KT-14357 Run RedundantCoercionToUnitTransformer before DeadCodeEliminatingMethodTransformer.

Remove empty try-catch blocks in DeadCodeEliminatingMethodTransformer.

compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/DeadCodeEliminationMethodTransformer.kt

@@ -20,6 +20,7 @@ import org.jetbrains.org.objectweb.asm.tree.MethodNode
 import org.jetbrains.kotlin.codegen.optimization.transformer.MethodTransformer
 import org.jetbrains.kotlin.codegen.optimization.common.OptimizationBasicInterpreter
 import org.jetbrains.kotlin.codegen.optimization.common.isMeaningful
+import org.jetbrains.kotlin.codegen.optimization.common.removeEmptyCatchBlocks
 
 class DeadCodeEliminationMethodTransformer : MethodTransformer() {
     override fun transform(internalClassName: String, methodNode: MethodNode) {
@@ -28,10 +29,12 @@ class DeadCodeEliminationMethodTransformer : MethodTransformer() {
         val insnsArray = insnList.toArray()
 
         // Do not remove not meaningful nodes (labels/linenumbers) because they can be referred
-        // by try/catch blocks or local variables table
+        // by try/catch blocks or local variables table.
-        // We remove unneeded ones further after all optimizations by calling CommonPackage.prepareForEmitting(methodNode)
         insnsArray.zip(frames).filter {
             it.second == null && it.first.isMeaningful
         }.forEach { insnList.remove(it.first) }
+
+        // Remove empty try-catch blocks to make sure we don't break data flow analysis invariants by dead code elimination.
+        methodNode.removeEmptyCatchBlocks()
     }
 }

compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/OptimizationMethodVisitor.java

@@ -35,9 +35,9 @@ public class OptimizationMethodVisitor extends TransformationMethodVisitor {
     private static final MethodTransformer[] OPTIMIZATION_TRANSFORMERS = new MethodTransformer[] {
             new RedundantNullCheckMethodTransformer(),
             new RedundantBoxingMethodTransformer(),
+            new RedundantCoercionToUnitTransformer(),
             new DeadCodeEliminationMethodTransformer(),
-            new RedundantGotoMethodTransformer(),
+            new RedundantGotoMethodTransformer()
-            new RedundantCoercionToUnitTransformer()
     };
 
     private final boolean disableOptimization;

compiler/testData/codegen/box/deadCodeElimination/kt14357.kt

@@ -0,0 +1,10 @@
+fun box(): String {
+    if (false) {
+        try {
+            null!!
+        } catch (e: Exception) {
+            throw e
+        }
+    }
+    return "OK"
+}

compiler/testData/codegen/bytecodeText/deadCodeElimination/kt14357.kt

@@ -0,0 +1,11 @@
+fun test() {
+    if (false) {
+        try {
+            println("Hello Kotlin")
+        } catch (e: Exception) {
+            e.printStackTrace()
+        }
+    }
+}
+
+// 0 INVOKE

compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java

@@ -5079,6 +5079,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/deadCodeElimination/intersectingVariableRangeInFinally.kt");
             doTest(fileName);
         }
+
+        @TestMetadata("kt14357.kt")
+        public void testKt14357() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/deadCodeElimination/kt14357.kt");
+            doTest(fileName);
+        }
     }
 
     @TestMetadata("compiler/testData/codegen/box/defaultArguments")

compiler/tests/org/jetbrains/kotlin/codegen/BytecodeTextTestGenerated.java

@@ -889,6 +889,12 @@ public class BytecodeTextTestGenerated extends AbstractBytecodeTextTest {
             doTest(fileName);
         }
 
+        @TestMetadata("kt14357.kt")
+        public void testKt14357() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/bytecodeText/deadCodeElimination/kt14357.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("lastReturn.kt")
         public void testLastReturn() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/bytecodeText/deadCodeElimination/lastReturn.kt");