1# functions for handling ABI checking of libraries
2
3import os
4import sys
5import re
6import fnmatch
7
8from waflib import Options, Utils, Logs, Task, Build, Errors
9from waflib.TaskGen import feature, before, after
10from wafsamba import samba_utils
11
12# these type maps cope with platform specific names for common types
13# please add new type mappings into the list below
14abi_type_maps = {
15    '_Bool' : 'bool',
16    'struct __va_list_tag *' : 'va_list'
17    }
18
19version_key = lambda x: list(map(int, x.split(".")))
20
21def normalise_signature(sig):
22    '''normalise a signature from gdb'''
23    sig = sig.strip()
24    sig = re.sub('^\$[0-9]+\s=\s\{(.+)\}$', r'\1', sig)
25    sig = re.sub('^\$[0-9]+\s=\s\{(.+)\}(\s0x[0-9a-f]+\s<\w+>)+$', r'\1', sig)
26    sig = re.sub('^\$[0-9]+\s=\s(0x[0-9a-f]+)\s?(<\w+>)?$', r'\1', sig)
27    sig = re.sub('0x[0-9a-f]+', '0xXXXX', sig)
28    sig = re.sub('", <incomplete sequence (\\\\[a-z0-9]+)>', r'\1"', sig)
29
30    for t in abi_type_maps:
31        # we need to cope with non-word characters in mapped types
32        m = t
33        m = m.replace('*', '\*')
34        if m[-1].isalnum() or m[-1] == '_':
35            m += '\\b'
36        if m[0].isalnum() or m[0] == '_':
37            m = '\\b' + m
38        sig = re.sub(m, abi_type_maps[t], sig)
39    return sig
40
41
42def normalise_varargs(sig):
43    '''cope with older versions of gdb'''
44    sig = re.sub(',\s\.\.\.', '', sig)
45    return sig
46
47
48def parse_sigs(sigs, abi_match):
49    '''parse ABI signatures file'''
50    abi_match = samba_utils.TO_LIST(abi_match)
51    ret = {}
52    a = sigs.split('\n')
53    for s in a:
54        if s.find(':') == -1:
55            continue
56        sa = s.split(':')
57        if abi_match:
58            matched = False
59            negative = False
60            for p in abi_match:
61                if p[0] == '!' and fnmatch.fnmatch(sa[0], p[1:]):
62                    negative = True
63                    break
64                elif fnmatch.fnmatch(sa[0], p):
65                    matched = True
66                    break
67            if (not matched) and negative:
68                continue
69        Logs.debug("%s -> %s" % (sa[1], normalise_signature(sa[1])))
70        ret[sa[0]] = normalise_signature(sa[1])
71    return ret
72
73def save_sigs(sig_file, parsed_sigs):
74    '''save ABI signatures to a file'''
75    sigs = "".join('%s: %s\n' % (s, parsed_sigs[s]) for s in sorted(parsed_sigs.keys()))
76    return samba_utils.save_file(sig_file, sigs, create_dir=True)
77
78
79def abi_check_task(self):
80    '''check if the ABI has changed'''
81    abi_gen = self.ABI_GEN
82
83    libpath = self.inputs[0].abspath(self.env)
84    libname = os.path.basename(libpath)
85
86    sigs = samba_utils.get_string(Utils.cmd_output([abi_gen, libpath]))
87    parsed_sigs = parse_sigs(sigs, self.ABI_MATCH)
88
89    sig_file = self.ABI_FILE
90
91    old_sigs = samba_utils.load_file(sig_file)
92    if old_sigs is None or Options.options.ABI_UPDATE:
93        if not save_sigs(sig_file, parsed_sigs):
94            raise Errors.WafError('Failed to save ABI file "%s"' % sig_file)
95        Logs.warn('Generated ABI signatures %s' % sig_file)
96        return
97
98    parsed_old_sigs = parse_sigs(old_sigs, self.ABI_MATCH)
99
100    # check all old sigs
101    got_error = False
102    for s in parsed_old_sigs:
103        if not s in parsed_sigs:
104            Logs.error('%s: symbol %s has been removed - please update major version\n\tsignature: %s' % (
105                libname, s, parsed_old_sigs[s]))
106            got_error = True
107        elif normalise_varargs(parsed_old_sigs[s]) != normalise_varargs(parsed_sigs[s]):
108            Logs.error('%s: symbol %s has changed - please update major version\n\told_signature: %s\n\tnew_signature: %s' % (
109                libname, s, parsed_old_sigs[s], parsed_sigs[s]))
110            got_error = True
111
112    for s in parsed_sigs:
113        if not s in parsed_old_sigs:
114            Logs.error('%s: symbol %s has been added - please mark it _PRIVATE_ or update minor version\n\tsignature: %s' % (
115                libname, s, parsed_sigs[s]))
116            got_error = True
117
118    if got_error:
119        raise Errors.WafError('ABI for %s has changed - please fix library version then build with --abi-update\nSee http://wiki.samba.org/index.php/Waf#ABI_Checking for more information\nIf you have not changed any ABI, and your platform always gives this error, please configure with --abi-check-disable to skip this check' % libname)
120
121
122t = Task.task_factory('abi_check', abi_check_task, color='BLUE', ext_in='.bin')
123t.quiet = True
124# allow "waf --abi-check" to force re-checking the ABI
125if '--abi-check' in sys.argv:
126    t.always_run = True
127
128@after('apply_link')
129@feature('abi_check')
130def abi_check(self):
131    '''check that ABI matches saved signatures'''
132    env = self.bld.env
133    if not env.ABI_CHECK or self.abi_directory is None:
134        return
135
136    # if the platform doesn't support -fvisibility=hidden then the ABI
137    # checks become fairly meaningless
138    if not env.HAVE_VISIBILITY_ATTR:
139        return
140
141    topsrc = self.bld.srcnode.abspath()
142    abi_gen = os.path.join(topsrc, 'buildtools/scripts/abi_gen.sh')
143
144    abi_file = "%s/%s-%s.sigs" % (self.abi_directory, self.version_libname,
145                                  self.vnum)
146
147    tsk = self.create_task('abi_check', self.link_task.outputs[0])
148    tsk.ABI_FILE = abi_file
149    tsk.ABI_MATCH = self.abi_match
150    tsk.ABI_GEN = abi_gen
151
152
153def abi_process_file(fname, version, symmap):
154    '''process one ABI file, adding new symbols to the symmap'''
155    for line in Utils.readf(fname).splitlines():
156        symname = line.split(":")[0]
157        if not symname in symmap:
158            symmap[symname] = version
159
160
161def abi_write_vscript(f, libname, current_version, versions, symmap, abi_match):
162    """Write a vscript file for a library in --version-script format.
163
164    :param f: File-like object to write to
165    :param libname: Name of the library, uppercased
166    :param current_version: Current version
167    :param versions: Versions to consider
168    :param symmap: Dictionary mapping symbols -> version
169    :param abi_match: List of symbols considered to be public in the current
170        version
171    """
172
173    invmap = {}
174    for s in symmap:
175        invmap.setdefault(symmap[s], []).append(s)
176
177    last_key = ""
178    versions = sorted(versions, key=version_key)
179    for k in versions:
180        symver = "%s_%s" % (libname, k)
181        if symver == current_version:
182            break
183        f.write("%s {\n" % symver)
184        if k in sorted(invmap.keys()):
185            f.write("\tglobal:\n")
186            for s in invmap.get(k, []):
187                f.write("\t\t%s;\n" % s);
188        f.write("}%s;\n\n" % last_key)
189        last_key = " %s" % symver
190    f.write("%s {\n" % current_version)
191    local_abi = list(filter(lambda x: x[0] == '!', abi_match))
192    global_abi = list(filter(lambda x: x[0] != '!', abi_match))
193    f.write("\tglobal:\n")
194    if len(global_abi) > 0:
195        for x in global_abi:
196            f.write("\t\t%s;\n" % x)
197    else:
198        f.write("\t\t*;\n")
199    # Always hide symbols that must be local if exist
200    local_abi.extend(["!_end", "!__bss_start", "!_edata"])
201    f.write("\tlocal:\n")
202    for x in local_abi:
203        f.write("\t\t%s;\n" % x[1:])
204    if global_abi != ["*"]:
205        if len(global_abi) > 0:
206            f.write("\t\t*;\n")
207    f.write("};\n")
208
209
210def abi_build_vscript(task):
211    '''generate a vscript file for our public libraries'''
212
213    tgt = task.outputs[0].bldpath(task.env)
214
215    symmap = {}
216    versions = []
217    for f in task.inputs:
218        fname = f.abspath(task.env)
219        basename = os.path.basename(fname)
220        version = basename[len(task.env.LIBNAME)+1:-len(".sigs")]
221        versions.append(version)
222        abi_process_file(fname, version, symmap)
223    f = open(tgt, mode='w')
224    try:
225        abi_write_vscript(f, task.env.LIBNAME, task.env.VERSION, versions,
226            symmap, task.env.ABI_MATCH)
227    finally:
228        f.close()
229
230
231def ABI_VSCRIPT(bld, libname, abi_directory, version, vscript, abi_match=None):
232    '''generate a vscript file for our public libraries'''
233    if abi_directory:
234        source = bld.path.ant_glob('%s/%s-[0-9]*.sigs' % (abi_directory, libname), flat=True)
235        def abi_file_key(path):
236            return version_key(path[:-len(".sigs")].rsplit("-")[-1])
237        source = sorted(source.split(), key=abi_file_key)
238    else:
239        source = ''
240
241    libname = os.path.basename(libname)
242    version = os.path.basename(version)
243    libname = libname.replace("-", "_").replace("+","_").upper()
244    version = version.replace("-", "_").replace("+","_").upper()
245
246    t = bld.SAMBA_GENERATOR(vscript,
247                            rule=abi_build_vscript,
248                            source=source,
249                            group='vscripts',
250                            target=vscript)
251    if abi_match is None:
252        abi_match = ["*"]
253    else:
254        abi_match = samba_utils.TO_LIST(abi_match)
255    t.env.ABI_MATCH = abi_match
256    t.env.VERSION = version
257    t.env.LIBNAME = libname
258    t.vars = ['LIBNAME', 'VERSION', 'ABI_MATCH']
259Build.BuildContext.ABI_VSCRIPT = ABI_VSCRIPT
260