#!/usr/bin/env python

# RISC-V multilib list generator.
# Copyright (C) 2011-2021 Free Software Foundation, Inc.
# Contributed by Andrew Waterman (andrew@sifive.com).
# 
# This file is part of GCC.
# 
# GCC is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3, or (at your option)
# any later version.
# 
# GCC is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# 
# You should have received a copy of the GNU General Public License
# along with GCC; see the file COPYING3.  If not see
# <http://www.gnu.org/licenses/>.

# Each argument to this script is of the form
#  <primary arch>-<abi>-<additional arches>-<extensions>
# Example 1:
#  rv32imafd-ilp32d-rv32g-c,v
# means that, in addition to rv32imafd, these configurations can also use the
# rv32imafd-ilp32d libraries: rv32imafdc, rv32imafdv, rv32g, rv32gc, rv32gv
#
# Example 2:
#  rv32imafd-ilp32d--c*b
# means that, in addition to rv32imafd, these configurations can also use the
# rv32imafd-ilp32d libraries: rv32imafdc-ilp32d, rv32imafdb-ilp32d,
#                             rv32imafdcb-ilp32d

from __future__ import print_function
import sys
import os
import collections
import itertools
from functools import reduce
import subprocess
import argparse

#
# TODO: Add test for this script.
#

arches = collections.OrderedDict()
abis = collections.OrderedDict()
required = []
reuse = []

def arch_canonicalize(arch):
  this_file = os.path.abspath(os.path.join( __file__))
  arch_can_script = \
    os.path.join(os.path.dirname(this_file), "arch-canonicalize")
  proc = subprocess.Popen([sys.executable, arch_can_script, arch],
                          stdout=subprocess.PIPE)
  out, err = proc.communicate()
  return out.decode().strip()

#
# Handle expansion operation.
#
# e.g. "a*b" -> [("a",), ("b",), ("a", "b")]
#      "a"   -> [("a",)]
#
def _expand_combination(ext):
  exts = list(ext.split("*"))

  # Add underline to every extension.
  # e.g.
  #  _b * zvamo => _b * _zvamo
  exts = list(map(lambda x: '_' + x, exts))

  # No need to expand if there is no `*`.
  if len(exts) == 1:
    return [(exts[0],)]

  # Generate combination!
  ext_combs = []
  for comb_len in range(1, len(exts)+1):
    for ext_comb in itertools.combinations(exts, comb_len):
      ext_combs.append(ext_comb)

  return ext_combs

#
# Input a list and drop duplicated entry.
# e.g.
#   ["a", "b", "ab", "a"] -> ["a", "b", "ab"]
#
def unique(x):
  #
  # Drop duplicated entry.
  # Convert list to set and then convert back to list.
  #
  # Add sorted to prevent non-deterministic results in different env.
  #
  return list(sorted(list(set(x))))

#
# Expand EXT string if there is any expansion operator (*).
# e.g.
#   "a*b,c" -> ["a", "b", "ab", "c"]
#
def expand_combination(ext):
  ext = list(filter(None, ext.split(',')))

  # Expand combination for EXT, got lots of list.
  # e.g.
  #   a * b => [[("a",), ("b",)], [("a", "b")]]
  ext_combs = list(map(_expand_combination, ext))

  # Then fold to single list.
  # e.g.
  #   [[("a",), ("b",)], [("a", "b")]] => [("a",), ("b",), ("a", "b")]
  ext = list(reduce(lambda x, y: x + y, ext_combs, []))

  # Fold the tuple to string.
  # e.g.
  #   [("a",), ("b",), ("a", "b")] => ["a", "b", "ab"]
  ext = map(lambda e : reduce(lambda x, y: x + y, e), ext)

  # Drop duplicated entry.
  ext = unique(ext)

  return ext

multilib_cfgs = filter(lambda x:not x.startswith("--"), sys.argv[1:])
options = filter(lambda x:x.startswith("--"), sys.argv[1:])

parser = argparse.ArgumentParser()
parser.add_argument("--cmodel", type=str)
parser.add_argument("cfgs", type=str, nargs='*')
args = parser.parse_args()

if args.cmodel:
  cmodels = [None] + args.cmodel.split(",")
else:
  cmodels = [None]

cmodel_options = '/'.join(['mcmodel=%s' % x for x in cmodels[1:]])
cmodel_dirnames = ' \\\n'.join(cmodels[1:])

for cmodel in cmodels:
  for cfg in args.cfgs:
    try:
      (arch, abi, extra, ext) = cfg.split('-')
    except:
      print ("Invalid configure string %s, <arch>-<abi>-<extra>-<extensions>\n"
             "<extra> and <extensions> can be empty, "
             "e.g. rv32imafd-ilp32--" % cfg)
      sys.exit(1)

    # Compact code model only support rv64.
    if cmodel == "compact" and arch.startswith("rv32"):
      continue

    arch = arch_canonicalize (arch)
    arches[arch] = 1
    abis[abi] = 1
    extra = list(filter(None, extra.split(',')))
    ext_combs = expand_combination(ext)
    alts = sum([[x] + [x + y for y in ext_combs] for x in [arch] + extra], [])
    alts = list(map(arch_canonicalize, alts))

    # Drop duplicated entry.
    alts = unique(alts)

    for alt in alts[1:]:
      if alt == arch:
        continue
      arches[alt] = 1
      reuse.append('march.%s/mabi.%s=march.%s/mabi.%s' % (arch, abi, alt, abi))

    if cmodel:
      required.append('march=%s/mabi=%s/mcmodel=%s' % (arch, abi, cmodel))
    else:
      required.append('march=%s/mabi=%s' % (arch, abi))

  arch_options = '/'.join(['march=%s' % x for x in arches.keys()])
  arch_dirnames = ' \\\n'.join(arches.keys())

  abi_options = '/'.join(['mabi=%s' % x for x in abis.keys()])
  abi_dirnames = ' \\\n'.join(abis.keys())

prog = sys.argv[0].split('/')[-1]
print('# This file was generated by %s with the command:' % prog)
print('#  %s' % ' '.join(sys.argv))

print('MULTILIB_OPTIONS = %s %s %s' % (arch_options, abi_options, cmodel_options))
print('MULTILIB_DIRNAMES = %s %s %s' % (arch_dirnames, abi_dirnames, cmodel_dirnames))
print('MULTILIB_REQUIRED = %s' % ' \\\n'.join(required))
print('MULTILIB_REUSE = %s' % ' \\\n'.join(reuse))