[codegen][debug-info] generate _this name for \<this\> special variable

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

@@ -29,6 +29,7 @@ import org.jetbrains.kotlin.ir.visitors.acceptChildrenVoid
 import org.jetbrains.kotlin.ir.visitors.acceptVoid
 import org.jetbrains.kotlin.konan.target.CompilerOutputKind
 import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.resolve.descriptorUtil.classId
 import org.jetbrains.kotlin.resolve.descriptorUtil.module
 
@@ -1274,7 +1275,7 @@ internal class CodeGeneratorVisitor(val context: Context, val lifetimes: Map<IrE
                     builder       = context.debugInfo.builder,
                     functionScope = locationInfo.scope,
                     diType        = element.type.diType(context, codegen.llvmTargetData),
-                    name          = element.descriptor.name,
+                    name          = element.debugNameConversion(),
                     file          = file,
                     line          = locationInfo.line,
                     location      = location)
@@ -1283,7 +1284,7 @@ internal class CodeGeneratorVisitor(val context: Context, val lifetimes: Map<IrE
                     builder       = context.debugInfo.builder,
                     functionScope = locationInfo.scope,
                     diType        = element.type.diType(context, codegen.llvmTargetData),
-                    name          = element.descriptor.name,
+                    name          = element.debugNameConversion(),
                     argNo         = function.allParameters.indexOf(element) + 1,
                     file          = file,
                     line          = locationInfo.line,
@@ -2489,6 +2490,24 @@ internal class CodeGeneratorVisitor(val context: Context, val lifetimes: Map<IrE
     }
 }
 
+private fun IrValueParameter.debugNameConversion() = descriptor.name.debugNameConversion()
+
+private fun IrVariable.debugNameConversion() = descriptor.name.debugNameConversion()
+
+private val thisName = Name.special("<this>")
+private val underscoreThisName = Name.identifier("_this")
+/**
+ * HACK: this is workaround for GH-2316, to let IDE some how operate with this.
+ * We're experiencing issue with libclang which is used as compiler of expression in lldb
+ * for current state support Kotlin in lldb:
+ *   1. <this> isn't accepted by libclang as valid variable name.
+ *   2. this is reserved name and compiled in special way.
+ */
+private fun Name.debugNameConversion(): Name = when(this) {
+    thisName -> underscoreThisName
+    else -> this
+}
+
 class NoContextFound : Throwable()
 
 internal class LocationInfo(val scope: DIScopeOpaqueRef,