Clear DF info for variables assigned in 'try' #KT-17929 Fixed

compiler/frontend/src/org/jetbrains/kotlin/types/expressions/ControlStructureTypingVisitor.java

@@ -22,6 +22,7 @@
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns;
+import org.jetbrains.kotlin.config.LanguageFeature;
 import org.jetbrains.kotlin.descriptors.*;
 import org.jetbrains.kotlin.diagnostics.Errors;
 import org.jetbrains.kotlin.psi.*;
@@ -513,11 +514,20 @@ public KotlinTypeInfo visitTryExpression(@NotNull KtTryExpression expression, Ex
             }
         }
 
-        KotlinTypeInfo result = TypeInfoFactoryKt.noTypeInfo(context);
         KotlinTypeInfo tryResult = facade.getTypeInfo(tryBlock, context);
+        ExpressionTypingContext tryOutputContext = context.replaceExpectedType(NO_EXPECTED_TYPE);
+        if (!nothingInAllCatchBranches &&
+            facade.getComponents().languageVersionSettings.supportsFeature(LanguageFeature.SoundSmartCastsAfterTry)) {
+            PreliminaryLoopVisitor tryVisitor = PreliminaryLoopVisitor.visitTryBlock(expression);
+            tryOutputContext = tryOutputContext.replaceDataFlowInfo(
+                    tryVisitor.clearDataFlowInfoForAssignedLocalVariables(tryOutputContext.dataFlowInfo,
+                                                                          components.languageVersionSettings)
+            );
+        }
+
+        KotlinTypeInfo result = TypeInfoFactoryKt.noTypeInfo(tryOutputContext);
         if (finallyBlock != null) {
-            result = facade.getTypeInfo(finallyBlock.getFinalExpression(),
-                                        context.replaceExpectedType(NO_EXPECTED_TYPE));
+            result = facade.getTypeInfo(finallyBlock.getFinalExpression(), tryOutputContext);
         }
         else if (nothingInAllCatchBranches) {
             result = tryResult;

compiler/frontend/src/org/jetbrains/kotlin/types/expressions/PreliminaryLoopVisitor.kt

@@ -19,6 +19,7 @@ package org.jetbrains.kotlin.types.expressions
 import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.descriptors.impl.LocalVariableDescriptor
 import org.jetbrains.kotlin.psi.KtLoopExpression
+import org.jetbrains.kotlin.psi.KtTryExpression
 import org.jetbrains.kotlin.resolve.calls.smartcasts.DataFlowInfo
 import org.jetbrains.kotlin.resolve.calls.smartcasts.DataFlowValue
 import org.jetbrains.kotlin.resolve.calls.smartcasts.IdentifierInfo
@@ -59,5 +60,12 @@ class PreliminaryLoopVisitor private constructor() : AssignedVariablesSearcher()
             loopExpression.accept(visitor, null)
             return visitor
         }
+
+        @JvmStatic
+        fun visitTryBlock(tryExpression: KtTryExpression): PreliminaryLoopVisitor {
+            val visitor = PreliminaryLoopVisitor()
+            tryExpression.tryBlock.accept(visitor, null)
+            return visitor
+        }
     }
 }

compiler/testData/diagnostics/tests/smartCasts/varnotnull/setNotNullInTry.kt

@@ -1,3 +1,5 @@
+// !LANGUAGE: +SoundSmartCastsAfterTry
+
 fun bar(arg: Any?) = arg
 
 fun foo() {
@@ -6,7 +8,7 @@ fun foo() {
     try {
         s = "Test"
     } catch (ex: Exception) {}
-    bar(<!DEBUG_INFO_CONSTANT!>s<!>)
-    if (<!SENSELESS_COMPARISON!><!DEBUG_INFO_CONSTANT!>s<!> != null<!>) { }
-    <!DEBUG_INFO_CONSTANT!>s<!><!UNSAFE_CALL!>.<!>hashCode()
+    bar(s)
+    if (s != null) { }
+    s<!UNSAFE_CALL!>.<!>hashCode()
 }

compiler/testData/diagnostics/tests/smartCasts/varnotnull/setNullInTry.kt

@@ -1,8 +1,10 @@
+// !LANGUAGE: +SoundSmartCastsAfterTry
+
 fun foo() {
     var s: String?
     s = "Test"
     try {
         s = null
     } catch (ex: Exception) {}
-    <!DEBUG_INFO_SMARTCAST!>s<!>.hashCode()
+    s<!UNSAFE_CALL!>.<!>hashCode()
 }

compiler/testData/diagnostics/tests/smartCasts/varnotnull/setNullInTryFinally.kt

@@ -1,3 +1,5 @@
+// !LANGUAGE: +SoundSmartCastsAfterTry
+
 fun bar() {}
 
 fun foo() {
@@ -10,5 +12,5 @@ fun foo() {
     finally {
         bar()
     }
-    <!DEBUG_INFO_SMARTCAST!>s<!>.hashCode()
+    s<!UNSAFE_CALL!>.<!>hashCode()
 }

compiler/testData/diagnostics/tests/smartCasts/varnotnull/setNullInTryUnsound.kt

@@ -0,0 +1,8 @@
+fun foo() {
+    var s: String?
+    s = "Test"
+    try {
+        s = null
+    } catch (ex: Exception) {}
+    <!DEBUG_INFO_SMARTCAST!>s<!>.hashCode()
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/setNullInTryUnsound.txt

@@ -0,0 +1,3 @@
+package
+
+public fun foo(): kotlin.Unit

compiler/testData/diagnostics/tests/smartCasts/varnotnull/setSameInTry.kt

@@ -1,8 +1,11 @@
+// !LANGUAGE: +SoundSmartCastsAfterTry
+
 fun foo() {
     var s: String?
     s = "Test"
     try {
         s = "Other"
     } catch (ex: Exception) {}
-    <!DEBUG_INFO_SMARTCAST!>s<!>.hashCode()
+    // Problem: here we do not see that 's' is always not-null
+    s<!UNSAFE_CALL!>.<!>hashCode()
 }

compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestGenerated.java

@@ -21186,6 +21186,12 @@ public void testSetNullInTryFinally() throws Exception {
                     doTest(fileName);
                 }
 
+                @TestMetadata("setNullInTryUnsound.kt")
+                public void testSetNullInTryUnsound() throws Exception {
+                    String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/smartCasts/varnotnull/setNullInTryUnsound.kt");
+                    doTest(fileName);
+                }
+
                 @TestMetadata("setSameInTry.kt")
                 public void testSetSameInTry() throws Exception {
                     String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/smartCasts/varnotnull/setSameInTry.kt");

compiler/util/src/org/jetbrains/kotlin/config/LanguageVersionSettings.kt

@@ -51,6 +51,7 @@ enum class LanguageFeature(
 
     ArrayLiteralsInAnnotations(KOTLIN_1_2),
     InlineDefaultFunctionalParameters(KOTLIN_1_2),
+    SoundSmartCastsAfterTry(KOTLIN_1_2),
 
     // Experimental features