From 9760e3ee1e97c59e2e39ea0b7d4d12039fd95d28 Mon Sep 17 00:00:00 2001
From: Zalim Bashorov <zalim.bashorov@jetbrains.com>
Date: Thu, 30 Mar 2023 20:50:07 +0200
Subject: [PATCH] [Wasm] Introduce `check` and `error` specialized for String
 to reduce output size

---
 compiler/testData/codegen/box/size/add.kt     |  4 +--
 .../testData/codegen/box/size/helloWorld.kt   |  2 +-
 .../codegen/box/size/helloWorldDOM.kt         |  4 +--
 compiler/testData/codegen/box/size/ok.kt      |  4 +--
 .../wasm/src/kotlin/util/PreconditionsWasm.kt | 28 +++++++++++++++++++
 5 files changed, 35 insertions(+), 7 deletions(-)
 create mode 100644 libraries/stdlib/wasm/src/kotlin/util/PreconditionsWasm.kt

diff --git a/compiler/testData/codegen/box/size/add.kt b/compiler/testData/codegen/box/size/add.kt
index 3a160b4105d..00e08c6584d 100644
--- a/compiler/testData/codegen/box/size/add.kt
+++ b/compiler/testData/codegen/box/size/add.kt
@@ -1,7 +1,7 @@
 // TARGET_BACKEND: WASM
 
-// WASM_DCE_EXPECTED_OUTPUT_SIZE: wasm 65_583 
-// WASM_DCE_EXPECTED_OUTPUT_SIZE:  mjs  6_517 
+// WASM_DCE_EXPECTED_OUTPUT_SIZE: wasm 34_990 
+// WASM_DCE_EXPECTED_OUTPUT_SIZE:  mjs  6_359 
 
 // FILE: test.kt
 
diff --git a/compiler/testData/codegen/box/size/helloWorld.kt b/compiler/testData/codegen/box/size/helloWorld.kt
index a2c991f6d48..8de2bba184b 100644
--- a/compiler/testData/codegen/box/size/helloWorld.kt
+++ b/compiler/testData/codegen/box/size/helloWorld.kt
@@ -1,6 +1,6 @@
 // TARGET_BACKEND: WASM
 
-// WASM_DCE_EXPECTED_OUTPUT_SIZE: wasm 65_908 
+// WASM_DCE_EXPECTED_OUTPUT_SIZE: wasm 65_772 
 // WASM_DCE_EXPECTED_OUTPUT_SIZE:  mjs  6_458 
 
 fun box(): String {
diff --git a/compiler/testData/codegen/box/size/helloWorldDOM.kt b/compiler/testData/codegen/box/size/helloWorldDOM.kt
index 6963a039d00..de06e869bd7 100644
--- a/compiler/testData/codegen/box/size/helloWorldDOM.kt
+++ b/compiler/testData/codegen/box/size/helloWorldDOM.kt
@@ -1,7 +1,7 @@
 // TARGET_BACKEND: WASM
 
-// WASM_DCE_EXPECTED_OUTPUT_SIZE: wasm 77_603 
-// WASM_DCE_EXPECTED_OUTPUT_SIZE:  mjs  6_956 
+// WASM_DCE_EXPECTED_OUTPUT_SIZE: wasm 38_291 
+// WASM_DCE_EXPECTED_OUTPUT_SIZE:  mjs  6_798
 
 // FILE: test.kt
 
diff --git a/compiler/testData/codegen/box/size/ok.kt b/compiler/testData/codegen/box/size/ok.kt
index 33c8ccfbc1e..e03504fbc8b 100644
--- a/compiler/testData/codegen/box/size/ok.kt
+++ b/compiler/testData/codegen/box/size/ok.kt
@@ -1,6 +1,6 @@
 // TARGET_BACKEND: WASM
 
-// WASM_DCE_EXPECTED_OUTPUT_SIZE: wasm 65_634 
-// WASM_DCE_EXPECTED_OUTPUT_SIZE:  mjs  6_389 
+// WASM_DCE_EXPECTED_OUTPUT_SIZE: wasm 35_038 
+// WASM_DCE_EXPECTED_OUTPUT_SIZE:  mjs  6_231 
 
 fun box() = "OK"
\ No newline at end of file
diff --git a/libraries/stdlib/wasm/src/kotlin/util/PreconditionsWasm.kt b/libraries/stdlib/wasm/src/kotlin/util/PreconditionsWasm.kt
new file mode 100644
index 00000000000..47631c678f1
--- /dev/null
+++ b/libraries/stdlib/wasm/src/kotlin/util/PreconditionsWasm.kt
@@ -0,0 +1,28 @@
+/*
+ * Copyright 2010-2018 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package kotlin
+
+import kotlin.contracts.contract
+
+// Here are functions specialized with String type to avoid marking Any.toString and its overrides as reachable in DCE.
+// Just making the declarations public is impossible since it may change the resolution in a user code. 
+// TODO: investigate other ways to achieve the same, preferably covering not stdlib only but user cases too.
+
+@PublishedApi
+@kotlin.internal.InlineOnly
+internal inline fun check(value: Boolean, lazyMessage: () -> String): Unit {
+    contract {
+        returns() implies value
+    }
+    if (!value) {
+        val message = lazyMessage()
+        throw IllegalStateException(message)
+    }
+}
+
+@PublishedApi
+@kotlin.internal.InlineOnly
+internal inline fun error(message: String): Nothing = throw IllegalStateException(message)