feat: add Windows cross-compilation support via MinGW and LLVM#313
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LunaStev merged 1 commit intoMay 8, 2026
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This commit introduces robust cross-compilation support for Windows (`x86_64-pc-windows-gnu`) from a Linux host. It resolves build and runtime dependencies for the Wave compiler on Windows by integrating MinGW, Wine, and native Windows LLVM binaries into the build and packaging pipeline. [Details] 1. Build System (`x.py`) Updates: - Added full environment configuration for MinGW (`x86_64-w64-mingw32-gcc`/`g++`) and Windows LLVM (`llvm-config.exe`). - Added automatic resolution and bundling of required MinGW runtime DLLs (`libgcc_s_seh-1.dll`, `libstdc++-6.dll`, `libwinpthread-1.dll`) during the `package` step to ensure the generated `.exe` is standalone. - Allowed passing specific target triples to `x.py` (e.g., `x.py build x86_64-pc-windows-gnu`). 2. LLVM and Feature Flags (`Cargo.toml` & `llvm/Cargo.toml`): - Abstracted target initialization via Cargo features (`llvm-target-all`, `llvm-target-x86`). - When building for Windows via MinGW, `x.py` now disables default features and explicitly enables only `llvm-target-x86` to significantly reduce compilation time and avoid linking issues with irrelevant LLVM targets. 3. Import & Backend Adjustments: - Added Windows to the supported targets in the `TargetAttr` parser (`#[target(os="windows")]`). - Adjusted the LLVM backend (`backend.rs`) to prevent injecting default Linux libc/libm (`-lc`, `-lm`) when the target is `x86_64-*-windows-gnu`. - Added custom ABI lowering classification (`classify_param_x86_64_windows`, `classify_ret_x86_64_windows`) to correctly handle C-ABI integer extensions and SRet/ByVal structs for the Windows x64 calling convention. 4. Documentation: - Promoted Windows (MinGW/GNU) from Tier 4 (Unofficial) to Tier 3 (Experimental) in `README.md`. Signed-off-by: LunaStev <luna@lunastev.org>
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This PR introduces robust cross-compilation support for Windows (
x86_64-pc-windows-gnu) from Linux hosts. By integrating the MinGW toolchain, Wine (for build-time introspection), and platform-specific ABI lowering, Wave can now generate standalone Windows executables with correctly bundled runtime dependencies.Key Changes
1. Build Orchestration (
x.py)x86_64-w64-mingw32-gcc/g++) and Windows-targeted LLVM tools (llvm-config.exe).packagecommand now automatically resolves and bundles essential MinGW runtime DLLs—includinglibgcc_s_seh-1.dll,libstdc++-6.dll, andlibwinpthread-1.dll—ensuring that the generated.exeruns on Windows systems without requiring a pre-installed MinGW environment.python3 x.py build x86_64-pc-windows-gnu).2. LLVM Optimization & Feature Flags
llvm-target-all,llvm-target-x86).x.pynow explicitly enables onlyllvm-target-x86. This significantly reduces compilation time and avoids linking conflicts with irrelevant LLVM targets.3. Backend & ABI Adjustments
classify_param_x86_64_windows,classify_ret_x86_64_windows). This ensures that integer extensions,SRet(Structured Return), andByValstructs strictly follow the Windows ABI, which differs from the System V ABI used on Linux/macOS.windowsto the supported OS list for the#[target(os="...")]attribute.-lc,-lm) when targeting Windows, allowing the MinGW linker to manage its own standard libraries.4. Platform Policy
README.mdto promote Windows (MinGW/GNU) from Tier 4 (Unofficial) to Tier 3 (Experimental), reflecting the increased stability and official support in the build pipeline.Rationale
Enabling Windows support from a Linux host allows for a more streamlined CI/CD process and empowers developers to target the most popular desktop OS without leaving their primary development environment. The implementation of the Windows-specific ABI is critical for reliable FFI with native Windows DLLs and the Win32 API.