Fix build of Rust on Windows

Author: alexcrichton

.github/workflows/main.yml

@@ -51,7 +51,7 @@ jobs:
           else
           curl -f -OL --retry 5 https://github.com/bytecodealliance/wasm-tools/releases/download/wasm-tools-1.0.54/wasm-tools-1.0.54-x86_64-macos.tar.gz
           tar xf wasm-tools-1.0.54-x86_64-macos.tar.gz
-          cp wasm-tools-1.0.54-x86_64-macos/wasm-tools ~/.wasmtime/bin/          
+          cp wasm-tools-1.0.54-x86_64-macos/wasm-tools ~/.wasmtime/bin/
           fi
       - uses: actions/checkout@v3
         with:
@@ -90,9 +90,11 @@ jobs:
           - arch: x64
             sys: clang64
             env: clang-x86_64
+            rust_target: x86_64-pc-windows-msvc
           - arch: x86
             sys: clang32
             env: clang-i686
+            rust_target: i686-pc-windows-msvc
     steps:
       - uses: actions/cache@v3
         with:
@@ -112,14 +114,15 @@ jobs:
           msystem: ${{ matrix.sys }}
           update: true
           release: false
+          path-type: inherit
       - uses: actions/checkout@v3
         with:
           fetch-depth: 0
       - run: git submodule update --init --depth 32 --jobs 3
       - name: Build
         shell: msys2 {0}
         run: |
-          make package LLVM_CMAKE_FLAGS=-DLLVM_CCACHE_BUILD=ON
+          make package LLVM_CMAKE_FLAGS=-DLLVM_CCACHE_BUILD=ON RUST_TARGET=${{ matrix.rust_target }}
           make check
       - name: Does it work sans msys2?
         run: |

Makefile

@@ -44,6 +44,8 @@ override LLVM_CMAKE_FLAGS += -DCMAKE_OSX_ARCHITECTURES="arm64;x86_64" \
 		    -DCMAKE_OSX_DEPLOYMENT_TARGET=10.12
 endif
 
+RUST_TARGET ?= $(lastword $(shell rustc -vV | grep host))
+
 # Only the major version is needed for Clang, see https://reviews.llvm.org/D125860.
 CLANG_VERSION=$(shell $(BASH) ./llvm_version_major.sh $(LLVM_PROJ_DIR))
 VERSION:=$(shell $(BASH) ./version.sh)
@@ -254,14 +256,16 @@ build/config.BUILT:
 	touch build/config.BUILT
 
 define COPY_SHIMS_FOR
-	cp ./src/clang-shims/target/release/clang-shims$(EXE_SUFFIX) \
+	cp $(BUILD_PREFIX)/clang-shims/$(RUST_TARGET)/release/clang-shims$(EXE_SUFFIX) \
 		$(BUILD_PREFIX)/bin/$(1)-clang
-	cp ./src/clang-shims/target/release/clang-shims$(EXE_SUFFIX) \
+	cp $(BUILD_PREFIX)/clang-shims/$(RUST_TARGET)/release/clang-shims$(EXE_SUFFIX) \
 		$(BUILD_PREFIX)/bin/$(1)-clang++
 endef
 
 build/clang-shims.BUILT: build/llvm.BUILT
-	cargo build --release --manifest-path ./src/clang-shims/Cargo.toml
+	CARGO_TARGET_DIR=$(BUILD_PREFIX)/clang-shims \
+	  cargo build --release --manifest-path ./src/clang-shims/Cargo.toml \
+	    --target $(RUST_TARGET)
 	$(call COPY_SHIMS_FOR,wasm32-wasi)
 	$(call COPY_SHIMS_FOR,wasm32-wasi-preview2)
 	$(call COPY_SHIMS_FOR,wasm32-wasi-threads)