Fix ghc rpath issue when dynamically linking

fix_rpath.py

#!/usr/bin/env python

'''
Fix the rpath issue when cabal (ghc) links dynamically on Linux and OS X.
Put this script in your .cabal/bin for execution.
'''

import os
import re
import sys
import platform
from subprocess import Popen, PIPE

def is_linux():
    return platform.system() == 'Linux'

def replace_path(orig_path, libname, fpath, libpath):
    found = False
    for root, directories, files in os.walk(libpath):
        for d in directories:
            if d.find(libname) != -1:
                new_path = os.path.join(root, d)
                if is_linux():
                    return new_path
                try:
                    process = Popen(['install_name_tool', '-rpath', orig_path, new_path, fpath], stdout=PIPE, stderr=PIPE)
                    result = process.communicate()[0]
                    if process.returncode != 0:
                        print "failed to fix @rpath for %s (%s): %s" % (fpath, libname, result)
                    else:
                        print "fix @rpath for %s (%s)" % (fpath, libname)
                except Exception, e:
                    print "Warning: run install_name_tool failed: %s" % str(e)
                found = True
                break
        if found:
            break

def check_link_elf(fpath, libpath):
    try:
        process = Popen(['readelf', '-d', fpath], stdout=PIPE, stderr=PIPE)
        lpaths = process.communicate()[0]
    except Exception, e:
        print "Warning: run readelf failed: %s" % str(e)
        return
    matches = re.search(r'Library rpath: \[(.+)\]', lpaths)
    if matches:
        orig_paths = matches.group(1).split(':')
        libnames = []
        for idx, orig_path in enumerate(orig_paths):
            if orig_path.startswith('/tmp'):
                lib_match = re.search(r'/tmp/.*/([^/]+)/dist/build', lpaths)
                if not lib_match:
                    continue
                libname = lib_match.group(1)
                new_path = replace_path(orig_path, libname, fpath, libpath)
                orig_paths[idx] = new_path
                libnames.append(libname)
        if libnames:
            try:
                process = Popen(['patchelf', '--set-rpath', ':'.join(orig_paths), fpath], stdout=PIPE, stderr=PIPE)
                result = process.communicate()[0]
                libnames_str = ', '.join(libnames)
                if process.returncode != 0:
                    print "failed to fix rpath for %s (%s): %s" % (fpath, libnames_str, result)
                else:
                    print "fix rpath for %s (%s)" % (fpath, libnames_str)
            except Exception, e:
                print "Warning: run patchelf failed: %s" % str(e)

def check_link(fpath, libpath):
    if is_linux():
        check_link_elf(fpath, libpath)
        return
    lpaths = None
    try:
        process = Popen(['otool', '-l', fpath], stdout=PIPE, stderr=PIPE)
        lpaths = process.communicate()[0]
    except Exception, e:
        print "Warning: run otool failed: %s" % str(e)
        return
    matches = re.search(r'/private/var/folders/.*/([^/]+)/dist/build', lpaths)
    if matches:
        orig_path = matches.group(0)
        libname = matches.group(1)
        replace_path(orig_path, libname, fpath, libpath)

def fix_library(fpath, libpath, libshort):
    if is_linux():
        return
    lpaths = None
    try:
        process = Popen(['otool', '-l', fpath], stdout=PIPE, stderr=PIPE)
        lpaths = process.communicate()[0]
    except Exception, e:
        print "Warning: run otool failed: %s" % str(e)
        return
    matches = re.search('path (/.*/(%s-?[0-9\\.]*)) ' % libshort, lpaths)
    if matches:
        orig_path = matches.group(1)
        libname = matches.group(2)
        replace_path(orig_path, libname, fpath, libpath)

def main():
    current_dir = os.path.dirname(os.path.realpath(__file__))
    script_name = os.path.basename(os.path.realpath(__file__))
    libpath = os.path.realpath(os.path.join(current_dir, '../lib'))
    for name in os.listdir(current_dir):
        fpath = os.path.join(current_dir, name)
        if fpath != script_name and os.path.isfile(fpath) and os.access(fpath, os.X_OK):
            if len(sys.argv) > 1:
                libs = sys.argv[1:]
                for lib in libs:
                    fix_library(fpath, libpath, lib)
            else:
                check_link(fpath, libpath)

if __name__ == '__main__':
    main()