Fix bitrot in Chrome clang tool infrastructure.

Fix bitrot in Chrome clang tool infrastructure.

- LLVM now uses C++11, so need to use LLVM_OVERRIDE anymore.
- Small changes in Clang interfaces for flags and FrontendFactory
  instantiation.
- clang-format-diff.py works slightly differently now, so update the
  run_tool.py wrapper to invoke it correctly.
- Delete tools that are no longer needed.

BUG=
R=thakis@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=287841

[dcheng, 2014-08-06 18:09:46]

Ideally we'd use the support for serializing a list of clang::Replacements into
YAML and then use clang-apply-replacements, which would remove the need for a
large portion of the run_tool.py helper script... but I'd rather get this
working again first.

[Nico, 2014-08-06 18:15:56]

rslgtm

https://codereview.chromium.org/448693003/diff/1/tools/clang/empty_string/Emp...
File tools/clang/empty_string/EmptyStringConverter.cpp (right):

https://codereview.chromium.org/448693003/diff/1/tools/clang/empty_string/Emp...
tools/clang/empty_string/EmptyStringConverter.cpp:185:
clang::tooling::newFrontendActionFactory(&match_finder);
Does c++11 library stuff work in tools? Does the build system set the rpath
right, or does the tool runner need to set LD_LIBRARY_PATH to let the tool find
libstdc++ 4.8 on linux (when running on Precise)?

[dcheng, 2014-08-06 20:06:54]

https://codereview.chromium.org/448693003/diff/1/tools/clang/empty_string/Emp...
File tools/clang/empty_string/EmptyStringConverter.cpp (right):

https://codereview.chromium.org/448693003/diff/1/tools/clang/empty_string/Emp...
tools/clang/empty_string/EmptyStringConverter.cpp:185:
clang::tooling::newFrontendActionFactory(&match_finder);
On 2014/08/06 18:15:56, Nico (very away) wrote:
> Does c++11 library stuff work in tools? Does the build system set the rpath
> right, or does the tool runner need to set LD_LIBRARY_PATH to let the tool
find
> libstdc++ 4.8 on linux (when running on Precise)?

The build system expects a "modern" C++ library to be installed and setup
correctly:

checking whether Clang will select a modern C++ standard library... no
configure: error:
We detected a missing feature in the standard C++ library that was known to be
missing in libstdc++4.6 and implemented in libstdc++4.7. There are numerous
C++11 problems with 4.6's library, and we don't support GCCs or libstdc++ older
than 4.7. You will need to update your system and ensure Clang uses the newer
standard library.

So I think it will just work as long as the dependencies are correctly set up.

[dcheng, 2014-08-06 20:08:34]

Committed patchset #1 manually as 287841 (presubmit successful).

[Nico, 2014-08-06 20:08:48]

On 2014/08/06 20:06:54, dcheng (OOO) wrote:
>
https://codereview.chromium.org/448693003/diff/1/tools/clang/empty_string/Emp...
> File tools/clang/empty_string/EmptyStringConverter.cpp (right):
> 
>
https://codereview.chromium.org/448693003/diff/1/tools/clang/empty_string/Emp...
> tools/clang/empty_string/EmptyStringConverter.cpp:185:
> clang::tooling::newFrontendActionFactory(&match_finder);
> On 2014/08/06 18:15:56, Nico (very away) wrote:
> > Does c++11 library stuff work in tools? Does the build system set the rpath
> > right, or does the tool runner need to set LD_LIBRARY_PATH to let the tool
> find
> > libstdc++ 4.8 on linux (when running on Precise)?
> 
> The build system expects a "modern" C++ library to be installed and setup
> correctly:
> 
> checking whether Clang will select a modern C++ standard library... no
> configure: error:
> We detected a missing feature in the standard C++ library that was known to be
> missing in libstdc++4.6 and implemented in libstdc++4.7. There are numerous
> C++11 problems with 4.6's library, and we don't support GCCs or libstdc++
older
> than 4.7. You will need to update your system and ensure Clang uses the newer
> standard library.
> 
> So I think it will just work as long as the dependencies are correctly set up.

No: It's possible to set CC and CXX to some gcc4.8 in a local folder but don't
get the RPATHs set. Then one needs to set LD_LIBRARY_PATH to make built binaries
run. (I know 'cause that's the state my linux box is in :-/)

But I suppose that's fine.