Standalone python3.dll import library generator

Generates import libraries for the Stable ABI Python DLL for MinGW-w64 and MSVC (cross-)compile targets.

See https://docs.python.org/3/c-api/stable.html for details.

This crate does not require Python 3 distribution files to be present on the (cross-)compile host system.

Note: MSVC (cross-)compile targets require LLVM binutils to be available on the host system. More specifically, python3-dll-a requires llvm-dlltool executable to be present in PATH when targeting *-pc-windows-msvc.

PyO3 integration

Since version 0.16.4, the pyo3 crate implements support for the Stable ABI Python DLL import library generation via its new generate-abi3-import-lib feature.

In this configuration, python3-dll-a becomes a pyo3 crate dependency and is automatically invoked by its build script in both native and cross compilation scenarios.

Example Cargo.toml usage for a PyO3 extension module

[dependencies]
pyo3 = { version = "0.16.4", features = ["extension-module", "abi3-py37", "generate-abi3-import-lib"] }

Standalone build script usage

If an older pyo3 crate version is used, or a different Python bindings library is required, python3-dll-a can be used directly from the crate build script.

The examples below assume using an older version of PyO3.

Example build.rs script

The following cargo build script can be used to cross-compile Stable ABI PyO3 extension modules for Windows (64/32-bit x86 or 64-bit ARM) using either MinGW-w64 or MSVC target environment ABI:

fn main() {
    if std::env::var("CARGO_CFG_TARGET_OS").unwrap() == "windows" {
        let cross_lib_dir = std::env::var_os("PYO3_CROSS_LIB_DIR")
            .expect("PYO3_CROSS_LIB_DIR is not set when cross-compiling");
        let arch = std::env::var("CARGO_CFG_TARGET_ARCH").unwrap();
        let env = std::env::var("CARGO_CFG_TARGET_ENV").unwrap();

        let libdir = std::path::Path::new(&cross_lib_dir);
        python3_dll_a::generate_implib_for_target(libdir, &arch, &env)
            .expect("python3.dll import library generator failed");
    }
}

A compatible python3.dll import library file named python3.dll.a or python3.lib will be automatically created in the directory pointed by the PYO3_CROSS_LIB_DIR environment variable.

Example cargo build invocation

PYO3_CROSS_LIB_DIR=target/python3-dll cargo build --target x86_64-pc-windows-gnu

Maintenance

This crate embeds the stable_abi.txt definitions file from CPython in the Misc subdirectory.

The upstream version of this file is located in the CPython project repository under the same path. This file should be updated for every subsequent CPython release (e.g. for CPython 3.12).