Using a `CMakePresets.json` file makes it much easier to manage
several alternate build configurations, such as the "ClangCL"
build for Windows. This also makes it easier for tools like
VSCode to run CMake-based builds.
It's not possible to build `gemma.cpp` with the standard MSVC front-end
as it doesn't support arrays more than `0x7ffffffff` bytes (see Compiler Error C2148),
however this isn't a problem with the optional Visual Studio Clang/LLVM frontend.
This can be specified using the `-T` flag when running CMake:
```
$ cmake -B build -T ClangCL
$ cmake --build build --config Release
```
Windows doesn't provide `pread`/`pwrite` so this must be emulated using
the `ReadFile`/`WriteFile` Win32 APIs.
`_CRT_SECURE_NO_WARNINGS` is defined to prevent a large number of warnings
about using "depricated" function names (e.g. `close` instead of `_close`).
`NOMINMAX` is defined to prevent the `min`/`max` macros from `windows.h`
from conflicting with expressions like `std::min`. Generally libraries should
avoid including `windows.h` in their public headers or define `WIN32_LEAN_AND_MEAN`
before including the `windows.h` header, but this unfortunately isn't always the case.
Discussed using dev branch instead of main branch for development.
We could revisit this once CI is hardened to test end-to-end correctness.
PiperOrigin-RevId: 609500897
Dan Zheng
Austin Huang
Austin Huang
Yuta Hayashibe
Jan Wassenberg
Ikko Eltociear Ashimine
Jan Wassenberg
The gemma.cpp Authors
David Coles
Silvio Traversaro