Error when building both static and shared libs on Windows with MSVC

[adriendelsalle]

Description

It's currently not possible to build both static and shared versions of libraries on Windows when using the MSVC-based toolchain because both variants produce a .lib file with the exact same output name.

For the shared libs it represents the export file and for static libs, the library itself.
It would be nice to detect such cases and automatically suffix the output name of the static lib with _static to disambiguate. It is also well documented in a conda-forge enhancement proposal.

I'll open a PR to discuss a possible fix!

Steps to reproduce

I'm building the project using a conda environment:

micromamba create -n sundials -y c-compiler cmake ninja
micromamba activate sundials
cmake -LAH -G "Ninja" -B build -DCMAKE_BUILD_TYPE=Release -DBUILD_SHARED_LIBS=ON -DBUILD_STATIC_LIBS=ON -S .
ninja -C build

Then you get at the last step:

ninja: error: build.ninja:997: multiple rules generate bin/sundials_core.lib

[balos1]

Hi @adriendelsalle, yes this is a known issue. A fix is currently in development. It is similar to your PR #455, but with an option for the user to control what is done. We would appreciate it if you could test the fix out when it is ready.

[adriendelsalle]

Sure! Could you share a link when ready for testing? Thanks for the quick reply :)

[adriendelsalle]

I also noticed that the SUNDIALS_EXPORT macro seems invalid when building both variants:

In the following code, sundials_core refers to the shared lib when building both static and shared ones;

sundials/src/sundials/CMakeLists.txt

Lines 159 to 164 in b685654

	include(GenerateExportHeader)
	generate_export_header(
	sundials_core BASE_NAME SUNDIALS
	EXPORT_FILE_NAME
	"${PROJECT_BINARY_DIR}/include/sundials/sundials_export.h"
	)

causing CMake's generate_export_header to generate the following sundials_export.h:

#ifdef SUNDIALS_STATIC_DEFINE
#  define SUNDIALS_EXPORT
#  define SUNDIALS_NO_EXPORT
#else
#  ifndef SUNDIALS_EXPORT
#    ifdef sundials_core_EXPORTS
        /* We are building this library */
#      define SUNDIALS_EXPORT __declspec(dllexport)
#    else
        /* We are using this library */
#      define SUNDIALS_EXPORT __declspec(dllimport)
#    endif
#  endif

but SUNDIALS_STATIC_DEFINE is set as PRIVATE compile definition of static targets:

sundials/cmake/macros/SundialsAddLibrary.cmake

Line 203 in b685654

target_compile_definitions(${obj_target} PRIVATE SUNDIALS_STATIC_DEFINE)

and

sundials/cmake/macros/SundialsAddLibrary.cmake

Line 299 in b685654

target_compile_definitions(${_actual_target_name} PRIVATE SUNDIALS_STATIC_DEFINE)

Causing the SUNDIALS_EXPORT macro to expand to __declspec(dllimport) even for the static target. Using MSVC it leads to this kind of errors: error LNK2019: unresolved external symbol __imp_CVodeSetLinearSolver (see https://stackoverflow.com/a/5159395)

I think SUNDIALS_STATIC_DEFINE should be a PUBLIC compile definition for static libs

[balos1]

Closed by #455.