support python3-dll-a free-threaded generation

[davidhewitt]

Companion to PyO3/python3-dll-a#82, which fixes the generate-import-lib feature to correctly generate a library with the free-threaded symbols.

Without this fix, a build attempting to generate import libs for the free-threaded interpreter will fail with link errors:

Example build failure

$ /Users/david/.virtualenvs/pyo3-3.13t/bin/maturin build --target x86_64-pc-windows-msvc -i 3.13t
🔗 Found pyo3 bindings
🐍 Found CPython 3.13t
📡 Using build options features from pyproject.toml
  Manifest [0s] ============================================================ 11.39 MiB/11.39 MiB 📥 downloaded
  CRT.headers [0s] =========================================================== 17.50 MiB/17.50 MiB 📦 splatted
  CRT.libs.x86_64.desktop [0s] ============================================= 183.89 MiB/183.89 MiB 📦 splatted
  CRT.libs.x86_64.store [0s] ================================================= 65.38 MiB/65.38 MiB 📦 splatted
  CRT.libs.aarch64.desktop [0s] ============================================ 211.59 MiB/211.59 MiB 📦 splatted
  CRT.libs.aarch64.store [0s] ============================================== 114.20 MiB/114.20 MiB 📦 splatted
  SDK.headers.all.none [0s] ================================================== 89.79 MiB/89.79 MiB 📦 splatted
  SDK.headers.all.store [0s] =============================================== 219.85 MiB/219.85 MiB 📦 splatted
  SDK.headers.x86_64.none [0s] =============================================== 45.17 KiB/45.17 KiB 📦 splatted
  SDK.headers.aarch64.none [0s] ============================================ 103.02 KiB/103.02 KiB 📦 splatted
  SDK.libs.x86_64 [0s] ======================================================= 71.15 MiB/71.15 MiB 📦 splatted
  SDK.libs.aarch64 [0s] ==================================================== 131.90 MiB/131.90 MiB 📦 splatted
  SDK.libs.store.all [0s] ================================================== 116.26 MiB/116.26 MiB 📦 splatted
  SDK.ucrt.all [0s] ======================================================== 241.38 MiB/241.38 MiB 📦 splatted   Compiling target-lexicon v0.12.16
   Compiling python3-dll-a v0.2.10
   Compiling once_cell v1.20.2
   Compiling proc-macro2 v1.0.87
   Compiling unicode-ident v1.0.13
   Compiling libc v0.2.159
   Compiling autocfg v1.4.0
   Compiling heck v0.5.0
   Compiling cfg-if v1.0.0
   Compiling indoc v2.0.5
   Compiling unindent v0.2.3
   Compiling memoffset v0.9.1
   Compiling quote v1.0.37
   Compiling syn v2.0.79
   Compiling pyo3-build-config v0.23.2 (/Users/david/Dev/pyo3/pyo3-build-config)
   Compiling pyo3-macros-backend v0.23.2 (/Users/david/Dev/pyo3/pyo3-macros-backend)
   Compiling pyo3-ffi v0.23.2 (/Users/david/Dev/pyo3/pyo3-ffi)
   Compiling pyo3 v0.23.2 (/Users/david/Dev/pyo3)
   Compiling pyo3-macros v0.23.2 (/Users/david/Dev/pyo3/pyo3-macros)
   Compiling pyo3-scratch v0.1.0 (/Users/david/Dev/pyo3-scratch)
error: linking with `lld-link` failed: exit status: 1
  |
  = note: LC_ALL="C" PATH="/Users/david/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/bin:/Users/david/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/bin:/Users/david/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/bin:/Users/david/.virtualenvs/pyo3-3.13t/bin:/Users/david/.vscode/extensions/ms-python.python-2024.20.0-darwin-arm64/python_files/deactivate/zsh:/Users/david/.virtualenvs/pyo3-3.12/bin:/Users/david/.local/state/fnm_multishells/18789_1732889105618/bin:/Users/david/.pyenv/shims:/Users/david/.vscode/extensions/ms-python.python-2024.20.0-darwin-arm64/python_files/deactivate/zsh:/Users/david/.virtualenvs/pyo3-3.12/bin:/Library/Frameworks/Python.framework/Versions/3.12/bin:/Library/Frameworks/Python.framework/Versions/3.11/bin:/opt/homebrew/bin:/opt/homebrew/sbin:/usr/local/bin:/System/Cryptexes/App/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/local/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/appleinternal/bin:/Library/Apple/usr/bin:/Users/david/.vscode/extensions/ms-python.python-2024.20.0-darwin-arm64/python_files/deactivate/zsh:/Users/david/.virtualenvs/pyo3-3.12/bin:/Users/david/.local/state/fnm_multishells/48683_1732139667691/bin:/Users/david/Library/Python/3.10/bin:/Users/david/.fly/bin:/Users/david/.pyenv/bin:/Users/david/.local/bin:/Users/david/bin:/Library/Frameworks/Python.framework/Versions/3.12/bin:/Library/Frameworks/Python.framework/Versions/3.11/bin:/Users/david/.cargo/bin:/Users/david/Library/Caches/cargo-xwin:/opt/homebrew/opt/llvm/bin" VSLANG="1033" "lld-link" "-flavor" "link" "/DEF:/var/folders/z2/3t02d9cn6gxg11n5yd9yk3wm0000gn/T/rustc2DywIY/lib.def" "/NOLOGO" "/var/folders/z2/3t02d9cn6gxg11n5yd9yk3wm0000gn/T/rustc2DywIY/symbols.o" "/Users/david/Dev/pyo3-scratch/target/x86_64-pc-windows-msvc/debug/deps/pyo3_scratch.02et0owkctrmvfz0dmcic5d7g.rcgu.o" "/Users/david/Dev/pyo3-scratch/target/x86_64-pc-windows-msvc/debug/deps/pyo3_scratch.05m0kjpg46g339e1vjyhtr1a3.rcgu.o" "/Users/david/Dev/pyo3-scratch/target/x86_64-pc-windows-msvc/debug/deps/pyo3_scratch.0gv6ppfiwqjb2k0owwnr9qk7s.rcgu.o" "/Users/david/Dev/pyo3-scratch/target/x86_64-pc-windows-msvc/debug/deps/pyo3_scratch.0v3hqzjbwzyqpvhr328mo1ww1.rcgu.o" "/Users/david/Dev/pyo3-scratch/target/x86_64-pc-windows-msvc/debug/deps/pyo3_scratch.3d1hkur3kmdx2wpiadwn9t2gf.rcgu.o" "/Users/david/Dev/pyo3-scratch/target/x86_64-pc-windows-msvc/debug/deps/pyo3_scratch.5i0wevsvp9z3fruoy54j5eqrv.rcgu.o" "/Users/david/Dev/pyo3-scratch/target/x86_64-pc-windows-msvc/debug/deps/pyo3_scratch.6n0i2ikz0wi3wlqz77bvv2uqs.rcgu.o" "/Users/david/Dev/pyo3-scratch/target/x86_64-pc-windows-msvc/debug/deps/pyo3_scratch.b9t4aemh1lhqsbu27uorkwlq7.rcgu.o" "/Users/david/Dev/pyo3-scratch/target/x86_64-pc-windows-msvc/debug/deps/pyo3_scratch.bd7r31mqecl3v83f2twep3mnj.rcgu.o" "/Users/david/Dev/pyo3-scratch/target/x86_64-pc-windows-msvc/debug/deps/pyo3_scratch.bwtn1htiiqu10r8o4swzsxgbb.rcgu.o" "/Users/david/Dev/pyo3-scratch/target/x86_64-pc-windows-msvc/debug/deps/pyo3_scratch.cxrj19bft77hw7o67tyxh3qbd.rcgu.o" "/Users/david/Dev/pyo3-scratch/target/x86_64-pc-windows-msvc/debug/deps/pyo3_scratch.e1zvwjwr5yhusuqg5wbsniftz.rcgu.o" "/Users/david/Dev/pyo3-scratch/target/x86_64-pc-windows-msvc/debug/deps/pyo3_scratch.e7oc6yuhe5qnfvjd0q6q4hhmf.rcgu.o" "/Users/david/Dev/pyo3-scratch/target/x86_64-pc-windows-msvc/debug/deps/libpyo3-b289257478b5385f.rlib" "/Users/david/Dev/pyo3-scratch/target/x86_64-pc-windows-msvc/debug/deps/libcfg_if-d0ce6dd80f2f48e8.rlib" "/Users/david/Dev/pyo3-scratch/target/x86_64-pc-windows-msvc/debug/deps/libmemoffset-3a6bc25fb0ac8bff.rlib" "/Users/david/Dev/pyo3-scratch/target/x86_64-pc-windows-msvc/debug/deps/libonce_cell-e27dcc30812c3bcf.rlib" "/Users/david/Dev/pyo3-scratch/target/x86_64-pc-windows-msvc/debug/deps/libpyo3_ffi-65c802c964a36bd7.rlib" "/Users/david/Dev/pyo3-scratch/target/x86_64-pc-windows-msvc/debug/deps/liblibc-597c4c4e65d94977.rlib" "/Users/david/Dev/pyo3-scratch/target/x86_64-pc-windows-msvc/debug/deps/libunindent-1891a7bfdae04cc5.rlib" "/Users/david/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/x86_64-pc-windows-msvc/lib/libstd-2df1f22abef96888.rlib" "/Users/david/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/x86_64-pc-windows-msvc/lib/libpanic_unwind-7fa781213a0698f8.rlib" "/Users/david/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/x86_64-pc-windows-msvc/lib/libwindows_targets-2440cb72ce7deb9b.rlib" "/Users/david/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/x86_64-pc-windows-msvc/lib/librustc_demangle-f04b9120076f20fa.rlib" "/Users/david/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/x86_64-pc-windows-msvc/lib/libstd_detect-b521ee511095af2f.rlib" "/Users/david/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/x86_64-pc-windows-msvc/lib/libhashbrown-124aa6c4c6ef4b4c.rlib" "/Users/david/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/x86_64-pc-windows-msvc/lib/librustc_std_workspace_alloc-c86a42f7194744c8.rlib" "/Users/david/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/x86_64-pc-windows-msvc/lib/libunwind-a416069596473508.rlib" "/Users/david/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/x86_64-pc-windows-msvc/lib/libcfg_if-e246a9218bd1ed0e.rlib" "/Users/david/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/x86_64-pc-windows-msvc/lib/liballoc-8f9b5fcbcd27c22e.rlib" "/Users/david/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/x86_64-pc-windows-msvc/lib/librustc_std_workspace_core-65178e86c6c71ba8.rlib" "/Users/david/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/x86_64-pc-windows-msvc/lib/libcore-fbeb171b69c59b37.rlib" "/Users/david/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/x86_64-pc-windows-msvc/lib/libcompiler_builtins-e3a3e7896142045d.rlib" "python313.lib" "legacy_stdio_definitions.lib" "kernel32.lib" "kernel32.lib" "advapi32.lib" "ntdll.lib" "userenv.lib" "ws2_32.lib" "dbghelp.lib" "/defaultlib:msvcrt" "/NXCOMPAT" "/LIBPATH:/Users/david/Library/Caches/cargo-xwin/xwin/crt/lib/x86_64" "/LIBPATH:/Users/david/Library/Caches/cargo-xwin/xwin/sdk/lib/um/x86_64" "/LIBPATH:/Users/david/Library/Caches/cargo-xwin/xwin/sdk/lib/ucrt/x86_64" "/LIBPATH:/Users/david/Dev/pyo3-scratch/target/x86_64-pc-windows-msvc/debug/build/pyo3-ffi-5a070067b51aacc2/out/lib" "/OUT:/Users/david/Dev/pyo3-scratch/target/x86_64-pc-windows-msvc/debug/deps/pyo3_scratch.dll" "/OPT:REF,NOICF" "/DLL" "/IMPLIB:/Users/david/Dev/pyo3-scratch/target/x86_64-pc-windows-msvc/debug/deps/pyo3_scratch.dll.lib" "/DEBUG" "/PDBALTPATH:%_PDB%"
  = note: lld-link: error: undefined symbol: PyCriticalSection_End
          >>> referenced by /Users/david/Dev/pyo3/src/sync.rs:468
          >>>               libpyo3-b289257478b5385f.rlib(pyo3-b289257478b5385f.7q0hxo5wi51vmvn3nkkwjadpy.rcgu.o):(_$LT$pyo3..sync..with_critical_section..Guard$u20$as$u20$core..ops..drop..Drop$GT$::drop::he26faa4e81b86f55)
          
          lld-link: error: undefined symbol: PyUnstable_Module_SetGIL
          >>> referenced by /Users/david/Dev/pyo3/src/types/module.rs:557
          >>>               libpyo3-b289257478b5385f.rlib(pyo3-b289257478b5385f.5bo3y7fokwn52hwe7ta23uzl9.rcgu.o):(_$LT$pyo3..instance..Bound$LT$pyo3..types..module..PyModule$GT$$u20$as$u20$pyo3..types..module..PyModuleMethods$GT$::gil_used::hce71703d33b4e5ef)
          >>> referenced by /Users/david/Dev/pyo3/src/impl_/pymodule.rs:153
          >>>               libpyo3-b289257478b5385f.rlib(pyo3-b289257478b5385f.7x4tmlb1l4x543cf0qix0t7v5.rcgu.o):(pyo3::impl_::pymodule::ModuleDef::make_module::_$u7b$$u7b$closure$u7d$$u7d$::h5229d7969c833544)
          

error: could not compile `pyo3-scratch` (lib) due to 1 previous error
💥 maturin failed
  Caused by: Failed to build a native library through cargo
  Caused by: Cargo build finished with "exit status: 101": `env -u CARGO AR_x86_64_pc_windows_msvc="llvm-lib" BINDGEN_EXTRA_CLANG_ARGS_x86_64_pc_windows_msvc="-I/Users/david/Library/Caches/cargo-xwin/xwin/crt/include -I/Users/david/Library/Caches/cargo-xwin/xwin/sdk/include/ucrt -I/Users/david/Library/Caches/cargo-xwin/xwin/sdk/include/um -I/Users/david/Library/Caches/cargo-xwin/xwin/sdk/include/shared" CARGO_ENCODED_RUSTFLAGS="-C\u{1f}linker-flavor=lld-link\u{1f}-Lnative=/Users/david/Library/Caches/cargo-xwin/xwin/crt/lib/x86_64\u{1f}-Lnative=/Users/david/Library/Caches/cargo-xwin/xwin/sdk/lib/um/x86_64\u{1f}-Lnative=/Users/david/Library/Caches/cargo-xwin/xwin/sdk/lib/ucrt/x86_64" CARGO_TARGET_X86_64_PC_WINDOWS_MSVC_LINKER="lld-link" CC_x86_64_pc_windows_msvc="clang-cl" CFLAGS_x86_64_pc_windows_msvc="--target=x86_64-pc-windows-msvc -Wno-unused-command-line-argument -fuse-ld=lld-link /imsvc/Users/david/Library/Caches/cargo-xwin/xwin/crt/include /imsvc/Users/david/Library/Caches/cargo-xwin/xwin/sdk/include/ucrt /imsvc/Users/david/Library/Caches/cargo-xwin/xwin/sdk/include/um /imsvc/Users/david/Library/Caches/cargo-xwin/xwin/sdk/include/shared  " CL_FLAGS="--target=x86_64-pc-windows-msvc -Wno-unused-command-line-argument -fuse-ld=lld-link /imsvc/Users/david/Library/Caches/cargo-xwin/xwin/crt/include /imsvc/Users/david/Library/Caches/cargo-xwin/xwin/sdk/include/ucrt /imsvc/Users/david/Library/Caches/cargo-xwin/xwin/sdk/include/um /imsvc/Users/david/Library/Caches/cargo-xwin/xwin/sdk/include/shared " CMAKE_GENERATOR="Ninja" CMAKE_SYSTEM_NAME="Windows" CMAKE_TOOLCHAIN_FILE_x86_64_pc_windows_msvc="/Users/david/Library/Caches/cargo-xwin/cmake/x86_64-pc-windows-msvc-toolchain.cmake" CXXFLAGS_x86_64_pc_windows_msvc="--target=x86_64-pc-windows-msvc -Wno-unused-command-line-argument -fuse-ld=lld-link /imsvc/Users/david/Library/Caches/cargo-xwin/xwin/crt/include /imsvc/Users/david/Library/Caches/cargo-xwin/xwin/sdk/include/ucrt /imsvc/Users/david/Library/Caches/cargo-xwin/xwin/sdk/include/um /imsvc/Users/david/Library/Caches/cargo-xwin/xwin/sdk/include/shared  " CXX_x86_64_pc_windows_msvc="clang-cl" PATH="/Users/david/.virtualenvs/pyo3-3.13t/bin:/Users/david/.vscode/extensions/ms-python.python-2024.20.0-darwin-arm64/python_files/deactivate/zsh:/Users/david/.virtualenvs/pyo3-3.12/bin:/Users/david/.local/state/fnm_multishells/18789_1732889105618/bin:/Users/david/.pyenv/shims:/Users/david/.vscode/extensions/ms-python.python-2024.20.0-darwin-arm64/python_files/deactivate/zsh:/Users/david/.virtualenvs/pyo3-3.12/bin:/Library/Frameworks/Python.framework/Versions/3.12/bin:/Library/Frameworks/Python.framework/Versions/3.11/bin:/opt/homebrew/bin:/opt/homebrew/sbin:/usr/local/bin:/System/Cryptexes/App/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/local/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/appleinternal/bin:/Library/Apple/usr/bin:/Users/david/.vscode/extensions/ms-python.python-2024.20.0-darwin-arm64/python_files/deactivate/zsh:/Users/david/.virtualenvs/pyo3-3.12/bin:/Users/david/.local/state/fnm_multishells/48683_1732139667691/bin:/Users/david/Library/Python/3.10/bin:/Users/david/.fly/bin:/Users/david/.pyenv/bin:/Users/david/.local/bin:/Users/david/bin:/Library/Frameworks/Python.framework/Versions/3.12/bin:/Library/Frameworks/Python.framework/Versions/3.11/bin:/Users/david/.cargo/bin:/Users/david/Library/Caches/cargo-xwin:/opt/homebrew/opt/llvm/bin" PYO3_CONFIG_FILE="/Users/david/Dev/pyo3-scratch/target/maturin/pyo3-config-x86_64-pc-windows-msvc-3.13.txt" RCFLAGS="-I/Users/david/Library/Caches/cargo-xwin/xwin/crt/include -I/Users/david/Library/Caches/cargo-xwin/xwin/sdk/include/ucrt -I/Users/david/Library/Caches/cargo-xwin/xwin/sdk/include/um -I/Users/david/Library/Caches/cargo-xwin/xwin/sdk/include/shared" TARGET_AR="llvm-lib" TARGET_CC="clang-cl" TARGET_CXX="clang-cl" "cargo" "rustc" "--features" "pyo3/extension-module" "--target" "x86_64-pc-windows-msvc" "--message-format" "json-render-diagnostics" "--manifest-path" "/Users/david/Dev/pyo3-scratch/Cargo.toml" "--lib"`