Document all build steps

Author: simolus3

sqlite3multipleciphers/README.md

@@ -12,3 +12,11 @@ docker build -t powersync_kotlin_sqlite3mc_build_helper --load src/jni
 
 To compile for Windows, we use [llvm-mingw](https://github.com/mstorsjo/llvm-mingw),
 which needs to be downloaded.
+
+With all dependencies ready, run the Gradle task:
+
+```shell
+./gradlew sqlite3multipleciphers:jniCompile -PllvmMingw='.../Downloads/llvm-mingw-20251104-ucrt-macos-universal'
+```
+
+This outputs binaries to `build/jni-build/`.

sqlite3multipleciphers/build.gradle.kts

@@ -265,9 +265,14 @@ fun registerCompileMacOsHostTask(arm: Boolean): TaskProvider<Exec> {
 
 fun registerCompileWindowsOnMacOsTask(arm: Boolean): TaskProvider<Exec> {
     val architecture = if (arm) JniTarget.WINDOWS_ARM else JniTarget.WINDOWS_X64
+    val path = providers.gradleProperty("llvmMingw")
 
     return tasks.register<Exec>("jniCompile${architecture.name}") {
-        registerCompileOnHostTask(architecture, clang = "/Users/simon/Downloads/llvm-mingw-20251104-ucrt-macos-universal/bin/clang")
+        val clang = path.orNull?.let {
+            Path(path.get()).resolve("bin/clang").toString()
+        } ?: "clang"
+
+        registerCompileOnHostTask(architecture, clang = clang)
     }
 }