remove source files from lib/pace;

add lib/pace/Install.py to automatically download the source files from github/ICAMS/lammps-user-pace;
add lib/pace/CMakeLists.txt to build libpace.a
add lib/pace/README
update src/USER-PACE/Install.sh

lib/pace/Install.py

@@ -1 +1,111 @@
-# TODO
+# TODO#!/usr/bin/env python
+
+"""
+Install.py tool to download, compile, and setup the pace library
+used to automate the steps described in the README file in this dir
+"""
+
+from __future__ import print_function
+import sys, os, subprocess, shutil
+from argparse import ArgumentParser
+
+sys.path.append('..')
+from install_helpers import fullpath, geturl, checkmd5sum
+
+parser = ArgumentParser(prog='Install.py',
+                        description="LAMMPS library build wrapper script")
+
+# settings
+
+thisdir = fullpath('.')
+version = "v.2021.2.3"
+
+# known checksums for different PACE versions. used to validate the download.
+checksums = { \
+        'v.2021.2.3' : '9ebb087cba7e4ca041fde52f7e9e640c', \
+        }
+
+
+# help message
+
+HELP = """
+Syntax from src dir: make lib-pace args="-b"
+                 or: make lib-pace args="-b -v version"
+Syntax from lib dir: python Install.py -b 
+                 or: python Install.py -b -v version 
+
+Examples:
+
+make lib-pace args="-b" # install default version of PACE lib
+make lib-pace args="-b -v version" # install specified version of PACE lib
+
+
+"""
+
+pgroup = parser.add_mutually_exclusive_group()
+pgroup.add_argument("-b", "--build", action="store_true",
+                    help="download and build base PACE  library")
+parser.add_argument("-v", "--version", default=version, choices=checksums.keys(),
+                    help="set version of PACE library to download and build (default: %s)" % version)
+parser.add_argument("-vv", "--verbose", action="store_true",
+                    help="be more verbose about is happening while this script runs")
+
+args = parser.parse_args()
+
+# print help message and exit, if neither build nor path options are given
+if not args.build:
+  parser.print_help()
+  sys.exit(HELP)
+
+buildflag = args.build
+
+verboseflag = args.verbose
+version = args.version
+
+
+archive_extension = "tar.gz"
+url = "https://github.com/ICAMS/lammps-user-pace/archive/refs/tags/%s.%s" % (version, archive_extension)
+unarchived_folder_name = "lammps-user-pace-%s"%(version)
+
+# download PACE tarball, unpack, build PACE
+if buildflag:
+
+  # download entire tarball
+
+  print("Downloading pace tarball ...")
+  archive_filename = "%s.%s" % (version, archive_extension)
+  download_filename = "%s/%s" % (thisdir, archive_filename)
+  print("Downloading from ",url," to ",download_filename, end=" ")
+  geturl(url, download_filename)
+  print(" done")
+
+  # verify downloaded archive integrity via md5 checksum, if known.
+  if version in checksums:
+    if not checkmd5sum(checksums[version], archive_filename):
+      sys.exit("Checksum for pace library does not match")
+
+  print("Unpacking pace tarball ...")
+  src_folder = thisdir+"/src"
+  cmd = 'cd "%s"; rm -rf "%s"; tar -xvf %s; mv %s %s' % (thisdir, src_folder, archive_filename, unarchived_folder_name, src_folder)
+  subprocess.check_output(cmd, stderr=subprocess.STDOUT, shell=True)
+
+  # configure
+
+  build_folder = "%s/build"%(thisdir)
+  print("Configuring libpace ...")
+  cmd = 'cd %s && mkdir build && cd build && cmake .. -DCMAKE_BUILD_TYPE=Release' % (thisdir)
+  txt = subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
+  if verboseflag: print(txt.decode("UTF-8"))
+
+  # build
+  print("Building libpace ...")
+  cmd = 'cd "%s" && make -j2 && cp libpace.a %s/' % (build_folder, thisdir)
+  txt = subprocess.check_output(cmd, stderr=subprocess.STDOUT, shell=True)
+  if verboseflag:
+    print(txt.decode("UTF-8"))
+
+#   remove source files
+
+  print("Removing pace build files and archive ...")
+  cmd = 'rm %s; rm -rf %s' % (download_filename, build_folder)
+  subprocess.check_output(cmd, stderr=subprocess.STDOUT, shell=True)