VisualStudio CMake dynamic library: include/link all used functions in *single* dll

Question

I have a VisualStudio-2019 C++ Project which uses CMake and Ninja to build a dll, the Project uses functions from a few Libraries like protobuf and spdlog, which I have installed using vcpkg.

When building, the output gets written to four distinct dll files and all of them are needed for the main-dll to run. Below are two screenshots: left the current state and right the expected state.

The main.dll file should include all the functions it imports, the compiler shouldn't create separate dlls for each library.

I don't which know knob I need to turn, I can imagine several ways to edit:

• The C++ Code of the Project (Classes, inlining functions ?)
• The CMakeList.txt
• The Arguments of MSVC (compiler, linker flags)
• The Arguments of Ninja

Where should I start ?

Answer 1

Setting the mentioned flags or appending -static to the import library components had no effect, I went as far as

set(BUILD_SHARED_LIBS OFF)
set(CMAKE_EXE_LINKER_FLAGS "-static")
set(CMAKE_MODULE_LINKER_FLAGS "-static")
set(CMAKE_SHARED_LINKER_FLAGS "-static")
set(CMAKE_STATIC_LINKER_FLAGS "-static")

But this didn't help a bit.

As it turned out this is a problem with vcpkg: I had installed the packages with the triplet x64-windows, which builds for dynamic linkage, installing the packages with vcpkg install --triplet=x64-windows-static protobuf spdlog makes static linking possible. If the static variants are not installed, the build proceeds silently with the dynamic ones.