Add cmake setting to build as dll

[TheGreatSageEqualToHeaven]

Adds LUAU_EXPORT_DLL to CMakeLists.txt.

[Mooshua]

This doesn't really work in practice, and shared linking to the Analysis target will require a little more spice.

In my build setup I compile lapi (plus other files that implement the core api), lcodegen, and lcode into a shared library, and then privately link that with the VM, Compiler, and CodeGen targets. On MSVC (with some added tuning of compiler flags) this builds into a little over 700kb.

add_subdirectory(pkg/luau)

add_library(Luau.Shared SHARED
    pkg/luau/VM/src/lapi.cpp
    pkg/luau/VM/src/laux.cpp
    pkg/luau/VM/src/lstate.cpp
    pkg/luau/VM/src/linit.cpp
    pkg/luau/VM/src/ldo.cpp
    pkg/luau/VM/src/lbaselib.cpp
    pkg/luau/VM/src/lvmload.cpp

    pkg/luau/CodeGen/src/lcodegen.cpp
    pkg/luau/Compiler/src/lcode.cpp
)
target_link_libraries(Luau.Shared PRIVATE Luau.VM Luau.Compiler Luau.CodeGen)
target_link_libraries(Luau.Shared PUBLIC Luau.Common Luau.Ast)

IF (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
    target_compile_definitions(Luau.Shared PRIVATE "LUA_API=__declspec(dllexport)")
    target_compile_definitions(Luau.Shared PRIVATE "LUACODE_API=__declspec(dllexport)")
    target_compile_definitions(Luau.Shared PRIVATE "LUACODEGEN_API=__declspec(dllexport)")

    target_compile_definitions(Luau.Shared INTERFACE "LUA_API=__declspec(dllimport)")
    target_compile_definitions(Luau.Shared INTERFACE "LUACODE_API=__declspec(dllimport)")
    target_compile_definitions(Luau.Shared INTERFACE "LUACODEGEN_API=__declspec(dllimport)")
ENDIF()

PS: This uses a local patch to remove the Luau.VM.Internal dependency from lcodegen.cpp. Nothing major, just deleting the lapi.h include.

[TheGreatSageEqualToHeaven]

This doesn't really work in practice, and shared linking to the Analysis target will require a little more spice.

This does work in practice and has worked in practice for the past nearly 4 years, however I only use it purely for linking with C# (without Analysis at all) so perhaps for your cases it wouldn't work.

[Mooshua]

This does work in practice and has worked in practice for the past nearly 4 years
@TheGreatSageEqualToHeaven

It doesn't even compile.

[TheGreatSageEqualToHeaven]

It doesn't even compile.

+ the existing image of me literally using the dll that I compiled with my changes in my original reply?

[TheGreatSageEqualToHeaven]

@vegorov-rbx