Bug 780561 - Import new packager code. r=gps

python/mozbuild/mozpack/executables.py

@@ -0,0 +1,107 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import os
+import struct
+from buildconfig import (
+    substs,
+    topobjdir,
+)
+import subprocess
+from mozpack.errors import errors
+
+MACHO_SIGNATURES = [
+    0xfeedface,  # mach-o 32-bits big endian
+    0xcefaedfe,  # mach-o 32-bits little endian
+    0xfeedfacf,  # mach-o 64-bits big endian
+    0xcffaedfe,  # mach-o 64-bits little endian
+]
+
+FAT_SIGNATURE = 0xcafebabe  # mach-o FAT binary
+
+EXECUTABLE_SIGNATURES = [
+    0x7f454c46,  # Elf
+] + MACHO_SIGNATURES
+
+
+def is_executable(path):
+    '''
+    Return whether a given file path points to an executable or a library,
+    where an executable or library is identified by:
+        - the file extension on OS/2
+        - the file signature on OS/X and ELF systems (GNU/Linux, Android, BSD,
+          Solaris)
+
+    As this function is intended for use to choose between the ExecutableFile
+    and File classes in FileFinder, and choosing ExecutableFile only matters
+    on OS/2, OS/X and ELF systems, we don't bother detecting other kind of
+    executables.
+    '''
+    if not os.path.exists(path):
+        return False
+
+    if substs['OS_ARCH'] == 'OS2':
+        return path.lower().endswith((substs['DLL_SUFFIX'],
+                                      substs['BIN_SUFFIX']))
+
+    with open(path, 'rb') as f:
+        signature = f.read(4)
+        if len(signature) < 4:
+            return False
+        signature = struct.unpack('>L', signature)[0]
+        if signature in EXECUTABLE_SIGNATURES:
+            return True
+        if signature != FAT_SIGNATURE:
+            return False
+        # We have to sanity check the second four bytes, because Java class
+        # files use the same magic number as Mach-O fat binaries.
+        # This logic is adapted from file(1), which says that Mach-O uses
+        # these bytes to count the number of architectures within, while
+        # Java uses it for a version number. Conveniently, there are only
+        # 18 labelled Mach-O architectures, and Java's first released
+        # class format used the version 43.0.
+        num = f.read(4)
+        if len(num) < 4:
+            return False
+        num = struct.unpack('>L', num)[0]
+        return num < 20
+
+
+def may_strip(path):
+    '''
+    Return whether strip() should be called
+    '''
+    return not substs['PKG_SKIP_STRIP']
+
+
+def strip(path):
+    '''
+    Execute the STRIP command with STRIP_FLAGS on the given path.
+    '''
+    strip = substs['STRIP']
+    flags = substs['STRIP_FLAGS'].split() if 'STRIP_FLAGS' in substs else []
+    cmd = [strip] + flags + [path]
+    if subprocess.call(cmd) != 0:
+        errors.fatal('Error executing ' + ' '.join(cmd))
+
+
+def may_elfhack(path):
+    '''
+    Return whether elfhack() should be called
+    '''
+    # elfhack only supports libraries. We should check the ELF header for
+    # the right flag, but checking the file extension works too.
+    return 'USE_ELF_HACK' in substs and substs['USE_ELF_HACK'] and \
+           path.endswith(substs['DLL_SUFFIX'])
+
+
+def elfhack(path):
+    '''
+    Execute the elfhack command on the given path.
+    '''
+    cmd = [os.path.join(topobjdir, 'build/unix/elfhack/elfhack'), path]
+    if 'ELF_HACK_FLAGS' in os.environ:
+        cmd[1:0] = os.environ['ELF_HACK_FLAGS'].split()
+    if subprocess.call(cmd) != 0:
+        errors.fatal('Error executing ' + ' '.join(cmd))