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ifx static library linking fails with MSVC, but works with Intel C++ — LLVM backend issue?

Kuoling
Beginner
‎07-19-2025 12:20 AM
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I'm transitioning from ifort (classic) to ifx (LLVM-based) and hit a linking issue specific to MSVC.

When I compile a Fortran static library with ifort, it links cleanly into a C++ application built with either Intel C++ or MSVC. But when I generate the static library with ifx, linking works with Intel C++, but fails with MSVC—typically due to linking issue (unresolved symbols).

I suspect this is related to ifx being LLVM-based and generating object files (.obj) or .lib archives that are not fully compatible with MSVC's linker, especially for static linking.

  • Has anyone successfully used ifx to produce a static .lib that links into MSVC-built code?

  • Are there known issues with COFF/ABI compatibility due to the LLVM backend?

Target: Windows x64, MSVC 2022 (C++ version 19.44; SDK version 10.0.22621), Intel oneAPI 2025.2

Thanks.

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Steve_Lionel
Honored Contributor III
‎07-19-2025 10:33 AM
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It would help if you showed the errors. I have built many C++/Fortran applications using the Microsoft C++ compiler and not had any issues. 

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