[FYI] {maint} configure: correctly identify missing GNU compilers as such

[Stefano Lattarini]

* configure.ac: Here, instead of mistakenly diagnose them as "botched".

Signed-off-by: Stefano Lattarini <address@hidden>
---
 configure.ac | 40 +++++++++++++++++++++++++---------------
 1 file changed, 25 insertions(+), 15 deletions(-)

diff --git a/configure.ac b/configure.ac
index a05ee03..8050648 100644
--- a/configure.ac
+++ b/configure.ac
@@ -523,9 +523,11 @@ if test $am_CC_is_GNU = yes; then
 else
   AC_CHECK_TOOLS([GNU_CC], [gcc], [false])
 fi
-AS_IF([AM_RUN_LOG([$GNU_CC --version && $GNU_CC -v])], [],
-      [AC_MSG_WARN([botched installation for GNU C compiler])
-       _AM_SKIP_COMP_TESTS([GNU C])])
+if test "$GNU_CC" != false; then
+  AS_IF([AM_RUN_LOG([$GNU_CC --version && $GNU_CC -v])], [],
+        [AC_MSG_WARN([botched installation for GNU C compiler])
+         _AM_SKIP_COMP_TESTS([GNU C])])
+fi
 
 # GNU C++ compiler.
 AC_ARG_VAR([GNU_CXX],      [GNU C++ compiler])
@@ -537,9 +539,11 @@ if test $am_CXX_is_GNU = yes; then
 else
   AC_CHECK_TOOLS([GNU_CXX], [g++ gpp], [false])
 fi
-AS_IF([AM_RUN_LOG([$GNU_CXX --version && $GNU_CXX -v])], [],
-      [AC_MSG_WARN([botched installation for GNU C++ compiler])
-       _AM_SKIP_COMP_TESTS([GNU C++])])
+if test "$GNU_CXX" != false; then
+  AS_IF([AM_RUN_LOG([$GNU_CXX --version && $GNU_CXX -v])], [],
+        [AC_MSG_WARN([botched installation for GNU C++ compiler])
+         _AM_SKIP_COMP_TESTS([GNU C++])])
+fi
 
 # GNU Fortran compiler.
 AC_ARG_VAR([GNU_FC],      [GNU Fortran compiler])
@@ -551,9 +555,11 @@ if test $am_FC_is_GNU = yes; then
 else
   AC_CHECK_TOOLS([GNU_FC], [gfortran], [false])
 fi
-AS_IF([AM_RUN_LOG([$GNU_FC --version && $GNU_FC -v])], [],
-      [AC_MSG_WARN([botched installation for GNU Fortran compiler])
-       _AM_SKIP_COMP_TESTS([GNU Fortran])])
+if test "$GNU_FC" != false; then
+  AS_IF([AM_RUN_LOG([$GNU_FC --version && $GNU_FC -v])], [],
+        [AC_MSG_WARN([botched installation for GNU Fortran compiler])
+         _AM_SKIP_COMP_TESTS([GNU Fortran])])
+fi
 
 # GNU Fortran 77 compiler.
 AC_ARG_VAR([GNU_F77],    [GNU Fortran 77 compiler])
@@ -565,17 +571,21 @@ if test $am_F77_is_GNU = yes; then
 else
   AC_CHECK_TOOLS([GNU_F77], [g77 gfortran], [false])
 fi
-AS_IF([AM_RUN_LOG([$GNU_F77 --version && $GNU_F77 -v])], [],
-      [AC_MSG_WARN([botched installation for GNU Fortran 77 compiler])
-      _AM_SKIP_COMP_TESTS([GNU Fortran 77])])
+if test "$GNU_F77" != false; then
+  AS_IF([AM_RUN_LOG([$GNU_F77 --version && $GNU_F77 -v])], [],
+        [AC_MSG_WARN([botched installation for GNU Fortran 77 compiler])
+        _AM_SKIP_COMP_TESTS([GNU Fortran 77])])
+fi
 
 # GNU Java compiler.
 AC_ARG_VAR([GNU_GCJ], [GNU Java compiler])
 AC_ARG_VAR([GNU_GCJFLAGS], [GNU Java compiler flags])
 AC_CHECK_TOOLS([GNU_GCJ], [gcj], [false])
-AS_IF([AM_RUN_LOG([$GNU_GCJ --version && $GNU_GCJ -v])], [],
-      [AC_MSG_WARN([botched installation for GNU Java compiler])
-      _AM_SKIP_COMP_TESTS([GNU Java])])
+if test "$GNU_GCJ" != false; then
+  AS_IF([AM_RUN_LOG([$GNU_GCJ --version && $GNU_GCJ -v])], [],
+        [AC_MSG_WARN([botched installation for GNU Java compiler])
+        _AM_SKIP_COMP_TESTS([GNU Java])])
+fi
 
 # If we have been able to find at least a working compiler above, we
 # know what the object and executable extensions for this platform are.
-- 
1.8.0