -15501,6 +15509,74 @@ sed 's/^/| /' conftest.$ac_ext >&5
 ac_c99_math=no
 fi
 rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
+else
+  if test x$gcc_no_link = xyes; then
+  { { echo "$as_me:$LINENO: error: Link tests are not allowed after GCC_NO_EXECUTABLES." >&5
+echo "$as_me: error: Link tests are not allowed after GCC_NO_EXECUTABLES." >&2;}
+   { (exit 1); exit 1; }; }
+fi
+cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+#include <math.h>
+      volatile double d1, d2;
+      volatile int i;
+int
+main ()
+{
+i = fpclassify(d1);
+      i = isfinite(d1);
+      i = isinf(d1);
+      i = isnan(d1);
+      i = isnormal(d1);
+      i = signbit(d1);
+      i = isgreater(d1, d2);
+      i = isgreaterequal(d1, d2);
+      i = isless(d1, d2);
+      i = islessequal(d1, d2);
+      i = islessgreater(d1, d2);
+      i = islessgreater(d1, d2);
+      i = isunordered(d1, d2);
+
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext conftest$ac_exeext
+if { (eval echo "$as_me:$LINENO: \"$ac_link\"") >&5
+  (eval $ac_link) 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_cxx_werror_flag"
+			 || test ! -s conftest.err'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest$ac_exeext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  ac_c99_math=yes
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+ac_c99_math=no
+fi
+rm -f conftest.err conftest.$ac_objext \
+      conftest$ac_exeext conftest.$ac_ext
+fi
 fi
@@ -15826,55 +15902,62 @@ done
   if test x"$ac_has_complex_h" = x"yes"; then
     echo "$as_me:$LINENO: checking for ISO C99 support in <complex.h>" >&5
 echo $ECHO_N "checking for ISO C99 support in <complex.h>... $ECHO_C" >&6
-    cat >conftest.$ac_ext <<_ACEOF
+    if test x$gcc_no_link = xyes; then
+  cat >conftest.$ac_ext <<_ACEOF
 /* confdefs.h.  */
 _ACEOF
 cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 #include <complex.h>
+	typedef __complex__ float float_type;
+	typedef __complex__ double double_type;
+	typedef __complex__ long double ld_type;
+	volatile float_type tmpf;
+	volatile double_type tmpd;
+	volatile ld_type tmpld;
+	volatile float f;
+	volatile double d;
+	volatile long double ld;
 int
 main ()
 {
-typedef __complex__ float float_type; float_type tmpf;
-	            cabsf(tmpf);
-		    cargf(tmpf);
-		    ccosf(tmpf);
-  		    ccoshf(tmpf);
-		    cexpf(tmpf);
-	            clogf(tmpf);
-		    csinf(tmpf);
-		    csinhf(tmpf);
-		    csqrtf(tmpf);
-		    ctanf(tmpf);
-		    ctanhf(tmpf);
-		    cpowf(tmpf, tmpf);
-		    typedef __complex__ double double_type; double_type tmpd;
-	            cabs(tmpd);
-		    carg(tmpd);
-		    ccos(tmpd);
-  		    ccosh(tmpd);
-		    cexp(tmpd);
-	            clog(tmpd);
-		    csin(tmpd);
-		    csinh(tmpd);
-		    csqrt(tmpd);
-		    ctan(tmpd);
-		    ctanh(tmpd);
-		    cpow(tmpd, tmpd);
-		    typedef __complex__ long double ld_type; ld_type tmpld;
-	            cabsl(tmpld);
-		    cargl(tmpld);
-		    ccosl(tmpld);
-  		    ccoshl(tmpld);
-		    cexpl(tmpld);
-	            clogl(tmpld);
-		    csinl(tmpld);
-		    csinhl(tmpld);
-		    csqrtl(tmpld);
-		    ctanl(tmpld);
-		    ctanhl(tmpld);
-		    cpowl(tmpld, tmpld);
+f = cabsf(tmpf);
+	f = cargf(tmpf);
+	tmpf = ccosf(tmpf);
+	tmpf = ccoshf(tmpf);
+	tmpf = cexpf(tmpf);
+	tmpf = clogf(tmpf);
+	tmpf = csinf(tmpf);
+	tmpf = csinhf(tmpf);
+	tmpf = csqrtf(tmpf);
+	tmpf = ctanf(tmpf);
+	tmpf = ctanhf(tmpf);
+	tmpf = cpowf(tmpf, tmpf);
+	d = cabs(tmpd);
+	d = carg(tmpd);
+	tmpd = ccos(tmpd);
+	tmpd = ccosh(tmpd);
+	tmpd = cexp(tmpd);
+	tmpd = clog(tmpd);
+	tmpd = csin(tmpd);
+	tmpd = csinh(tmpd);
+	tmpd = csqrt(tmpd);
+	tmpd = ctan(tmpd);
+	tmpd = ctanh(tmpd);
+	tmpd = cpow(tmpd, tmpd);
+	ld = cabsl(tmpld);
+	ld = cargl(tmpld);
+	tmpld = ccosl(tmpld);
+	tmpld = ccoshl(tmpld);
+	tmpld = cexpl(tmpld);
+	tmpld = clogl(tmpld);
+	tmpld = csinl(tmpld);
+	tmpld = csinhl(tmpld);
+	tmpld = csqrtl(tmpld);
+	tmpld = ctanl(tmpld);
+	tmpld = ctanhl(tmpld);
+	tmpld = cpowl(tmpld, tmpld);
   ;
   return 0;
@@ -15910,6 +15993,104 @@ sed 's/^/| /' conftest.$ac_ext >&5
 ac_c99_complex=no
 fi
 rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
+else
+  if test x$gcc_no_link = xyes; then
+  { { echo "$as_me:$LINENO: error: Link tests are not allowed after GCC_NO_EXECUTABLES." >&5
+echo "$as_me: error: Link tests are not allowed after GCC_NO_EXECUTABLES." >&2;}
+   { (exit 1); exit 1; }; }
+fi
+cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+#include <complex.h>
+	typedef __complex__ float float_type;
+	typedef __complex__ double double_type;
+	typedef __complex__ long double ld_type;
+	volatile float_type tmpf;
+	volatile double_type tmpd;
+	volatile ld_type tmpld;
+	volatile float f;
+	volatile double d;
+	volatile long double ld;
+int
+main ()
+{
+f = cabsf(tmpf);
+	f = cargf(tmpf);
+	tmpf = ccosf(tmpf);
+	tmpf = ccoshf(tmpf);
+	tmpf = cexpf(tmpf);
+	tmpf = clogf(tmpf);
+	tmpf = csinf(tmpf);
+	tmpf = csinhf(tmpf);
+	tmpf = csqrtf(tmpf);
+	tmpf = ctanf(tmpf);
+	tmpf = ctanhf(tmpf);
+	tmpf = cpowf(tmpf, tmpf);
+	d = cabs(tmpd);
+	d = carg(tmpd);
+	tmpd = ccos(tmpd);
+	tmpd = ccosh(tmpd);
+	tmpd = cexp(tmpd);
+	tmpd = clog(tmpd);
+	tmpd = csin(tmpd);
+	tmpd = csinh(tmpd);
+	tmpd = csqrt(tmpd);
+	tmpd = ctan(tmpd);
+	tmpd = ctanh(tmpd);
+	tmpd = cpow(tmpd, tmpd);
+	ld = cabsl(tmpld);
+	ld = cargl(tmpld);
+	tmpld = ccosl(tmpld);
+	tmpld = ccoshl(tmpld);
+	tmpld = cexpl(tmpld);
+	tmpld = clogl(tmpld);
+	tmpld = csinl(tmpld);
+	tmpld = csinhl(tmpld);
+	tmpld = csqrtl(tmpld);
+	tmpld = ctanl(tmpld);
+	tmpld = ctanhl(tmpld);
+	tmpld = cpowl(tmpld, tmpld);
+
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext conftest$ac_exeext
+if { (eval echo "$as_me:$LINENO: \"$ac_link\"") >&5
+  (eval $ac_link) 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_cxx_werror_flag"
+			 || test ! -s conftest.err'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest$ac_exeext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  ac_c99_complex=yes
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+ac_c99_complex=no
+fi
+rm -f conftest.err conftest.$ac_objext \
+      conftest$ac_exeext conftest.$ac_ext
+fi
   fi
   echo "$as_me:$LINENO: result: $ac_c99_complex" >&5
 echo "${ECHO_T}$ac_c99_complex" >&6
@@ -15928,6 +16109,7 @@ echo $ECHO_N "checking for ISO C99 support in <stdio.h>... $ECHO_C" >&6
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
+  if test x$gcc_no_link = xyes; then
   cat >conftest.$ac_ext <<_ACEOF
 /* confdefs.h.  */
 _ACEOF
@@ -15935,15 +16117,15 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 #include <stdio.h>
-		  #include <stdarg.h>
-                  void foo(char* fmt, ...)
-                  {
-	            va_list args; va_start(args, fmt);
-                    vfscanf(stderr, "%i", args);
-		    vscanf("%i", args);
-                    vsnprintf(fmt, 0, "%i", args);
-                    vsscanf(fmt, "%i", args);
-		  }
+      #include <stdarg.h>
+      void foo(char* fmt, ...)
+      {
+	va_list args; va_start(args, fmt);
+	vfscanf(stderr, "%i", args);
+	vscanf("%i", args);
+	vsnprintf(fmt, 0, "%i", args);
+	vsscanf(fmt, "%i", args);
+      }
 int
 main ()
 {
@@ -15982,6 +16164,68 @@ sed 's/^/| /' conftest.$ac_ext >&5
 ac_c99_stdio=no
 fi
 rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
+else
+  if test x$gcc_no_link = xyes; then
+  { { echo "$as_me:$LINENO: error: Link tests are not allowed after GCC_NO_EXECUTABLES." >&5
+echo "$as_me: error: Link tests are not allowed after GCC_NO_EXECUTABLES." >&2;}
+   { (exit 1); exit 1; }; }
+fi
+cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+#include <stdio.h>
+      #include <stdarg.h>
+      void foo(char* fmt, ...)
+      {
+	va_list args; va_start(args, fmt);
+	vfscanf(stderr, "%i", args);
+	vscanf("%i", args);
+	vsnprintf(fmt, 0, "%i", args);
+	vsscanf(fmt, "%i", args);
+      }
+int
+main ()
+{
+snprintf("12", 0, "%i");
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext conftest$ac_exeext
+if { (eval echo "$as_me:$LINENO: \"$ac_link\"") >&5
+  (eval $ac_link) 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_cxx_werror_flag"
+			 || test ! -s conftest.err'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest$ac_exeext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  ac_c99_stdio=yes
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+ac_c99_stdio=no
+fi
+rm -f conftest.err conftest.$ac_objext \
+      conftest$ac_exeext conftest.$ac_ext
+fi
 fi
@@ -15995,6 +16239,7 @@ echo $ECHO_N "checking for ISO C99 support in <stdlib.h>... $ECHO_C" >&6
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
+  if test x$gcc_no_link = xyes; then
   cat >conftest.$ac_ext <<_ACEOF
 /* confdefs.h.  */
 _ACEOF
@@ -16002,19 +16247,25 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 #include <stdlib.h>
+      volatile float f;
+      volatile long double ld;
+      volatile unsigned long long ll;
+      lldiv_t mydivt;
 int
 main ()
 {
 char* tmp;
-	    	  strtof("gnu", &tmp);
-		  strtold("gnu", &tmp);
-	          strtoll("gnu", &tmp, 10);
-	          strtoull("gnu", &tmp, 10);
-	          llabs(10);
-		  lldiv(10,1);
-		  atoll("10");
-		  _Exit(0);
-		  lldiv_t mydivt;
+      f = strtof("gnu", &tmp);
+      ld = strtold("gnu", &tmp);
+      ll = strtoll("gnu", &tmp, 10);
+      ll = strtoull("gnu", &tmp, 10);
+      ll = llabs(10);
+      mydivt = lldiv(10,1);
+      ll = mydivt.quot;
+      ll = mydivt.rem;
+      ll = atoll("10");
+      _Exit(0);
+
   ;
   return 0;
 }
@@ -16049,6 +16300,74 @@ sed 's/^/| /' conftest.$ac_ext >&5
 ac_c99_stdlib=no
 fi
 rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
+else
+  if test x$gcc_no_link = xyes; then
+  { { echo "$as_me:$LINENO: error: Link tests are not allowed after GCC_NO_EXECUTABLES." >&5
+echo "$as_me: error: Link tests are not allowed after GCC_NO_EXECUTABLES." >&2;}
+   { (exit 1); exit 1; }; }
+fi
+cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+#include <stdlib.h>
+      volatile float f;
+      volatile long double ld;
+      volatile unsigned long long ll;
+      lldiv_t mydivt;
+int
+main ()
+{
+char* tmp;
+      f = strtof("gnu", &tmp);
+      ld = strtold("gnu", &tmp);
+      ll = strtoll("gnu", &tmp, 10);
+      ll = strtoull("gnu", &tmp, 10);
+      ll = llabs(10);
+      mydivt = lldiv(10,1);
+      ll = mydivt.quot;
+      ll = mydivt.rem;
+      ll = atoll("10");
+      _Exit(0);
+
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext conftest$ac_exeext
+if { (eval echo "$as_me:$LINENO: \"$ac_link\"") >&5
+  (eval $ac_link) 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_cxx_werror_flag"
+			 || test ! -s conftest.err'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest$ac_exeext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  ac_c99_stdlib=yes
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+ac_c99_stdlib=no
+fi
+rm -f conftest.err conftest.$ac_objext \
+      conftest$ac_exeext conftest.$ac_ext
+fi
 fi
@@ -16386,6 +16705,7 @@ _ACEOF
   fi
+  CXXFLAGS="$ac_save_CXXFLAGS"
   ac_ext=c
 ac_cpp='$CPP $CPPFLAGS'
 ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
@@ -17305,7 +17625,7 @@ ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
   # Fake what AC_TRY_COMPILE does.  XXX Look at redoing this new-style.
     cat > conftest.$ac_ext << EOF
-#line 17308 "configure"
+#line 17628 "configure"
 int main()
 {
   // NB: _Atomic_word not necessarily int.