[K/JS] Remove the possibility to have negative lines and columns in Source Maps

Author: JSMonk

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/coroutines/AddContinuationToFunctionsLowering.kt

@@ -79,12 +79,12 @@ private fun transformSuspendFunction(context: CommonBackendContext, function: Ir
         newBody.statements.lastOrNull() !is IrReturn
     ) {
         // Adding explicit return of Unit.
-        // Set both offsets of the IrReturn to body.endOffset - 1 so that a breakpoint set at the closing brace of a lambda expression
-        // could be hit.
+        // Set both offsets of the IrReturn to body.endOffset.previousOffset (check the description of the `previousOffset` method)
+        // so that a breakpoint set at the closing brace of a lambda expression could be hit.
         newBody.statements += context.createIrBuilder(
             newFunctionWithContinuation.symbol,
-            startOffset = newBody.endOffset - 1,
-            endOffset = newBody.endOffset - 1
+            startOffset = newBody.endOffset.previousOffset,
+            endOffset = newBody.endOffset.previousOffset
         ).irReturnUnit()
     }
 

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/coroutines/AbstractSuspendFunctionsLowering.kt

@@ -487,9 +487,13 @@ abstract class AbstractSuspendFunctionsLowering<C : CommonBackendContext>(val co
             else delegatingCall
         val body = irFunction.body as IrBlockBody
 
-        // Set both offsets to body.endOffset - 1 so that a breakpoint set at the closing brace of a lambda expression
-        // could be hit.
-        context.createIrBuilder(irFunction.symbol, startOffset = body.endOffset - 1, endOffset = body.endOffset - 1).run {
+        // Set both offsets to body.endOffset.previousOffset (check the description of the `previousOffset` method)
+        // so that a breakpoint set at the closing brace of a lambda expression could be hit.
+        context.createIrBuilder(
+            irFunction.symbol,
+            startOffset = body.endOffset.previousOffset,
+            endOffset = body.endOffset.previousOffset
+        ).run {
             val statements = body.statements
             val lastStatement = statements.last()
             assert(lastStatement == delegatingCall || lastStatement is IrReturn) { "Unexpected statement $lastStatement" }

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/coroutines/StateMachineBuilder.kt

@@ -29,6 +29,7 @@ import org.jetbrains.kotlin.ir.types.isUnit
 import org.jetbrains.kotlin.ir.util.deepCopyWithSymbols
 import org.jetbrains.kotlin.ir.util.isElseBranch
 import org.jetbrains.kotlin.ir.util.isSuspend
+import org.jetbrains.kotlin.ir.util.previousOffset
 import org.jetbrains.kotlin.ir.visitors.*
 
 class SuspendState(type: IrType) {
@@ -96,13 +97,13 @@ class StateMachineBuilder(
     fun finalizeStateMachine() {
         globalCatch = buildGlobalCatch()
         if (currentBlock.statements.lastOrNull() !is IrReturn) {
-            // Set both offsets to rootLoop.endOffset - 1 so that a breakpoint set at the closing brace of a lambda expression
-            // could be hit.
+            // Set both offsets to rootLoop.endOffset.previousOffset (check the description of the `previousOffset` method)
+            // so that a breakpoint set at the closing brace of a lambda expression could be hit.
             // NOTE: rootLoop's offsets are the same as in the original function.
             addStatement(
                 IrReturnImpl(
-                    startOffset = rootLoop.endOffset - 1,
-                    endOffset = rootLoop.endOffset - 1,
+                    startOffset = rootLoop.endOffset.previousOffset,
+                    endOffset = rootLoop.endOffset.previousOffset,
                     nothing,
                     function,
                     unitValue

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/IrUtils.kt

@@ -1369,3 +1369,15 @@ val IrFunction.isValueClassTypedEquals: Boolean
                 && contextReceiverParametersCount == 0 && extensionReceiverParameter == null
                 && (parentClass.isValue)
     }
+
+/**
+ * The method is used to calculate the previous offset from the current one to prevent situations when it can calculate
+ * [UNDEFINED_OFFSET] from 0 offset and -2 offset from the [UNDEFINED OFFSET]
+ */
+val Int.previousOffset
+    get(): Int =
+        when (compareTo(0)) {
+            0 -> 0
+            -1 -> UNDEFINED_OFFSET
+            else -> minus(1)
+        }