Crate python3_dll_a

Expand description

Standalone `python3(y).dll` import library generator

Generates import libraries for the Python DLL (either python3.dll or python3y.dll) for MinGW-w64 and MSVC (cross-)compile targets.

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

Note: MSVC cross-compile targets require either LLVM binutils or Zig 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 from Linux.

Alternatively, ZIG_COMMAND environment variable may be set to e.g. "zig" or "python -m ziglang", then zig dlltool will be used in place of llvm-dlltool (or MinGW binutils).

PyO3 integration

Since version 0.16.5, the pyo3 crate implements support for both the Stable ABI and version-specific Python DLL import library generation via its new generate-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 an `abi3` PyO3 extension module

[dependencies]
pyo3 = { version = "0.16.5", features = ["extension-module", "abi3-py37", "generate-import-lib"] }

Example `Cargo.toml` usage for a standard PyO3 extension module

[dependencies]
pyo3 = { version = "0.16.5", features = ["extension-module", "generate-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 for an `abi3` PyO3 extension

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