1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/config/check_vanilla_allocations.py Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,159 @@
1.4 +# vim: set ts=8 sts=4 et sw=4 tw=79:
1.5 +# This Source Code Form is subject to the terms of the Mozilla Public
1.6 +# License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 +# file, You can obtain one at http://mozilla.org/MPL/2.0/.
1.8 +
1.9 +#----------------------------------------------------------------------------
1.10 +# All heap allocations in SpiderMonkey must go through js_malloc, js_calloc,
1.11 +# js_realloc, and js_free. This is so that any embedder who uses a custom
1.12 +# allocator (by defining JS_USE_CUSTOM_ALLOCATOR) will see all heap allocation
1.13 +# go through that custom allocator.
1.14 +#
1.15 +# Therefore, the presence of any calls to "vanilla" allocation/free functions
1.16 +# (e.g. malloc(), free()) is a bug.
1.17 +#
1.18 +# This script checks for the presence of such disallowed vanilla
1.19 +# allocation/free function in SpiderMonkey when it's built as a library. It
1.20 +# relies on |nm| from the GNU binutils, and so only works on Linux, but one
1.21 +# platform is good enough to catch almost all violations.
1.22 +#
1.23 +# This checking is only 100% reliable in a JS_USE_CUSTOM_ALLOCATOR build in
1.24 +# which the default definitions of js_malloc et al (in Utility.h) -- which call
1.25 +# malloc et al -- are replaced with empty definitions. This is because the
1.26 +# presence and possible inlining of the default js_malloc et al can cause
1.27 +# malloc/calloc/realloc/free calls show up in unpredictable places.
1.28 +#
1.29 +# Unfortunately, that configuration cannot be tested on Mozilla's standard
1.30 +# testing infrastructure. Instead, by default this script only tests that none
1.31 +# of the other vanilla allocation/free functions (operator new, memalign, etc)
1.32 +# are present. If given the --aggressive flag, it will also check for
1.33 +# malloc/calloc/realloc/free.
1.34 +#
1.35 +# Note: We don't check for |operator delete| and |operator delete[]|. These
1.36 +# can be present somehow due to virtual destructors, but this is not too
1.37 +# because vanilla delete/delete[] calls don't make sense without corresponding
1.38 +# vanilla new/new[] calls, and any explicit calls will be caught by Valgrind's
1.39 +# mismatched alloc/free checking.
1.40 +#----------------------------------------------------------------------------
1.41 +
1.42 +from __future__ import print_function
1.43 +
1.44 +import argparse
1.45 +import re
1.46 +import subprocess
1.47 +import sys
1.48 +
1.49 +# The obvious way to implement this script is to search for occurrences of
1.50 +# malloc et al, succeed if none are found, and fail is some are found.
1.51 +# However, "none are found" does not necessarily mean "none are present" --
1.52 +# this script could be buggy. (Or the output format of |nm| might change in
1.53 +# the future.)
1.54 +#
1.55 +# So jsutil.cpp deliberately contains a (never-called) function that contains a
1.56 +# single use of all the vanilla allocation/free functions. And this script
1.57 +# fails if it (a) finds uses of those functions in files other than jsutil.cpp,
1.58 +# *or* (b) fails to find them in jsutil.cpp.
1.59 +
1.60 +# Tracks overall success of the test.
1.61 +has_failed = False
1.62 +
1.63 +
1.64 +def fail(msg):
1.65 + print('TEST-UNEXPECTED-FAIL | check_vanilla_allocations.py |', msg)
1.66 + global has_failed
1.67 + has_failed = True
1.68 +
1.69 +
1.70 +def main():
1.71 + parser = argparse.ArgumentParser()
1.72 + parser.add_argument('--aggressive', action='store_true',
1.73 + help='also check for malloc, calloc, realloc and free')
1.74 + parser.add_argument('file', type=str,
1.75 + help='name of the file to check')
1.76 + args = parser.parse_args()
1.77 +
1.78 + # Run |nm|. Options:
1.79 + # -u: show only undefined symbols
1.80 + # -C: demangle symbol names
1.81 + # -l: show a filename and line number for each undefined symbol
1.82 + cmd = ['nm', '-u', '-C', '-l', args.file]
1.83 + lines = subprocess.check_output(cmd, universal_newlines=True,
1.84 + stderr=subprocess.PIPE).split('\n')
1.85 +
1.86 + # alloc_fns contains all the vanilla allocation/free functions that we look
1.87 + # for. Regexp chars are escaped appropriately.
1.88 +
1.89 + alloc_fns = [
1.90 + # Matches |operator new(unsigned T)|, where |T| is |int| or |long|.
1.91 + r'operator new\(unsigned',
1.92 +
1.93 + # Matches |operator new[](unsigned T)|, where |T| is |int| or |long|.
1.94 + r'operator new\[\]\(unsigned',
1.95 +
1.96 + r'memalign',
1.97 + # These two aren't available on all Linux configurations.
1.98 + #r'posix_memalign',
1.99 + #r'aligned_alloc',
1.100 + r'valloc',
1.101 + r'strdup'
1.102 + ]
1.103 +
1.104 + if args.aggressive:
1.105 + alloc_fns += [
1.106 + r'malloc',
1.107 + r'calloc',
1.108 + r'realloc',
1.109 + r'free'
1.110 + ]
1.111 +
1.112 + # This is like alloc_fns, but regexp chars are not escaped.
1.113 + alloc_fns_unescaped = [fn.translate(None, r'\\') for fn in alloc_fns]
1.114 +
1.115 + # This regexp matches the relevant lines in the output of |nm|, which look
1.116 + # like the following.
1.117 + #
1.118 + # U malloc /path/to/objdir/dist/include/js/Utility.h:142
1.119 + #
1.120 + alloc_fns_re = r'U (' + r'|'.join(alloc_fns) + r').*\/([\w\.]+):(\d+)$'
1.121 +
1.122 + # This tracks which allocation/free functions have been seen in jsutil.cpp.
1.123 + jsutil_cpp = set([])
1.124 +
1.125 + for line in lines:
1.126 + m = re.search(alloc_fns_re, line)
1.127 + if m is None:
1.128 + continue
1.129 +
1.130 + fn = m.group(1)
1.131 + filename = m.group(2)
1.132 + linenum = m.group(3)
1.133 + if filename == 'jsutil.cpp':
1.134 + jsutil_cpp.add(fn)
1.135 + else:
1.136 + # An allocation is present in a non-special file. Fail!
1.137 + fail("'" + fn + "' present at " + filename + ':' + linenum)
1.138 +
1.139 +
1.140 + # Check that all functions we expect are used in jsutil.cpp. (This will
1.141 + # fail if the function-detection code breaks at any point.)
1.142 + for fn in alloc_fns_unescaped:
1.143 + if fn not in jsutil_cpp:
1.144 + fail("'" + fn + "' isn't used as expected in jsutil.cpp")
1.145 + else:
1.146 + jsutil_cpp.remove(fn)
1.147 +
1.148 + # This should never happen, but check just in case.
1.149 + if jsutil_cpp:
1.150 + fail('unexpected allocation fns used in jsutil.cpp: ' +
1.151 + ', '.join(jsutil_cpp))
1.152 +
1.153 + if has_failed:
1.154 + sys.exit(1)
1.155 +
1.156 + print('TEST-PASS | check_vanilla_allocations.py | ok')
1.157 + sys.exit(0)
1.158 +
1.159 +
1.160 +if __name__ == '__main__':
1.161 + main()
1.162 +
