michael@0: # This Source Code Form is subject to the terms of the Mozilla Public
michael@0: # License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0: # file, You can obtain one at http://mozilla.org/MPL/2.0/.
michael@0: 
michael@0: import os
michael@0: import struct
michael@0: import subprocess
michael@0: from mozpack.errors import errors
michael@0: 
michael@0: MACHO_SIGNATURES = [
michael@0:     0xfeedface,  # mach-o 32-bits big endian
michael@0:     0xcefaedfe,  # mach-o 32-bits little endian
michael@0:     0xfeedfacf,  # mach-o 64-bits big endian
michael@0:     0xcffaedfe,  # mach-o 64-bits little endian
michael@0: ]
michael@0: 
michael@0: FAT_SIGNATURE = 0xcafebabe  # mach-o FAT binary
michael@0: 
michael@0: ELF_SIGNATURE = 0x7f454c46  # Elf binary
michael@0: 
michael@0: UNKNOWN = 0
michael@0: MACHO = 1
michael@0: ELF = 2
michael@0: 
michael@0: def get_type(path):
michael@0:     '''
michael@0:     Check the signature of the give file and returns what kind of executable
michael@0:     matches.
michael@0:     '''
michael@0:     with open(path, 'rb') as f:
michael@0:         signature = f.read(4)
michael@0:         if len(signature) < 4:
michael@0:             return UNKNOWN
michael@0:         signature = struct.unpack('>L', signature)[0]
michael@0:         if signature == ELF_SIGNATURE:
michael@0:             return ELF
michael@0:         if signature in MACHO_SIGNATURES:
michael@0:             return MACHO
michael@0:         if signature != FAT_SIGNATURE:
michael@0:             return UNKNOWN
michael@0:         # We have to sanity check the second four bytes, because Java class
michael@0:         # files use the same magic number as Mach-O fat binaries.
michael@0:         # This logic is adapted from file(1), which says that Mach-O uses
michael@0:         # these bytes to count the number of architectures within, while
michael@0:         # Java uses it for a version number. Conveniently, there are only
michael@0:         # 18 labelled Mach-O architectures, and Java's first released
michael@0:         # class format used the version 43.0.
michael@0:         num = f.read(4)
michael@0:         if len(num) < 4:
michael@0:             return UNKNOWN
michael@0:         num = struct.unpack('>L', num)[0]
michael@0:         if num < 20:
michael@0:             return MACHO
michael@0:         return UNKNOWN
michael@0: 
michael@0: 
michael@0: def is_executable(path):
michael@0:     '''
michael@0:     Return whether a given file path points to an executable or a library,
michael@0:     where an executable or library is identified by:
michael@0:         - the file extension on OS/2 and WINNT
michael@0:         - the file signature on OS/X and ELF systems (GNU/Linux, Android, BSD,
michael@0:           Solaris)
michael@0: 
michael@0:     As this function is intended for use to choose between the ExecutableFile
michael@0:     and File classes in FileFinder, and choosing ExecutableFile only matters
michael@0:     on OS/2, OS/X, ELF and WINNT (in GCC build) systems, we don't bother
michael@0:     detecting other kind of executables.
michael@0:     '''
michael@0:     from buildconfig import substs
michael@0:     if not os.path.exists(path):
michael@0:         return False
michael@0: 
michael@0:     if substs['OS_ARCH'] == 'WINNT':
michael@0:         return path.lower().endswith((substs['DLL_SUFFIX'],
michael@0:                                       substs['BIN_SUFFIX']))
michael@0: 
michael@0:     return get_type(path) != UNKNOWN
michael@0: 
michael@0: 
michael@0: def may_strip(path):
michael@0:     '''
michael@0:     Return whether strip() should be called
michael@0:     '''
michael@0:     from buildconfig import substs
michael@0:     return not substs['PKG_SKIP_STRIP']
michael@0: 
michael@0: 
michael@0: def strip(path):
michael@0:     '''
michael@0:     Execute the STRIP command with STRIP_FLAGS on the given path.
michael@0:     '''
michael@0:     from buildconfig import substs
michael@0:     strip = substs['STRIP']
michael@0:     flags = substs['STRIP_FLAGS'].split() if 'STRIP_FLAGS' in substs else []
michael@0:     cmd = [strip] + flags + [path]
michael@0:     if subprocess.call(cmd) != 0:
michael@0:         errors.fatal('Error executing ' + ' '.join(cmd))
michael@0: 
michael@0: 
michael@0: def may_elfhack(path):
michael@0:     '''
michael@0:     Return whether elfhack() should be called
michael@0:     '''
michael@0:     # elfhack only supports libraries. We should check the ELF header for
michael@0:     # the right flag, but checking the file extension works too.
michael@0:     from buildconfig import substs
michael@0:     return 'USE_ELF_HACK' in substs and substs['USE_ELF_HACK'] and \
michael@0:            path.endswith(substs['DLL_SUFFIX'])
michael@0: 
michael@0: 
michael@0: def elfhack(path):
michael@0:     '''
michael@0:     Execute the elfhack command on the given path.
michael@0:     '''
michael@0:     from buildconfig import topobjdir
michael@0:     cmd = [os.path.join(topobjdir, 'build/unix/elfhack/elfhack'), path]
michael@0:     if 'ELF_HACK_FLAGS' in os.environ:
michael@0:         cmd[1:0] = os.environ['ELF_HACK_FLAGS'].split()
michael@0:     if subprocess.call(cmd) != 0:
michael@0:         errors.fatal('Error executing ' + ' '.join(cmd))