From 71f9341e088bb3347ecfea2f114e5e40bdc4326b Mon Sep 17 00:00:00 2001
From: Evgeny Mandrikov <138671+Godin@users.noreply.github.com>
Date: Sun, 9 Feb 2020 20:14:24 +0200
Subject: [PATCH] Update filter for suspending functions with tail call
 optimization (#1016)

---
 .../pom.xml                                   |  2 +-
 .../kotlin/targets/KotlinCoroutineTarget.kt   |  6 ++
 .../filter/KotlinCoroutineFilterTest.java     | 76 +++++++++++++++++++
 .../filter/KotlinCoroutineFilter.java         | 20 ++++-
 org.jacoco.doc/docroot/doc/changes.html       |  3 +
 5 files changed, 105 insertions(+), 2 deletions(-)

diff --git a/org.jacoco.core.test.validation.kotlin/pom.xml b/org.jacoco.core.test.validation.kotlin/pom.xml
index 635c8642f2..468b6472c9 100644
--- a/org.jacoco.core.test.validation.kotlin/pom.xml
+++ b/org.jacoco.core.test.validation.kotlin/pom.xml
@@ -26,7 +26,7 @@
 
   <properties>
     <bytecode.version>6</bytecode.version>
-    <kotlin.version>1.3.31</kotlin.version>
+    <kotlin.version>1.3.61</kotlin.version>
   </properties>
 
   <dependencies>
diff --git a/org.jacoco.core.test.validation.kotlin/src/org/jacoco/core/test/validation/kotlin/targets/KotlinCoroutineTarget.kt b/org.jacoco.core.test.validation.kotlin/src/org/jacoco/core/test/validation/kotlin/targets/KotlinCoroutineTarget.kt
index 784e488d65..bef0cebae0 100644
--- a/org.jacoco.core.test.validation.kotlin/src/org/jacoco/core/test/validation/kotlin/targets/KotlinCoroutineTarget.kt
+++ b/org.jacoco.core.test.validation.kotlin/src/org/jacoco/core/test/validation/kotlin/targets/KotlinCoroutineTarget.kt
@@ -25,6 +25,11 @@ object KotlinCoroutineTarget {
         nop() // assertFullyCovered()
     } // assertFullyCovered()
 
+    private suspend fun suspendingFunctionWithTailCallOptimization() { // assertEmpty()
+        nop() // assertFullyCovered()
+        anotherSuspendingFunction() // assertFullyCovered()
+    } // assertFullyCovered()
+
     private suspend fun anotherSuspendingFunction() {
         nop() // assertFullyCovered()
     }
@@ -37,6 +42,7 @@ object KotlinCoroutineTarget {
             nop(x) // assertFullyCovered()
             suspendingFunction() // assertFullyCovered()
             nop(x) // assertFullyCovered()
+            suspendingFunctionWithTailCallOptimization()
         } // assertFullyCovered()
 
     }
diff --git a/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/filter/KotlinCoroutineFilterTest.java b/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/filter/KotlinCoroutineFilterTest.java
index c8ba9eb386..4f471c3c3b 100644
--- a/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/filter/KotlinCoroutineFilterTest.java
+++ b/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/filter/KotlinCoroutineFilterTest.java
@@ -374,4 +374,80 @@ public void should_filter_suspending_functions() {
 		assertIgnored(range0, range1, range2);
 	}
 
+	/**
+	 * <pre>
+	 *     suspend fun example(b: Boolean) {
+	 *         if (b)
+	 *             suspendingFunction()
+	 *         else
+	 *             suspendingFunction()
+	 *     }
+	 * </pre>
+	 */
+	@Test
+	public void should_filter_suspending_functions_with_tail_call_optimization() {
+		final MethodNode m = new MethodNode(InstrSupport.ASM_API_VERSION, 0,
+				"example",
+				"(ZLkotlin/coroutines/Continuation;)Ljava/lang/Object;", null,
+				null);
+		context.classAnnotations
+				.add(KotlinGeneratedFilter.KOTLIN_METADATA_DESC);
+
+		final Label exit = new Label();
+
+		m.visitVarInsn(Opcodes.ILOAD, 1);
+		final Label next = new Label();
+		m.visitJumpInsn(Opcodes.IFEQ, next);
+
+		m.visitVarInsn(Opcodes.ALOAD, 0);
+		m.visitVarInsn(Opcodes.ALOAD, 2);
+		m.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "", "suspendingFunction",
+				"(Lkotlin/coroutines/Continuation;)Ljava/lang/Object;", false);
+		final Range range1 = new Range();
+		{
+			m.visitInsn(Opcodes.DUP);
+			range1.fromInclusive = m.instructions.getLast();
+			m.visitMethodInsn(Opcodes.INVOKESTATIC,
+					"kotlin/coroutines/intrinsics/IntrinsicsKt",
+					"getCOROUTINE_SUSPENDED", "()Ljava/lang/Object;", false);
+			final Label label = new Label();
+			m.visitJumpInsn(Opcodes.IF_ACMPNE, label);
+			m.visitInsn(Opcodes.ARETURN);
+			m.visitLabel(label);
+			m.visitInsn(Opcodes.POP);
+			range1.toInclusive = m.instructions.getLast();
+		}
+
+		m.visitJumpInsn(Opcodes.GOTO, exit);
+		m.visitLabel(next);
+
+		m.visitVarInsn(Opcodes.ALOAD, 0);
+		m.visitVarInsn(Opcodes.ALOAD, 2);
+		m.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "", "suspendingFunction",
+				"(Lkotlin/coroutines/Continuation;)Ljava/lang/Object;", false);
+		final Range range2 = new Range();
+		{
+			m.visitInsn(Opcodes.DUP);
+			range2.fromInclusive = m.instructions.getLast();
+			m.visitMethodInsn(Opcodes.INVOKESTATIC,
+					"kotlin/coroutines/intrinsics/IntrinsicsKt",
+					"getCOROUTINE_SUSPENDED", "()Ljava/lang/Object;", false);
+			final Label label = new Label();
+			m.visitJumpInsn(Opcodes.IF_ACMPNE, label);
+			m.visitInsn(Opcodes.ARETURN);
+			m.visitLabel(label);
+			m.visitInsn(Opcodes.POP);
+			range2.toInclusive = m.instructions.getLast();
+		}
+
+		m.visitLabel(exit);
+		m.visitFieldInsn(Opcodes.GETSTATIC, "kotlin/Unit", "INSTANCE",
+				"Lkotlin/Unit;");
+		m.visitInsn(Opcodes.ARETURN);
+
+		filter.filter(m, context, output);
+
+		assertIgnored(range1, range2);
+	}
+
 }
diff --git a/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/KotlinCoroutineFilter.java b/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/KotlinCoroutineFilter.java
index 814f59f6eb..35ac6665ba 100644
--- a/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/KotlinCoroutineFilter.java
+++ b/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/KotlinCoroutineFilter.java
@@ -43,10 +43,28 @@ public void filter(final MethodNode methodNode,
 		}
 
 		new Matcher().match(methodNode, output);
-
+		new Matcher().matchOptimizedTailCall(methodNode, output);
 	}
 
 	private static class Matcher extends AbstractMatcher {
+
+		private void matchOptimizedTailCall(final MethodNode methodNode,
+				final IFilterOutput output) {
+			for (final AbstractInsnNode i : methodNode.instructions) {
+				cursor = i;
+				nextIs(Opcodes.DUP);
+				nextIsInvoke(Opcodes.INVOKESTATIC,
+						"kotlin/coroutines/intrinsics/IntrinsicsKt",
+						"getCOROUTINE_SUSPENDED", "()Ljava/lang/Object;");
+				nextIs(Opcodes.IF_ACMPNE);
+				nextIs(Opcodes.ARETURN);
+				nextIs(Opcodes.POP);
+				if (cursor != null) {
+					output.ignore(i.getNext(), cursor);
+				}
+			}
+		}
+
 		private void match(final MethodNode methodNode,
 				final IFilterOutput output) {
 			cursor = methodNode.instructions.getFirst();
diff --git a/org.jacoco.doc/docroot/doc/changes.html b/org.jacoco.doc/docroot/doc/changes.html
index 5f4ed69e8a..e466f1c13f 100644
--- a/org.jacoco.doc/docroot/doc/changes.html
+++ b/org.jacoco.doc/docroot/doc/changes.html
@@ -32,6 +32,9 @@ <h3>New Features</h3>
   <li>Methods generated by Kotlin compiler for non-overridden non-abstract methods
       of interfaces are filtered out during generation of report
       (GitHub <a href="https://github.com/jacoco/jacoco/issues/1012">#1012</a>).</li>
+  <li>Branches added by the Kotlin compiler version 1.3.60 for suspending functions
+      with tail call optimization are filtered out during generation of report
+      (GitHub <a href="https://github.com/jacoco/jacoco/issues/1016">#1016</a>).</li>
 </ul>
 
 <h3>Non-functional Changes</h3>