Allows sel_ldr.py to run arm binaries through qemu-arm.

Allows sel_ldr.py to run arm binaries through qemu-arm.

This only works on linux, so the script still errors out on non-linux platforms.

R=sbc@chromium.org
BUG=369189
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=269869

[Sam Clegg, 2014-05-01 19:19:10]

I created a bug for this issue.   Ideally we'd have unittests running in this
mode (and system qemu installed on the bots), but I'm OK with doing that as a
second stage.

https://codereview.chromium.org/262753005/diff/1/native_client_sdk/src/tools/...
File native_client_sdk/src/tools/sel_ldr.py (right):

https://codereview.chromium.org/262753005/diff/1/native_client_sdk/src/tools/...
native_client_sdk/src/tools/sel_ldr.py:15: sys.path.append(SCRIPT_DIR)
This is the default for python normally.

I think its a google3-ism that this is needed so we should probably instead
include this patch in the google3 import scripts.

I wonder if there is a way we can tell google3 python to behave like normal
python?

https://codereview.chromium.org/262753005/diff/1/native_client_sdk/src/tools/...
native_client_sdk/src/tools/sel_ldr.py:109: for path in
os.environ["PATH"].split(os.pathsep)]
Can probably drop these two lines?  Isn't it always called qemu-arm when its in
the system PATH?

https://codereview.chromium.org/262753005/diff/1/native_client_sdk/src/tools/...
native_client_sdk/src/tools/sel_ldr.py:126: '. Try installing QEMU
(http://wiki.qemu.org/).')
How about a separate FindQemu() function?

[cdonner, 2014-05-02 17:58:05]

https://codereview.chromium.org/262753005/diff/1/native_client_sdk/src/tools/...
File native_client_sdk/src/tools/sel_ldr.py (right):

https://codereview.chromium.org/262753005/diff/1/native_client_sdk/src/tools/...
native_client_sdk/src/tools/sel_ldr.py:15: sys.path.append(SCRIPT_DIR)
> I think its a google3-ism that this is needed so we should probably instead
> include this patch in the google3 import scripts.
Reverted.

> I wonder if there is a way we can tell google3 python to behave like normal
> python?
Unlikely, since it's not python that's the problem, it's the build system.

https://codereview.chromium.org/262753005/diff/1/native_client_sdk/src/tools/...
native_client_sdk/src/tools/sel_ldr.py:109: for path in
os.environ["PATH"].split(os.pathsep)]
> Can probably drop these two lines?  Isn't it always called qemu-arm when its
in
> the system PATH?
google3 has qemu_arm, but I noticed that the native_client repo has
toolchain/linux_x86/arm_trusted/qemu-arm.  I'm ok dropping qemu-arm since that
doens't seem to be common, but if that's the case perhaps the file in
arm_trusted here should be renamed?

https://codereview.chromium.org/262753005/diff/1/native_client_sdk/src/tools/...
native_client_sdk/src/tools/sel_ldr.py:126: '. Try installing QEMU
(http://wiki.qemu.org/).')
On 2014/05/01 19:19:10, Sam Clegg wrote:
> How about a separate FindQemu() function?

Done.

[Sam Clegg, 2014-05-08 18:10:51]

lgtm

[cdonner, 2014-05-12 20:23:12]

The CQ bit was checked by cdonner@chromium.org

[commit-bot: I haz the power, 2014-05-12 20:24:41]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/cdonner@chromium.org/262753005/40001

[cdonner, 2014-05-12 20:25:14]

The CQ bit was unchecked by cdonner@chromium.org

[cdonner, 2014-05-12 20:25:37]

The CQ bit was checked by cdonner@chromium.org

[commit-bot: I haz the power, 2014-05-12 20:26:21]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/cdonner@chromium.org/262753005/40001

[commit-bot: I haz the power, 2014-05-12 20:52:50]

Change committed as 269869