i#1551 port to ARM: add cross-compile to unix suite

Commit log for first patchset:
---------------
i#1551 port to ARM: add cross-compile to unix suite

Adds two cross-compile builds to the unix test suite
to verify that the ARM build works. Skips ARM tests.
---------------

[Byron, 2015-12-14 00:38:17]

I can't find any way to disable the output of ctest_configure(), so it will
print the dreaded "Error(s) while configuring the project" for the optional ARM
build. The suite still passes though.

https://codereview.appspot.com/281820043/diff/1/suite/runsuite.cmake
File suite/runsuite.cmake (right):

https://codereview.appspot.com/281820043/diff/1/suite/runsuite.cmake#newcode269
suite/runsuite.cmake:269: set(arm_cross_compile ON)
These two variables could be new args to testbuild_ex(), though they are not
used anywhere else.

[bruening, 2015-12-14 15:55:49]

https://codereview.appspot.com/281820043/diff/1/suite/runsuite.cmake
File suite/runsuite.cmake (right):

https://codereview.appspot.com/281820043/diff/1/suite/runsuite.cmake#newcode266
suite/runsuite.cmake:266: if (UNIX)
Not a sufficient if(): this should not be done if the suite is being run on ARM

https://codereview.appspot.com/281820043/diff/1/suite/runsuite.cmake#newcode267
suite/runsuite.cmake:267: set(run_tests OFF)
It would be better to simply ensure that no tests are enabled for running for a
cross-compilation build, as we don't want "ctest" from that build dir to try
running anything.

https://codereview.appspot.com/281820043/diff/1/suite/runsuite.cmake#newcode269
suite/runsuite.cmake:269: set(arm_cross_compile ON)
Seems better to unset ARCH_IS_X86, right?

https://codereview.appspot.com/281820043/diff/1/suite/runsuite.cmake#newcode270
suite/runsuite.cmake:270: testbuild_ex("arm-debug-internal-build-only-32" OFF "
"build-only" should not be in the name -- we already have build-only builds and
they do not have this in the name.

https://codereview.appspot.com/281820043/diff/1/suite/runsuite_common_pre.cmake
File suite/runsuite_common_pre.cmake (right):

https://codereview.appspot.com/281820043/diff/1/suite/runsuite_common_pre.cma...
suite/runsuite_common_pre.cmake:601: message("Warning: cross-compile for ARM is
not available--skipping ARM build")
Will this be lost in the output when using ctest -V or -VV?  Can we put this in
the summary too?

[Byron, 2015-12-14 21:37:02]

Commit log for latest patchset:
---------------
i#1551 port to ARM: add cross-compile to unix suite

Adds two cross-compile builds to the unix test suite
to verify that the ARM build works. Skips ARM tests.

Review-URL: https://codereview.appspot.com/281820043
---------------

[Byron, 2015-12-14 21:38:46]

The summary now looks like this when the ARM cross-compile is not available:


==================================================
RESULTS

arm-debug-internal-32: build successful; skipped (platform unavailable)
arm-release-external-32: build successful; skipped (platform unavailable)
debug-internal-32: all 230 tests passed
debug-internal-64: all 224 tests passed
release-external-32: build successful; no tests for this build
release-external-64: build successful; no tests for this build
vmsafe-debug-internal-32: build successful; no tests for this build
vps-debug-internal-32: build successful; no tests for this build

Error in read script: /hd/crowd-safe/drjo/dr1/dynamorio/suite/runsuite.cmake

https://codereview.appspot.com/281820043/diff/1/suite/runsuite.cmake
File suite/runsuite.cmake (right):

https://codereview.appspot.com/281820043/diff/1/suite/runsuite.cmake#newcode266
suite/runsuite.cmake:266: if (UNIX)
On 2015/12/14 15:55:48, bruening wrote:
> Not a sufficient if(): this should not be done if the suite is being run on
ARM

Done.

https://codereview.appspot.com/281820043/diff/1/suite/runsuite.cmake#newcode267
suite/runsuite.cmake:267: set(run_tests OFF)
On 2015/12/14 15:55:48, bruening wrote:
> It would be better to simply ensure that no tests are enabled for running for
a
> cross-compilation build, as we don't want "ctest" from that build dir to try
> running anything.

Done.

https://codereview.appspot.com/281820043/diff/1/suite/runsuite.cmake#newcode269
suite/runsuite.cmake:269: set(arm_cross_compile ON)
On 2015/12/14 15:55:48, bruening wrote:
> Seems better to unset ARCH_IS_X86, right?

Done, though it still requires manually clearing the CFLAGS, since environment
variables do not obey the normal scope rules.

https://codereview.appspot.com/281820043/diff/1/suite/runsuite.cmake#newcode270
suite/runsuite.cmake:270: testbuild_ex("arm-debug-internal-build-only-32" OFF "
On 2015/12/14 15:55:48, bruening wrote:
> "build-only" should not be in the name -- we already have build-only builds
and
> they do not have this in the name.

Done.

https://codereview.appspot.com/281820043/diff/1/suite/runsuite_common_pre.cmake
File suite/runsuite_common_pre.cmake (right):

https://codereview.appspot.com/281820043/diff/1/suite/runsuite_common_pre.cma...
suite/runsuite_common_pre.cmake:601: message("Warning: cross-compile for ARM is
not available--skipping ARM build")
On 2015/12/14 15:55:49, bruening wrote:
> Will this be lost in the output when using ctest -V or -VV?  Can we put this
in
> the summary too?

Done.

[Byron, 2015-12-14 21:40:25]

Correction (pasted a buggy summary above): 
 
 
 ==================================================
 RESULTS
 
 arm-debug-internal-32: skipped (platform unavailable)
 arm-release-external-32: skipped (platform unavailable)
 debug-internal-32: all 230 tests passed
 debug-internal-64: all 224 tests passed
 release-external-32: build successful; no tests for this build
 release-external-64: build successful; no tests for this build
 vmsafe-debug-internal-32: build successful; no tests for this build
 vps-debug-internal-32: build successful; no tests for this build
 
 Error in read script: /hd/crowd-safe/drjo/dr1/dynamorio/suite/runsuite.cmake

[bruening, 2015-12-15 16:47:09]

A few issues to clean up some hardcoded vs generic behavior, but after that LGTM

https://codereview.appspot.com/281820043/diff/20001/suite/runsuite_common_pre...
File suite/runsuite_common_pre.cmake (right):

https://codereview.appspot.com/281820043/diff/20001/suite/runsuite_common_pre...
suite/runsuite_common_pre.cmake:592: if (optional_build)
Add an XXX about this being a hidden param via global var that would be cleaner
as a real param but that would break back compat.  Add a note about it as
another param to the comment at the top of testbuild_ex.

https://codereview.appspot.com/281820043/diff/20001/suite/runsuite_common_pre...
suite/runsuite_common_pre.cmake:598: message("Warning: cross-compile for ARM is
not available--skipping ARM build")
This hardcoded message about an ARM cross-compile for a generic variable
"optional_build" does not seem right.  This should be changed to just print sthg
generic like "optional build ${name} failed".

https://codereview.appspot.com/281820043/diff/20001/suite/runsuite_common_pre...
suite/runsuite_common_pre.cmake:599: file(WRITE
${CTEST_BINARY_DIRECTORY}/Testing/platform-unavailable "${name}")
The docs for "optional_build" should state that it is meant for
cross-compilation or other cases, to justify this "platform unavailable"
message.  Maybe it should be "optional_cross_compile" or sthg.

[Byron, 2015-12-18 03:47:23]

Committed as
https://github.com/DynamoRIO/dynamorio/commit/beacb913e0b6dbeb80f69a6cc13e1d0...

Final commit log: 
---------------
i#1551 port to ARM: add cross-compile to unix suite

Adds two cross-compile builds to the unix test suite
to verify that the ARM build works. Skips ARM tests.

Review-URL: https://codereview.appspot.com/281820043
---------------

[Byron, 2015-12-18 03:49:28]

https://codereview.appspot.com/281820043/diff/20001/suite/runsuite_common_pre...
File suite/runsuite_common_pre.cmake (right):

https://codereview.appspot.com/281820043/diff/20001/suite/runsuite_common_pre...
suite/runsuite_common_pre.cmake:592: if (optional_build)
On 2015/12/15 16:47:09, bruening wrote:
> Add an XXX about this being a hidden param via global var that would be
cleaner
> as a real param but that would break back compat.  Add a note about it as
> another param to the comment at the top of testbuild_ex.

Done.

https://codereview.appspot.com/281820043/diff/20001/suite/runsuite_common_pre...
suite/runsuite_common_pre.cmake:598: message("Warning: cross-compile for ARM is
not available--skipping ARM build")
On 2015/12/15 16:47:09, bruening wrote:
> This hardcoded message about an ARM cross-compile for a generic variable
> "optional_build" does not seem right.  This should be changed to just print
sthg
> generic like "optional build ${name} failed".

Done.

https://codereview.appspot.com/281820043/diff/20001/suite/runsuite_common_pre...
suite/runsuite_common_pre.cmake:599: file(WRITE
${CTEST_BINARY_DIRECTORY}/Testing/platform-unavailable "${name}")
On 2015/12/15 16:47:09, bruening wrote:
> The docs for "optional_build" should state that it is meant for
> cross-compilation or other cases, to justify this "platform unavailable"
> message.  Maybe it should be "optional_cross_compile" or sthg.

Done.