Hi Chris,
Thanks for doing this. I've had a quick scan and I have a few minor comments.
# Scripting overview
This is personal preference but I don't like ``add_definitions()`` due
to its global behaviour so I think its use should be discouraged. I
much prefer ``target_compile_definitions()`` which isn't global.
# Dereferencing
One "Gotcha" I think that is worth mentioning is implicit derefencing
of variables in ``if()`` conditionals
for example
```
if ("${SOME_VAR}" STREQUAL "MSVC")
```
behaves very strangely because CMake will implicitly dereference
"MSVC" (as if it was "${MSVC}") where as someone reading the code
probably thinks that it is trying to check if the contents of the
SOME_VAR as a string are "MSVC".
This behaviour is prevented by setting CMP0054 to NEW but this was
only introduced with CMake 3.1 and I don't think that's LLVM's minimum
version so developers might hit this issue. Run ``cmake --help-policy
CMP0054`` for more details.
A hacky work around I employ is to write conditionals like that like this
```
if ("X${SOME_VAR}" STREQUAL "XMSVC")
```
It's not good though...
# Scope
You don't mention "GLOBAL" properties. IIRC LLVM's CMake code uses
these so it might be worth mentioning these
# LLVM specific macros/functions
LLVM's CMake code pretty much avoids using many of the standard CMake
commands for declaring targets favouring its own (sometimes
confusingly named, e.g. add_llvm_library Vs. llvm_add_library) which I
sometime find quite confusing. Seeing as this guide is aimed at LLVM
developers I think this document (or an accompanying document) should
describe these macros/functions.
Thanks,
Dan.
--
Powered by www.kitware.com
Please keep messages on-topic and check the CMake FAQ at:
http://www.cmake.org/Wiki/CMake_FAQ
Kitware offers various services to support the CMake community. For more
information on each offering, please visit:
CMake Support: http://cmake.org/cmake/help/support.html
CMake Consulting: http://cmake.org/cmake/help/consulting.html
CMake Training Courses: http://cmake.org/cmake/help/training.html
Visit other Kitware open-source projects at
http://www.kitware.com/opensource/opensource.html
Follow this link to subscribe/unsubscribe:
http://public.kitware.com/mailman/listinfo/cmake-developers
