Specify sanitizer parameters in CMake

[wusatosi]

This PR attempts adopts @bretbrownjr 's suggestion in #44 (review).

You can use variables like CMAKE_CXX_FLAGS_Debug_INIT to tune what a Debug or Release build entails, for what it's worth. It's maybe a little nicer to use those variables instead of CMAKE_CXX_FLAGS. But not a huge deal.

https://cmake.org/cmake/help/latest/variable/CMAKE_LANG_FLAGS_CONFIG_INIT.html

However, instead of implementing a toolchain file, this PR introduces a apply_sanitzer util.

The reason for not adopting a toolchain file is because CMAKE_CXX_COMPILER_ID is not resolved during toolchain execution, which means we are unable to customize sanitizer use according to compiler support.

This PR updates CI script to use the new sanitizer utility.

This sanitizer utility exports an undocumented option of BEMAN_BUILDSYS_SANITIZER and is not to be used outside of internal build script/ preset/ CI. Using BEMAN_BUILDSYS as its namespace so that this functionality could be copied over across projects easily.

This PR fixes #65 as it does not add leak sanitizer when apple clang is detected, this needs testing (I think @camio have a mac environment?).

Preset change will be filed after #82 is merged.

[steve-downey]

"We need to verify CMAKE_CXX_COMPILER_ID for g++ on macos is AppleClang."

Confirm what the compiler identification is for the default false g++ on Darwin is.

Marking "Request changes" so this doesn't get landed prematurely.

[steve-downey]

So, yes:
The CXX compiler identification is AppleClang 16.0.0.16000026

[steve-downey]

Not sure if picking the toolchain for Darwin better, or making the generic toolchain smarter would work better, but either should work?

[ClausKlein]

Wait, that can't work!

iMac:exemplar clausklein$ cmake --preset gcc-debug  --trace-expand --trace-source=toolchain.cmake
Put cmake in trace mode, but with variables expanded.
Put cmake in trace mode, but output only lines of a specified file. Multiple options are allowed.
Preset CMake variables:

  BEMAN_BUILDSYS_SANITIZER="ASan"
  CMAKE_BUILD_TYPE="Debug"
  CMAKE_CXX_COMPILER="g++"
  CMAKE_CXX_STANDARD="20"
  CMAKE_TOOLCHAIN_FILE="cmake/toolchain.cmake"

/Users/clausklein/Workspace/cpp/beman-project/exemplar/cmake/toolchain.cmake(3):  set(CMAKE_C_FLAGS_RELEASE_INIT -O3 )
/Users/clausklein/Workspace/cpp/beman-project/exemplar/cmake/toolchain.cmake(4):  set(CMAKE_CXX_FLAGS_RELEASE_INIT -O3 )
/Users/clausklein/Workspace/cpp/beman-project/exemplar/cmake/toolchain.cmake(6):  set(CMAKE_C_FLAGS_RELWITHDEBINFO_INIT -O3 )
/Users/clausklein/Workspace/cpp/beman-project/exemplar/cmake/toolchain.cmake(7):  set(CMAKE_CXX_FLAGS_RELWITHDEBINFO_INIT -O3 )
/Users/clausklein/Workspace/cpp/beman-project/exemplar/cmake/toolchain.cmake(16):  if(DEFINED BEMAN_BUILDSYS_SANITIZER )
/Users/clausklein/Workspace/cpp/beman-project/exemplar/cmake/toolchain.cmake(17):  if(BEMAN_BUILDSYS_SANITIZER STREQUAL ASan )
/Users/clausklein/Workspace/cpp/beman-project/exemplar/cmake/toolchain.cmake(19):  set(SANITIZER_FLAGS -fsanitize=address -fsanitize=pointer-compare -fsanitize=pointer-subtract -fsanitize=undefined )
/Users/clausklein/Workspace/cpp/beman-project/exemplar/cmake/toolchain.cmake(24):  if(NOT CMAKE_CXX_COMPILER_ID )
/Users/clausklein/Workspace/cpp/beman-project/exemplar/cmake/toolchain.cmake(25):  message(WARNING toolchain is used before CMAKE_CXX_COMPILER_ID was set! )
CMake Warning at cmake/toolchain.cmake:25 (message):
  toolchain is used before CMAKE_CXX_COMPILER_ID was set!
Call Stack (most recent call first):
  build/gcc-debug/CMakeFiles/3.31.0-dirty/CMakeSystem.cmake:6 (include)
  CMakeLists.txt:5 (project)


/Users/clausklein/Workspace/cpp/beman-project/exemplar/cmake/toolchain.cmake(27):  if(APPLE )
/Users/clausklein/Workspace/cpp/beman-project/exemplar/cmake/toolchain.cmake(28):  message(STATUS Using GCC on macOS; excluding -fsanitize=leak )
-- Using GCC on macOS; excluding -fsanitize=leak
/Users/clausklein/Workspace/cpp/beman-project/exemplar/cmake/toolchain.cmake(44):  list(APPEND CMAKE_C_FLAGS_DEBUG_INIT -fsanitize=address -fsanitize=pointer-compare -fsanitize=pointer-subtract -fsanitize=undefined )
/Users/clausklein/Workspace/cpp/beman-project/exemplar/cmake/toolchain.cmake(45):  list(APPEND CMAKE_CXX_FLAGS_DEBUG_INIT -fsanitize=address -fsanitize=pointer-compare -fsanitize=pointer-subtract -fsanitize=undefined )
-- The CXX compiler identification is AppleClang 16.0.0.16000026
-- Detecting CXX compiler ABI info
/Users/clausklein/Workspace/cpp/beman-project/exemplar/cmake/toolchain.cmake(3):  set(CMAKE_C_FLAGS_RELEASE_INIT -O3 )
/Users/clausklein/Workspace/cpp/beman-project/exemplar/cmake/toolchain.cmake(4):  set(CMAKE_CXX_FLAGS_RELEASE_INIT -O3 )
/Users/clausklein/Workspace/cpp/beman-project/exemplar/cmake/toolchain.cmake(6):  set(CMAKE_C_FLAGS_RELWITHDEBINFO_INIT -O3 )
/Users/clausklein/Workspace/cpp/beman-project/exemplar/cmake/toolchain.cmake(7):  set(CMAKE_CXX_FLAGS_RELWITHDEBINFO_INIT -O3 )
/Users/clausklein/Workspace/cpp/beman-project/exemplar/cmake/toolchain.cmake(16):  if(DEFINED BEMAN_BUILDSYS_SANITIZER )
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/g++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
Examples to be built: identity_direct_usage;identity_as_default_projection
-- Configuring done (2.4s)

[wusatosi]

Not sure if picking the toolchain for Darwin better, or making the generic toolchain smarter would work better, but either should work?

I am leaning on having separate tool chain files and having like a central tool chain dispatch logic based on compiler and platform.

But then I realized there's not that much variance in building across platforms and compilers, at least in exemplar, to warrant separate files.

[ClausKlein]

But then I realized there's not that much variance in building across platforms and compilers, at least in exemplar, to warrant separate files.

That is why often I use the project_options
see i.e.: https://github.com/aminya/project_options/blob/main/src/Sanitizers.cmake

[wusatosi]

That is why often I use the project_options see i.e.: https://github.com/aminya/project_options/blob/main/src/Sanitizers.cmake

That's project looks fantastic!

I can bring this up in weekly sync and see if we want to use this.
Clang-tidy support, coverage, doxygen (and potentially vcpkg) are improvement features we would love to have, it would be fantastic if we can get all these done with this dependency.

[wusatosi]

Ah I think tool chain file is executed before project(), so CMAKE_CXX_COMPILER_ID maybe unset?

[ClausKlein]

Ah I think tool chain file is executed before project(), so CMAKE_CXX_COMPILER_ID maybe unset?

Yes, and call N times for each LANGUAGES enabled in project.

[wusatosi]

So I decide to not implement a toolchain file instead adding a generic apply_sanitizer util cmake script under the cmake directory. I will update the PR description accordingly.

I added a macos run of gcc-debug to confirm we are building correctly.

@steve-downey you may review and unblock this PR

[ClausKlein]

FYI: I have just added project_options as demo here:
bemanproject/execution26#80

[wusatosi]

nudging @steve-downey @neatudarius @camio to review as #80 maybe improved if this is merged.