1 files changed, 70 insertions, 0 deletions
diff --git a/m4/libgmp.m4 b/m4/libgmp.m4
new file mode 100644
index 0000000..eb20ada
--- /dev/null
+++ b/m4/libgmp.m4
@@ -0,0 +1,70 @@
+# libgmp.m4 serial 8
+# Configure the GMP library or a replacement.
+dnl Copyright 2020-2023 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl gl_LIBGMP
+dnl Search for an installed libgmp.
+dnl If found, set and AC_SUBST HAVE_LIBGMP=yes and the LIBGMP and LTLIBGMP
+dnl variables, and augment the CPPFLAGS variable, and #define HAVE_LIBGMP to 1.
+dnl Otherwise, set and AC_SUBST HAVE_LIBGMP=no and LIBGMP and LTLIBGMP to
+dnl empty.
+
+AC_DEFUN([gl_LIBGMP],
+[
+  AC_ARG_WITH([libgmp],
+    [AS_HELP_STRING([[--without-libgmp]],
+       [do not use the GNU Multiple Precision (GMP) library;
+        this is the default on systems lacking libgmp.])])
+  HAVE_LIBGMP=no
+  LIBGMP=
+  LTLIBGMP=
+  AS_IF([test "$with_libgmp" != no],
+    [AC_CHECK_HEADERS([gmp.h gmp/gmp.h], [break])
+     dnl Prefer AC_LIB_HAVE_LINKFLAGS if the havelib module is also in use.
+     AS_IF([test "$ac_cv_header_gmp_h" = yes ||
+            test "$ac_cv_header_gmp_gmp_h" = yes],
+       [m4_ifdef([gl_HAVE_MODULE_HAVELIB],
+          [AC_LIB_HAVE_LINKFLAGS([gmp], [],
+             [#if HAVE_GMP_H
+              # include <gmp.h>
+              #else
+              # include <gmp/gmp.h>
+              #endif],
+             [static const mp_limb_t x[2] = { 0x73, 0x55 };
+              mpz_t tmp;
+              mpz_roinit_n (tmp, x, 2);
+             ],
+             [no])],
+          [gl_saved_LIBS=$LIBS
+           AC_SEARCH_LIBS([__gmpz_roinit_n], [gmp])
+           LIBS=$gl_saved_LIBS
+           case $ac_cv_search___gmpz_roinit_n in
+             'none needed')
+               HAVE_LIBGMP=yes;;
+             -*)
+               HAVE_LIBGMP=yes
+               LIBGMP=$ac_cv_search___gmpz_roinit_n
+               LTLIBGMP=$LIBGMP;;
+           esac
+           AC_SUBST([HAVE_LIBGMP])
+           AC_SUBST([LIBGMP])
+           AC_SUBST([LTLIBGMP])])])
+     if test "$with_libgmp,$HAVE_LIBGMP" = yes,no; then
+       AC_MSG_ERROR(
+         [GMP not found, although --with-libgmp was specified.m4_ifdef(
+            [AC_LIB_HAVE_LINKFLAGS],
+            [ Try specifying --with-libgmp-prefix=DIR.])])
+     fi])
+  if test $HAVE_LIBGMP = yes && test "$ac_cv_header_gmp_h" = yes; then
+    GL_GENERATE_GMP_H=false
+  else
+    GL_GENERATE_GMP_H=true
+  fi
+  gl_CONDITIONAL([GL_GENERATE_MINI_GMP_H],
+    [test $HAVE_LIBGMP != yes])
+  gl_CONDITIONAL([GL_GENERATE_GMP_GMP_H],
+    [test $HAVE_LIBGMP = yes && test "$ac_cv_header_gmp_h" != yes])
+])