Improve configure check reporting.

Adds numerous AC_MSG_CHECKING and AC_MSG_RESULT pairings for
configuration tests that were previously unreported.  Relocates
the debug configuration to the same part of the file as the command
line option declaration for associative clarity.  Makes it easier
to confirm the resultant configuration matches original intentions.

Signed-off-by: Zachary T Welch <zwelch@codesourcery.com>

configure.in

@@ -46,11 +46,6 @@ AC_TYPE_SIGNAL
 AC_TYPE_SIZE_T
 
 CPPFLAGS="${CPPFLAGS} -D_GNU_SOURCE"
-if test x$enable_debug = xyes; then
-  CPPFLAGS="${CPPFLAGS} -DDEBUG"
-else
-  CPPFLAGS="${CPPFLAGS} -DNDEBUG"
-fi
 
 AC_CHECK_MEMBERS([struct dl_phdr_info.dlpi_subs],,,[#include <link.h>])
 AC_CHECK_TYPES([sighandler_t], [], [],
@@ -91,8 +86,14 @@ is_gcc_altivec() {
  fi;
 }
 
+AC_MSG_CHECKING([if building with AltiVec])
 use_altivec=`is_gcc_altivec`
 AM_CONDITIONAL(USE_ALTIVEC, test x$use_altivec = xhas_altivec)
+if test x$use_altivec = xhas_altivec; then
+  AC_MSG_RESULT([yes])
+else
+  AC_MSG_RESULT([no])
+fi
 
 get_arch() {
  case "$1" in
@@ -110,6 +111,15 @@ build_arch=`get_arch $build_cpu`
 host_arch=`get_arch $host_cpu`
 target_arch=`get_arch $target_cpu`
 
+AC_MSG_CHECKING([for build architecture])
+AC_MSG_RESULT([$build_arch])
+AC_MSG_CHECKING([for host architecture])
+AC_MSG_RESULT([$host_arch])
+AC_MSG_CHECKING([for target architecture])
+AC_MSG_RESULT([$target_arch])
+AC_MSG_CHECKING([for target operating system])
+AC_MSG_RESULT([$target_os])
+
 AM_CONDITIONAL(REMOTE_ONLY, test x$target_arch != x$host_arch)
 AM_CONDITIONAL(ARCH_ARM, test x$target_arch = xarm)
 AM_CONDITIONAL(ARCH_IA64, test x$target_arch = xia64)
@@ -129,14 +139,27 @@ if test x$target_arch = xppc64; then
         AC_SUBST([libdir])
 fi
 
+AC_MSG_CHECKING([whether to restrict build to remote support])
 if test x$target_arch != x$host_arch; then
   CPPFLAGS="${CPPFLAGS} -DUNW_REMOTE_ONLY"
+  remote_only=yes
+else
+  remote_only=no
 fi
+AC_MSG_RESULT([$remote_only])
 
+AC_MSG_CHECKING([whether to enable debug support])
 AC_ARG_ENABLE(debug,
 [  --enable-debug          turn on debug support (slows down execution)],
-[enable_debug=yes], [])
+[enable_debug=yes], [enable_debug=no])
+if test x$enable_debug = xyes; then
+  CPPFLAGS="${CPPFLAGS} -DDEBUG"
+else
+  CPPFLAGS="${CPPFLAGS} -DNDEBUG"
+fi
+AC_MSG_RESULT([$enable_debug])
 
+AC_MSG_CHECKING([whether to enable C++ exception support])
 AC_ARG_ENABLE(cxx_exceptions,
 [  --enable-cxx-exceptions use libunwind to handle C++ exceptions],
 [enable_cxx_exceptions=$enableval], 
@@ -150,50 +173,58 @@ case $target_arch in
 esac
 ])
 
-if test x$enable_cxx_exceptions = xyes; then
-  AC_MSG_NOTICE([Enabling C++ exception support])
-fi
 AM_CONDITIONAL([SUPPORT_CXX_EXCEPTIONS], [test x$enable_cxx_exceptions = xyes])
+AC_MSG_RESULT([$enable_cxx_exceptions])
 
+AC_MSG_CHECKING([whether to load .debug_frame sections])
 AC_ARG_ENABLE(debug_frame,
 [  --enable-debug-frame Load the ".debug_frame" section if available],
 [enable_debug_frame=$enableval], [enable_debug_frame=no])
 if test x$enable_debug_frame = xyes; then
   AC_DEFINE([CONFIG_DEBUG_FRAME], [], [Enable Debug Frame])
 fi
+AC_MSG_RESULT([$enable_debug_frame])
 
+AC_MSG_CHECKING([whether to block signals during mutex ops])
 AC_ARG_ENABLE(block_signals,
 [  --enable-block-signals Block signals before performing mutex operations],
 [enable_block_signals=$enableval], [enable_block_signals=yes])
 if test x$enable_block_signals = xyes; then
   AC_DEFINE([CONFIG_BLOCK_SIGNALS], [], [Block signals before mutex operations])
 fi
+AC_MSG_RESULT([$enable_block_signals])
 
+AC_MSG_CHECKING([whether to validate memory addresses before use])
 AC_ARG_ENABLE(conservative_checks,
 [ --enable-conservative-checks Validate all memory addresses before use],
 [enable_conservative_checks=$enableval], [enable_conservative_checks=yes])
 if test x$enable_conservative_checks = xyes; then
   CPPFLAGS="${CPPFLAGS} -DCONSERVATIVE_CHECKS"
 fi
+AC_MSG_RESULT([$enable_conservative_checks])
 
 LIBUNWIND___THREAD
 
+AC_MSG_CHECKING([if linker supports -static-libcxa])
 save_LDFLAGS="$LDFLAGS"
 LDFLAGS="$LDFLAGS -static-libcxa"
-AC_TRY_LINK([], [], [have_static_libcxa=yes])
+AC_TRY_LINK([], [], [have_static_libcxa=yes], [have_static_libcxa=no])
 LDFLAGS="$save_LDFLAGS"
 if test "x$have_static_libcxa" = xyes; then
   LDFLAGS_STATIC_LIBCXA="-XCClinker -static-libcxa"
 fi
+AC_MSG_RESULT([$have_static_libcxa])
 
+AC_MSG_CHECKING([for Intel compiler])
 AC_TRY_COMPILE([], [#ifndef __INTEL_COMPILER
 #error choke me
-#endif], [intel_compiler=yes])
+#endif], [intel_compiler=yes], [intel_compiler=no])
 
 if test x$GCC = xyes -a x$intel_compiler != xyes; then
   CFLAGS="${CFLAGS} -fexceptions -Wall -Wsign-compare"
   LIBCRTS="-lgcc"
 fi
+AC_MSG_RESULT([$intel_compiler])
 
 CCASFLAGS="${CCASFLAGS} ${CPPFLAGS}"