Unable to link rust static lib to C code on 1.57.0

[PunitLodha]

I am working on ccextractor, and recently the tests failed on rustc 1.57.0, with the error:-

"D:\a\ccextractor\ccextractor\windows\ccextractor.sln" (default target) (1) ->
"D:\a\ccextractor\ccextractor\windows\ccextractor.vcxproj" (default target) (2) ->
(Link target) -> 
  ccx_rust.lib(std-f87c887dcbebcf7e.std.06878a67-cgu.0.rcgu.o) : error LNK2019: unresolved external symbol __imp_BCryptGenRandom referenced in function _ZN3std6thread5local4fast12Key$LT$T$GT$14try_initialize17h6f0eaa92973cfc73E [D:\a\ccextractor\ccextractor\windows\ccextractor.vcxproj]
  D:\a\ccextractor\ccextractor\windows\x64\Release\ccextractorwin.exe : fatal error LNK1120: 1 unresolved externals [D:\a\ccextractor\ccextractor\windows\ccextractor.vcxproj]

Error relates to an undefined symbol __imp_BCryptGenRandom referenced in std:: thread::localfastkey::try_initialize
Switching to rustc 1.56.0 or below does not cause any errors

Here are the logs for 1.57.0 test run, and here for 1.56.0 test run.

Looking into the static libraries, only the lib built with 1.57.0 has the symbol specified in the error

C:\ccextractor>dumpbin /symbols ccx_rust_1-56.lib | FIND "BCrypt"

C:\ccextractor>dumpbin /symbols ccx_rust_1-57.lib | FIND "BCrypt"
3283 00000000 UNDEF  notype       External     | __imp_BCryptGenRandom

[hkratz]

Are you targetting Windows XP? #84096 introduced a dependency on BCryptGenRandom which is not available in XP. XP support has been dropped a while ago.

@rustbot label O-windows A-linkage

[PunitLodha]

I am using the i686-pc-windows-msvc target. Is that causing this issue?

[ChrisDenton]

You need to link Bcrypt.lib as well. When using a static library outside of Rust, the required import libraries won't be linked automatically.

[bjorn3]

If you compile the staticlib with --print native-static-libs rustc will print all extra linker arguments you need.

[Luthaf]

It looks like bcrypt is no longer included in --print native-static-libs for rustc 1.78, which make linking fail with the error above in my project:

Rust 1.77.2: https://github.com/lab-cosmo/metatensor/actions/runs/8907669658/job/24461939439

Cargo default link libraries are: kernel32;advapi32;bcrypt;ntdll;userenv;ws2_32;$<$CONFIG:Debug:msvcrtd>

($<$<CONFIG:Debug>:msvcrtd> is some manual post-processing, cargo returns msvcrt)

Rust 1.78.0: https://github.com/lab-cosmo/metatensor/actions/runs/8925096694/job/24512982693?pr=605

Cargo default link libraries are: kernel32;advapi32;ntdll;userenv;ws2_32;$<$CONFIG:Debug:msvcrtd>

I am getting this list in CMake by calling cargo rustc --target=... -- --print=native-static-libs on a new empty project. Could it be that this is now detecting whether there is actually a need for bcrypt inside the project?

[bjorn3]

I believe instead of referencing an external import library for bcrypt we now embed one inside the staticlib we output, thus avoiding the need to specify it as linker arg.

[ChrisDenton]

Yes std no longer uses bcrypt. If another crate is relying on it then --print=native-static-libs won't be aware unless that crate is included when it's building.