Add support for windows builds

Makefile

@@ -92,6 +92,13 @@ release-build-macos:
 	cp libwasmvm/artifacts/libwasmvm.dylib internal/api
 	make update-bindings
 
+# Creates a release build in a containerized build environment of the shared library for Windows (.dll)
+release-build-windows:
+	rm -rf libwasmvm/target/release
+	docker run --rm -u $(USER_ID):$(USER_GROUP) -v $(shell pwd)/libwasmvm:/code $(BUILDERS_PREFIX)-cross build_windows.sh
+	cp libwasmvm/target/x86_64-pc-windows-gnu/release/wasmvm.dll internal/api
+	make update-bindings
+
 update-bindings:
 # After we build libwasmvm, we have to copy the generated bindings for Go code to use.
 # We cannot use symlinks as those are not reliably resolved by `go get` (https://github.com/CosmWasm/wasmvm/pull/235).

builders/Dockerfile.cross

@@ -2,14 +2,16 @@ FROM rust:1.63.0-bullseye
 
 # Install build dependencies
 RUN apt-get update \
-  && apt install -y clang gcc g++ zlib1g-dev libmpc-dev libmpfr-dev libgmp-dev build-essential cmake
+  && apt install -y clang gcc g++ zlib1g-dev libmpc-dev libmpfr-dev libgmp-dev build-essential cmake \
+    # Support for Windows cross-compile
+    mingw-w64
 
 ## ADD MACOS SUPPORT
 
 WORKDIR /opt
 
-# Add macOS Rust targets
-RUN rustup target add x86_64-apple-darwin aarch64-apple-darwin
+# Add macOS and Windows Rust targets
+RUN rustup target add x86_64-apple-darwin x86_64-pc-windows-gnu
 
 # Build osxcross
 # See https://github.com/tpoechtrager/osxcross/blob/master/build.sh#L31-L49 for SDK overview.

builders/README.md

@@ -17,6 +17,7 @@ can do the cross-compilation.
 **Version 0013:**
 
 - Update Rust to 1.63.0.
+- Add Windows support to cosmwasm/go-ext-builder:0013-cross. This image builds for macOS and Windows now.
 
 **Version 0012:**
 

builders/guest/build_windows.sh

@@ -0,0 +1,6 @@
+#!/bin/bash
+set -o errexit -o nounset -o pipefail
+
+# ref: https://www.reddit.com/r/rust/comments/5k8uab/crosscompiling_from_ubuntu_to_windows_with_rustup/
+
+cargo build --release --target x86_64-pc-windows-gnu

builders/guest/cargo-config

@@ -9,3 +9,7 @@ ar = "aarch64-apple-darwin20.4-ar"
 [target.aarch64-unknown-linux-gnu]
 linker = "/usr/aarch64-linux-gnu/bin/ld"
 ar = "/usr/aarch64-linux-gnu/bin/ar"
+
+[target.x86_64-pc-windows-gnu]
+linker = "x86_64-w64-mingw32-gcc"
+ar = "x86_64-w64-mingw32-gcc-ar"

internal/api/link_windows.go

@@ -0,0 +1,6 @@
+//go:build windows && !sys_wasmvm
+
+package api
+
+// #cgo LDFLAGS: -Wl,-rpath,${SRCDIR} -L${SRCDIR} -lwasmvm
+import "C"