[WIN] Preprocessing fails on paths with unicode characters

[facchinm]

As reported by @gril002 on arduino/Arduino#6816 , the preprocessor fails if launched from a path containing unicode characters.
The error message is

LLVM ERROR: Cannot chdir into "C:\Users\Gašper Gril

This call doesn't fails

"C:\Users\IEUser\Desktop\arduino-PR-beta1.9-BUILD-41\tools-builder\arduino-preprocessor\0.1.3/arduino-preprocessor" "C:\Users\GAPERG~1\AppData\Local\Temp\arduino_build_861144\preproc\ctags_target_for_gcc_minus_e.cpp" "" -- -std=gnu++11

This does

"C:\Users\Gašper Gril\Desktop\arduino-PR-beta1.9-BUILD-41\tools-builder\arduino-preprocessor\0.1.3/arduino-preprocessor" "C:\Users\GAPERG~1\AppData\Local\Temp\arduino_build_779924\preproc\ctags_target_for_gcc_minus_e.cpp" "" -- -std=gnu++11

The builder seems to mangle the path in strange ways but gcc is unaffected so I believe the bug is not there.

Unable to reproduce on Linux, testing on Mac later today

[facchinm]

Error from here: http://clang.llvm.org/doxygen/Tooling_8cpp_source.html which applies here https://github.com/arduino/arduino-preprocessor/blob/master/main.cpp#L290

[facchinm]

Does only affect Windows, Linux and Mac are unaffected as far as I have tested. The patch could be quite complicated, requiring to recompile the whole clang project

[facchinm]

Closing as "fixed" by arduino/arduino-builder@7de76a9