Use toplevel configure for GMP and MPFR for gdb

This patch uses the toplevel configure parts for GMP/MPFR for
gdb. The only thing is that gdb now requires MPFR for building.
Before it was a recommended but not required library.
Also this allows building of GMP and MPFR with the toplevel
directory just like how it is done for GCC.
We now error out in the toplevel configure of the version
of GMP and MPFR that is wrong.

OK after GDB 13 branches? Build gdb 3 ways:
with GMP and MPFR in the toplevel (static library used at that point for both)
With only MPFR in the toplevel (GMP distro library used and MPFR built from source)
With neither GMP and MPFR in the toplevel (distro libraries used)

Changes from v1:
* Updated gdb/README and gdb/doc/gdb.texinfo.
* Regenerated using unmodified autoconf-2.69

Thanks,
Andrew Pinski

ChangeLog:
	* Makefile.def: Add configure-gdb dependencies
	on all-gmp and all-mpfr.
	* configure.ac: Split out MPC checking from MPFR.
	Require GMP and MPFR if the gdb directory exist.
	* Makefile.in: Regenerate.
	* configure: Regenerate.

gdb/ChangeLog:

	PR bug/28500
	* configure.ac: Remove AC_LIB_HAVE_LINKFLAGS
	for gmp and mpfr.
	Use GMPLIBS and GMPINC which is provided by the
	toplevel configure.
	* Makefile.in (LIBGMP, LIBMPFR): Remove.
	(GMPLIBS, GMPINC): Add definition.
	(INTERNAL_CFLAGS_BASE): Add GMPINC.
	(CLIBS): Exchange LIBMPFR and LIBGMP
	for GMPLIBS.
	* target-float.c: Make the code conditional on
	HAVE_LIBMPFR unconditional.
	* top.c: Remove code checking HAVE_LIBMPFR.
	* configure: Regenerate.
	* config.in: Regenerate.
	* README: Update GMP/MPFR section of the config
	options.
	* doc/gdb.texinfo: Likewise.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28500

1 files changed, 7 insertions, 6 deletions

diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index bef63eb..21a00ed 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -39317,7 +39317,8 @@ make program.  Other variants of @code{make} will not work.
 This library may be included with your operating system distribution;
 if it is not, you can get the latest version from
 @url{https://gmplib.org/}. If GMP is installed at an unusual path,
-you can use the @option{--with-libgmp-prefix} option to specify
+you can use the @option{--with-gmp} option or options
+@option{--with-gmp-include} and @option{--with-gmp-lib} to specify
 its location.
 
 @end table
@@ -39399,18 +39400,18 @@ automatically.  If it is installed in an unusual path, you can use the
 
 @item MPFR
 @anchor{MPFR}
-@value{GDBN} can use the GNU MPFR multiple-precision floating-point
+@value{GDBN} now uses the GNU MPFR multiple-precision floating-point
 library.  This library may be included with your operating system
 distribution; if it is not, you can get the latest version from
 @url{http://www.mpfr.org}.  The @file{configure} script will search
 for this library in several standard locations; if it is installed
-in an unusual path, you can use the @option{--with-libmpfr-prefix}
-option to specify its location.
+in an unusual path, you can use the @option{--with-mpfr} option or options
+@option{--with-mpfr-include} and @option{--with-mpfr-lib} to specify
+its location.
 
 GNU MPFR is used to emulate target floating-point arithmetic during
 expression evaluation when the target uses different floating-point
-formats than the host.  If GNU MPFR it is not available, @value{GDBN}
-will fall back to using host floating-point arithmetic.
+formats than the host.
 
 @item Python
 @value{GDBN} can be scripted using Python language.  @xref{Python}.