Explicitly sign extend arguments of exported C functions. (#2370)

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/ContextUtils.kt

@@ -5,10 +5,7 @@
 
 package org.jetbrains.kotlin.backend.konan.llvm
 
-import kotlinx.cinterop.allocArray
+import kotlinx.cinterop.*
-import kotlinx.cinterop.cValuesOf
-import kotlinx.cinterop.get
-import kotlinx.cinterop.memScoped
 import llvm.*
 import org.jetbrains.kotlin.backend.konan.Context
 import org.jetbrains.kotlin.backend.konan.descriptors.findPackage
@@ -31,16 +28,22 @@ import kotlin.reflect.KProperty
 internal sealed class SlotType {
     // Frame local arena slot can be used.
     object ARENA : SlotType()
+
     // Return slot can be used.
     object RETURN : SlotType()
+
     // Return slot, if it is an arena, can be used.
     object RETURN_IF_ARENA : SlotType()
+
     // Param slot, if it is an arena, can be used.
     class PARAM_IF_ARENA(val parameter: Int) : SlotType()
+
     // Params slot, if it is an arena, can be used.
     class PARAMS_IF_ARENA(val parameters: IntArray, val useReturnSlot: Boolean) : SlotType()
+
     // Anonymous slot.
     object ANONYMOUS : SlotType()
+
     // Unknown slot type.
     object UNKNOWN : SlotType()
 }
@@ -245,6 +248,7 @@ internal val Name.localHash: LocalHash
 internal val FqName.localHash: LocalHash
     get() = this.toString().localHash
 
+
 internal class Llvm(val context: Context, val llvmModule: LLVMModuleRef) {
 
     private fun importFunction(name: String, otherModule: LLVMModuleRef): LLVMValueRef {
@@ -302,7 +306,21 @@ internal class Llvm(val context: Context, val llvmModule: LLVMModuleRef) {
             assert(LLVMGetLinkage(found) == LLVMLinkage.LLVMExternalLinkage)
             return found
         } else {
-            return LLVMAddFunction(llvmModule, name, type)!!
+            // As exported functions are written in C++ they assume sign extension for promoted types -
+            // mention that in attributes.
+            val function = LLVMAddFunction(llvmModule, name, type)!!
+            return memScoped {
+                val paramCount = LLVMCountParamTypes(type)
+                val paramTypes = allocArray<LLVMTypeRefVar>(paramCount)
+                LLVMGetParamTypes(type, paramTypes)
+                (0 until paramCount).forEach { index ->
+                    val paramType = paramTypes[index]
+                    addFunctionSignext(function, index + 1, paramType)
+                }
+                val returnType = LLVMGetReturnType(type)
+                addFunctionSignext(function, 0, returnType)
+                function
+            }
         }
     }
 
@@ -338,7 +356,8 @@ internal class Llvm(val context: Context, val llvmModule: LLVMModuleRef) {
                 .getFullList(TopologicalLibraryOrder)
     }
 
-    val librariesForLibraryManifest: List<KonanLibrary> get() {
+    val librariesForLibraryManifest: List<KonanLibrary>
+        get() {
             // Note: library manifest should contain the list of all user libraries and frontend-used default libraries.
             // However this would result into linking too many default libraries into the application which uses current
             // library. This problem should probably be fixed by adding different kind of dependencies to library
@@ -411,10 +430,8 @@ internal class Llvm(val context: Context, val llvmModule: LLVMModuleRef) {
     val tlsMode by lazy {
         when (target) {
             KonanTarget.WASM32,
-            is KonanTarget.ZEPHYR 
+            is KonanTarget.ZEPHYR -> LLVMThreadLocalMode.LLVMNotThreadLocal
-                -> LLVMThreadLocalMode.LLVMNotThreadLocal
+            else -> LLVMThreadLocalMode.LLVMGeneralDynamicTLSModel
-            else 
-                -> LLVMThreadLocalMode.LLVMGeneralDynamicTLSModel
         }
     }
 

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/LlvmUtils.kt

@@ -267,8 +267,14 @@ fun parseBitcodeFile(path: String): LLVMModuleRef = memScoped {
     }
 }
 
-private val nounwindAttrKindId: Int
+private val nounwindAttrKindId by lazy {
-    get() = getAttributeKindId("nounwind")
+    getAttributeKindId("nounwind")
+}
+
+private val signextAttrKindId by lazy {
+    getAttributeKindId("signext")
+}
+
 
 fun isFunctionNoUnwind(function: LLVMValueRef): Boolean {
 
@@ -289,6 +295,13 @@ fun setFunctionNoUnwind(function: LLVMValueRef) {
     LLVMAddAttributeAtIndex(function, LLVMAttributeFunctionIndex, attribute)
 }
 
+fun addFunctionSignext(function: LLVMValueRef, index: Int, type: LLVMTypeRef?) {
+    if (type == int1Type || type == int8Type || type == int16Type) {
+        val attribute = LLVMCreateEnumAttribute(LLVMGetTypeContext(function.type), signextAttrKindId, 0)!!
+        LLVMAddAttributeAtIndex(function, index, attribute)
+    }
+}
+
 internal fun String.mdString() = LLVMMDString(this, this.length)!!
 internal fun node(vararg it:LLVMValueRef) = LLVMMDNode(it.toList().toCValues(), it.size)