Add line numbers for suspend function to enhance stepping (KT-16025)

Stop at function start on step into.
Step at function end on step out.

Both cases should actually be skipped by debugger, but this is postponed
till new backend generation for suspend functions is ready.

 #KT-16025 Fixed

compiler/backend/src/org/jetbrains/kotlin/codegen/coroutines/SuspendFunctionGenerationStrategy.kt

@@ -33,20 +33,18 @@ class SuspendFunctionGenerationStrategy(
 
     override fun doGenerateBody(codegen: ExpressionCodegen, signature: JvmMethodSignature) {
         if (!originalSuspendDescriptor.containsNonTailSuspensionCalls(state.bindingContext)) {
-            return codegen.returnExpression(declaration.bodyExpression)
+            codegen.returnExpression(declaration.bodyExpression)
+            return
         }
 
         val coroutineCodegen = CoroutineCodegen.create(codegen, originalSuspendDescriptor, declaration, state)
         coroutineCodegen.generate()
 
+        codegen.markLineNumber(declaration, false)
         codegen.putClosureInstanceOnStack(coroutineCodegen, null).put(Type.getObjectType(coroutineCodegen.className), codegen.v)
+        codegen.v.invokeDoResumeWithUnit(coroutineCodegen.v.thisName)
 
-        with(codegen.v) {
-            invokeDoResumeWithUnit(coroutineCodegen.v.thisName)
-
-            codegen.markLineNumber(declaration, true)
-
-            areturn(AsmTypes.OBJECT_TYPE)
-        }
+        codegen.markLineNumber(declaration, true)
+        codegen.v.areturn(AsmTypes.OBJECT_TYPE)
     }
 }

idea/testData/debugger/tinyApp/outs/siSuspendFun.out

@@ -0,0 +1,14 @@
+LineBreakpoint created at siSuspendFun.kt:29
+Run Java
+Connected to the target VM
+siSuspendFun.kt:29
+siSuspendFun.kt:21
+siSuspendFun.kt:22
+siSuspendFun.kt:18
+siSuspendFun.kt:18
+siSuspendFun.kt:14
+siSuspendFun.kt:10
+siSuspendFun.kt:6
+Disconnected from the target VM
+
+Process finished with exit code 0

idea/testData/debugger/tinyApp/outs/souSuspendFun.out

@@ -0,0 +1,14 @@
+LineBreakpoint created at souSuspendFun.kt:7
+Run Java
+Connected to the target VM
+souSuspendFun.kt:7
+souSuspendFun.kt:11
+souSuspendFun.kt:15
+souSuspendFun.kt:19
+souSuspendFun.kt:19
+souSuspendFun.kt:23
+souSuspendFun.kt:25
+souSuspendFun.kt:29
+Disconnected from the target VM
+
+Process finished with exit code 0

idea/testData/debugger/tinyApp/src/stepping/stepInto/siSuspendFun.kt

@@ -0,0 +1,34 @@
+package siSuspendFun
+
+import forTests.builder
+
+private fun foo(): Int {
+    return 42                                                      // 8
+}
+
+// One line suspend wihtout doResume
+suspend fun fourth() = foo()                                       // 7
+
+// Multiline suspend without doResume
+suspend fun third() : Int? {
+    return fourth()                                                // 6
+}
+
+// One line suspend with doResume
+suspend fun second(): Int = third()?.let { return it } ?: 0        // 4 (FIX IT!) 5
+
+// Multiline suspend with doResume
+suspend fun first(): Int {                                         // 2 (FIX IT!)
+    second()                                                       // 3
+    return 12
+}
+
+fun main(args: Array<String>) {
+    builder {
+        //Breakpoint!
+        first()                                                    // 1
+        foo()
+    }
+}
+
+// STEP_INTO: 7

idea/testData/debugger/tinyApp/src/stepping/stepOut/souSuspendFun.kt

@@ -0,0 +1,33 @@
+package souSuspendFun
+
+import forTests.builder
+
+private fun foo(): Int {
+    //Breakpoint!
+    return 42                                                      // 1
+}
+
+// One line suspend wihtout doResume
+suspend fun fourth() = foo()                                       // 2
+
+// Multiline suspend without doResume
+suspend fun third() : Int? {
+    return fourth()                                                // 3
+}
+
+// One line suspend with doResume
+suspend fun second(): Int = third()?.let { return it } ?: 0        // 4 5 (FIX IT)
+
+// Multiline suspend with doResume
+suspend fun first(): Int {
+    second()                                                       // 6
+    return 12
+}                                                                  // 7 (FIX IT)
+
+fun main(args: Array<String>) {
+    builder {
+        first()                                                    // 8
+    }
+}
+
+// STEP_OUT: 7

idea/tests/org/jetbrains/kotlin/idea/debugger/KotlinSteppingTestGenerated.java

@@ -272,6 +272,12 @@ public class KotlinSteppingTestGenerated extends AbstractKotlinSteppingTest {
             doStepIntoTest(fileName);
         }
 
+        @TestMetadata("siSuspendFun.kt")
+        public void testSiSuspendFun() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/debugger/tinyApp/src/stepping/stepInto/siSuspendFun.kt");
+            doStepIntoTest(fileName);
+        }
+
         @TestMetadata("skipSimpleGetter.kt")
         public void testSkipSimpleGetter() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/debugger/tinyApp/src/stepping/stepInto/skipSimpleGetter.kt");
@@ -353,6 +359,12 @@ public class KotlinSteppingTestGenerated extends AbstractKotlinSteppingTest {
             doStepOutTest(fileName);
         }
 
+        @TestMetadata("souSuspendFun.kt")
+        public void testSouSuspendFun() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/debugger/tinyApp/src/stepping/stepOut/souSuspendFun.kt");
+            doStepOutTest(fileName);
+        }
+
         @TestMetadata("stepOutInlineFunction.kt")
         public void testStepOutInlineFunction() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/debugger/tinyApp/src/stepping/stepOut/stepOutInlineFunction.kt");