diff options
Diffstat (limited to 'Lib')
| -rw-r--r-- | Lib/ctypes/__init__.py | 8 | ||||
| -rw-r--r-- | Lib/ctypes/_aix.py | 331 | ||||
| -rw-r--r-- | Lib/ctypes/util.py | 25 |
3 files changed, 364 insertions, 0 deletions
diff --git a/Lib/ctypes/__init__.py b/Lib/ctypes/__init__.py index 972ea0a..6146773 100644 --- a/Lib/ctypes/__init__.py +++ b/Lib/ctypes/__init__.py @@ -338,6 +338,14 @@ class CDLL(object): flags |= _FUNCFLAG_USE_ERRNO if use_last_error: flags |= _FUNCFLAG_USE_LASTERROR + if _sys.platform.startswith("aix"): + """When the name contains ".a(" and ends with ")", + e.g., "libFOO.a(libFOO.so)" - this is taken to be an + archive(member) syntax for dlopen(), and the mode is adjusted. + Otherwise, name is presented to dlopen() as a file argument. + """ + if name and name.endswith(")") and ".a(" in name: + mode |= ( _os.RTLD_MEMBER | _os.RTLD_NOW ) class _FuncPtr(_CFuncPtr): _flags_ = flags diff --git a/Lib/ctypes/_aix.py b/Lib/ctypes/_aix.py new file mode 100644 index 0000000..5c4d8d9 --- /dev/null +++ b/Lib/ctypes/_aix.py @@ -0,0 +1,331 @@ +""" +Lib/ctypes.util.find_library() support for AIX +Similar approach as done for Darwin support by using separate files +but unlike Darwin - no extension such as ctypes.macholib.* + +dlopen() is an interface to AIX initAndLoad() - primary documentation at: +https://www.ibm.com/support/knowledgecenter/en/ssw_aix_61/com.ibm.aix.basetrf1/dlopen.htm +https://www.ibm.com/support/knowledgecenter/en/ssw_aix_61/com.ibm.aix.basetrf1/load.htm + +AIX supports two styles for dlopen(): svr4 (System V Release 4) which is common on posix +platforms, but also a BSD style - aka SVR3. + +From AIX 5.3 Difference Addendum (December 2004) +2.9 SVR4 linking affinity +Nowadays, there are two major object file formats used by the operating systems: +XCOFF: The COFF enhanced by IBM and others. The original COFF (Common +Object File Format) was the base of SVR3 and BSD 4.2 systems. +ELF: Executable and Linking Format that was developed by AT&T and is a +base for SVR4 UNIX. + +While the shared library content is identical on AIX - one is located as a filepath name +(svr4 style) and the other is located as a member of an archive (and the archive +is located as a filepath name). + +The key difference arises when supporting multiple abi formats (i.e., 32 and 64 bit). +For svr4 either only one ABI is supported, or there are two directories, or there +are different file names. The most common solution for multiple ABI is multiple +directories. + +For the XCOFF (aka AIX) style - one directory (one archive file) is sufficient +as multiple shared libraries can be in the archive - even sharing the same name. +In documentation the archive is also referred to as the "base" and the shared +library object is referred to as the "member". + +For dlopen() on AIX (read initAndLoad()) the calls are similiar. +Default activity occurs when no path information is provided. When path +information is provided dlopen() does not search any other directories. + +For SVR4 - the shared library name is the name of the file expected: libFOO.so +For AIX - the shared library is expressed as base(member). The search is for the +base (e.g., libFOO.a) and once the base is found the shared library - identified by +member (e.g., libFOO.so, or shr.o) is located and loaded. + +The mode bit RTLD_MEMBER tells initAndLoad() that it needs to use the AIX (SVR3) +naming style. +""" +__author__ = "Michael Felt <aixtools@felt.demon.nl>" + +import re +from os import environ, path +from sys import executable +from ctypes import c_void_p, sizeof +from subprocess import Popen, PIPE, DEVNULL + +# Executable bit size - 32 or 64 +# Used to filter the search in an archive by size, e.g., -X64 +AIX_ABI = sizeof(c_void_p) * 8 + + +from sys import maxsize +def _last_version(libnames, sep): + def _num_version(libname): + # "libxyz.so.MAJOR.MINOR" => [MAJOR, MINOR] + parts = libname.split(sep) + nums = [] + try: + while parts: + nums.insert(0, int(parts.pop())) + except ValueError: + pass + return nums or [maxsize] + return max(reversed(libnames), key=_num_version) + +def get_ld_header(p): + # "nested-function, but placed at module level + ld_header = None + for line in p.stdout: + if line.startswith(('/', './', '../')): + ld_header = line + elif "INDEX" in line: + return ld_header.rstrip('\n') + return None + +def get_ld_header_info(p): + # "nested-function, but placed at module level + # as an ld_header was found, return known paths, archives and members + # these lines start with a digit + info = [] + for line in p.stdout: + if re.match("[0-9]", line): + info.append(line) + else: + # blank line (seperator), consume line and end for loop + break + return info + +def get_ld_headers(file): + """ + Parse the header of the loader section of executable and archives + This function calls /usr/bin/dump -H as a subprocess + and returns a list of (ld_header, ld_header_info) tuples. + """ + # get_ld_headers parsing: + # 1. Find a line that starts with /, ./, or ../ - set as ld_header + # 2. If "INDEX" in occurs in a following line - return ld_header + # 3. get info (lines starting with [0-9]) + ldr_headers = [] + p = Popen(["/usr/bin/dump", "-X%s" % AIX_ABI, "-H", file], + universal_newlines=True, stdout=PIPE, stderr=DEVNULL) + # be sure to read to the end-of-file - getting all entries + while True: + ld_header = get_ld_header(p) + if ld_header: + ldr_headers.append((ld_header, get_ld_header_info(p))) + else: + break + p.stdout.close() + p.wait + return ldr_headers + +def get_shared(ld_headers): + """ + extract the shareable objects from ld_headers + character "[" is used to strip off the path information. + Note: the "[" and "]" characters that are part of dump -H output + are not removed here. + """ + shared = [] + for (line, _) in ld_headers: + # potential member lines contain "[" + # otherwise, no processing needed + if "[" in line: + # Strip off trailing colon (:) + shared.append(line[line.index("["):-1]) + return shared + +def get_one_match(expr, lines): + """ + Must be only one match, otherwise result is None. + When there is a match, strip leading "[" and trailing "]" + """ + # member names in the ld_headers output are between square brackets + expr = r'\[(%s)\]' % expr + matches = list(filter(None, (re.search(expr, line) for line in lines))) + if len(matches) == 1: + return matches[0].group(1) + else: + return None + +# additional processing to deal with AIX legacy names for 64-bit members +def get_legacy(members): + """ + This routine provides historical aka legacy naming schemes started + in AIX4 shared library support for library members names. + e.g., in /usr/lib/libc.a the member name shr.o for 32-bit binary and + shr_64.o for 64-bit binary. + """ + if AIX_ABI == 64: + # AIX 64-bit member is one of shr64.o, shr_64.o, or shr4_64.o + expr = r'shr4?_?64\.o' + member = get_one_match(expr, members) + if member: + return member + else: + # 32-bit legacy names - both shr.o and shr4.o exist. + # shr.o is the preffered name so we look for shr.o first + # i.e., shr4.o is returned only when shr.o does not exist + for name in ['shr.o', 'shr4.o']: + member = get_one_match(re.escape(name), members) + if member: + return member + return None + +def get_version(name, members): + """ + Sort list of members and return highest numbered version - if it exists. + This function is called when an unversioned libFOO.a(libFOO.so) has + not been found. + + Versioning for the member name is expected to follow + GNU LIBTOOL conventions: the highest version (x, then X.y, then X.Y.z) + * find [libFoo.so.X] + * find [libFoo.so.X.Y] + * find [libFoo.so.X.Y.Z] + + Before the GNU convention became the standard scheme regardless of + binary size AIX packagers used GNU convention "as-is" for 32-bit + archive members but used an "distinguishing" name for 64-bit members. + This scheme inserted either 64 or _64 between libFOO and .so + - generally libFOO_64.so, but occasionally libFOO64.so + """ + # the expression ending for versions must start as + # '.so.[0-9]', i.e., *.so.[at least one digit] + # while multiple, more specific expressions could be specified + # to search for .so.X, .so.X.Y and .so.X.Y.Z + # after the first required 'dot' digit + # any combination of additional 'dot' digits pairs are accepted + # anything more than libFOO.so.digits.digits.digits + # should be seen as a member name outside normal expectations + exprs = [r'lib%s\.so\.[0-9]+[0-9.]*' % name, + r'lib%s_?64\.so\.[0-9]+[0-9.]*' % name] + for expr in exprs: + versions = [] + for line in members: + m = re.search(expr, line) + if m: + versions.append(m.group(0)) + if versions: + return _last_version(versions, '.') + return None + +def get_member(name, members): + """ + Return an archive member matching the request in name. + Name is the library name without any prefix like lib, suffix like .so, + or version number. + Given a list of members find and return the most appropriate result + Priority is given to generic libXXX.so, then a versioned libXXX.so.a.b.c + and finally, legacy AIX naming scheme. + """ + # look first for a generic match - prepend lib and append .so + expr = r'lib%s\.so' % name + member = get_one_match(expr, members) + if member: + return member + elif AIX_ABI == 64: + expr = r'lib%s64\.so' % name + member = get_one_match(expr, members) + if member: + return member + # since an exact match with .so as suffix was not found + # look for a versioned name + # If a versioned name is not found, look for AIX legacy member name + member = get_version(name, members) + if member: + return member + else: + return get_legacy(members) + +def get_libpaths(): + """ + On AIX, the buildtime searchpath is stored in the executable. + as "loader header information". + The command /usr/bin/dump -H extracts this info. + Prefix searched libraries with LD_LIBRARY_PATH (preferred), + or LIBPATH if defined. These paths are appended to the paths + to libraries the python executable is linked with. + This mimics AIX dlopen() behavior. + """ + libpaths = environ.get("LD_LIBRARY_PATH") + if libpaths is None: + libpaths = environ.get("LIBPATH") + if libpaths is None: + libpaths = [] + else: + libpaths = libpaths.split(":") + objects = get_ld_headers(executable) + for (_, lines) in objects: + for line in lines: + # the second (optional) argument is PATH if it includes a / + path = line.split()[1] + if "/" in path: + libpaths.extend(path.split(":")) + return libpaths + +def find_shared(paths, name): + """ + paths is a list of directories to search for an archive. + name is the abbreviated name given to find_library(). + Process: search "paths" for archive, and if an archive is found + return the result of get_member(). + If an archive is not found then return None + """ + for dir in paths: + # /lib is a symbolic link to /usr/lib, skip it + if dir == "/lib": + continue + # "lib" is prefixed to emulate compiler name resolution, + # e.g., -lc to libc + base = 'lib%s.a' % name + archive = path.join(dir, base) + if path.exists(archive): + members = get_shared(get_ld_headers(archive)) + member = get_member(re.escape(name), members) + if member != None: + return (base, member) + else: + return (None, None) + return (None, None) + +def find_library(name): + """AIX implementation of ctypes.util.find_library() + Find an archive member that will dlopen(). If not available, + also search for a file (or link) with a .so suffix. + + AIX supports two types of schemes that can be used with dlopen(). + The so-called SystemV Release4 (svr4) format is commonly suffixed + with .so while the (default) AIX scheme has the library (archive) + ending with the suffix .a + As an archive has multiple members (e.g., 32-bit and 64-bit) in one file + the argument passed to dlopen must include both the library and + the member names in a single string. + + find_library() looks first for an archive (.a) with a suitable member. + If no archive+member pair is found, look for a .so file. + """ + + libpaths = get_libpaths() + (base, member) = find_shared(libpaths, name) + if base != None: + return "%s(%s)" % (base, member) + + # To get here, a member in an archive has not been found + # In other words, either: + # a) a .a file was not found + # b) a .a file did not have a suitable member + # So, look for a .so file + # Check libpaths for .so file + # Note, the installation must prepare a link from a .so + # to a versioned file + # This is common practice by GNU libtool on other platforms + soname = "lib%s.so" % name + for dir in libpaths: + # /lib is a symbolic link to /usr/lib, skip it + if dir == "/lib": + continue + shlib = path.join(dir, soname) + if path.exists(shlib): + return soname + # if we are here, we have not found anything plausible + return None diff --git a/Lib/ctypes/util.py b/Lib/ctypes/util.py index 8856f65..e837abb 100644 --- a/Lib/ctypes/util.py +++ b/Lib/ctypes/util.py @@ -80,6 +80,15 @@ if os.name == "posix" and sys.platform == "darwin": continue return None +if sys.platform.startswith("aix"): + # AIX has two styles of storing shared libraries + # GNU auto_tools refer to these as svr4 and aix + # svr4 (System V Release 4) is a regular file, often with .so as suffix + # AIX style uses an archive (suffix .a) with members (e.g., shr.o, libssl.so) + # see issue#26439 and _aix.py for more details + + from ctypes._aix import find_library + elif os.name == "posix": # Andreas Degert's find functions, using gcc, /sbin/ldconfig, objdump import re, tempfile @@ -324,6 +333,22 @@ def test(): print(cdll.LoadLibrary("libcrypto.dylib")) print(cdll.LoadLibrary("libSystem.dylib")) print(cdll.LoadLibrary("System.framework/System")) + # issue-26439 - fix broken test call for AIX + elif sys.platform.startswith("aix"): + from ctypes import CDLL + if sys.maxsize < 2**32: + print("Using CDLL(name, os.RTLD_MEMBER): %s" % CDLL("libc.a(shr.o)", os.RTLD_MEMBER)) + print("Using cdll.LoadLibrary(): %s" % cdll.LoadLibrary("libc.a(shr.o)")) + # librpm.so is only available as 32-bit shared library + print(find_library("rpm")) + print(cdll.LoadLibrary("librpm.so")) + else: + print("Using CDLL(name, os.RTLD_MEMBER): %s" % CDLL("libc.a(shr_64.o)", os.RTLD_MEMBER)) + print("Using cdll.LoadLibrary(): %s" % cdll.LoadLibrary("libc.a(shr_64.o)")) + print("crypt\t:: %s" % find_library("crypt")) + print("crypt\t:: %s" % cdll.LoadLibrary(find_library("crypt"))) + print("crypto\t:: %s" % find_library("crypto")) + print("crypto\t:: %s" % cdll.LoadLibrary(find_library("crypto"))) else: print(cdll.LoadLibrary("libm.so")) print(cdll.LoadLibrary("libcrypt.so")) |