From 8f7ebe7f511d5700cf559c854f9202bf55240e11 Mon Sep 17 00:00:00 2001
From: SvyatoslavScherbina <Svyatoslav.Scherbina@jetbrains.com>
Date: Tue, 11 Feb 2020 14:45:36 +0300
Subject: [PATCH] Improve coverage of ObjCExport bridges by debug information
 (#3843)

---
 .../backend/konan/llvm/CodeGenerator.kt       | 16 ++++++--------
 .../objcexport/ObjCExportCodeGenerator.kt     | 21 ++++++++++++-------
 2 files changed, 19 insertions(+), 18 deletions(-)

diff --git a/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/CodeGenerator.kt b/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/CodeGenerator.kt
index 9382cafff36..152c95ddb7b 100644
--- a/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/CodeGenerator.kt
+++ b/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/CodeGenerator.kt
@@ -124,8 +124,9 @@ internal inline fun<R> generateFunction(codegen: CodeGenerator,
 
 
 internal inline fun<R> generateFunction(codegen: CodeGenerator, function: LLVMValueRef,
+                                        startLocation: LocationInfo? = null, endLocation: LocationInfo? = null,
                                         code:FunctionGenerationContext.(FunctionGenerationContext) -> R) {
-    val functionGenerationContext = FunctionGenerationContext(function, codegen, null, null)
+    val functionGenerationContext = FunctionGenerationContext(function, codegen, startLocation, endLocation)
     try {
         generateFunctionBody(functionGenerationContext, code)
     } finally {
@@ -140,7 +141,7 @@ internal inline fun generateFunction(
         block: FunctionGenerationContext.(FunctionGenerationContext) -> Unit
 ): LLVMValueRef {
     val function = LLVMAddFunction(codegen.context.llvmModule, name, functionType)!!
-    generateFunction(codegen, function, block)
+    generateFunction(codegen, function, startLocation = null, endLocation = null, code = block)
     return function
 }
 
@@ -155,11 +156,6 @@ private inline fun <R> generateFunctionBody(
     functionGenerationContext.resetDebugLocation()
 }
 
-internal fun FunctionGenerationContext.initBridgeDebugInfo() {
-    val location = setupBridgeDebugInfo(context, function) ?: return
-    debugLocation(location, location)
-}
-
 /**
  * There're cases when we don't need end position or it is meaningless.
  */
@@ -672,7 +668,7 @@ internal class FunctionGenerationContext(val function: LLVMValueRef,
     fun kotlinExceptionHandler(
             block: FunctionGenerationContext.(exception: LLVMValueRef) -> Unit
     ): ExceptionHandler {
-        val lpBlock = basicBlock("kotlinExceptionHandler", null)
+        val lpBlock = basicBlock("kotlinExceptionHandler", position()?.end)
 
         appendingTo(lpBlock) {
             val exception = catchKotlinException()
@@ -1127,8 +1123,8 @@ internal class FunctionGenerationContext(val function: LLVMValueRef,
                 val clause = ConstArray(int8TypePtr, listOf(kotlinExceptionRtti))
                 LLVMAddClause(landingpad, clause.llvm)
 
-                val bbCleanup = basicBlock("forwardException", null)
-                val bbUnexpected = basicBlock("unexpectedException", null)
+                val bbCleanup = basicBlock("forwardException", position()?.end)
+                val bbUnexpected = basicBlock("unexpectedException", position()?.end)
 
                 val selector = extractValue(landingpad, 1)
                 condBr(
diff --git a/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/objcexport/ObjCExportCodeGenerator.kt b/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/objcexport/ObjCExportCodeGenerator.kt
index b898321880b..fdbe67b02ad 100644
--- a/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/objcexport/ObjCExportCodeGenerator.kt
+++ b/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/objcexport/ObjCExportCodeGenerator.kt
@@ -684,11 +684,18 @@ private fun ObjCExportCodeGenerator.emitCollectionConverters() {
 
 private inline fun ObjCExportCodeGenerator.generateObjCImpBy(
         methodBridge: MethodBridge,
+        debugInfo: Boolean = false,
         genBody: FunctionGenerationContext.() -> Unit
 ): LLVMValueRef {
     val result = LLVMAddFunction(context.llvmModule, "objc2kotlin", objCFunctionType(context, methodBridge))!!
 
-    generateFunction(codegen, result) {
+    val location = if (debugInfo) {
+        setupBridgeDebugInfo(context, result)
+    } else {
+        null
+    }
+
+    generateFunction(codegen, result, startLocation = location, endLocation = location) {
         genBody()
     }
 
@@ -737,13 +744,11 @@ private fun ObjCExportCodeGenerator.generateObjCImp(
                 resultLifetime: Lifetime,
                 exceptionHandler: ExceptionHandler
         ) -> LLVMValueRef?
-): LLVMValueRef = generateObjCImpBy(methodBridge) {
-    if (isDirect) {
-        // Consider this call inlinable. If it is inlined into a bridge with no debug information,
-        // lldb will not decode the inlined frame even if the callee has debug information.
-        initBridgeDebugInfo()
-        // TODO: consider adding debug info to other bridges.
-    }
+): LLVMValueRef = generateObjCImpBy(methodBridge, debugInfo = isDirect /* see below */) {
+    // Considering direct calls inlinable above. If such a call is inlined into a bridge with no debug information,
+    // lldb will not decode the inlined frame even if the callee has debug information.
+    // So generate dummy debug information for bridge in this case.
+    // TODO: consider adding debug info to other bridges.
 
     val returnType = methodBridge.returnBridge