build: Add CMake build

[HuidaeCho]

This PR replaces #3021. Branched from https://github.com/nilason/grass/tree/cmake_build_work. Thanks @nilason!

Current status: I can compile the entire gisbase using CMake 3.29.1 and GCC 13.2.0. Running grass directly from build/gisbase works fine.

Windows Tests

For my records, message from message(WIN32=${WIN32}, MSVC=${MSVC}, MSYS=${MSYS}, MINGW=${MINGW}) on Windows (all from cmd in ssh):

• Using MSYS cmake (cmd for MSVC): WIN32=,MSVC=,MSYS=1,MINGW= (WIN32 not set?)
  • CMake no longer defines WIN32 on MSYS xmrig/xmrig#950
  • https://developercommunity.visualstudio.com/t/win32-not-defined/722576
• Using MinGW-w64 cmake (bash for MinGW-w64 GCC): WIN32=1,MSVC=,MSYS=,MINGW=1

CMake variables:

• WIN32
• MSVC
• MSYS
• MINGW

TODOs

• Windows
• macOS
• locale
• addon support
• ...

Documentation

@Mahesh1998 and I are testing, fixing, and documenting this PR on Ubuntu. https://github.com/Mahesh1998/grass-docs/blob/main/cmake_build_docs/

• Slackware with system libraries
• Ubuntu with system libraries
• Ubuntu with Conda libraries (without root permissions)
• Windows with Conda libraries

Building on Slackware with Conda packages

Install Miniconda

wget https://repo.anaconda.com/miniconda/Miniconda3-latest-Linux-x86_64.sh
chmod a+x Miniconda3-latest-Linux-x86_64.sh
./Miniconda3-latest-Linux-x86_64.sh -b -u -p ~/usr/local/opt/miniconda
~/usr/local/opt/miniconda/bin/conda init
. ~/.bashrc
conda config --add channels conda-forge
conda config --set channel_priority strict

Create a new environment and install libraries

conda create -n grass
conda activate grass
conda install proj libgdal fftw blas libpdal wxpython

Build GRASS

mkdir build
cd build
# ignore warnings about runtime path (Conda libraries will be picked over system libraries)
cmake .. -DCMAKE_PREFIX_PATH=$HOME/usr/local/opt/miniconda/envs/grass
make -j`nproc`

Run GRASS

./output/bin/grass

[echoix]

It's really nice to see this real collaborative effort all on one PR. Many different authors all for one same goal.

[HuidaeCho]

It's really nice to see this real collaborative effort all on one PR. Many different authors all for one same goal.

Yes, this is really great!

[echoix]

Resolved one conflict manually

[HuidaeCho]

Resolved one conflict manually

Thanks!

[echoix]

Once #4101 is merged (soon), there will be a new configure flag in the header files to integrate.

[HuidaeCho]

msvc/gettimeofday.c is copied from https://github.com/postgres/postgres/blob/master/src/port/win32gettimeofday.c based on the commit log of the original PR: add gettimeofday windowss implemenation from postgresql. I assume we can use this file in GRASS because their license is BSD or MIT-like (more permissive than GPL). If that's not the case, there is another version from StackOverflow and we may be able to use it, but I'm not a copyright expert.

[lbartoletti]

I assume we can use this file in GRASS because their license is BSD or MIT-like

Yes, you can re use it.