#!/usr/bin/env python2

'''
You should normally never use this! Use emcc instead.

This is a small wrapper script around the core JS compiler. This calls that
compiler with the settings given to it. It can also read data from C/C++
header files (so that the JS compiler can see the constants in those
headers, for the libc implementation in JS).
'''

from tools.toolchain_profiler import ToolchainProfiler
if __name__ == '__main__':
  ToolchainProfiler.record_process_start()

import os, sys, json, optparse, subprocess, re, time, logging

from tools import shared
from tools import jsrun, cache as cache_module, tempfiles
from tools.response_file import read_response_file
from tools.shared import WINDOWS

__rootpath__ = os.path.abspath(os.path.dirname(__file__))
def path_from_root(*pathelems):
  """Returns the absolute path for which the given path elements are
  relative to the emscripten root.
  """
  return os.path.join(__rootpath__, *pathelems)

def get_configuration():
  if hasattr(get_configuration, 'configuration'):
    return get_configuration.configuration

  configuration = shared.Configuration(environ=os.environ)
  get_configuration.configuration = configuration
  return configuration

STDERR_FILE = os.environ.get('EMCC_STDERR_FILE')
if STDERR_FILE:
  STDERR_FILE = os.path.abspath(STDERR_FILE)
  logging.info('logging stderr in js compiler phase into %s' % STDERR_FILE)
  STDERR_FILE = open(STDERR_FILE, 'w')

def quoter(settings):
  def quote(prop):
    if settings['USE_CLOSURE_COMPILER'] == 2:
      return ''.join(map(lambda p: "'" + p + "'", prop.split('.')))
    else:
      return prop
  return quote

def access_quoter(settings):
  def access_quote(prop):
    if settings['USE_CLOSURE_COMPILER'] == 2:
      return ''.join(map(lambda p: "['" + p + "']", prop.split('.')))
    else:
      return '.' + prop
  return access_quote


def emscript(infile, settings, outfile, libraries=None, compiler_engine=None,
             temp_files=None, DEBUG=None):
  """Runs the emscripten LLVM-to-JS compiler.

  Args:
    infile: The path to the input LLVM assembly file.
    settings: JSON-formatted settings that override the values
      defined in src/settings.js.
    outfile: The file where the output is written.
  """

  if libraries is None: libraries = []

  assert settings['ASM_JS'], 'fastcomp is asm.js-only (mode 1 or 2)'

  success = False

  try:

    # Overview:
    #   * Run LLVM backend to emit JS. JS includes function bodies, memory initializer,
    #     and various metadata
    #   * Run compiler.js on the metadata to emit the shell js code, pre/post-ambles,
    #     JS library dependencies, etc.

    # metadata and settings are modified by reference in some of the below
    # these functions are split up to force variables to go out of scope and allow
    # memory to be reclaimed

    with ToolchainProfiler.profile_block('get_and_parse_backend'):
      funcs, metadata, mem_init = get_and_parse_backend(infile, settings, temp_files, DEBUG)
    with ToolchainProfiler.profile_block('compiler_glue'):
      glue, forwarded_data = compiler_glue(metadata, settings, libraries, compiler_engine, temp_files, DEBUG)

    with ToolchainProfiler.profile_block('function_tables_and_exports'):
      post, funcs_js, need_asyncify, provide_fround, asm_safe_heap, sending, receiving, asm_setup, the_global, asm_global_vars, asm_global_funcs, pre_tables, final_function_tables, exports, last_forwarded_json = function_tables_and_exports(funcs, metadata, mem_init, glue, forwarded_data, settings, outfile, DEBUG)
    with ToolchainProfiler.profile_block('finalize_output'):
      finalize_output(metadata, post, funcs_js, need_asyncify, provide_fround, asm_safe_heap, sending, receiving, asm_setup, the_global, asm_global_vars, asm_global_funcs, pre_tables, final_function_tables, exports, last_forwarded_json, settings, outfile, DEBUG)

    success = True

  finally:
    outfile.close()
    if not success:
      shared.try_delete(outfile.name) # remove partial output

def get_and_parse_backend(infile, settings, temp_files, DEBUG):
    with temp_files.get_file('.4.js') as temp_js:
      backend_compiler = os.path.join(shared.LLVM_ROOT, 'llc')
      backend_args = [backend_compiler, infile, '-march=js', '-filetype=asm', '-o', temp_js]
      if settings['PRECISE_F32']:
        backend_args += ['-emscripten-precise-f32']
      if settings['USE_PTHREADS']:
        backend_args += ['-emscripten-enable-pthreads']
      if settings['WARN_UNALIGNED']:
        backend_args += ['-emscripten-warn-unaligned']
      if settings['RESERVED_FUNCTION_POINTERS'] > 0:
        backend_args += ['-emscripten-reserved-function-pointers=%d' % settings['RESERVED_FUNCTION_POINTERS']]
      if settings['ASSERTIONS'] > 0:
        backend_args += ['-emscripten-assertions=%d' % settings['ASSERTIONS']]
      if settings['ALIASING_FUNCTION_POINTERS'] == 0:
        backend_args += ['-emscripten-no-aliasing-function-pointers']
      if settings['EMULATED_FUNCTION_POINTERS']:
        backend_args += ['-emscripten-emulated-function-pointers']
      if settings['RELOCATABLE']:
        backend_args += ['-emscripten-relocatable']
        backend_args += ['-emscripten-global-base=0']
      elif settings['GLOBAL_BASE'] >= 0:
        backend_args += ['-emscripten-global-base=%d' % settings['GLOBAL_BASE']]
      backend_args += ['-O' + str(settings['OPT_LEVEL'])]
      if settings['DISABLE_EXCEPTION_CATCHING'] != 1:
        backend_args += ['-enable-emscripten-cxx-exceptions']
        if settings['DISABLE_EXCEPTION_CATCHING'] == 2:
          backend_args += ['-emscripten-cxx-exceptions-whitelist=' + ','.join(settings['EXCEPTION_CATCHING_WHITELIST'] or ['fake'])]
      if settings['ASYNCIFY']:
        backend_args += ['-emscripten-asyncify']
        backend_args += ['-emscripten-asyncify-functions=' + ','.join(settings['ASYNCIFY_FUNCTIONS'])]
        backend_args += ['-emscripten-asyncify-whitelist=' + ','.join(settings['ASYNCIFY_WHITELIST'])]
      if settings['NO_EXIT_RUNTIME']:
        backend_args += ['-emscripten-no-exit-runtime']
      if settings['BINARYEN']:
        backend_args += ['-emscripten-wasm']
        if shared.Building.is_wasm_only():
          backend_args += ['-emscripten-only-wasm']
      if settings['CYBERDWARF']:
        backend_args += ['-enable-cyberdwarf']

      if DEBUG:
        logging.debug('emscript: llvm backend: ' + ' '.join(backend_args))
        t = time.time()
      with ToolchainProfiler.profile_block('emscript_llvm_backend'):
        shared.jsrun.timeout_run(subprocess.Popen(backend_args, stdout=subprocess.PIPE))
      if DEBUG:
        logging.debug('  emscript: llvm backend took %s seconds' % (time.time() - t))

      # Split up output
      backend_output = open(temp_js).read()
      #if DEBUG: print >> sys.stderr, backend_output

    start_funcs_marker = '// EMSCRIPTEN_START_FUNCTIONS'
    end_funcs_marker = '// EMSCRIPTEN_END_FUNCTIONS'
    metadata_split_marker = '// EMSCRIPTEN_METADATA'

    start_funcs = backend_output.index(start_funcs_marker)
    end_funcs = backend_output.rindex(end_funcs_marker)
    metadata_split = backend_output.rindex(metadata_split_marker)

    funcs = backend_output[start_funcs+len(start_funcs_marker):end_funcs]
    metadata_raw = backend_output[metadata_split+len(metadata_split_marker):]
    #if DEBUG: print >> sys.stderr, "METAraw", metadata_raw
    try:
      metadata = json.loads(metadata_raw)
    except Exception, e:
      logging.error('emscript: failure to parse metadata output from compiler backend. raw output is: \n' + metadata_raw)
      raise e
    mem_init = backend_output[end_funcs+len(end_funcs_marker):metadata_split]
    #if DEBUG: print >> sys.stderr, "FUNCS", funcs
    #if DEBUG: print >> sys.stderr, "META", metadata
    #if DEBUG: print >> sys.stderr, "meminit", mem_init

    # if emulating pointer casts, force all tables to the size of the largest
    if settings['EMULATE_FUNCTION_POINTER_CASTS']:
      max_size = 0
      for k, v in metadata['tables'].iteritems():
        max_size = max(max_size, v.count(',')+1)
      for k, v in metadata['tables'].iteritems():
        curr = v.count(',')+1
        if curr < max_size:
          metadata['tables'][k] = v.replace(']', (',0'*(max_size - curr)) + ']')

    if settings['SIDE_MODULE']:
      for k in metadata['tables'].keys():
        metadata['tables'][k] = metadata['tables'][k].replace('var FUNCTION_TABLE_', 'var SIDE_FUNCTION_TABLE_')

    # function table masks

    table_sizes = {}
    for k, v in metadata['tables'].iteritems():
      table_sizes[k] = str(v.count(',')) # undercounts by one, but that is what we want
      #if settings['ASSERTIONS'] >= 2 and table_sizes[k] == 0:
      #  print >> sys.stderr, 'warning: no function pointers with signature ' + k + ', but there is a call, which will abort if it occurs (this can result from undefined behavior, check for compiler warnings on your source files and consider -Werror)'
    funcs = re.sub(r"#FM_(\w+)#", lambda m: table_sizes[m.groups(0)[0]], funcs)

    # fix +float into float.0, if not running js opts
    if not settings['RUNNING_JS_OPTS']:
      def fix_dot_zero(m):
        num = m.group(3)
        # TODO: handle 0x floats?
        if num.find('.') < 0:
          e = num.find('e')
          if e < 0:
            num += '.0'
          else:
            num = num[:e] + '.0' + num[e:]
        return m.group(1) + m.group(2) + num
      funcs = re.sub(r'([(=,+\-*/%<>:?] *)\+(-?)((0x)?[0-9a-f]*\.?[0-9]+([eE][-+]?[0-9]+)?)', fix_dot_zero, funcs)

    return funcs, metadata, mem_init

def compiler_glue(metadata, settings, libraries, compiler_engine, temp_files, DEBUG):
    # js compiler

    if DEBUG:
      logging.debug('emscript: js compiler glue')
      t = time.time()

    # Settings changes
    i64_funcs = ['i64Add', 'i64Subtract', '__muldi3', '__divdi3', '__udivdi3', '__remdi3', '__uremdi3']
    for i64_func in i64_funcs:
      if i64_func in metadata['declares']:
        settings['PRECISE_I64_MATH'] = 2
        break

    metadata['declares'] = filter(lambda i64_func: i64_func not in ['getHigh32', 'setHigh32'], metadata['declares']) # FIXME: do these one by one as normal js lib funcs

    # Syscalls optimization. Our syscalls are static, and so if we see a very limited set of them - in particular,
    # no open() syscall and just simple writing - then we don't need full filesystem support.
    # If FORCE_FILESYSTEM is set, we can't do this. We also don't do it if INCLUDE_FULL_LIBRARY, since
    # not including the filesystem would mean not including the full JS libraries, and the same for
    # MAIN_MODULE since a side module might need the filesystem.
    if not settings['NO_FILESYSTEM'] and not settings['FORCE_FILESYSTEM'] and not settings['INCLUDE_FULL_LIBRARY'] and not settings['MAIN_MODULE']:
      syscall_prefix = '__syscall'
      syscalls = filter(lambda declare: declare.startswith(syscall_prefix), metadata['declares'])
      def is_int(x):
        try:
          int(x)
          return True
        except:
          return False
      syscalls = filter(lambda declare: is_int(declare[len(syscall_prefix):]), syscalls)
      syscalls = map(lambda declare: int(declare[len(syscall_prefix):]), syscalls)
      if set(syscalls).issubset(set([6, 54, 140, 146])): # close, ioctl, llseek, writev
        if DEBUG: logging.debug('very limited syscalls (%s) so disabling full filesystem support' % ', '.join(map(str, syscalls)))
        settings['NO_FILESYSTEM'] = 1

    if settings['CYBERDWARF']:
      settings['DEFAULT_LIBRARY_FUNCS_TO_INCLUDE'].append("cyberdwarf_Debugger")
      settings['EXPORTED_FUNCTIONS'].append("cyberdwarf_Debugger")

    # Integrate info from backend
    if settings['SIDE_MODULE']:
      settings['DEFAULT_LIBRARY_FUNCS_TO_INCLUDE'] = [] # we don't need any JS library contents in side modules
    settings['DEFAULT_LIBRARY_FUNCS_TO_INCLUDE'] = list(
      set(settings['DEFAULT_LIBRARY_FUNCS_TO_INCLUDE'] + map(shared.JS.to_nice_ident, metadata['declares'])).difference(
        map(lambda x: x[1:], metadata['implementedFunctions'])
      )
    ) + map(lambda x: x[1:], metadata['externs'])
    if metadata['simd']:
      settings['SIMD'] = 1
    if metadata['cantValidate'] and settings['ASM_JS'] != 2:
      logging.warning('disabling asm.js validation due to use of non-supported features: ' + metadata['cantValidate'])
      settings['ASM_JS'] = 2

    settings['MAX_GLOBAL_ALIGN'] = metadata['maxGlobalAlign']

    settings['IMPLEMENTED_FUNCTIONS'] = metadata['implementedFunctions']

    assert not (metadata['simd'] and settings['SPLIT_MEMORY']), 'SIMD is used, but not supported in SPLIT_MEMORY'

    # Save settings to a file to work around v8 issue 1579
    with temp_files.get_file('.txt') as settings_file:
      def save_settings():
        global settings_text
        settings_text = json.dumps(settings, sort_keys=True)
        s = open(settings_file, 'w')
        s.write(settings_text)
        s.close()
      save_settings()

      # Call js compiler
      out = jsrun.run_js(path_from_root('src', 'compiler.js'), compiler_engine,
                         [settings_file] + libraries, stdout=subprocess.PIPE, stderr=STDERR_FILE,
                         cwd=path_from_root('src'), error_limit=300)
    assert '//FORWARDED_DATA:' in out, 'Did not receive forwarded data in pre output - process failed?'
    glue, forwarded_data = out.split('//FORWARDED_DATA:')

    if DEBUG:
      logging.debug('  emscript: glue took %s seconds' % (time.time() - t))

    return glue, forwarded_data

def function_tables_and_exports(funcs, metadata, mem_init, glue, forwarded_data, settings, outfile, DEBUG):

    if DEBUG:
      logging.debug('emscript: python processing: function tables and exports')
      t = time.time()

    access_quote = access_quoter(settings)
    quote = quoter(settings)

    last_forwarded_json = forwarded_json = json.loads(forwarded_data)

    # merge in information from llvm backend

    last_forwarded_json['Functions']['tables'] = metadata['tables']

    pre, post = glue.split('// EMSCRIPTEN_END_FUNCS')

    #print >> sys.stderr, 'glue:', pre, '\n\n||||||||||||||||\n\n', post, '...............'

    # memory and global initializers

    global_initializers = str(', '.join(map(lambda i: '{ func: function() { %s() } }' % i, metadata['initializers'])))

    if settings['SIMD'] == 1:
      pre = open(path_from_root(os.path.join('src', 'ecmascript_simd.js'))).read() + '\n\n' + pre

    staticbump = metadata['staticBump']
    while staticbump % 16 != 0: staticbump += 1
    pre = pre.replace('STATICTOP = STATIC_BASE + 0;', '''STATICTOP = STATIC_BASE + %d;%s
  /* global initializers */ %s __ATINIT__.push(%s);
  %s''' % (staticbump,
           'assert(STATICTOP < SPLIT_MEMORY, "SPLIT_MEMORY size must be big enough so the entire static memory, need " + STATICTOP);' if settings['SPLIT_MEMORY'] else '',
           'if (!ENVIRONMENT_IS_PTHREAD)' if settings['USE_PTHREADS'] else '',
           global_initializers,
           mem_init))

    if settings['SIDE_MODULE']:
      pre = pre.replace('Runtime.GLOBAL_BASE', 'gb')
    if settings['SIDE_MODULE'] or settings['BINARYEN']:
      pre = pre.replace('{{{ STATIC_BUMP }}}', str(staticbump))

    funcs_js = [funcs]
    parts = pre.split('// ASM_LIBRARY FUNCTIONS\n')
    if len(parts) > 1:
      pre = parts[0]
      funcs_js.append(parts[1])

    # merge forwarded data
    settings['EXPORTED_FUNCTIONS'] = forwarded_json['EXPORTED_FUNCTIONS']
    all_exported_functions = set(shared.expand_response(settings['EXPORTED_FUNCTIONS'])) # both asm.js and otherwise

    for additional_export in settings['DEFAULT_LIBRARY_FUNCS_TO_INCLUDE']: # additional functions to export from asm, if they are implemented
      all_exported_functions.add('_' + additional_export)
    if settings['EXPORT_FUNCTION_TABLES']:
      for table in last_forwarded_json['Functions']['tables'].values():
        for func in table.split('[')[1].split(']')[0].split(','):
          if func[0] == '_':
            all_exported_functions.add(func)
    exported_implemented_functions = set(metadata['exports'])
    export_bindings = settings['EXPORT_BINDINGS']
    export_all = settings['EXPORT_ALL']
    all_implemented = metadata['implementedFunctions'] + forwarded_json['Functions']['implementedFunctions'].keys() # XXX perf?
    for key in all_implemented:
      if key in all_exported_functions or export_all or (export_bindings and key.startswith('_emscripten_bind')):
        exported_implemented_functions.add(key)
    implemented_functions = set(metadata['implementedFunctions'])
    if settings['ASSERTIONS'] and settings.get('ORIGINAL_EXPORTED_FUNCTIONS'):
      original_exports = settings['ORIGINAL_EXPORTED_FUNCTIONS']
      if original_exports[0] == '@': original_exports = json.loads(open(original_exports[1:]).read())
      for requested in original_exports:
        # check if already implemented
        # special-case malloc, EXPORTED by default for internal use, but we bake in a trivial allocator and warn at runtime if used in ASSERTIONS \
        if requested not in all_implemented and \
           requested != '_malloc' and \
           (('function ' + requested.encode('utf-8')) not in pre): # could be a js library func
          logging.warning('function requested to be exported, but not implemented: "%s"', requested)

    asm_consts = [0]*len(metadata['asmConsts'])
    all_sigs = []
    for k, v in metadata['asmConsts'].iteritems():
      const = v[0].encode('utf-8')
      sigs = v[1]
      if len(const) > 1 and const[0] == '"' and const[-1] == '"':
        const = const[1:-1]
      const = '{ ' + const + ' }'
      args = []
      arity = max(map(len, sigs)) - 1
      for i in range(arity):
        args.append('$' + str(i))
      const = 'function(' + ', '.join(args) + ') ' + const
      asm_consts[int(k)] = const
      all_sigs += sigs

    asm_const_funcs = []
    for sig in set(all_sigs):
      forwarded_json['Functions']['libraryFunctions']['_emscripten_asm_const_' + sig] = 1
      args = ['a%d' % i for i in range(len(sig)-1)]
      all_args = ['code'] + args
      asm_const_funcs.append(r'''
function _emscripten_asm_const_%s(%s) {
 return ASM_CONSTS[code](%s);
}''' % (sig.encode('utf-8'), ', '.join(all_args), ', '.join(args)))

    pre = pre.replace('// === Body ===', '// === Body ===\n' + '\nvar ASM_CONSTS = [' + ',\n '.join(asm_consts) + '];\n' + '\n'.join(asm_const_funcs) + '\n')

    #if DEBUG: outfile.write('// pre\n')
    outfile.write(pre)
    pre = None

    #if DEBUG: outfile.write('// funcs\n')

    # when emulating function pointer casts, we need to know what is the target of each pointer
    if settings['EMULATE_FUNCTION_POINTER_CASTS']:
      function_pointer_targets = {}
      for sig, table in last_forwarded_json['Functions']['tables'].iteritems():
        start = table.index('[')
        end = table.rindex(']')
        body = table[start+1:end].split(',')
        parsed = map(lambda x: x.strip(), body)
        for i in range(len(parsed)):
          if parsed[i] != '0':
            assert i not in function_pointer_targets
            function_pointer_targets[i] = [sig, str(parsed[i])]

    # Move preAsms to their right place
    def move_preasm(m):
      contents = m.groups(0)[0]
      outfile.write(contents + '\n')
      return ''
    if not settings['BOOTSTRAPPING_STRUCT_INFO'] and len(funcs_js) > 1:
      funcs_js[1] = re.sub(r'/\* PRE_ASM \*/(.*)\n', move_preasm, funcs_js[1])

    class Counter:
      i = 0
      j = 0
    if 'pre' in last_forwarded_json['Functions']['tables']:
      pre_tables = last_forwarded_json['Functions']['tables']['pre']
      del last_forwarded_json['Functions']['tables']['pre']
    else:
      pre_tables = ''

    def unfloat(s):
      return 'd' if s == 'f' else s # lower float to double for ffis

    if settings['ASSERTIONS'] >= 2:
      debug_tables = {}

    def make_params(sig): return ','.join(['p%d' % p for p in range(len(sig)-1)])
    def make_coerced_params(sig): return ','.join([shared.JS.make_coercion('p%d', unfloat(sig[p+1]), settings) % p for p in range(len(sig)-1)])
    def make_coercions(sig): return ';'.join(['p%d = %s' % (p, shared.JS.make_coercion('p%d' % p, sig[p+1], settings)) for p in range(len(sig)-1)]) + ';'
    def make_func(name, code, params, coercions): return 'function %s(%s) {\n %s %s\n}' % (name, params, coercions, code)

    in_table = set()

    def make_table(sig, raw):
      params = make_params(sig)
      coerced_params = make_coerced_params(sig)
      coercions = make_coercions(sig)
      def make_bad(target=None):
        i = Counter.i
        Counter.i += 1
        if target is None: target = i
        name = 'b' + str(i)
        if not settings['ASSERTIONS']:
          code = 'abort(%s);' % target
        else:
          code = 'nullFunc_' + sig + '(%d);' % target
        if sig[0] != 'v':
          code += 'return %s' % shared.JS.make_initializer(sig[0], settings) + ';'
        return name, make_func(name, code, params, coercions)
      bad, bad_func = make_bad() # the default bad func
      if settings['ASSERTIONS'] <= 1:
        Counter.pre = [bad_func]
      else:
        Counter.pre = []
      start = raw.index('[')
      end = raw.rindex(']')
      body = raw[start+1:end].split(',')
      if settings['EMULATED_FUNCTION_POINTERS']:
        def receive(item):
          if item == '0':
            return item
          else:
            if item in all_implemented:
              in_table.add(item)
              return "asm['" + item + "']"
            else:
              return item # this is not implemented; it would normally be wrapped, but with emulation, we just use it directly outside
        body = map(receive, body)
      for j in range(settings['RESERVED_FUNCTION_POINTERS']):
        curr = 'jsCall_%s_%s' % (sig, j)
        body[settings['FUNCTION_POINTER_ALIGNMENT'] * (1 + j)] = curr
        implemented_functions.add(curr)
      Counter.j = 0
      def fix_item(item):
        j = Counter.j
        Counter.j += 1
        newline = Counter.j % 30 == 29
        if item == '0':
          if j > 0 and settings['EMULATE_FUNCTION_POINTER_CASTS'] and j in function_pointer_targets: # emulate all non-null pointer calls, if asked to
            proper_sig, proper_target = function_pointer_targets[j]
            if settings['EMULATED_FUNCTION_POINTERS']:
              if proper_target in all_implemented:
                proper_target = "asm['" + proper_target + "']"
            def make_emulated_param(i):
              if i >= len(sig): return shared.JS.make_initializer(proper_sig[i], settings) # extra param, just send a zero
              return shared.JS.make_coercion('p%d' % (i-1), proper_sig[i], settings, convert_from=sig[i])
            proper_code = proper_target + '(' + ','.join(map(lambda i: make_emulated_param(i+1), range(len(proper_sig)-1))) + ')'
            if proper_sig[0] != 'v':
              # proper sig has a return, which the wrapper may or may not use
              proper_code = shared.JS.make_coercion(proper_code, proper_sig[0], settings)
              if proper_sig[0] != sig[0]:
                # first coercion ensured we call the target ok; this one ensures we return the right type in the wrapper
                proper_code = shared.JS.make_coercion(proper_code, sig[0], settings, convert_from=proper_sig[0])
              if sig[0] != 'v':
                proper_code = 'return ' + proper_code
            else:
              # proper sig has no return, we may need a fake return
              if sig[0] != 'v':
                proper_code = 'return ' + shared.JS.make_initializer(sig[0], settings)
            name = 'fpemu_%s_%d' % (sig, j)
            wrapper = make_func(name, proper_code, params, coercions)
            Counter.pre.append(wrapper)
            return name if not newline else (name + '\n')
          if settings['ASSERTIONS'] <= 1:
            return bad if not newline else (bad + '\n')
          else:
            specific_bad, specific_bad_func = make_bad(j)
            Counter.pre.append(specific_bad_func)
            return specific_bad if not newline else (specific_bad + '\n')
        clean_item = item.replace("asm['", '').replace("']", '')
        # when emulating function pointers, we don't need wrappers
        # but if relocating, then we also have the copies in-module, and do
        # also if binaryen, as wasm requires wrappers for the function table
        if clean_item not in implemented_functions and not (settings['EMULATED_FUNCTION_POINTERS'] and not settings['RELOCATABLE'] and not settings['BINARYEN']):
          # this is imported into asm, we must wrap it
          call_ident = clean_item
          if call_ident in metadata['redirects']: call_ident = metadata['redirects'][call_ident]
          if not call_ident.startswith('_') and not call_ident.startswith('Math_'): call_ident = '_' + call_ident
          code = call_ident + '(' + coerced_params + ')'
          if sig[0] != 'v':
            # ffis cannot return float
            if sig[0] == 'f': code = '+' + code
            code = 'return ' + shared.JS.make_coercion(code, sig[0], settings)
          code += ';'
          Counter.pre.append(make_func(clean_item + '__wrapper', code, params, coercions))
          return clean_item + '__wrapper'
        return item if not newline else (item + '\n')
      if settings['ASSERTIONS'] >= 2:
        debug_tables[sig] = body
      body = ','.join(map(fix_item, body))
      return ('\n'.join(Counter.pre), ''.join([raw[:start+1], body, raw[end:]]))

    infos = [make_table(sig, raw) for sig, raw in last_forwarded_json['Functions']['tables'].iteritems()]
    Counter.pre = []

    function_tables_defs = '\n'.join([info[0] for info in infos]) + '\n'
    function_tables_defs += '\n// EMSCRIPTEN_END_FUNCS\n'
    function_tables_defs += '\n'.join([info[1] for info in infos])

    asm_setup = ''

    if settings['ASSERTIONS'] >= 2:
      for sig in last_forwarded_json['Functions']['tables']:
        asm_setup += '\nvar debug_table_' + sig + ' = ' + json.dumps(debug_tables[sig]) + ';'

    maths = ['Math.' + func for func in ['floor', 'abs', 'sqrt', 'pow', 'cos', 'sin', 'tan', 'acos', 'asin', 'atan', 'atan2', 'exp', 'log', 'ceil', 'imul', 'min', 'max', 'clz32']]
    simdfloattypes = []
    simdinttypes = []
    simdbooltypes = []
    simdfuncs = ['splat', 'check', 'extractLane', 'replaceLane']
    simdintfloatfuncs = ['add', 'sub', 'neg', 'mul',
                         'equal', 'lessThan', 'greaterThan',
                         'notEqual', 'lessThanOrEqual', 'greaterThanOrEqual',
                         'select', 'swizzle', 'shuffle',
                         'load', 'store', 'load1', 'store1', 'load2', 'store2']
    simdintboolfuncs = ['and', 'xor', 'or', 'not']
    if metadata['simdUint8x16']:
      simdinttypes += ['Uint8x16']
      simdintfloatfuncs += ['fromUint8x16Bits']
    if metadata['simdInt8x16']:
      simdinttypes += ['Int8x16']
      simdintfloatfuncs += ['fromInt8x16Bits']
    if metadata['simdUint16x8']:
      simdinttypes += ['Uint16x8']
      simdintfloatfuncs += ['fromUint16x8Bits']
    if metadata['simdInt16x8']:
      simdinttypes += ['Int16x8']
      simdintfloatfuncs += ['fromInt16x8Bits']
    if metadata['simdUint32x4']:
      simdinttypes += ['Uint32x4']
      simdintfloatfuncs += ['fromUint32x4Bits']
    if metadata['simdInt32x4']:
      simdinttypes += ['Int32x4']
      simdintfloatfuncs += ['fromInt32x4Bits']
    if metadata['simdFloat32x4']:
      simdfloattypes += ['Float32x4']
      simdintfloatfuncs += ['fromFloat32x4Bits']
    if metadata['simdFloat64x2']:
      simdfloattypes += ['Float64x2']
      simdintfloatfuncs += ['fromFloat64x2Bits']
    if metadata['simdBool8x16']:
      simdbooltypes += ['Bool8x16']
    if metadata['simdBool16x8']:
      simdbooltypes += ['Bool16x8']
    if metadata['simdBool32x4']:
      simdbooltypes += ['Bool32x4']
    if metadata['simdBool64x2']:
      simdbooltypes += ['Bool64x2']

    simdfloatfuncs = simdfuncs + simdintfloatfuncs + ['div', 'min', 'max', 'minNum', 'maxNum', 'sqrt',
                                  'abs', 'reciprocalApproximation', 'reciprocalSqrtApproximation']
    simdintfuncs = simdfuncs + simdintfloatfuncs + simdintboolfuncs + ['shiftLeftByScalar', 'shiftRightByScalar', 'addSaturate', 'subSaturate']
    simdboolfuncs = simdfuncs + simdintboolfuncs + ['anyTrue', 'allTrue']
    simdtypes = simdfloattypes + simdinttypes + simdbooltypes

    fundamentals = ['Math']
    fundamentals += ['Int8Array', 'Int16Array', 'Int32Array', 'Uint8Array', 'Uint16Array', 'Uint32Array', 'Float32Array', 'Float64Array']
    fundamentals += ['NaN', 'Infinity']
    if metadata['simd']:
        fundamentals += ['SIMD']
    if settings['ALLOW_MEMORY_GROWTH']: fundamentals.append('byteLength')
    math_envs = []

    provide_fround = settings['PRECISE_F32'] or settings['SIMD']

    if provide_fround: maths += ['Math.fround']

    def get_function_pointer_error(sig):
      if settings['ASSERTIONS'] <= 1:
        extra = ' Module["printErr"]("Build with ASSERTIONS=2 for more info.");'
        pointer = ' '
      else:
        pointer = ' \'" + x + "\' '
        extra = ' Module["printErr"]("This pointer might make sense in another type signature: '
        # sort signatures, attempting to show most likely related ones first
        sigs = last_forwarded_json['Functions']['tables'].keys()
        def keyfunc(other):
          ret = 0
          minlen = min(len(other), len(sig))
          maxlen = min(len(other), len(sig))
          if other.startswith(sig) or sig.startswith(other): ret -= 1000 # prioritize prefixes, could be dropped params
          ret -= 133*difflib.SequenceMatcher(a=other, b=sig).ratio() # prioritize on diff similarity
          ret += 15*abs(len(other) - len(sig))/float(maxlen) # deprioritize the bigger the length difference is
          for i in range(minlen):
            if other[i] == sig[i]: ret -= 5/float(maxlen) # prioritize on identically-placed params
          ret += 20*len(other) # deprioritize on length
          return ret
        sigs.sort(key=keyfunc)
        for other in sigs:
          if other != sig:
            extra += other + ': " + debug_table_' + other + '[x] + "  '
        extra += '"); '
      return 'Module["printErr"]("Invalid function pointer' + pointer + 'called with signature \'' + sig + '\'. ' + \
             'Perhaps this is an invalid value (e.g. caused by calling a virtual method on a NULL pointer)? ' + \
             'Or calling a function with an incorrect type, which will fail? ' + \
             '(it is worth building your source files with -Werror (warnings are errors), as warnings can indicate undefined behavior which can cause this)' + \
             '"); ' + extra

    basic_funcs = ['abort', 'assert', 'enlargeMemory', 'getTotalMemory'] + [m.replace('.', '_') for m in math_envs]
    if settings['ABORTING_MALLOC']: basic_funcs += ['abortOnCannotGrowMemory']
    if settings['STACK_OVERFLOW_CHECK']: basic_funcs += ['abortStackOverflow']

    asm_safe_heap = settings['SAFE_HEAP'] and not settings['SAFE_HEAP_LOG'] and not settings['RELOCATABLE'] # optimized safe heap in asm, when we can

    if settings['SAFE_HEAP']:
      if asm_safe_heap:
        basic_funcs += ['segfault', 'alignfault', 'ftfault']
      else:
        basic_funcs += ['SAFE_HEAP_LOAD', 'SAFE_HEAP_LOAD_D', 'SAFE_HEAP_STORE', 'SAFE_HEAP_STORE_D', 'SAFE_FT_MASK']
    if settings['ASSERTIONS']:
      if settings['ASSERTIONS'] >= 2: import difflib
      for sig in last_forwarded_json['Functions']['tables'].iterkeys():
        basic_funcs += ['nullFunc_' + sig]
        asm_setup += '\nfunction nullFunc_' + sig + '(x) { ' + get_function_pointer_error(sig) + 'abort(x) }\n'

    basic_vars = ['STACKTOP', 'STACK_MAX', 'DYNAMICTOP_PTR', 'tempDoublePtr', 'ABORT']
    basic_float_vars = []

    if metadata.get('preciseI64MathUsed'):
      basic_vars += ['cttz_i8']
    else:
      if forwarded_json['Functions']['libraryFunctions'].get('_llvm_cttz_i32'):
        basic_vars += ['cttz_i8']

    if settings['RELOCATABLE']:
      basic_vars += ['gb', 'fb']
      if not settings['SIDE_MODULE']:
        asm_setup += 'var gb = Runtime.GLOBAL_BASE, fb = 0;\n'

    asm_runtime_funcs = ['stackAlloc', 'stackSave', 'stackRestore', 'establishStackSpace', 'setThrew']
    if not settings['RELOCATABLE']:
      asm_runtime_funcs += ['setTempRet0', 'getTempRet0']
    else:
      basic_funcs += ['setTempRet0', 'getTempRet0']
      asm_setup += 'var setTempRet0 = Runtime.setTempRet0, getTempRet0 = Runtime.getTempRet0;\n'

    if settings['BINARYEN']:
      asm_setup += "\nModule['wasmTableSize'] = %d;\n" % sum(map(lambda table: table.count(',') + 1, last_forwarded_json['Functions']['tables'].values()))

    # See if we need ASYNCIFY functions
    # We might not need them even if ASYNCIFY is enabled
    need_asyncify = '_emscripten_alloc_async_context' in exported_implemented_functions
    if need_asyncify:
      basic_vars += ['___async', '___async_unwind', '___async_retval', '___async_cur_frame']
      asm_runtime_funcs += ['setAsync']

    if settings.get('EMTERPRETIFY'):
      asm_runtime_funcs += ['emterpret']
      if settings.get('EMTERPRETIFY_ASYNC'):
        asm_runtime_funcs += ['setAsyncState', 'emtStackSave', 'emtStackRestore']

    if settings['SAFE_HEAP']:
      asm_runtime_funcs += ['setDynamicTop']

    if settings['ONLY_MY_CODE']:
      asm_runtime_funcs = []

    # function tables
    if not settings['EMULATED_FUNCTION_POINTERS']:
      function_tables = ['dynCall_' + table for table in last_forwarded_json['Functions']['tables']]
    else:
      function_tables = []
    function_tables_impls = []

    for sig in last_forwarded_json['Functions']['tables'].iterkeys():
      args = ','.join(['a' + str(i) for i in range(1, len(sig))])
      arg_coercions = ' '.join(['a' + str(i) + '=' + shared.JS.make_coercion('a' + str(i), sig[i], settings) + ';' for i in range(1, len(sig))])
      coerced_args = ','.join([shared.JS.make_coercion('a' + str(i), sig[i], settings) for i in range(1, len(sig))])
      ret = ('return ' if sig[0] != 'v' else '') + shared.JS.make_coercion('FUNCTION_TABLE_%s[index&{{{ FTM_%s }}}](%s)' % (sig, sig, coerced_args), sig[0], settings)
      if not settings['EMULATED_FUNCTION_POINTERS']:
        function_tables_impls.append('''
function dynCall_%s(index%s%s) {
  index = index|0;
  %s
  %s;
}
''' % (sig, ',' if len(sig) > 1 else '', args, arg_coercions, ret))
      else:
        function_tables_impls.append('''
var dynCall_%s = ftCall_%s;
''' % (sig, sig))

      ffi_args = ','.join([shared.JS.make_coercion('a' + str(i), sig[i], settings, ffi_arg=True) for i in range(1, len(sig))])
      for i in range(settings['RESERVED_FUNCTION_POINTERS']):
        jsret = ('return ' if sig[0] != 'v' else '') + shared.JS.make_coercion('jsCall_%s(%d%s%s)' % (sig, i, ',' if ffi_args else '', ffi_args), sig[0], settings, ffi_result=True)
        function_tables_impls.append('''
function jsCall_%s_%s(%s) {
  %s
  %s;
}

''' % (sig, i, args, arg_coercions, jsret))
      shared.Settings.copy(settings)
      asm_setup += '\n' + shared.JS.make_invoke(sig) + '\n'
      basic_funcs.append('invoke_%s' % sig)
      if settings.get('RESERVED_FUNCTION_POINTERS'):
        asm_setup += '\n' + shared.JS.make_jscall(sig) + '\n'
        basic_funcs.append('jsCall_%s' % sig)
      if settings.get('EMULATED_FUNCTION_POINTERS'):
        args = ['a%d' % i for i in range(len(sig)-1)]
        full_args = ['x'] + args
        table_access = 'FUNCTION_TABLE_' + sig
        if settings['SIDE_MODULE']:
          table_access = 'parentModule["' + table_access + '"]' # side module tables were merged into the parent, we need to access the global one
        prelude = '''
  if (x < 0 || x >= %s.length) { Module.printErr("Function table mask error (out of range)"); %s ; abort(x) }''' % (table_access, get_function_pointer_error(sig))
        asm_setup += '''
function ftCall_%s(%s) {%s
  return %s[x](%s);
}
''' % (sig, ', '.join(full_args), prelude, table_access, ', '.join(args))
        basic_funcs.append('ftCall_%s' % sig)

        if settings.get('RELOCATABLE'):
          params = ','.join(['ptr'] + ['p%d' % p for p in range(len(sig)-1)])
          coerced_params = ','.join([shared.JS.make_coercion('ptr', 'i', settings)] + [shared.JS.make_coercion('p%d', unfloat(sig[p+1]), settings) % p for p in range(len(sig)-1)])
          coercions = ';'.join(['ptr = ptr | 0'] + ['p%d = %s' % (p, shared.JS.make_coercion('p%d' % p, unfloat(sig[p+1]), settings)) for p in range(len(sig)-1)]) + ';'
          mini_coerced_params = ','.join([shared.JS.make_coercion('p%d', sig[p+1], settings) % p for p in range(len(sig)-1)])
          maybe_return = '' if sig[0] == 'v' else 'return'
          final_return = maybe_return + ' ' + shared.JS.make_coercion('ftCall_' + sig + '(' + coerced_params + ')', unfloat(sig[0]), settings) + ';'
          if settings['EMULATED_FUNCTION_POINTERS'] == 1:
            body = final_return
          else:
            body = 'if (((ptr|0) >= (fb|0)) & ((ptr|0) < (fb + {{{ FTM_' + sig + ' }}} | 0))) { ' + maybe_return + ' ' + shared.JS.make_coercion('FUNCTION_TABLE_' + sig + '[(ptr-fb)&{{{ FTM_' + sig + ' }}}](' + mini_coerced_params + ')', sig[0], settings, ffi_arg=True) + '; ' + ('return;' if sig[0] == 'v' else '') + ' }' + final_return
          funcs_js.append(make_func('mftCall_' + sig, body, params, coercions) + '\n')

    # calculate exports
    exported_implemented_functions = list(exported_implemented_functions) + metadata['initializers']
    if not settings['ONLY_MY_CODE']:
      exported_implemented_functions.append('runPostSets')
    if settings['ALLOW_MEMORY_GROWTH']:
      exported_implemented_functions.append('_emscripten_replace_memory')
    all_exported = exported_implemented_functions + asm_runtime_funcs + function_tables
    exported_implemented_functions = list(set(exported_implemented_functions))
    if settings['EMULATED_FUNCTION_POINTERS']:
      all_exported = list(set(all_exported).union(in_table))
    exports = []
    for export in all_exported:
      exports.append(quote(export) + ": " + export)
    exports = '{ ' + ', '.join(exports) + ' }'
    # calculate globals
    try:
      del forwarded_json['Variables']['globals']['_llvm_global_ctors'] # not a true variable
    except:
      pass
    if not settings['RELOCATABLE']:
      global_vars = metadata['externs']
    else:
      global_vars = [] # linkable code accesses globals through function calls
    global_funcs = list(set([key for key, value in forwarded_json['Functions']['libraryFunctions'].iteritems() if value != 2]).difference(set(global_vars)).difference(implemented_functions))
    if settings['RELOCATABLE']:
      global_funcs += ['g$' + extern for extern in metadata['externs']]
      side = 'parent' if settings['SIDE_MODULE'] else ''
      def check(extern):
        if settings['ASSERTIONS']: return 'assert(' + side + 'Module["' + extern + '"], "external function \'' + extern + '\' is missing. perhaps a side module was not linked in? if this symbol was expected to arrive from a system library, try to build the MAIN_MODULE with EMCC_FORCE_STDLIBS=1 in the environment");'
        return ''
      for extern in metadata['externs']:
        asm_setup += 'var g$' + extern + ' = function() { ' + check(extern) + ' return ' + side + 'Module["' + extern + '"] };\n'
    def math_fix(g):
      return g if not g.startswith('Math_') else g.split('_')[1]
    asm_global_funcs = ''.join(['  var ' + g.replace('.', '_') + '=global' + access_quote(g) + ';\n' for g in maths])
    asm_global_funcs += ''.join(['  var ' + g + '=env' + access_quote(math_fix(g)) + ';\n' for g in basic_funcs + global_funcs])
    if metadata['simd']:
      def string_contains_any(s, str_list):
        for sub in str_list:
          if sub in s:
            return True
        return False
      nonexisting_simd_symbols = ['Int8x16_fromInt8x16', 'Uint8x16_fromUint8x16', 'Int16x8_fromInt16x8', 'Uint16x8_fromUint16x8', 'Int32x4_fromInt32x4', 'Uint32x4_fromUint32x4', 'Float32x4_fromFloat32x4', 'Float64x2_fromFloat64x2']
      nonexisting_simd_symbols += ['Int32x4_addSaturate', 'Int32x4_subSaturate', 'Uint32x4_addSaturate', 'Uint32x4_subSaturate']
      nonexisting_simd_symbols += [(x + '_' + y) for x in ['Int8x16', 'Uint8x16', 'Int16x8', 'Uint16x8', 'Float64x2'] for y in ['load2', 'store2']]
      nonexisting_simd_symbols += [(x + '_' + y) for x in ['Int8x16', 'Uint8x16', 'Int16x8', 'Uint16x8'] for y in ['load1', 'store1']]

      asm_global_funcs += ''.join(['  var SIMD_' + ty + '=global' + access_quote('SIMD') + access_quote(ty) + ';\n' for ty in simdtypes])

      simd_int_symbols = ['  var SIMD_' + ty + '_' + g + '=SIMD_' + ty + access_quote(g) + ';\n' for ty in simdinttypes for g in simdintfuncs]
      simd_int_symbols = filter(lambda x: not string_contains_any(x, nonexisting_simd_symbols), simd_int_symbols)
      asm_global_funcs += ''.join(simd_int_symbols)

      simd_float_symbols = ['  var SIMD_' + ty + '_' + g + '=SIMD_' + ty + access_quote(g) + ';\n' for ty in simdfloattypes for g in simdfloatfuncs]
      simd_float_symbols = filter(lambda x: not string_contains_any(x, nonexisting_simd_symbols), simd_float_symbols)
      asm_global_funcs += ''.join(simd_float_symbols)

      simd_bool_symbols = ['  var SIMD_' + ty + '_' + g + '=SIMD_' + ty + access_quote(g) + ';\n' for ty in simdbooltypes for g in simdboolfuncs]
      simd_bool_symbols = filter(lambda x: not string_contains_any(x, nonexisting_simd_symbols), simd_bool_symbols)
      asm_global_funcs += ''.join(simd_bool_symbols)

      # SIMD conversions (not bitcasts) between same lane sizes:
      def add_simd_cast(dst, src):
        return '  var SIMD_' + dst + '_from' + src + '=SIMD_' + dst + '.from' + src + ';\n'
      def add_simd_casts(t1, t2):
        return add_simd_cast(t1, t2) + add_simd_cast(t2, t1)

      # Bug: Skip importing conversions for int<->uint for now, they don't validate as asm.js. https://bugzilla.mozilla.org/show_bug.cgi?id=1313512
      # This is not an issue when building SSEx code, because it doesn't use these. (but it will be an issue if using SIMD.js intrinsics from vector.h to explicitly call these)
#      if metadata['simdInt8x16'] and metadata['simdUint8x16']: asm_global_funcs += add_simd_casts('Int8x16', 'Uint8x16')
#      if metadata['simdInt16x8'] and metadata['simdUint16x8']: asm_global_funcs += add_simd_casts('Int16x8', 'Uint16x8')
#      if metadata['simdInt32x4'] and metadata['simdUint32x4']: asm_global_funcs += add_simd_casts('Int32x4', 'Uint32x4')

      if metadata['simdInt32x4'] and metadata['simdFloat32x4']: asm_global_funcs += add_simd_casts('Int32x4', 'Float32x4')
      if metadata['simdUint32x4'] and metadata['simdFloat32x4']: asm_global_funcs += add_simd_casts('Uint32x4', 'Float32x4')
      if metadata['simdInt32x4'] and metadata['simdFloat64x2']: asm_global_funcs += add_simd_cast('Int32x4', 'Float64x2') # Unofficial, needed for emscripten_int32x4_fromFloat64x2
      if metadata['simdUint32x4'] and metadata['simdFloat64x2']: asm_global_funcs += add_simd_cast('Uint32x4', 'Float64x2') # Unofficial, needed for emscripten_uint32x4_fromFloat64x2

      # Unofficial, Bool64x2 does not yet exist, but needed for Float64x2 comparisons.
      if metadata['simdFloat64x2']:
        asm_global_funcs += '  var SIMD_Int32x4_fromBool64x2Bits = global.SIMD.Int32x4.fromBool64x2Bits;\n'
    if settings['USE_PTHREADS']:
      asm_global_funcs += ''.join(['  var Atomics_' + ty + '=global' + access_quote('Atomics') + access_quote(ty) + ';\n' for ty in ['load', 'store', 'exchange', 'compareExchange', 'add', 'sub', 'and', 'or', 'xor']])
    asm_global_vars = ''.join(['  var ' + g + '=env' + access_quote(g) + '|0;\n' for g in basic_vars + global_vars])

    # sent data
    the_global = '{ ' + ', '.join(['"' + math_fix(s) + '": ' + s for s in fundamentals]) + ' }'
    sending = '{ ' + ', '.join(['"' + math_fix(s) + '": ' + s for s in basic_funcs + global_funcs + basic_vars + basic_float_vars + global_vars]) + ' }'
    # received
    receiving = ''
    if settings['ASSERTIONS']:
      # assert on the runtime being in a valid state when calling into compiled code. The only exceptions are
      # some support code
      receiving = '\n'.join(['var real_' + s + ' = asm["' + s + '"]; asm["' + s + '''"] = function() {
assert(runtimeInitialized, 'you need to wait for the runtime to be ready (e.g. wait for main() to be called)');
assert(!runtimeExited, 'the runtime was exited (use NO_EXIT_RUNTIME to keep it alive after main() exits)');
return real_''' + s + '''.apply(null, arguments);
};
''' for s in exported_implemented_functions if s not in ['_memcpy', '_memset', 'runPostSets', '_emscripten_replace_memory']])

    if not settings['SWAPPABLE_ASM_MODULE']:
      receiving += ';\n'.join(['var ' + s + ' = Module["' + s + '"] = asm["' + s + '"]' for s in exported_implemented_functions + function_tables])
    else:
      receiving += 'Module["asm"] = asm;\n' + ';\n'.join(['var ' + s + ' = Module["' + s + '"] = function() { return Module["asm"]["' + s + '"].apply(null, arguments) }' for s in exported_implemented_functions + function_tables])
    receiving += ';\n'

    if settings['EXPORT_FUNCTION_TABLES']:
      for table in last_forwarded_json['Functions']['tables'].values():
        tableName = table.split()[1]
        table = table.replace('var ' + tableName, 'var ' + tableName + ' = Module["' + tableName + '"]')
        receiving += table + '\n'

    if DEBUG: logging.debug('asm text sizes' + str([map(len, funcs_js), len(asm_setup), len(asm_global_vars), len(asm_global_funcs), len(pre_tables), len('\n'.join(function_tables_impls)), len(function_tables_defs) + (function_tables_defs.count('\n') * len('  ')), len(exports), len(the_global), len(sending), len(receiving)]))

    final_function_tables = '\n'.join(function_tables_impls) + '\n' + function_tables_defs
    if settings.get('EMULATED_FUNCTION_POINTERS'):
      asm_setup += '\n' + '\n'.join(function_tables_impls) + '\n'
      receiving += '\n' + function_tables_defs.replace('// EMSCRIPTEN_END_FUNCS\n', '') + '\n' + ''.join(['Module["dynCall_%s"] = dynCall_%s\n' % (sig, sig) for sig in last_forwarded_json['Functions']['tables']])
      for sig in last_forwarded_json['Functions']['tables'].keys():
        name = 'FUNCTION_TABLE_' + sig
        fullname = name if not settings['SIDE_MODULE'] else ('SIDE_' + name)
        receiving += 'Module["' + name + '"] = ' + fullname + ';\n'

      final_function_tables = final_function_tables.replace("asm['", '').replace("']", '').replace('var SIDE_FUNCTION_TABLE_', 'var FUNCTION_TABLE_').replace('var dynCall_', '//')

    if DEBUG:
      logging.debug('  emscript: python processing: function tables and exports took %s seconds' % (time.time() - t))

    return post, funcs_js, need_asyncify, provide_fround, asm_safe_heap, sending, receiving, asm_setup, the_global, asm_global_vars, asm_global_funcs, pre_tables, final_function_tables, exports, last_forwarded_json

def finalize_output(metadata, post, funcs_js, need_asyncify, provide_fround, asm_safe_heap, sending, receiving, asm_setup, the_global, asm_global_vars, asm_global_funcs, pre_tables, final_function_tables, exports, last_forwarded_json, settings, outfile, DEBUG):

    if DEBUG:
      logging.debug('emscript: python processing: finalize')
      t = time.time()

    access_quote = access_quoter(settings)

    if settings['RELOCATABLE']:
      receiving += '''
var NAMED_GLOBALS = { %s };
for (var named in NAMED_GLOBALS) {
  Module['_' + named] = gb + NAMED_GLOBALS[named];
}
Module['NAMED_GLOBALS'] = NAMED_GLOBALS;
''' % ', '.join('"' + k + '": ' + str(v) for k, v in metadata['namedGlobals'].iteritems())

      receiving += ''.join(["Module['%s'] = Module['%s']\n" % (k, v) for k, v in metadata['aliases'].iteritems()])

    if settings['USE_PTHREADS']:
      shared_array_buffer = "if (typeof SharedArrayBuffer !== 'undefined') Module.asmGlobalArg['Atomics'] = Atomics;"
    else:
      shared_array_buffer = ''

    first_in_asm = ''
    if settings['SPLIT_MEMORY']:
      if not settings['SAFE_SPLIT_MEMORY']:
        first_in_asm += '''
function get8(ptr) {
  ptr = ptr | 0;
  return HEAP8s[ptr >> SPLIT_MEMORY_BITS][ptr & SPLIT_MEMORY_MASK] | 0;
}
function get16(ptr) {
  ptr = ptr | 0;
  return HEAP16s[ptr >> SPLIT_MEMORY_BITS][(ptr & SPLIT_MEMORY_MASK) >> 1] | 0;
}
function get32(ptr) {
  ptr = ptr | 0;
  return HEAP32s[ptr >> SPLIT_MEMORY_BITS][(ptr & SPLIT_MEMORY_MASK) >> 2] | 0;
}
function getU8(ptr) {
  ptr = ptr | 0;
  return HEAPU8s[ptr >> SPLIT_MEMORY_BITS][(ptr & SPLIT_MEMORY_MASK) >> 0] | 0;
}
function getU16(ptr) {
  ptr = ptr | 0;
  return HEAPU16s[ptr >> SPLIT_MEMORY_BITS][(ptr & SPLIT_MEMORY_MASK) >> 1] | 0;
}
function getU32(ptr) {
  ptr = ptr | 0;
  return HEAPU32s[ptr >> SPLIT_MEMORY_BITS][(ptr & SPLIT_MEMORY_MASK) >> 2] | 0;
}
function getF32(ptr) {
  ptr = ptr | 0;
  return +HEAPF32s[ptr >> SPLIT_MEMORY_BITS][(ptr & SPLIT_MEMORY_MASK) >> 2]; // TODO: fround when present
}
function getF64(ptr) {
  ptr = ptr | 0;
  return +HEAPF64s[ptr >> SPLIT_MEMORY_BITS][(ptr & SPLIT_MEMORY_MASK) >> 3];
}
function set8(ptr, value) {
  ptr = ptr | 0;
  value = value | 0;
  HEAP8s[ptr >> SPLIT_MEMORY_BITS][ptr & SPLIT_MEMORY_MASK] = value;
}
function set16(ptr, value) {
  ptr = ptr | 0;
  value = value | 0;
  HEAP16s[ptr >> SPLIT_MEMORY_BITS][(ptr & SPLIT_MEMORY_MASK) >> 1] = value;
}
function set32(ptr, value) {
  ptr = ptr | 0;
  value = value | 0;
  HEAP32s[ptr >> SPLIT_MEMORY_BITS][(ptr & SPLIT_MEMORY_MASK) >> 2] = value;
}
function setU8(ptr, value) {
  ptr = ptr | 0;
  value = value | 0;
  HEAPU8s[ptr >> SPLIT_MEMORY_BITS][(ptr & SPLIT_MEMORY_MASK) >> 0] = value;
}
function setU16(ptr, value) {
  ptr = ptr | 0;
  value = value | 0;
  HEAPU16s[ptr >> SPLIT_MEMORY_BITS][(ptr & SPLIT_MEMORY_MASK) >> 1] = value;
}
function setU32(ptr, value) {
  ptr = ptr | 0;
  value = value | 0;
  HEAPU32s[ptr >> SPLIT_MEMORY_BITS][(ptr & SPLIT_MEMORY_MASK) >> 2] = value;
}
function setF32(ptr, value) {
  ptr = ptr | 0;
  value = +value;
  HEAPF32s[ptr >> SPLIT_MEMORY_BITS][(ptr & SPLIT_MEMORY_MASK) >> 2] = value;
}
function setF64(ptr, value) {
  ptr = ptr | 0;
  value = +value;
  HEAPF64s[ptr >> SPLIT_MEMORY_BITS][(ptr & SPLIT_MEMORY_MASK) >> 3] = value;
}
'''
      first_in_asm += 'buffer = new ArrayBuffer(32); // fake\n'

    runtime_funcs = []
    if not settings['ONLY_MY_CODE']:
      runtime_funcs = ['''
function stackAlloc(size) {
  size = size|0;
  var ret = 0;
  ret = STACKTOP;
  STACKTOP = (STACKTOP + size)|0;
  STACKTOP = (STACKTOP + 15)&-16;
''' + ('  if ((STACKTOP|0) >= (STACK_MAX|0)) abortStackOverflow(size|0);\n' if (settings['ASSERTIONS'] or settings['STACK_OVERFLOW_CHECK'] >= 2) else '') + '''
  return ret|0;
}
function stackSave() {
  return STACKTOP|0;
}
function stackRestore(top) {
  top = top|0;
  STACKTOP = top;
}
function establishStackSpace(stackBase, stackMax) {
  stackBase = stackBase|0;
  stackMax = stackMax|0;
  STACKTOP = stackBase;
  STACK_MAX = stackMax;
}
''' + ('''
function setAsync() {
  ___async = 1;
}''' if need_asyncify else '') + ('''
function emterpret(pc) { // this will be replaced when the emterpreter code is generated; adding it here allows validation until then
  pc = pc | 0;
  assert(0);
}
''' if settings['EMTERPRETIFY'] else '') + ('''
function setAsyncState(x) {
  x = x | 0;
  asyncState = x;
}
function emtStackSave() {
  return EMTSTACKTOP|0;
}
function emtStackRestore(x) {
  x = x | 0;
  EMTSTACKTOP = x;
}
''' if settings['EMTERPRETIFY_ASYNC'] else '') + '''
function setThrew(threw, value) {
  threw = threw|0;
  value = value|0;
  if ((__THREW__|0) == 0) {
    __THREW__ = threw;
    threwValue = value;
  }
}
'''] + ['' if not settings['SAFE_HEAP'] else '''
function setDynamicTop(value) {
  value = value | 0;
  HEAP32[DYNAMICTOP_PTR>>2] = value;
}
'''] + ['' if not asm_safe_heap else '''
function SAFE_HEAP_STORE(dest, value, bytes) {
  dest = dest | 0;
  value = value | 0;
  bytes = bytes | 0;
  if ((dest|0) <= 0) segfault();
  if (((dest + bytes)|0) > (HEAP32[DYNAMICTOP_PTR>>2]|0)) segfault();
  if ((bytes|0) == 4) {
    if ((dest&3)) alignfault();
    HEAP32[dest>>2] = value;
  } else if ((bytes|0) == 1) {
    HEAP8[dest>>0] = value;
  } else {
    if ((dest&1)) alignfault();
    HEAP16[dest>>1] = value;
  }
}
function SAFE_HEAP_STORE_D(dest, value, bytes) {
  dest = dest | 0;
  value = +value;
  bytes = bytes | 0;
  if ((dest|0) <= 0) segfault();
  if (((dest + bytes)|0) > (HEAP32[DYNAMICTOP_PTR>>2]|0)) segfault();
  if ((bytes|0) == 8) {
    if ((dest&7)) alignfault();
    HEAPF64[dest>>3] = value;
  } else {
    if ((dest&3)) alignfault();
    HEAPF32[dest>>2] = value;
  }
}
function SAFE_HEAP_LOAD(dest, bytes, unsigned) {
  dest = dest | 0;
  bytes = bytes | 0;
  unsigned = unsigned | 0;
  if ((dest|0) <= 0) segfault();
  if ((dest + bytes|0) > (HEAP32[DYNAMICTOP_PTR>>2]|0)) segfault();
  if ((bytes|0) == 4) {
    if ((dest&3)) alignfault();
    return HEAP32[dest>>2] | 0;
  } else if ((bytes|0) == 1) {
    if (unsigned) {
      return HEAPU8[dest>>0] | 0;
    } else {
      return HEAP8[dest>>0] | 0;
    }
  }
  if ((dest&1)) alignfault();
  if (unsigned) return HEAPU16[dest>>1] | 0;
  return HEAP16[dest>>1] | 0;
}
function SAFE_HEAP_LOAD_D(dest, bytes) {
  dest = dest | 0;
  bytes = bytes | 0;
  if ((dest|0) <= 0) segfault();
  if ((dest + bytes|0) > (HEAP32[DYNAMICTOP_PTR>>2]|0)) segfault();
  if ((bytes|0) == 8) {
    if ((dest&7)) alignfault();
    return +HEAPF64[dest>>3];
  }
  if ((dest&3)) alignfault();
  return +HEAPF32[dest>>2];
}
function SAFE_FT_MASK(value, mask) {
  value = value | 0;
  mask = mask | 0;
  var ret = 0;
  ret = value & mask;
  if ((ret|0) != (value|0)) ftfault();
  return ret | 0;
}
'''] + ['''
function setTempRet0(value) {
  value = value|0;
  tempRet0 = value;
}
function getTempRet0() {
  return tempRet0|0;
}
''' if not settings['RELOCATABLE'] else '']

    funcs_js = ['''
%s
Module%s = %s;
%s
Module%s = %s;
// EMSCRIPTEN_START_ASM
var asm = (function(global, env, buffer) {
  %s
  %s
  %s
''' % (asm_setup,
       access_quote('asmGlobalArg'), the_global,
       shared_array_buffer,
       access_quote('asmLibraryArg'), sending,
       "'use asm';" if not metadata.get('hasInlineJS') and settings['ASM_JS'] == 1 else "'almost asm';",
       first_in_asm,
       '''
  var HEAP8 = new global%s(buffer);
  var HEAP16 = new global%s(buffer);
  var HEAP32 = new global%s(buffer);
  var HEAPU8 = new global%s(buffer);
  var HEAPU16 = new global%s(buffer);
  var HEAPU32 = new global%s(buffer);
  var HEAPF32 = new global%s(buffer);
  var HEAPF64 = new global%s(buffer);
''' % (access_quote('Int8Array'),
     access_quote('Int16Array'),
     access_quote('Int32Array'),
     access_quote('Uint8Array'),
     access_quote('Uint16Array'),
     access_quote('Uint32Array'),
     access_quote('Float32Array'),
     access_quote('Float64Array'))
     if not settings['ALLOW_MEMORY_GROWTH'] else '''
  var Int8View = global%s;
  var Int16View = global%s;
  var Int32View = global%s;
  var Uint8View = global%s;
  var Uint16View = global%s;
  var Uint32View = global%s;
  var Float32View = global%s;
  var Float64View = global%s;
  var HEAP8 = new Int8View(buffer);
  var HEAP16 = new Int16View(buffer);
  var HEAP32 = new Int32View(buffer);
  var HEAPU8 = new Uint8View(buffer);
  var HEAPU16 = new Uint16View(buffer);
  var HEAPU32 = new Uint32View(buffer);
  var HEAPF32 = new Float32View(buffer);
  var HEAPF64 = new Float64View(buffer);
  var byteLength = global.byteLength;
''' % (access_quote('Int8Array'),
     access_quote('Int16Array'),
     access_quote('Int32Array'),
     access_quote('Uint8Array'),
     access_quote('Uint16Array'),
     access_quote('Uint32Array'),
     access_quote('Float32Array'),
     access_quote('Float64Array'))) + '\n' + asm_global_vars + ('''
  var __THREW__ = 0;
  var threwValue = 0;
  var setjmpId = 0;
  var undef = 0;
  var nan = global%s, inf = global%s;
  var tempInt = 0, tempBigInt = 0, tempBigIntP = 0, tempBigIntS = 0, tempBigIntR = 0.0, tempBigIntI = 0, tempBigIntD = 0, tempValue = 0, tempDouble = 0.0;
  var tempRet0 = 0;
''' % (access_quote('NaN'), access_quote('Infinity'))) + '\n' + asm_global_funcs] + \
  ['  var tempFloat = %s;\n' % ('Math_fround(0)' if provide_fround else '0.0')] + \
  ['  var asyncState = 0;\n' if settings.get('EMTERPRETIFY_ASYNC') else ''] + \
  (['  const f0 = Math_fround(0);\n'] if provide_fround else []) + \
  ['' if not settings['ALLOW_MEMORY_GROWTH'] else '''
function _emscripten_replace_memory(newBuffer) {
  if ((byteLength(newBuffer) & 0xffffff || byteLength(newBuffer) <= 0xffffff) || byteLength(newBuffer) > 0x80000000) return false;
  HEAP8 = new Int8View(newBuffer);
  HEAP16 = new Int16View(newBuffer);
  HEAP32 = new Int32View(newBuffer);
  HEAPU8 = new Uint8View(newBuffer);
  HEAPU16 = new Uint16View(newBuffer);
  HEAPU32 = new Uint32View(newBuffer);
  HEAPF32 = new Float32View(newBuffer);
  HEAPF64 = new Float64View(newBuffer);
  buffer = newBuffer;
  return true;
}
'''] + ['''
// EMSCRIPTEN_START_FUNCS
'''] + runtime_funcs + funcs_js + ['''
  ''', pre_tables, final_function_tables, '''

  return %s;
})
// EMSCRIPTEN_END_ASM
(%s, %s, buffer);
''' % (exports,
       'Module' + access_quote('asmGlobalArg'),
       'Module' + access_quote('asmLibraryArg')), '''
''', receiving, ''';
''']

    if not settings.get('SIDE_MODULE'):
      funcs_js.append('''
Runtime.stackAlloc = asm['stackAlloc'];
Runtime.stackSave = asm['stackSave'];
Runtime.stackRestore = asm['stackRestore'];
Runtime.establishStackSpace = asm['establishStackSpace'];
''')
      if settings['SAFE_HEAP']:
        funcs_js.append('''
Runtime.setDynamicTop = asm['setDynamicTop'];
''')

    if not settings['RELOCATABLE']:
      funcs_js.append('''
Runtime.setTempRet0 = asm['setTempRet0'];
Runtime.getTempRet0 = asm['getTempRet0'];
''')

    # Set function table masks
    masks = {}
    max_mask = 0
    for sig, table in last_forwarded_json['Functions']['tables'].iteritems():
      mask = table.count(',')
      masks[sig] = str(mask)
      max_mask = max(mask, max_mask)
    def function_table_maskize(js, masks):
      def fix(m):
        sig = m.groups(0)[0]
        return masks[sig]
      return re.sub(r'{{{ FTM_([\w\d_$]+) }}}', fix, js) # masks[m.groups(0)[0]]
    for i in range(len(funcs_js)): # in-place as this can be large
      funcs_js[i] = function_table_maskize(funcs_js[i], masks)

    if settings['SIDE_MODULE']:
      funcs_js.append('''
Runtime.registerFunctions(%(sigs)s, Module);
''' % { 'sigs': str(map(str, last_forwarded_json['Functions']['tables'].keys())) })

    for i in range(len(funcs_js)): # do this loop carefully to save memory
      if WINDOWS: funcs_js[i] = funcs_js[i].replace('\r\n', '\n') # Normalize to UNIX line endings, otherwise writing to text file will duplicate \r\n to \r\r\n!
      outfile.write(funcs_js[i])
    funcs_js = None

    if WINDOWS: post = post.replace('\r\n', '\n') # Normalize to UNIX line endings, otherwise writing to text file will duplicate \r\n to \r\r\n!
    outfile.write(post)

    if DEBUG:
      logging.debug('  emscript: python processing: finalize took %s seconds' % (time.time() - t))

    if settings['CYBERDWARF']:
      assert('cyberdwarf_data' in metadata)
      cd_file_name = outfile.name + ".cd"
      with open(cd_file_name, "w") as cd_file:
        json.dump({ 'cyberdwarf': metadata['cyberdwarf_data'] }, cd_file)

def emscript_wasm_backend(infile, settings, outfile, libraries=None, compiler_engine=None,
                          temp_files=None, DEBUG=None):
  # Overview:
  #   * Run LLVM backend to emit .s
  #   * Run Binaryen's s2wasm to generate WebAssembly.
  #   * We may also run some Binaryen passes here.

  if libraries is None: libraries = []

  with temp_files.get_file('.wb.s') as temp_s:
    backend_compiler = os.path.join(shared.LLVM_ROOT, 'llc')
    backend_args = [backend_compiler, infile, '-march=wasm32', '-filetype=asm',
                    '-asm-verbose=false',
                    '-o', temp_s]
    backend_args += ['-thread-model=single'] # no threads support in backend, tell llc to not emit atomics
    # disable slow and relatively unimportant optimization passes
    backend_args += ['-combiner-global-alias-analysis=false']

    # asm.js-style exception handling
    if settings['DISABLE_EXCEPTION_CATCHING'] != 1:
      backend_args += ['-enable-emscripten-cxx-exceptions']
    if settings['DISABLE_EXCEPTION_CATCHING'] == 2:
      whitelist = ','.join(settings['EXCEPTION_CATCHING_WHITELIST'] or ['__fake'])
      backend_args += ['-emscripten-cxx-exceptions-whitelist=' + whitelist]

    # asm.js-style setjmp/longjmp handling
    backend_args += ['-enable-emscripten-sjlj']

    if DEBUG:
      logging.debug('emscript: llvm wasm backend: ' + ' '.join(backend_args))
      t = time.time()
    shared.check_call(backend_args)
    if DEBUG:
      logging.debug('  emscript: llvm wasm backend took %s seconds' % (time.time() - t))
      t = time.time()
      import shutil
      shutil.copyfile(temp_s, os.path.join(shared.CANONICAL_TEMP_DIR, 'emcc-llvm-backend-output.s'))

    assert shared.Settings.BINARYEN_ROOT, 'need BINARYEN_ROOT config set so we can use Binaryen s2wasm on the backend output'
    wasm = outfile.name[:-3] + '.wast'
    s2wasm_args = [os.path.join(shared.Settings.BINARYEN_ROOT, 'bin', 's2wasm'), temp_s]
    s2wasm_args += ['--emscripten-glue']
    s2wasm_args += ['--global-base=%d' % shared.Settings.GLOBAL_BASE]
    s2wasm_args += ['--initial-memory=%d' % shared.Settings.TOTAL_MEMORY]
    s2wasm_args += ['--allow-memory-growth'] if shared.Settings.ALLOW_MEMORY_GROWTH else []
    def compiler_rt_fail(): raise Exception('Expected wasm_compiler_rt.a to already be built')
    compiler_rt_lib = shared.Cache.get('wasm_compiler_rt.a', lambda: compiler_rt_fail(), 'a')
    s2wasm_args += ['-l', compiler_rt_lib]
    if DEBUG:
      logging.debug('emscript: binaryen s2wasm: ' + ' '.join(s2wasm_args))
      t = time.time()
      #s2wasm_args += ['--debug']
    shared.check_call(s2wasm_args, stdout=open(wasm, 'w'))

  if DEBUG:
    logging.debug('  emscript: binaryen s2wasm took %s seconds' % (time.time() - t))
    t = time.time()
    import shutil
    shutil.copyfile(wasm, os.path.join(shared.CANONICAL_TEMP_DIR, 'emcc-s2wasm-output.wast'))

  # js compiler

  if DEBUG: logging.debug('emscript: js compiler glue')

  # Integrate info from backend

  output = open(wasm).read()
  parts = output.split('\n;; METADATA:')
  assert len(parts) == 2
  metadata_raw = parts[1]
  parts = output = None

  if DEBUG: logging.debug("METAraw %s", metadata_raw)
  try:
    metadata_json = json.loads(metadata_raw)
  except Exception, e:
    logging.error('emscript: failure to parse metadata output from s2wasm. raw output is: \n' + metadata_raw)
    raise e

  metadata = {
    'declares': [],
    'implementedFunctions': [],
    'externs': [],
    'simd': False,
    'maxGlobalAlign': 0,
    'initializers': [],
    'exports': [],
  }

  for k, v in metadata_json.iteritems():
    metadata[k] = v

  def asmjs_mangle(name):
    # Mangle a name the way asm.js/JSBackend globals are mangled (i.e. prepend
    # '_' and replace non-alphanumerics with '_')
    if name.startswith('dynCall_'): return name
    return '_' + ''.join(['_' if not c.isalnum() else c for c in name])

  # Initializers call the global var version of the export, so they get the mangled name.
  metadata['initializers'] = [asmjs_mangle(i) for i in metadata['initializers']]

  # TODO: emit it from s2wasm; for now, we parse it right here
  for line in open(wasm).readlines():
    if line.startswith('  (import '):
      parts = line.split()
      # Don't include Invoke wrapper names (for asm.js-style exception handling)
      # in metadata[declares], the invoke wrappers will be generated in
      # this script later.
      import_type = parts[3][1:]
      import_name = parts[2][1:-1]
      if import_type == 'memory':
        continue
      elif import_type == 'func':
        if not import_name.startswith('invoke_'):
          metadata['declares'].append(import_name)
      elif import_type == 'global':
        metadata['externs'].append('_' + import_name)
      else:
        assert False, 'Unhandled import type "%s"' % import_type
    elif line.startswith('  (func '):
      parts = line.split()
      func_name = parts[1][1:]
      metadata['implementedFunctions'].append(func_name)
    elif line.startswith('  (export '):
      parts = line.split()
      export_name = parts[1][1:-1]
      export_type = parts[2][1:]
      if export_type == 'func':
        assert asmjs_mangle(export_name) not in metadata['exports']
        metadata['exports'].append(export_name)
      else:
        assert False, 'Unhandled export type "%s"' % export_type

  metadata['declares'] = filter(lambda x: not x.startswith('emscripten_asm_const'), metadata['declares']) # we emit those ourselves

  if DEBUG: logging.debug(repr(metadata))

  settings['DEFAULT_LIBRARY_FUNCS_TO_INCLUDE'] = list(
    set(settings['DEFAULT_LIBRARY_FUNCS_TO_INCLUDE'] + map(shared.JS.to_nice_ident, metadata['declares'])).difference(
      map(lambda x: x[1:], metadata['implementedFunctions'])
    )
  ) + map(lambda x: x[1:], metadata['externs'])
  if metadata['simd']:
    settings['SIMD'] = 1

  settings['MAX_GLOBAL_ALIGN'] = metadata['maxGlobalAlign']

  settings['IMPLEMENTED_FUNCTIONS'] = metadata['implementedFunctions']

  # Save settings to a file to work around v8 issue 1579
  with temp_files.get_file('.txt') as settings_file:
    def save_settings():
      global settings_text
      settings_text = json.dumps(settings, sort_keys=True)
      s = open(settings_file, 'w')
      s.write(settings_text)
      s.close()
    save_settings()

    # Call js compiler
    if DEBUG: t = time.time()
    out = jsrun.run_js(path_from_root('src', 'compiler.js'), compiler_engine,
                       [settings_file] + libraries, stdout=subprocess.PIPE, stderr=STDERR_FILE,
                       cwd=path_from_root('src'), error_limit=300)
  assert '//FORWARDED_DATA:' in out, 'Did not receive forwarded data in pre output - process failed?'
  glue, forwarded_data = out.split('//FORWARDED_DATA:')

  if DEBUG:
    logging.debug('  emscript: glue took %s seconds' % (time.time() - t))
    t = time.time()

  forwarded_json = json.loads(forwarded_data)

  pre, post = glue.split('// EMSCRIPTEN_END_FUNCS')

  # memory and global initializers

  global_initializers = str(', '.join(map(lambda i: '{ func: function() { %s() } }' % i, metadata['initializers'])))

  staticbump = metadata['staticBump']
  while staticbump % 16 != 0: staticbump += 1
  pre = pre.replace('STATICTOP = STATIC_BASE + 0;', '''STATICTOP = STATIC_BASE + %d;%s
/* global initializers */ %s __ATINIT__.push(%s);
''' % (staticbump,
         'assert(STATICTOP < SPLIT_MEMORY, "SPLIT_MEMORY size must be big enough so the entire static memory, need " + STATICTOP);' if settings['SPLIT_MEMORY'] else '',
         'if (!ENVIRONMENT_IS_PTHREAD)' if settings['USE_PTHREADS'] else '',
         global_initializers))

  pre = pre.replace('{{{ STATIC_BUMP }}}', str(staticbump))

  # merge forwarded data
  settings['EXPORTED_FUNCTIONS'] = forwarded_json['EXPORTED_FUNCTIONS']
  all_exported_functions = set(shared.expand_response(settings['EXPORTED_FUNCTIONS'])) # both asm.js and otherwise

  for additional_export in settings['DEFAULT_LIBRARY_FUNCS_TO_INCLUDE']: # additional functions to export from asm, if they are implemented
    all_exported_functions.add('_' + additional_export)
  exported_implemented_functions = set(metadata['exports'])
  export_bindings = settings['EXPORT_BINDINGS']
  export_all = settings['EXPORT_ALL']
  all_implemented = metadata['implementedFunctions'] + forwarded_json['Functions']['implementedFunctions'].keys() # XXX perf?
  for key in all_implemented:
    if key in all_exported_functions or export_all or (export_bindings and key.startswith('_emscripten_bind')):
      exported_implemented_functions.add(key)
  implemented_functions = set(metadata['implementedFunctions'])
  if settings['ASSERTIONS'] and settings.get('ORIGINAL_EXPORTED_FUNCTIONS'):
    original_exports = settings['ORIGINAL_EXPORTED_FUNCTIONS']
    if original_exports[0] == '@': original_exports = json.loads(open(original_exports[1:]).read())
    for requested in original_exports:
      # check if already implemented
      # special-case malloc, EXPORTED by default for internal use, but we bake in a trivial allocator and warn at runtime if used in ASSERTIONS \
      if requested not in all_implemented and \
         requested != '_malloc' and \
         (('function ' + requested.encode('utf-8')) not in pre): # could be a js library func
        logging.warning('function requested to be exported, but not implemented: "%s"', requested)

  asm_consts = [0]*len(metadata['asmConsts'])
  all_sigs = []
  for k, v in metadata['asmConsts'].iteritems():
    const = v[0].encode('utf-8')
    sigs = v[1]
    if len(const) > 1 and const[0] == '"' and const[-1] == '"':
      const = const[1:-1]
    const = '{ ' + const + ' }'
    args = []
    arity = max(map(len, sigs)) - 1
    for i in range(arity):
      args.append('$' + str(i))
    const = 'function(' + ', '.join(args) + ') ' + const
    asm_consts[int(k)] = const
    all_sigs += sigs

  asm_const_funcs = []
  for sig in set(all_sigs):
    forwarded_json['Functions']['libraryFunctions']['_emscripten_asm_const_' + sig] = 1
    args = ['a%d' % i for i in range(len(sig)-1)]
    all_args = ['code'] + args
    asm_const_funcs.append(r'''
function _emscripten_asm_const_%s(%s) {
return ASM_CONSTS[code](%s);
}''' % (sig.encode('utf-8'), ', '.join(all_args), ', '.join(args)))

  pre = pre.replace('// === Body ===', '// === Body ===\n' + '\nvar ASM_CONSTS = [' + ',\n '.join(asm_consts) + '];\n' + '\n'.join(asm_const_funcs) + '\n')

  outfile.write(pre)
  pre = None

  basic_funcs = ['abort', 'assert', 'enlargeMemory', 'getTotalMemory']
  if settings['ABORTING_MALLOC']: basic_funcs += ['abortOnCannotGrowMemory']

  access_quote = access_quoter(settings)

  # calculate globals
  try:
    del forwarded_json['Variables']['globals']['_llvm_global_ctors'] # not a true variable
  except:
    pass
  if not settings['RELOCATABLE']:
    global_vars = metadata['externs']
  else:
    global_vars = [] # linkable code accesses globals through function calls
  global_funcs = list(set([key for key, value in forwarded_json['Functions']['libraryFunctions'].iteritems() if value != 2]).difference(set(global_vars)).difference(implemented_functions))
  def math_fix(g):
    return g if not g.startswith('Math_') else g.split('_')[1]

  basic_vars = ['STACKTOP', 'STACK_MAX', 'DYNAMICTOP_PTR', 'ABORT']
  basic_float_vars = []

  # Asm.js-style exception handling: invoke wrapper generation
  invoke_wrappers = ''
  with open(wasm) as f:
    for line in f:
      if line.startswith('  (import '):
        parts = line.split()
        func_name = parts[2][1:-1]
        if func_name.startswith('invoke_'):
          sig = func_name[len('invoke_'):]
          invoke_wrappers += '\n' + shared.JS.make_invoke(sig) + '\n'
          basic_funcs.append(func_name)

  # sent data
  the_global = '{}'
  sending = '{ ' + ', '.join(['"' + math_fix(s) + '": ' + s for s in basic_funcs + global_funcs + basic_vars + basic_float_vars + global_vars]) + ' }'
  # received
  receiving = ''
  if settings['ASSERTIONS']:
    # assert on the runtime being in a valid state when calling into compiled code. The only exceptions are
    # some support code
    receiving = '\n'.join(['var real_' + asmjs_mangle(s) + ' = asm["' + s + '"]; asm["' + s + '''"] = function() {
assert(runtimeInitialized, 'you need to wait for the runtime to be ready (e.g. wait for main() to be called)');
assert(!runtimeExited, 'the runtime was exited (use NO_EXIT_RUNTIME to keep it alive after main() exits)');
return real_''' + asmjs_mangle(s) + '''.apply(null, arguments);
};
''' for s in exported_implemented_functions if s not in ['_memcpy', '_memset', 'runPostSets', '_emscripten_replace_memory']])

  if not settings['SWAPPABLE_ASM_MODULE']:
    receiving += ';\n'.join(['var ' + asmjs_mangle(s) + ' = Module["' + asmjs_mangle(s) + '"] = asm["' + s + '"]' for s in exported_implemented_functions])
  else:
    receiving += 'Module["asm"] = asm;\n' + ';\n'.join(['var ' + asmjs_mangle(s) + ' = Module["' + asmjs_mangle(s) + '"] = function() { return Module["asm"]["' + s + '"].apply(null, arguments) }' for s in exported_implemented_functions])
  receiving += ';\n'

  # finalize

  if settings['USE_PTHREADS']:
    shared_array_buffer = "if (typeof SharedArrayBuffer !== 'undefined') Module.asmGlobalArg['Atomics'] = Atomics;"
  else:
    shared_array_buffer = ''

  funcs_js = ['''
Module%s = %s;
%s
Module%s = %s;
''' % (access_quote('asmGlobalArg'), the_global,
     shared_array_buffer,
     access_quote('asmLibraryArg'), sending) + '''
var asm = Module['asm'](%s, %s, buffer);
%s;
''' % ('Module' + access_quote('asmGlobalArg'),
     'Module' + access_quote('asmLibraryArg'),
     receiving)]

  # wasm backend stack goes down, and is stored in the first global var location
  funcs_js.append('''
STACKTOP = STACK_BASE + TOTAL_STACK;
STACK_MAX = STACK_BASE;
HEAP32[%d >> 2] = STACKTOP;
Runtime.stackAlloc = asm['stackAlloc'];
Runtime.stackSave = asm['stackSave'];
Runtime.stackRestore = asm['stackRestore'];
Runtime.establishStackSpace = asm['establishStackSpace'];
''' % shared.Settings.GLOBAL_BASE)

  funcs_js.append('''
Runtime.setTempRet0 = asm['setTempRet0'];
Runtime.getTempRet0 = asm['getTempRet0'];
''')

  funcs_js.append(invoke_wrappers)

  for i in range(len(funcs_js)): # do this loop carefully to save memory
    if WINDOWS: funcs_js[i] = funcs_js[i].replace('\r\n', '\n') # Normalize to UNIX line endings, otherwise writing to text file will duplicate \r\n to \r\r\n!
    outfile.write(funcs_js[i])
  funcs_js = None

  if WINDOWS: post = post.replace('\r\n', '\n') # Normalize to UNIX line endings, otherwise writing to text file will duplicate \r\n to \r\r\n!
  outfile.write(post)

  outfile.close()

if os.environ.get('EMCC_FAST_COMPILER') == '0':
  logging.critical('Non-fastcomp compiler is no longer available, please use fastcomp or an older version of emscripten')
  sys.exit(1)

def main(args, compiler_engine, cache, temp_files, DEBUG):
  # Prepare settings for serialization to JSON.
  settings = {}
  for setting in args.settings:
    name, value = setting.strip().split('=', 1)
    settings[name] = json.loads(value)

  # libraries
  libraries = args.libraries[0].split(',') if len(args.libraries) > 0 else []

  settings.setdefault('STRUCT_INFO', shared.path_from_root('src', 'struct_info.compiled.json'))
  struct_info = settings.get('STRUCT_INFO')

  if not os.path.exists(struct_info) and not settings.get('BOOTSTRAPPING_STRUCT_INFO') and not settings.get('ONLY_MY_CODE'):
    if DEBUG: logging.debug('  emscript: bootstrapping struct info...')
    shared.Building.ensure_struct_info(struct_info)
    if DEBUG: logging.debug('  emscript: bootstrapping struct info complete')

  emscripter = emscript_wasm_backend if settings['WASM_BACKEND'] else emscript

  emscripter(args.infile, settings, args.outfile, libraries, compiler_engine=compiler_engine,
             temp_files=temp_files, DEBUG=DEBUG)

def _main(args=None):
  if args is None:
    args = sys.argv[1:]

  response_file = True
  while response_file:
    response_file = None
    for index in range(len(args)):
      if args[index][0] == '@':
        # found one, loop again next time
        response_file = True
        response_file_args = read_response_file(args[index])
        # slice in extra_args in place of the response file arg
        args[index:index+1] = response_file_args
        break

  parser = optparse.OptionParser(
    usage='usage: %prog [-h] [-H HEADERS] [-o OUTFILE] [-c COMPILER_ENGINE] [-s FOO=BAR]* infile',
    description=('You should normally never use this! Use emcc instead. '
                 'This is a wrapper around the JS compiler, converting .ll to .js.'),
    epilog='')
  parser.add_option('-H', '--headers',
                    default=[],
                    action='append',
                    help='System headers (comma separated) whose #defines should be exposed to the compiled code.')
  parser.add_option('-L', '--libraries',
                    default=[],
                    action='append',
                    help='Library files (comma separated) to use in addition to those in emscripten src/library_*.')
  parser.add_option('-o', '--outfile',
                    default=sys.stdout,
                    help='Where to write the output; defaults to stdout.')
  parser.add_option('-c', '--compiler',
                    default=None,
                    help='Which JS engine to use to run the compiler; defaults to the one in ~/.emscripten.')
  parser.add_option('-s', '--setting',
                    dest='settings',
                    default=[],
                    action='append',
                    metavar='FOO=BAR',
                    help=('Overrides for settings defined in settings.js. '
                          'May occur multiple times.'))
  parser.add_option('-T', '--temp-dir',
                    default=None,
                    help=('Where to create temporary files.'))
  parser.add_option('-v', '--verbose',
                    action='store_true',
                    dest='verbose',
                    help='Displays debug output')
  parser.add_option('-q', '--quiet',
                    action='store_false',
                    dest='verbose',
                    help='Hides debug output')
  parser.add_option('--suppressUsageWarning',
                    action='store_true',
                    default=os.environ.get('EMSCRIPTEN_SUPPRESS_USAGE_WARNING'),
                    help=('Suppress usage warning'))

  # Convert to the same format that argparse would have produced.
  keywords, positional = parser.parse_args(args)

  if not keywords.suppressUsageWarning:
    logging.warning('''
==============================================================
WARNING: You should normally never use this! Use emcc instead.
==============================================================
  ''')

  if len(positional) != 1:
    raise RuntimeError('Must provide exactly one positional argument. Got ' + str(len(positional)) + ': "' + '", "'.join(positional) + '"')
  keywords.infile = os.path.abspath(positional[0])
  if isinstance(keywords.outfile, basestring):
    keywords.outfile = open(keywords.outfile, 'w')

  if keywords.temp_dir is None:
    temp_files = get_configuration().get_temp_files()
    temp_dir = get_configuration().TEMP_DIR
  else:
    temp_dir = os.path.abspath(keywords.temp_dir)
    if not os.path.exists(temp_dir):
      os.makedirs(temp_dir)
    temp_files = tempfiles.TempFiles(temp_dir)

  if keywords.compiler is None:
    keywords.compiler = shared.COMPILER_ENGINE

  if keywords.verbose is None:
    DEBUG = get_configuration().DEBUG
  else:
    DEBUG = keywords.verbose

  cache = cache_module.Cache()
  temp_files.run_and_clean(lambda: main(
    keywords,
    compiler_engine=keywords.compiler,
    cache=cache,
    temp_files=temp_files,
    DEBUG=DEBUG,
  ))

if __name__ == '__main__':
  _main()
  sys.exit(0)
