kn: implement SystemDefaultProvider for Native

gradle.properties

@@ -2,6 +2,7 @@ kotlin.code.style=official
 kotlin.incremental.js=true
 kotlin.incremental.multiplatform=true
 kotlin.mpp.stability.nowarn=true
+kotlin.mpp.enableCInteropCommonization=true
 kotlin.native.ignoreDisabledTargets=true
 
 # atomicfu

runtime/runtime-core/api/runtime-core.api

@@ -2383,9 +2383,12 @@ public final class aws/smithy/kotlin/runtime/util/OperatingSystem {
 public final class aws/smithy/kotlin/runtime/util/OsFamily : java/lang/Enum {
 	public static final field Android Laws/smithy/kotlin/runtime/util/OsFamily;
 	public static final field Ios Laws/smithy/kotlin/runtime/util/OsFamily;
+	public static final field IpadOs Laws/smithy/kotlin/runtime/util/OsFamily;
 	public static final field Linux Laws/smithy/kotlin/runtime/util/OsFamily;
 	public static final field MacOs Laws/smithy/kotlin/runtime/util/OsFamily;
+	public static final field TvOs Laws/smithy/kotlin/runtime/util/OsFamily;
 	public static final field Unknown Laws/smithy/kotlin/runtime/util/OsFamily;
+	public static final field WatchOs Laws/smithy/kotlin/runtime/util/OsFamily;
 	public static final field Windows Laws/smithy/kotlin/runtime/util/OsFamily;
 	public static fun getEntries ()Lkotlin/enums/EnumEntries;
 	public fun toString ()Ljava/lang/String;

runtime/runtime-core/build.gradle.kts

@@ -3,6 +3,8 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+import org.jetbrains.kotlin.gradle.plugin.mpp.KotlinNativeTarget
+
 plugins {
     alias(libs.plugins.kotlinx.serialization)
 }
@@ -54,4 +56,15 @@ kotlin {
             languageSettings.optIn("aws.smithy.kotlin.runtime.InternalApi")
         }
     }
+
+    targets.withType<KotlinNativeTarget> {
+        compilations["main"].cinterops {
+            val interopDir = "$projectDir/native/src/nativeInterop/cinterop"
+            create("environ") {
+                includeDirs(interopDir)
+                packageName("aws.smithy.platform.posix")
+                headers(listOf("$interopDir/environ.h"))
+            }
+        }
+    }
 }

runtime/runtime-core/common/src/aws/smithy/kotlin/runtime/util/Platform.kt

@@ -58,6 +58,9 @@ public enum class OsFamily {
     Windows,
     Android,
     Ios,
+    IpadOs,
+    TvOs,
+    WatchOs,
     Unknown,
     ;
 
@@ -67,6 +70,9 @@ public enum class OsFamily {
         Windows -> "windows"
         Android -> "android"
         Ios -> "ios"
+        IpadOs -> "ipados"
+        TvOs -> "tvos"
+        WatchOs -> "watchos"
         Unknown -> "unknown"
     }
 }

runtime/runtime-core/common/test/aws/smithy/kotlin/runtime/util/SystemPlatformProviderTest.kt

@@ -0,0 +1,62 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package aws.smithy.kotlin.runtime.util
+
+import kotlinx.coroutines.test.runTest
+import kotlin.test.Test
+import kotlin.test.assertContentEquals
+import kotlin.test.assertNotEquals
+import kotlin.test.assertNotNull
+import kotlin.test.assertNull
+import kotlin.test.assertTrue
+
+class SystemPlatformProviderTest {
+    @Test
+    fun testReadWriteFile() = runTest {
+        val ps = PlatformProvider.System
+
+        val tempDir = if (ps.osInfo().family == OsFamily.Windows) {
+            requireNotNull(ps.getenv("TEMP")) { "%TEMP% unexpectedly null" }
+        } else {
+            "/tmp"
+        }
+        val path = "$tempDir/testReadWriteFile-${Uuid.random()}.txt"
+
+        val expected = "Hello, File!".encodeToByteArray()
+
+        ps.writeFile(path, expected)
+        assertTrue(ps.fileExists(path))
+
+        val actual = ps.readFileOrNull(path)
+        assertContentEquals(expected, actual)
+    }
+
+    @Test
+    fun testGetEnv() = runTest {
+        val envVarKeys = listOf("PATH", "USERPROFILE") // PATH is not set on Windows CI
+        assertNotNull(
+            envVarKeys.firstNotNullOfOrNull { PlatformProvider.System.getenv(it) },
+        )
+
+        assertNull(PlatformProvider.System.getenv("THIS_ENV_VAR_IS_NOT_SET"))
+    }
+
+    @Test
+    fun testGetAllEnvVars() = runTest {
+        val allEnv = PlatformProvider.System.getAllEnvVars()
+        assertTrue(allEnv.isNotEmpty())
+
+        val envVarKeys = listOf("PATH", "USERPROFILE") // PATH is not set on Windows CI
+        assertTrue(
+            envVarKeys.any { allEnv.contains(it) },
+        )
+    }
+
+    @Test
+    fun testOsInfo() = runTest {
+        val osInfo = PlatformProvider.System.osInfo()
+        assertNotEquals(OsFamily.Unknown, osInfo.family)
+    }
+}

runtime/runtime-core/linuxX64/test/aws/smithy/kotlin/runtime/util/SystemPlatformProviderLinuxX64Test.kt

@@ -0,0 +1,17 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package aws.smithy.kotlin.runtime.util
+
+import kotlinx.coroutines.test.runTest
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+class SystemPlatformProviderLinuxX64Test {
+    @Test
+    fun testOsInfo() = runTest {
+        val osInfo = PlatformProvider.System.osInfo()
+        assertEquals(OsFamily.Linux, osInfo.family)
+    }
+}

runtime/runtime-core/native/src/aws/smithy/kotlin/runtime/util/PlatformNative.kt

@@ -4,50 +4,104 @@
  */
 package aws.smithy.kotlin.runtime.util
 
+import aws.smithy.kotlin.runtime.io.IOException
+import aws.smithy.kotlin.runtime.io.internal.SdkDispatchers
+import aws.smithy.platform.posix.get_environ_ptr
+import kotlinx.cinterop.*
+import kotlinx.coroutines.withContext
+import platform.posix.*
+
 internal actual object SystemDefaultProvider : PlatformProvider {
-    actual override fun getAllEnvVars(): Map<String, String> {
-        TODO("Not yet implemented")
+    actual override fun getAllEnvVars(): Map<String, String> = memScoped {
+        val environ = get_environ_ptr()
+        generateSequence(0) { it + 1 }
+            .map { idx -> environ?.get(idx)?.toKString() }
+            .takeWhile { it != null }
+            .associate { env ->
+                val parts = env?.split("=", limit = 2)
+                check(parts?.size == 2) { "Environment entry \"$env\" is malformed" }
+                parts[0] to parts[1]
+            }
     }
 
-    actual override fun getenv(key: String): String? {
-        TODO("Not yet implemented")
-    }
+    actual override fun getenv(key: String): String? = platform.posix.getenv(key)?.toKString()
 
     actual override val filePathSeparator: String
-        get() = TODO("Not yet implemented")
+        get() = when (osInfo().family) {
+            OsFamily.Windows -> "\\"
+            else -> "/"
+        }
 
-    actual override suspend fun readFileOrNull(path: String): ByteArray? {
-        TODO("Not yet implemented")
-    }
+    actual override suspend fun readFileOrNull(path: String): ByteArray? = withContext(SdkDispatchers.IO) {
+        try {
+            val file = fopen(path, "rb") ?: return@withContext null
 
-    actual override suspend fun writeFile(path: String, data: ByteArray) {
-        TODO("Not yet implemented")
-    }
+            try {
+                // Get file size
+                fseek(file, 0L, SEEK_END)
+                val size = ftell(file)
+                fseek(file, 0L, SEEK_SET)
 
-    actual override fun fileExists(path: String): Boolean {
-        TODO("Not yet implemented")
+                // Read file content
+                val buffer = ByteArray(size.toInt()).pin()
+                val rc = fread(buffer.addressOf(0), 1uL, size.toULong(), file)
+                if (rc == size.toULong()) buffer.get() else null
+            } finally {
+                fclose(file)
+            }
+        } catch (_: Exception) {
+            null
+        }
     }
 
-    actual override fun osInfo(): OperatingSystem {
-        TODO("Not yet implemented")
+    actual override suspend fun writeFile(path: String, data: ByteArray) = withContext(SdkDispatchers.IO) {
+        val file = fopen(path, "wb") ?: throw IOException("Cannot open file for writing: $path")
+        try {
+            val wc = fwrite(data.refTo(0), 1uL, data.size.toULong(), file)
+            if (wc != data.size.toULong()) {
+                throw IOException("Failed to write all bytes to file $path, expected ${data.size.toLong()}, wrote $wc")
+            }
+        } finally {
+            fclose(file)
+        }
     }
 
-    actual override val isJvm: Boolean
-        get() = TODO("Not yet implemented")
-    actual override val isAndroid: Boolean
-        get() = TODO("Not yet implemented")
-    actual override val isBrowser: Boolean
-        get() = TODO("Not yet implemented")
-    actual override val isNode: Boolean
-        get() = TODO("Not yet implemented")
-    actual override val isNative: Boolean
-        get() = TODO("Not yet implemented")
-
-    actual override fun getAllProperties(): Map<String, String> {
-        TODO("Not yet implemented")
-    }
+    actual override fun fileExists(path: String): Boolean = access(path, F_OK) == 0
 
-    actual override fun getProperty(key: String): String? {
-        TODO("Not yet implemented")
+    actual override fun osInfo(): OperatingSystem = memScoped {
+        val utsname = alloc<utsname>()
+        uname(utsname.ptr)
+
+        val sysName = utsname.sysname.toKString().lowercase()
+        val version = utsname.release.toKString()
+        val machine = utsname.machine.toKString().lowercase() // Helps differentiate Apple platforms
+
+        val family = when {
+            sysName.contains("darwin") -> {
+                when {
+                    machine.startsWith("iphone") -> OsFamily.Ios
+                    // TODO Validate that iPadOS/tvOS/watchOS resolves correctly on each of these devices
+                    machine.startsWith("ipad") -> OsFamily.IpadOs
+                    machine.startsWith("tv") -> OsFamily.TvOs
+                    machine.startsWith("watch") -> OsFamily.WatchOs
+                    else -> OsFamily.MacOs
+                }
+            }
+            sysName.contains("linux") -> OsFamily.Linux
+            sysName.contains("windows") -> OsFamily.Windows
+            else -> OsFamily.Unknown
+        }
+
+        return OperatingSystem(family, version)
     }
+
+    actual override val isJvm: Boolean = false
+    actual override val isAndroid: Boolean = false
+    actual override val isBrowser: Boolean = false
+    actual override val isNode: Boolean = false
+    actual override val isNative: Boolean = true
+
+    // Kotlin/Native doesn't have system properties
+    actual override fun getAllProperties(): Map<String, String> = emptyMap()
+    actual override fun getProperty(key: String): String? = null
 }

runtime/runtime-core/native/src/nativeInterop/cinterop/environ.h

@@ -0,0 +1,12 @@
+#ifndef ENVIRON_H
+#define ENVIRON_H
+
+// External declaration to get environment variables
+extern char **environ;
+
+// Helper function to get the environ pointer
+char** get_environ_ptr() {
+    return environ;
+}
+
+#endif