[m-rev.] [PATCH 3/4] Support 64-bit Windows target in configure_mingw_cross.

[Peter Wang]

Add support for MinGW-w64 cross-compilers targeting 64-bit Windows
in configure_mingw_cross.

tools/configure_mingw_cross:
	If the host triplet begins with "x86_64" then assume
	configuration values for a 64-bit target.

README.MinGW-cross:
	Update documentation.
---
 README.MinGW-cross          | 40 ++++++++++++++++++----------------------
 tools/configure_mingw_cross | 37 +++++++++++++++++++++++++++++++------
 2 files changed, 49 insertions(+), 28 deletions(-)

diff --git a/README.MinGW-cross b/README.MinGW-cross
index 3bd4214..010fe3d 100644
--- a/README.MinGW-cross
+++ b/README.MinGW-cross
@@ -1,11 +1,11 @@
 -----------------------------------------------------------------------------
 
-COMPILING MERCURY WITH A MINGW CROSS-COMPILER
+COMPILING MERCURY WITH A MINGW / MINGW-W64 CROSS-COMPILER
 
-You can cross-compile Mercury on Linux with a MinGW cross-compiler.  After
-copying and adjusting some paths, the Mercury installation should be usable
-on Windows.  Alternatively, when combined with a native Mercury compiler,
-it could be used to cross-compile Mercury applications for Windows.
+You can compile Mercury on Linux with a MinGW or MinGW-w64 cross-compiler.
+After copying and adjusting some paths, the Mercury installation should be
+usable on Windows.  When combined with a native Mercury compiler, it can be
+used to cross-compile Mercury applications for Windows.
 
 -----------------------------------------------------------------------------
 
@@ -15,34 +15,30 @@ We assume you are on Linux.  You will need a native Mercury installation
 installed in the normal way.  The native Mercury version should match the
 version of Mercury you intend to cross-compile.
 
-Obviously you need a MinGW cross-compiler, as well as a pthreads
-implementation.  Many Linux distributions will have packages available,
-e.g. gcc-mingw32 and friends on Debian.
+You need a MinGW or MinGW-w64 cross-compiler, and a pthreads implementation.
+Many Linux distributions will have packages available, e.g. gcc-mingw32 and
+friends on Debian.  Otherwise, you may try <http://mxe.cc/>.
 
-Otherwise, you may try <http://mingw-cross-env.nongnu.org/>.
-If the latest release of that project does not work due to out of date URLs,
-try using the development version.
-
-    tar xf mingw-cross-env-2.21.tar.gz
-    cd mingw-cross-env-2.21
+    git clone -b stable https://github.com/mxe/mxe.git
+    cd mxe
     make gcc pthreads JOBS=6
 
 -----------------------------------------------------------------------------
 
 INSTALLATION
 
-Ensure that the MinGW cross-compiler i686-pc-mingw-gcc (the name may vary)
-is in your PATH.  In a fresh copy of the Mercury source tree, run the following
-in place of the configure script:
+Ensure that the MinGW cross-compiler i686-pc-mingw-gcc or similar is in your
+PATH.  In a fresh copy of the Mercury source tree, run the following in place
+of the configure script:
 
-    tools/configure_mingw_cross
+    tools/configure_mingw_cross [--host=HOST] OPTIONS...
 
-If your MinGW uses a host triplet other than "i686-pc-mingw32" then you must
-pass that using the --host= option.  You may pass other options through to
-configure as well, e.g.
+If your installation uses a host triplet other than "i686-pc-mingw32" then
+you must pass that using the --host= option.  You may pass other options
+through to configure as well, e.g.
 
     tools/configure_mingw_cross \
-        --host=i686-pc-mingw32 \
+        --host=x86_64-w64-mingw32 \
         --prefix=/usr/local/mercury-mingw
 
 Then install Mercury as usual:
diff --git a/tools/configure_mingw_cross b/tools/configure_mingw_cross
index 98bc968..5906c04 100755
--- a/tools/configure_mingw_cross
+++ b/tools/configure_mingw_cross
@@ -1,6 +1,7 @@
 #!/bin/sh -e
 #---------------------------------------------------------------------------#
 # Copyright (C) 2012 The University of Melbourne.
+# Copyright (C) 2014 The Mercury team.
 # This file may only be copied under the terms of the GNU General
 # Public License - see the file COPYING in the Mercury distribution.
 #-----------------------------------------------------------------------------#
@@ -23,7 +24,14 @@ done
 host=${host:-i686-pc-mingw32}
 hostcc=$host-gcc
 
-echo "Configuring for host $host"
+case $host in
+    x86_64*)
+        bits=64 ;;
+    *)
+        bits=32 ;;
+esac
+
+echo "Configuring for host $host, assuming ${bits}-bit"
 
 if which $hostcc >/dev/null
 then
@@ -55,19 +63,36 @@ fi
 # Set values which would otherwise be determined with AC_TRY_RUN.
 # Taken from the config.cache file after running configure -C in msys.
 
+case $bits in
+    32)
+        mercury_cv_word_type=int
+        mercury_cv_low_tag_bits=2
+        mercury_cv_bytes_per_word=4
+        mercury_cv_bits_per_word=32
+        mercury_cv_unboxed_floats=no
+        ;;
+    64)
+        mercury_cv_word_type='long long'
+        mercury_cv_low_tag_bits=3
+        mercury_cv_bytes_per_word=8
+        mercury_cv_bits_per_word=64
+        mercury_cv_unboxed_floats=yes
+        ;;
+esac
+
 mercury_cv_cc_type=gcc \
 mercury_cv_sigaction_field=no \
 mercury_cv_sigcontext_struct_2arg=no \
 mercury_cv_sigcontext_struct_3arg=no \
 mercury_cv_siginfo_t=no \
-mercury_cv_word_type=int \
+mercury_cv_word_type=$mercury_cv_word_type \
 mercury_cv_int_least64_type='long long' \
 mercury_cv_int_least32_type=int \
 mercury_cv_int_least16_type=short \
-mercury_cv_low_tag_bits=2 \
-mercury_cv_bytes_per_word=4 \
-mercury_cv_bits_per_word=32 \
-mercury_cv_unboxed_floats=no \
+mercury_cv_low_tag_bits=$mercury_cv_low_tag_bits \
+mercury_cv_bytes_per_word=$mercury_cv_bytes_per_word \
+mercury_cv_bits_per_word=$mercury_cv_bits_per_word \
+mercury_cv_unboxed_floats=$mercury_cv_unboxed_floats \
 mercury_cv_float_is_64_bit=no \
 mercury_cv_double_is_64_bit=yes \
 mercury_cv_long_double_is_64_bit=no \
-- 
1.8.4