michael@0: # vim: set ts=8 sts=4 et sw=4 tw=79:
michael@0: # This Source Code Form is subject to the terms of the Mozilla Public
michael@0: # License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0: # file, You can obtain one at http://mozilla.org/MPL/2.0/.
michael@0: 
michael@0: #----------------------------------------------------------------------------
michael@0: # All heap allocations in SpiderMonkey must go through js_malloc, js_calloc,
michael@0: # js_realloc, and js_free.  This is so that any embedder who uses a custom
michael@0: # allocator (by defining JS_USE_CUSTOM_ALLOCATOR) will see all heap allocation
michael@0: # go through that custom allocator.
michael@0: #
michael@0: # Therefore, the presence of any calls to "vanilla" allocation/free functions
michael@0: # (e.g. malloc(), free()) is a bug.
michael@0: #
michael@0: # This script checks for the presence of such disallowed vanilla
michael@0: # allocation/free function in SpiderMonkey when it's built as a library.  It
michael@0: # relies on |nm| from the GNU binutils, and so only works on Linux, but one
michael@0: # platform is good enough to catch almost all violations.
michael@0: #
michael@0: # This checking is only 100% reliable in a JS_USE_CUSTOM_ALLOCATOR build in
michael@0: # which the default definitions of js_malloc et al (in Utility.h) -- which call
michael@0: # malloc et al -- are replaced with empty definitions.  This is because the
michael@0: # presence and possible inlining of the default js_malloc et al can cause
michael@0: # malloc/calloc/realloc/free calls show up in unpredictable places.
michael@0: #
michael@0: # Unfortunately, that configuration cannot be tested on Mozilla's standard
michael@0: # testing infrastructure.  Instead, by default this script only tests that none
michael@0: # of the other vanilla allocation/free functions (operator new, memalign, etc)
michael@0: # are present.  If given the --aggressive flag, it will also check for
michael@0: # malloc/calloc/realloc/free.
michael@0: #
michael@0: # Note:  We don't check for |operator delete| and |operator delete[]|.  These
michael@0: # can be present somehow due to virtual destructors, but this is not too
michael@0: # because vanilla delete/delete[] calls don't make sense without corresponding
michael@0: # vanilla new/new[] calls, and any explicit calls will be caught by Valgrind's
michael@0: # mismatched alloc/free checking.
michael@0: #----------------------------------------------------------------------------
michael@0: 
michael@0: from __future__ import print_function
michael@0: 
michael@0: import argparse
michael@0: import re
michael@0: import subprocess
michael@0: import sys
michael@0: 
michael@0: # The obvious way to implement this script is to search for occurrences of
michael@0: # malloc et al, succeed if none are found, and fail is some are found.
michael@0: # However, "none are found" does not necessarily mean "none are present" --
michael@0: # this script could be buggy.  (Or the output format of |nm| might change in
michael@0: # the future.)
michael@0: #
michael@0: # So jsutil.cpp deliberately contains a (never-called) function that contains a
michael@0: # single use of all the vanilla allocation/free functions.  And this script
michael@0: # fails if it (a) finds uses of those functions in files other than jsutil.cpp,
michael@0: # *or* (b) fails to find them in jsutil.cpp.
michael@0: 
michael@0: # Tracks overall success of the test.
michael@0: has_failed = False
michael@0: 
michael@0: 
michael@0: def fail(msg):
michael@0:     print('TEST-UNEXPECTED-FAIL | check_vanilla_allocations.py |', msg)
michael@0:     global has_failed
michael@0:     has_failed = True
michael@0: 
michael@0: 
michael@0: def main():
michael@0:     parser = argparse.ArgumentParser()
michael@0:     parser.add_argument('--aggressive', action='store_true',
michael@0:                         help='also check for malloc, calloc, realloc and free')
michael@0:     parser.add_argument('file', type=str,
michael@0:                         help='name of the file to check')
michael@0:     args = parser.parse_args()
michael@0: 
michael@0:     # Run |nm|.  Options:
michael@0:     # -u: show only undefined symbols
michael@0:     # -C: demangle symbol names
michael@0:     # -l: show a filename and line number for each undefined symbol
michael@0:     cmd = ['nm', '-u', '-C', '-l', args.file]
michael@0:     lines = subprocess.check_output(cmd, universal_newlines=True,
michael@0:                                     stderr=subprocess.PIPE).split('\n')
michael@0: 
michael@0:     # alloc_fns contains all the vanilla allocation/free functions that we look
michael@0:     # for. Regexp chars are escaped appropriately.
michael@0: 
michael@0:     alloc_fns = [
michael@0:         # Matches |operator new(unsigned T)|, where |T| is |int| or |long|.
michael@0:         r'operator new\(unsigned',
michael@0: 
michael@0:         # Matches |operator new[](unsigned T)|, where |T| is |int| or |long|.
michael@0:         r'operator new\[\]\(unsigned',
michael@0: 
michael@0:         r'memalign',
michael@0:         # These two aren't available on all Linux configurations.
michael@0:         #r'posix_memalign',
michael@0:         #r'aligned_alloc',
michael@0:         r'valloc',
michael@0:         r'strdup'
michael@0:     ]
michael@0: 
michael@0:     if args.aggressive:
michael@0:         alloc_fns += [
michael@0:             r'malloc',
michael@0:             r'calloc',
michael@0:             r'realloc',
michael@0:             r'free'
michael@0:         ]
michael@0: 
michael@0:     # This is like alloc_fns, but regexp chars are not escaped.
michael@0:     alloc_fns_unescaped = [fn.translate(None, r'\\') for fn in alloc_fns]
michael@0: 
michael@0:     # This regexp matches the relevant lines in the output of |nm|, which look
michael@0:     # like the following.
michael@0:     #
michael@0:     #   U malloc  /path/to/objdir/dist/include/js/Utility.h:142
michael@0:     #
michael@0:     alloc_fns_re = r'U (' + r'|'.join(alloc_fns) + r').*\/([\w\.]+):(\d+)$'
michael@0: 
michael@0:     # This tracks which allocation/free functions have been seen in jsutil.cpp.
michael@0:     jsutil_cpp = set([])
michael@0: 
michael@0:     for line in lines:
michael@0:         m = re.search(alloc_fns_re, line)
michael@0:         if m is None:
michael@0:             continue
michael@0: 
michael@0:         fn = m.group(1)
michael@0:         filename = m.group(2)
michael@0:         linenum = m.group(3)
michael@0:         if filename == 'jsutil.cpp':
michael@0:             jsutil_cpp.add(fn)
michael@0:         else:
michael@0:             # An allocation is present in a non-special file.  Fail!
michael@0:             fail("'" + fn + "' present at " + filename + ':' + linenum)
michael@0: 
michael@0: 
michael@0:     # Check that all functions we expect are used in jsutil.cpp.  (This will
michael@0:     # fail if the function-detection code breaks at any point.)
michael@0:     for fn in alloc_fns_unescaped:
michael@0:         if fn not in jsutil_cpp:
michael@0:             fail("'" + fn + "' isn't used as expected in jsutil.cpp")
michael@0:         else:
michael@0:             jsutil_cpp.remove(fn)
michael@0: 
michael@0:     # This should never happen, but check just in case.
michael@0:     if jsutil_cpp:
michael@0:         fail('unexpected allocation fns used in jsutil.cpp: ' +
michael@0:              ', '.join(jsutil_cpp))
michael@0: 
michael@0:     if has_failed:
michael@0:         sys.exit(1)
michael@0: 
michael@0:     print('TEST-PASS | check_vanilla_allocations.py | ok')
michael@0:     sys.exit(0)
michael@0: 
michael@0: 
michael@0: if __name__ == '__main__':
michael@0:     main()
michael@0: