cmake updates required

[nbuwe]

cmake is now in its cmake-4.* versions (e.g. pkgsrc 2025Q3 provides cmake-4.1.1) and they have dropped compatibility with the old versions.

Self cmake files set:

cmake_minimum_required(VERSION 2.8 FATAL_ERROR)

and newer cmake refuses to work with that, as its minimum compat level is 3.5. The problem is that Self's cmake files don't seem to work with 3.5.

Current files with cmake-3.* warn:

CMake Warning (dev) in vm/CMakeLists.txt:
  Policy CMP0043 is not set: Ignore COMPILE_DEFINITIONS_<Config> properties.
  Run "cmake --help-policy CMP0043" for policy details.  Use the cmake_policy
  command to set the policy and suppress this warning.

If I bump the minimum version to

cmake_minimum_required(VERSION 3.5 FATAL_ERROR)

The flags from COMPILE_DEFINITIONS_<Config> disappear from the build flags:

$ grep --count IS_FOR build-debug{,-3.5}/vm/CMakeFiles/Self.dir/flags.make
build-debug/vm/CMakeFiles/Self.dir/flags.make:2
build-debug-3.5/vm/CMakeFiles/Self.dir/flags.make:0

PS: This is also related to #141 where the same flags are missing from the precompiled header rules messing up precompiled header use.

[russellallen]

I have created a new branch https://github.com/russellallen/self/tree/cmake-update with a commit which bumps required version of CMake to 3.12, which CMake4 seems OK with.

Things build fine with GCC on amd64 Linux.

Not sure what to do with old MacOS, if we are to keep it compiling I need to get up a build enironment and I'm not sure what CMake versions are available.

[nbuwe]

But does that build gets the same defines? You'll probably find it's missing these flags:

-DGENERATE_ASSERTIONS=""
-DGENERATE_DEBUGGING_AIDS=1
-DSPEND_TIME_FOR_DEBUGGING_BY_DEFAULT=1
-DTARGET_IS_FOR_DEBUGGING=1
-DTARGET_IS_OPTIMIZED=0
-DTARGET_IS_PROFILED=0

(the values are for Debug build), exactly the ones set in configurations.cmake via COMPILE_DEFINITIONS_<Config> that the cmake currently complains about:

CMake Warning (dev) in vm/CMakeLists.txt:
  Policy CMP0043 is not set: Ignore COMPILE_DEFINITIONS_<Config> properties.
  Run "cmake --help-policy CMP0043" for policy details.  Use the cmake_policy
  command to set the policy and suppress this warning.
This warning is for project developers.  Use -Wno-dev to suppress it.

and exactly the ones that precompiled headers misses (#141).

[russellallen]

Sorry, didn’t explain myself well. I didn’t just increase the required Cmake minimum version but also reworked configurations.cmake to use a cmake 3.12 facility for adding flags. It seems to work, ie Release and Debug have different and appropriate flags. But I’m not convinced I’m doing it right just yet.

Edit: ok, i think i understand the issue a bit more, i need to look more into how this is working with #141

[russellallen]

New attempt at 439c1e8

Seems to work(TM)

[nbuwe]

That looks good, indeed! And incls/_precompiled.hh.gch seems to get the right flags now (#141).

But now I run into another problem with newer cmake. vm/cmake/netbsd.cmake has

macro(setup_target target)
  # "super"
  setup_target_common(${target})

  add_custom_command(TARGET ${PROJECT_NAME} POST_BUILD
    COMMAND paxctl +m "$<TARGET_FILE:${PROJECT_NAME}>"
    VERBATIM)
endmacro()

which used to warn about:

CMake Warning (dev) at vm/cmake/netbsd.cmake:73 (add_custom_command):
  Policy CMP0040 is not set: The target in the TARGET signature of
  add_custom_command() must exist and must be defined in the current
  directory.  Run "cmake --help-policy CMP0040" for policy details.  Use the
  cmake_policy command to set the policy and suppress this warning.

  No TARGET 'Self' has been created in this directory.
Call Stack (most recent call first):
  vm/cmake/makeDeps.cmake:15 (setup_target)
  vm/CMakeLists.txt:79 (include)
This warning is for project developers.  Use -Wno-dev to suppress it.

but with the raised compat level it's now an error:

CMake Error at vm/cmake/netbsd.cmake:73 (add_custom_command):
  No TARGET 'Self' has been created in this directory.
Call Stack (most recent call first):
  vm/cmake/makeDeps.cmake:15 (setup_target)
  vm/CMakeLists.txt:79 (include)

As that code was just cargo-culted from somewhere, I'm not sure, off the top of my head, how to properly fix this. Advise is appreciated.

[nbuwe]

The precompiled header rule still seems to be missing optimization flags and that affects the preprocessor defines. E.g. with my bugfix/macos-powerpc branch (never mind the "powerpc" in the name) with cmake-update merged on top, I get the following on x86 macos (Xcode 8.2.1, SDK 10.10):

error: __OPTIMIZE__ predefined macro was disabled in PCH file but is currently enabled

b/c the precompiled header rule is missing -O3 -DNDEBUG.