ci: +crt-static flag on Windows (#3)

Author: Brooooooklyn

.github/workflows/ci.yml

@@ -174,6 +174,7 @@ jobs:
           yarn install
 
       - name: Install wasi-sdk
+        if: ${{ matrix.settings.target == 'wasm32-wasip1-threads' }}
         run: |
           mkdir -p $HOME/wasi-sdk
           curl -L https://github.com/WebAssembly/wasi-sdk/releases/download/wasi-sdk-25/wasi-sdk-25.0-x86_64-linux.tar.gz | tar -xzf - -C $HOME/wasi-sdk --strip-components=1
@@ -195,3 +196,9 @@ jobs:
             yarn build --target ${{ matrix.settings.target }}
             yarn build --target ${{ matrix.settings.target }} --release
           fi
+      - name: Build with static CRT
+        if: ${{ matrix.settings.target == 'x86_64-pc-windows-msvc' }}
+        working-directory: example
+        run: yarn build --target ${{ matrix.settings.target }} --release
+        env:
+          RUSTFLAGS: "-C target-feature=+crt-static -C link-arg=/FORCE:MULTIPLE"

libmimalloc-sys/build.rs

@@ -83,10 +83,15 @@ fn main() {
         cmake_config
             .define("MI_USE_CXX", "ON")
             .define("MI_WIN_USE_FIXED_TLS", "ON");
-        if profile == "debug" {
-            println!("cargo:rustc-link-lib=ucrtd");
-        } else {
-            println!("cargo:rustc-link-lib=ucrt");
+        if !std::env::var("CARGO_CFG_TARGET_FEATURE")
+            .map(|s| s.contains("+crt-static"))
+            .unwrap_or(false)
+        {
+            if profile == "debug" {
+                println!("cargo:rustc-link-lib=ucrtd");
+            } else {
+                println!("cargo:rustc-link-lib=ucrt");
+            }
         }
     }