- AC_TRY_RUN does not work in case of cross-compilation environments.

Tests based on preprocessor CPP output, won't help either, as they
   don't spit out nice computed numerical values, but rather the
   #define itselve.

This commit was SVN r21364.

config/opal_check_compiler_version.m4

@@ -29,9 +29,10 @@ AC_DEFUN([OPAL_CHECK_COMPILER], [
     lower=m4_tolower($1)
     AC_CACHE_CHECK([for compiler $lower], opal_cv_compiler_[$1],
     [
-        CPPFLAGS_orig=$CPPFLAGS
+        if test "$cross_compiling" != "yes" ; then
-        CPPFLAGS="-I${top_ompi_srcdir}/ompi/include $CPPFLAGS"
+            CPPFLAGS_orig=$CPPFLAGS
-        AC_TRY_RUN([
+            CPPFLAGS="-I${top_ompi_srcdir}/ompi/include $CPPFLAGS"
+            AC_TRY_RUN([
 #include <stdio.h>
 #include <stdlib.h>
 #include "mpi_portable_platform.h.in"   /* Yes, it is supposed to be a .in-file */
@@ -44,12 +45,15 @@ int main (int argc, char * argv[])
     fprintf (f, "%d", PLATFORM_COMPILER_$1);
     return 0;
 }
-        ], [
+            ], [
-            eval opal_cv_compiler_$1=`cat conftestval`;
+                eval opal_cv_compiler_$1=`cat conftestval`;
-        ], [
+            ], [
-            eval opal_cv_compiler_$1=0
+                eval opal_cv_compiler_$1=0
-        ])
+            ])
-        CPPFLAGS=$CPPFLAGS_orig
+            CPPFLAGS=$CPPFLAGS_orig
+        else
+            opal_cv_compiler_$1=0
+        fi
     ])
     AC_DEFINE_UNQUOTED([OPAL_BUILD_PLATFORM_COMPILER_$1], $opal_cv_compiler_[$1],
                        [The compiler $lower which OMPI was built with])
@@ -60,9 +64,10 @@ AC_DEFUN([OPAL_CHECK_COMPILER_STRINGIFY], [
     lower=m4_tolower($1)
     AC_CACHE_CHECK([for compiler $lower], opal_cv_compiler_[$1],
     [
-        CPPFLAGS_orig=$CPPFLAGS
+        if test "$cross_compiling" != "yes" ; then
-        CPPFLAGS="-I${top_ompi_srcdir}/ompi/include $CPPFLAGS"
+            CPPFLAGS_orig=$CPPFLAGS
-        AC_TRY_RUN([
+            CPPFLAGS="-I${top_ompi_srcdir}/ompi/include $CPPFLAGS"
+            AC_TRY_RUN([
 #include <stdio.h>
 #include <stdlib.h>
 #include "mpi_portable_platform.h.in"   /* Yes, it is supposed to be a .in-file */
@@ -75,12 +80,15 @@ int main (int argc, char * argv[])
     fprintf (f, "%s", _STRINGIFY(PLATFORM_COMPILER_$1));
     return 0;
 }
-        ], [
+            ], [
-            eval opal_cv_compiler_$1=`cat conftestval`;
+                eval opal_cv_compiler_$1=`cat conftestval`;
-        ], [
+            ], [
-            eval opal_cv_compiler_$1=UNKNOWN
+                eval opal_cv_compiler_$1=UNKNOWN
-        ])
+            ])
-        CPPFLAGS=$CPPFLAGS_orig
+            CPPFLAGS=$CPPFLAGS_orig
+        else
+            opal_cv_compiler_$1=UNKNOWN
+        fi
     ])
     AC_DEFINE_UNQUOTED([OPAL_BUILD_PLATFORM_COMPILER_$1], $opal_cv_compiler_[$1],
                        [The compiler $lower which OMPI was built with])