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, 19 insertions, 9 deletions

diff --git a/gdb/README b/gdb/README
index 406df04..fbe480f 100644
--- a/gdb/README
+++ b/gdb/README
@@ -484,22 +484,32 @@ more obscure GDB `configure' options are not listed here.
      not have liblzma installed, you can get the latest version from
      `https://tukaani.org/xz/'.
 
-`--with-libgmp-prefix=DIR'
+`--with-gmp=DIR'
+`--with-gmp-lib=LIBDIR'
+`--with-gmp-include=INCDIR'
      Build GDB using the GMP library installed at the directory DIR.
      If your host does not have GMP installed, you can get the latest
      version at `https://gmplib.org/'.
-
-`--with-mpfr'
-     Build GDB with GNU MPFR, a library for multiple-precision
-     floating-point computation with correct rounding.  (Done by
-     default if GNU MPFR is installed and found at configure time.)
+     The `--with-gmp=gmpinstalldir` option is shorthand for
+     `--with-gmp-lib=gmpinstalldir/lib` and
+     `--with-gmp-include=gmpinstalldir/include`.
+
+`--with-mpfr=DIR'
+`--with-mpfr-lib=LIBDIR'
+`--with-mpfr-include=INCDIR'
+     Build GDB using GNU MPFR installed at the directory DIR,
+     a library for multiple-precision floating-point computation
+     with correct rounding.
      This library 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 is not
-     available, GDB will fall back to using host floating-point
-     arithmetic.  If your host does not have GNU MPFR installed, you
+     floating-point formats than the host.
+     If your host does not have GNU MPFR installed, you
      can get the latest version from `https://www.mpfr.org/'.
 
+     The `--with-mpfr=mpfrinstalldir` option is shorthand for
+     `--with-mpfr-lib=mpfrinstalldir/lib` and
+     `--with-mpfr-include=mpfrinstalldir/include`.
+
 `--with-python[=PYTHON]'
      Build GDB with Python scripting support.  (Done by default if
      libpython is present and found at configure time.)  Python makes