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-rw-r--r--python/mozbuild/mozpack/executables.py135
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+# 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
+import subprocess
+from io import BytesIO
+
+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
+
+ELF_SIGNATURE = 0x7F454C46 # Elf binary
+
+UNKNOWN = 0
+MACHO = 1
+ELF = 2
+
+
+def get_type(path_or_fileobj):
+ """
+ Check the signature of the give file and returns what kind of executable
+ matches.
+ """
+ if hasattr(path_or_fileobj, "peek"):
+ f = BytesIO(path_or_fileobj.peek(8))
+ elif hasattr(path_or_fileobj, "read"):
+ f = path_or_fileobj
+ else:
+ f = open(path_or_fileobj, "rb")
+ signature = f.read(4)
+ if len(signature) < 4:
+ return UNKNOWN
+ signature = struct.unpack(">L", signature)[0]
+ if signature == ELF_SIGNATURE:
+ return ELF
+ if signature in MACHO_SIGNATURES:
+ return MACHO
+ if signature != FAT_SIGNATURE:
+ return UNKNOWN
+ # 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 UNKNOWN
+ num = struct.unpack(">L", num)[0]
+ if num < 20:
+ return MACHO
+ return UNKNOWN
+
+
+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 and WINNT
+ - 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, ELF and WINNT (in GCC build) systems, we don't bother
+ detecting other kind of executables.
+ """
+ from buildconfig import substs
+
+ if not os.path.exists(path):
+ return False
+
+ if substs["OS_ARCH"] == "WINNT":
+ return path.lower().endswith((substs["DLL_SUFFIX"], substs["BIN_SUFFIX"]))
+
+ return get_type(path) != UNKNOWN
+
+
+def may_strip(path):
+ """
+ Return whether strip() should be called
+ """
+ from buildconfig import substs
+
+ return bool(substs.get("PKG_STRIP"))
+
+
+def strip(path):
+ """
+ Execute the STRIP command with STRIP_FLAGS on the given path.
+ """
+ from buildconfig import substs
+
+ strip = substs["STRIP"]
+ flags = substs.get("STRIP_FLAGS", [])
+ 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.
+ from buildconfig import substs
+
+ return (
+ "USE_ELF_HACK" in substs
+ and substs["USE_ELF_HACK"]
+ and path.endswith(substs["DLL_SUFFIX"])
+ and "COMPILE_ENVIRONMENT" in substs
+ and substs["COMPILE_ENVIRONMENT"]
+ )
+
+
+def elfhack(path):
+ """
+ Execute the elfhack command on the given path.
+ """
+ from buildconfig import topobjdir
+
+ cmd = [os.path.join(topobjdir, "build/unix/elfhack/elfhack"), path]
+ if subprocess.call(cmd) != 0:
+ errors.fatal("Error executing " + " ".join(cmd))