# Updating idl files

This directory has a variety of .idl files (such as corprof.idl) that need
a little special handling when you make changes. Originally when we built
on Windows only the build rules would automatically convert the idls into
corresponding .h/.c files and include them in compilations. On non-windows
platforms we don't have an equivalent for midl.exe which did that conversion
so we work around the issue by doing:

- Build on Windows as normal, which will generate files in artifacts\obj\Windows_NT.x64.Debug\src\inc\idls_out\
- Copy any updated headers into src\pal\prebuilt\inc\
- If needed, adjust any of the .cpp files in src\pal\prebuilt\idl\ by hand,
  using the corresponding
  artifacts\obj\Windows_NT.x64.Debug\src\inc\idls_out\*_i.c as a guide.
  Typically this is just adding MIDL_DEFINE_GUID(...)
  for any new classes/interfaces that have been added to the idl file.

Include these src changes with the remainder of your work when you submit a PR.
