config/find_vanilla_new_calls
author Gervase Markham <gerv@gerv.net>
Mon, 21 May 2012 12:12:37 +0100
changeset 98983 f4157e8c410708d76703f19e4dfb61859bfe32d8
parent 64559 f949c8533aa03f15fb568d5b5ea2f2c7a9005e74
child 111831 f8d6117f911e3a500a75426e137fcc5a2d42518c
permissions -rwxr-xr-x
Bug 716478 - update licence to MPL 2.

# /bin/bash

#----------------------------------------------------------------------------
# We must avoid using the vanilla new/new[] operators (and consequently, the
# vanilla delete/delete[] operators) in SpiderMonkey, see bug 624878 for why.
#
# This script:
# - Detects if any of the vanilla new/new[] operators are used in a file.
#   Its exit code is 1 if it found some, and 0 if it didn't.
# - Doesn't detect delete/delete[] because it appears they can be present
#   somehow due to virtual destructors, but this is ok because vanilla
#   delete/delete[] calls don't make sense without corresponding new/new[]
#   calls, and any explicit calls will be caught by Valgrind's mismatched
#   alloc/free checking.
# - Doesn't detect the 'nothrow' variants, which are ok but probably still
#   best avoided.
# - Is designed to only run on Linux (though it may also work on Mac);  one
#   platform will be enough to catch any violations.
#
# If this script fails:
# - You need to find the uses of vanilla new/delete and replace them with
#   {js::OffTheBooks,JSContext,JSRuntime}::{new_,/array_new}.
# - Run this script on each of the .o files, that should narrow it down.
# - After that, one way to find them is to run 'objdump -r -C' on the
#   relevant .o files.  For example, you might search for 'operator new' and
#   find a record like this:
#
#  RELOCATION RECORDS FOR [.text._ZN3JSC14ExecutablePool6createEj]:
#  OFFSET   TYPE              VALUE
#  00000009 R_386_PC32        __i686.get_pc_thunk.bx
#  0000000f R_386_GOTPC       _GLOBAL_OFFSET_TABLE_
#  0000001b R_386_PLT32       operator new(unsigned int)
#  0000002e R_386_PC32        JSC::ExecutablePool::ExecutablePool(unsigned int)
#  0000004a R_386_PC32        JSC::ExecutablePool::~ExecutablePool()
#  00000052 R_386_PLT32       operator delete(void*)
#
#   This says that vanilla 'new' and 'delete' are both used in
#   JSC::ExecutablePool::create(unsigned int).  This doesn't always work,
#   though.  (Nb: use 'c++filt' to demangle names like
#   _ZN3JSC14ExecutablePool6createEj.)
#
# If that doesn't work, use grep.
#----------------------------------------------------------------------------

if [ -z $1 ] ; then
    echo "usage: find_vanilla_new_calls <file>"
    exit 1
fi

file=$1

if [ ! -f $file ] ; then
    echo "TEST-UNEXPECTED-FAIL | find_vanilla_new_calls | file '$file' not found"
    exit 1
fi

tmpfile1=`mktemp`
tmpfile2=`mktemp`
nm -C $file > $tmpfile1

# Need to double-escape '[' and ']' to stop grep from interpreting them
# specially.
grep 'operator new(unsigned int)'        $tmpfile1 >> $tmpfile2
grep 'operator new(unsigned long)'       $tmpfile1 >> $tmpfile2
grep 'operator new\\[\\](unsigned int)'  $tmpfile1 >> $tmpfile2
grep 'operator new\\[\\](unsigned long)' $tmpfile1 >> $tmpfile2
rm -f $tmpfile1

if [ -s $tmpfile2 ] ; then
    echo "TEST-UNEXPECTED-FAIL | find_vanilla_new_calls | found calls are listed below"
    cat $tmpfile2
    echo
    rm -f $tmpfile2
    exit 1
fi

echo "TEST-PASS | find_vanilla_new_calls | ok"
echo

exit 0