emscripten/tools/nativize_llvm.py

#!/usr/bin/env python2

'''
Small utility to build some llvm bitcode into native code. Useful when lli (called
from exec_llvm) fails for some reason.

 * Use llc to generate x86 asm
 * Use as to generate an object file
 * Use g++ to link it to an executable
'''

import os, sys
from subprocess import Popen, PIPE, STDOUT

__rootpath__ = os.path.abspath(os.path.dirname(os.path.dirname(__file__)))
def path_from_root(*pathelems):
  return os.path.join(__rootpath__, *pathelems)
exec(open(path_from_root('tools', 'shared.py'), 'r').read())

filename = sys.argv[1]
libs = sys.argv[2:] # e.g.: dl for dlopen/dlclose, util for openpty/forkpty

print 'bc => clean bc'
Popen([LLVM_OPT, filename, '-strip-debug', '-o', filename + '.clean.bc']).communicate()[0]
print 'bc => s'
for params in [['-march=x86'], ['-march=x86-64']]: # try x86, then x86-64 FIXME
  print 'params', params
  for triple in [['-mtriple=i386-pc-linux-gnu'], []]:
    Popen([LLVM_COMPILER] + params + triple + [filename + '.clean.bc', '-o', filename + '.s']).communicate()[0]
    print 's => o'
    Popen(['as', filename + '.s', '-o', filename + '.o']).communicate()[0]
    if os.path.exists(filename + '.o'): break
  if os.path.exists(filename + '.o'): break
print 'o => runnable'
Popen(['g++', path_from_root('system', 'lib', 'debugging.cpp'), filename + '.o', '-o', filename + '.run'] + ['-l' + lib for lib in libs]).communicate()[0]