Describe the motivation for the feature request

hipSYCL colorful debug output is great when viewed in the terminal. It's not so great when redirected to a file.

Currently, switching the colors off require rebuilding hipSYCL with HIPSYCL_DEBUG_NOCOLOR set, which is a bit inconvenient (additionally, there is no CMake support, so the compiler flags have to be tinkered with directly).

Describe the solution you'd like

Automatic detection of whether stderr/stdout is redirected based on isatty() result.

If applicable, describe alternatives you've considered

• Checking NO_COLOR environment variable. Could be complementary to the automatic detection.
• Leaving things the way they are.
• For the compiler plugin, using llvm::WithColor::error and its friends might be preferred to make the output more consistent with the rest of Clang messages.