From a07066f98b608a80fc451fab5fa36cef10d83c24 Mon Sep 17 00:00:00 2001
From: Pavel Kunyavskiy <pavel.kunyavskiy@jetbrains.com>
Date: Thu, 9 Jun 2022 16:28:10 +0200
Subject: [PATCH] [K/N] Make overridden runtime variables available during
 stdlib lto

---
 .../backend/konan/RuntimeLinkageStrategy.kt   |  5 +-
 .../kotlin/backend/konan/llvm/IrToBitcode.kt  | 48 +++++++++----------
 .../src/main/cpp/CompilerConstants.hpp        |  2 +-
 3 files changed, 28 insertions(+), 27 deletions(-)

diff --git a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/RuntimeLinkageStrategy.kt b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/RuntimeLinkageStrategy.kt
index dfedc9c288a..3593987c3e3 100644
--- a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/RuntimeLinkageStrategy.kt
+++ b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/RuntimeLinkageStrategy.kt
@@ -8,10 +8,9 @@ package org.jetbrains.kotlin.backend.konan
 import llvm.LLVMModuleCreateWithNameInContext
 import llvm.LLVMModuleRef
 import llvm.LLVMStripModuleDebugInfo
-import org.jetbrains.kotlin.backend.konan.llvm.getName
+import org.jetbrains.kotlin.backend.konan.llvm.*
 import org.jetbrains.kotlin.backend.konan.llvm.llvmContext
 import org.jetbrains.kotlin.backend.konan.llvm.llvmLinkModules2
-import org.jetbrains.kotlin.backend.konan.llvm.parseBitcodeFile
 
 /**
  * To avoid combinatorial explosion, we split runtime into several LLVM modules.
@@ -83,6 +82,8 @@ internal sealed class RuntimeLinkageStrategy {
                     LLVMStripModuleDebugInfo(parsedModule)
                 }
                 parsedModule
+            }?.let {
+              it + context.generateRuntimeConstantsModule()
             }
             return when {
                 runtimeLlvmModules == null -> return None
diff --git a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/IrToBitcode.kt b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/IrToBitcode.kt
index b1ac4208b7f..0d075093a16 100644
--- a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/IrToBitcode.kt
+++ b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/IrToBitcode.kt
@@ -439,7 +439,6 @@ internal class CodeGeneratorVisitor(val context: Context, val lifetimes: Map<IrE
             codegen.objCDataGenerator?.finishModule()
 
             context.coverage.writeRegionInfo()
-            setRuntimeConstGlobals()
             overrideRuntimeGlobals()
             appendLlvmUsed("llvm.used", context.llvm.usedFunctions + context.llvm.usedGlobals)
             appendLlvmUsed("llvm.compiler.used", context.llvm.compilerUsedGlobals)
@@ -2721,29 +2720,6 @@ internal class CodeGeneratorVisitor(val context: Context, val lifetimes: Map<IrE
         LLVMSetSection(llvmUsedGlobal.llvmGlobal, "llvm.metadata")
     }
 
-    // Globals set this way will be const, but can only be built into runtime-containing module. Which
-    // means they are set at stdlib-cache compilation time.
-    private fun setRuntimeConstGlobal(name: String, value: ConstValue) {
-        val global = context.llvm.staticData.placeGlobal(name, value)
-        global.setConstant(true)
-        global.setLinkage(LLVMLinkage.LLVMExternalLinkage)
-    }
-
-    private fun setRuntimeConstGlobals() {
-        if (!context.producedLlvmModuleContainsStdlib)
-            return
-
-        setRuntimeConstGlobal("Kotlin_needDebugInfo", Int32(if (context.shouldContainDebugInfo()) 1 else 0))
-        setRuntimeConstGlobal("Kotlin_runtimeAssertsMode", Int32(context.config.runtimeAssertsMode.value))
-        val runtimeLogs = context.config.runtimeLogs?.let {
-            context.llvm.staticData.cStringLiteral(it)
-        } ?: NullPointer(int8Type)
-        setRuntimeConstGlobal("Kotlin_runtimeLogs", runtimeLogs)
-        setRuntimeConstGlobal("Kotlin_freezingEnabled", Int32(if (context.config.freezing.enableFreezeAtRuntime) 1 else 0))
-        setRuntimeConstGlobal("Kotlin_freezingChecksEnabled", Int32(if (context.config.freezing.enableFreezeChecks) 1 else 0))
-        setRuntimeConstGlobal("Kotlin_gcSchedulerType", Int32(context.config.gcSchedulerType.value))
-    }
-
     // Globals set this way cannot be const, but are overridable when producing final executable.
     private fun overrideRuntimeGlobal(name: String, value: ConstValue) {
         // TODO: A similar mechanism is used in `ObjCExportCodeGenerator`. Consider merging them.
@@ -2964,3 +2940,27 @@ internal class LocationInfo(val scope: DIScopeOpaqueRef,
         assert(line != 0)
     }
 }
+
+internal fun Context.generateRuntimeConstantsModule() : LLVMModuleRef {
+    val llvmModule = LLVMModuleCreateWithNameInContext("constants", llvmContext)!!
+    LLVMSetDataLayout(llvmModule, llvm.runtime.dataLayout)
+    val static = StaticData(llvmModule)
+
+    fun setRuntimeConstGlobal(name: String, value: ConstValue) {
+        val global = static.placeGlobal(name, value)
+        global.setConstant(true)
+        global.setLinkage(LLVMLinkage.LLVMExternalLinkage)
+    }
+
+    setRuntimeConstGlobal("Kotlin_needDebugInfo", Int32(if (shouldContainDebugInfo()) 1 else 0))
+    setRuntimeConstGlobal("Kotlin_runtimeAssertsMode", Int32(config.runtimeAssertsMode.value))
+    val runtimeLogs = config.runtimeLogs?.let {
+        static.cStringLiteral(it)
+    } ?: NullPointer(int8Type)
+    setRuntimeConstGlobal("Kotlin_runtimeLogs", runtimeLogs)
+    setRuntimeConstGlobal("Kotlin_freezingEnabled", Int32(if (config.freezing.enableFreezeAtRuntime) 1 else 0))
+    setRuntimeConstGlobal("Kotlin_freezingChecksEnabled", Int32(if (config.freezing.enableFreezeChecks) 1 else 0))
+    setRuntimeConstGlobal("Kotlin_gcSchedulerType", Int32(config.gcSchedulerType.value))
+
+    return llvmModule
+}
\ No newline at end of file
diff --git a/kotlin-native/runtime/src/main/cpp/CompilerConstants.hpp b/kotlin-native/runtime/src/main/cpp/CompilerConstants.hpp
index d4b0bdf6470..acf39284a75 100644
--- a/kotlin-native/runtime/src/main/cpp/CompilerConstants.hpp
+++ b/kotlin-native/runtime/src/main/cpp/CompilerConstants.hpp
@@ -27,7 +27,7 @@ using string_view = std::experimental::string_view;
 /**
  * There are two ways, how compiler can define variables for runtime usage. This one, and the other one with details in source file.
  *
- * This is one is variables defined by setRuntimeConstGlobals in IrToBitcode.kt. They are eligible for runtime optimizations,
+ * This is one is variables defined by generateRuntimeConstantsModule in IrToBitcode.kt. They are eligible for runtime optimizations,
  * and fixed at the point of compiling caches. So use this way for variables, which are heavily used on performance-critical passes or
  * will significantly increase code size, if not eliminated.
  *