Remove static initializers in v8.

tools/check-static-initializers.sh

Index: tools/check-static-initializers.sh
diff --git a/tools/check-static-initializers.sh b/tools/check-static-initializers.sh
new file mode 100755
index 0000000000000000000000000000000000000000..9e1f0928bc52ca49990c6cd1cb33d1048a9294a2
--- /dev/null
+++ b/tools/check-static-initializers.sh
@@ -0,0 +1,53 @@
+#!/bin/bash
+# Copyright 2012 the V8 project authors. All rights reserved.
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+#       notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+#       copyright notice, this list of conditions and the following
+#       disclaimer in the documentation and/or other materials provided
+#       with the distribution.
+#     * Neither the name of Google Inc. nor the names of its
+#       contributors may be used to endorse or promote products derived
+#       from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+# Checks that the number of static initializers contained in the static
+# libraries matches the one defined below.
+
+# Allow:
+#  - _GLOBAL__I__ZN2v88internal32AtomicOps_Internalx86CPUFeaturesE
+expected_static_init_count=1
+
+v8_out=$(readlink -f $(dirname $BASH_SOURCE)/../out)

[fschneider, 2012/02/28 16:54:48]

Not sure if this works with the current build configuration on the buildbot
which I believe uses the SCons build. Somehow specifying the binary output
directory would be useful, I guess.

[Sven Panne, 2012/02/29 08:05:35]

A few points:

 * A non-shared scons build only generates a library for the preparser.

 * You typically have various build variants lying around, which get added
together and therefore things will almost always fail.

  * You can't use this for a presubmit script, because there is no guarantee
that the objects you find are the ones created from the current sources.

  * Just to be nitpicking: What is being counted here is *not* the number of
static initializers, it is the number of compilation units having at least 1
static initializer.

  * You can greatly simplify the whole script by just looking at the final
executable, doing something like "objdump --headers --section=.ctors d8" and
look at the size of the section.

[Philippe, 2012/02/29 10:24:45]

I changed the script to work on d8 instead after a SCons build.
I reverted the changes that I previously made in presubmit.py.
I still use nm as ctors is not always the right name (init_array on ARM).

Also, d8 contains some static initializers which I didn't remove since it is not
affecting clients.

+libs_list=$(find $v8_out -name '*.a')
+
+if [ -z "$libs_list" ]; then
+  echo "Please build the project."
+  exit 1
+fi
+
+static_inits=$(echo "$libs_list" | xargs nm | grep _GLOBAL__I | \
+    awk '{ print $NF; }' | uniq)
+
+static_init_count=$(echo "$static_inits" | uniq | wc -l)
+
+if [ $static_init_count -gt $expected_static_init_count ]; then
+  echo "Too many static initializers."
+  echo "$static_inits"
+  exit 1
+fi