[K2] Allow using simple boolean expressions in constant position

Such behavior is not the same as in K1, but it is more consistent.

#KT-64400 Fixed

analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosticCompilerTestFE10TestdataTestGenerated.java

@@ -23951,6 +23951,12 @@ public class DiagnosticCompilerTestFE10TestdataTestGenerated extends AbstractDia
                     runTest("compiler/testData/diagnostics/tests/modifiers/const/arrayInAnnotationArgumentType.kt");
                 }
 
+                @Test
+                @TestMetadata("compare.kt")
+                public void testCompare() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/modifiers/const/compare.kt");
+                }
+
                 @Test
                 @TestMetadata("constInteraction.kt")
                 public void testConstInteraction() throws Exception {

analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/LLFirPreresolvedReversedDiagnosticCompilerFE10TestDataTestGenerated.java

@@ -23951,6 +23951,12 @@ public class LLFirPreresolvedReversedDiagnosticCompilerFE10TestDataTestGenerated
                     runTest("compiler/testData/diagnostics/tests/modifiers/const/arrayInAnnotationArgumentType.kt");
                 }
 
+                @Test
+                @TestMetadata("compare.kt")
+                public void testCompare() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/modifiers/const/compare.kt");
+                }
+
                 @Test
                 @TestMetadata("constInteraction.kt")
                 public void testConstInteraction() throws Exception {

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirLightTreeOldFrontendDiagnosticsTestGenerated.java

@@ -23945,6 +23945,12 @@ public class FirLightTreeOldFrontendDiagnosticsTestGenerated extends AbstractFir
                     runTest("compiler/testData/diagnostics/tests/modifiers/const/arrayInAnnotationArgumentType.kt");
                 }
 
+                @Test
+                @TestMetadata("compare.kt")
+                public void testCompare() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/modifiers/const/compare.kt");
+                }
+
                 @Test
                 @TestMetadata("constInteraction.kt")
                 public void testConstInteraction() throws Exception {

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirPsiOldFrontendDiagnosticsTestGenerated.java

@@ -23951,6 +23951,12 @@ public class FirPsiOldFrontendDiagnosticsTestGenerated extends AbstractFirPsiDia
                     runTest("compiler/testData/diagnostics/tests/modifiers/const/arrayInAnnotationArgumentType.kt");
                 }
 
+                @Test
+                @TestMetadata("compare.kt")
+                public void testCompare() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/modifiers/const/compare.kt");
+                }
+
                 @Test
                 @TestMetadata("constInteraction.kt")
                 public void testConstInteraction() throws Exception {

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/FirConstChecks.kt

@@ -96,10 +96,6 @@ internal fun checkConstantArguments(
                 return ConstantArgumentKind.NOT_CONST
             }
 
-            if (expression.isForbiddenComplexConstant(session)) {
-                return ConstantArgumentKind.NOT_CONST
-            }
-
             for (exp in (expression as FirCall).arguments) {
                 if (exp is FirResolvedQualifier || exp is FirGetClassCall || exp.getExpandedType().isUnsignedType) {
                     return ConstantArgumentKind.NOT_CONST
@@ -162,7 +158,7 @@ internal fun checkConstantArguments(
             if (calleeReference !is FirResolvedNamedReference) return ConstantArgumentKind.NOT_CONST
             val symbol = calleeReference.resolvedSymbol as? FirNamedFunctionSymbol ?: return ConstantArgumentKind.NOT_CONST
 
-            if (!symbol.canBeEvaluated() && !expression.isCompileTimeBuiltinCall(session) || expression.isForbiddenComplexConstant(session)) {
+            if (!symbol.canBeEvaluated() && !expression.isCompileTimeBuiltinCall(session)) {
                 return ConstantArgumentKind.NOT_CONST
             }
 
@@ -214,34 +210,6 @@ internal fun checkConstantArguments(
     return null
 }
 
-private fun FirExpression.isForbiddenComplexConstant(session: FirSession): Boolean {
-    val forbidComplexBooleanExpressions = session.languageVersionSettings.supportsFeature(
-        LanguageFeature.ProhibitSimplificationOfNonTrivialConstBooleanExpressions
-    )
-    val intrinsicConstEvaluation = session.languageVersionSettings.supportsFeature(
-        LanguageFeature.IntrinsicConstEvaluation
-    )
-    return !intrinsicConstEvaluation && forbidComplexBooleanExpressions && isComplexBooleanConstant(session)
-}
-
-private fun FirExpression.isComplexBooleanConstant(session: FirSession): Boolean {
-    return when {
-        !resolvedType.fullyExpandedType(session).isBoolean -> false
-        this is FirConstExpression<*> -> false
-        usesVariableAsConstant -> false
-        else -> true
-    }
-}
-
-/**
- * See: org.jetbranis.kotlin.resolve.constants.CompileTimeConstant.Parameters.usesVariableAsConstant
- */
-@Suppress("RecursivePropertyAccessor")
-private val FirExpression.usesVariableAsConstant: Boolean
-    get() = this is FirPropertyAccessExpression && toResolvedCallableSymbol()?.isConst == true
-            || this is FirQualifiedAccessExpression && explicitReceiver?.usesVariableAsConstant != false
-            || this is FirCall && this.arguments.any { it.usesVariableAsConstant }
-
 private val compileTimeFunctions = setOf(
     *OperatorNameConventions.BINARY_OPERATION_NAMES.toTypedArray(), *OperatorNameConventions.UNARY_OPERATION_NAMES.toTypedArray(),
     OperatorNameConventions.SHL, OperatorNameConventions.SHR, OperatorNameConventions.USHR,

compiler/testData/diagnostics/tests/modifiers/const/compare.fir.kt

@@ -0,0 +1,22 @@
+const val INT = 0
+const val LONG = 0L
+
+const val compareInt1 = 1 < 2
+const val compareInt2 = 1 <= 3
+const val compareInt3 = 1 > 4
+const val compareInt4 = 1 >= 5
+
+const val compareInt5 = INT < 2
+const val compareInt6 = INT <= 3
+const val compareInt7 = INT > 4
+const val compareInt8 = INT >= 5
+
+const val compareLong1 = 1L < 2L
+const val compareLong2 = 1L <= 3L
+const val compareLong3 = 1L > 4L
+const val compareLong4 = 1L >= 5L
+
+const val compareLong5 = LONG < 2L
+const val compareLong6 = LONG <= 3L
+const val compareLong7 = LONG > 4L
+const val compareLong8 = LONG >= 5L

compiler/testData/diagnostics/tests/modifiers/const/compare.kt

@@ -0,0 +1,22 @@
+const val INT = 0
+const val LONG = 0L
+
+const val compareInt1 = <!CONST_VAL_WITH_NON_CONST_INITIALIZER!>1 < 2<!>
+const val compareInt2 = <!CONST_VAL_WITH_NON_CONST_INITIALIZER!>1 <= 3<!>
+const val compareInt3 = <!CONST_VAL_WITH_NON_CONST_INITIALIZER!>1 > 4<!>
+const val compareInt4 = <!CONST_VAL_WITH_NON_CONST_INITIALIZER!>1 >= 5<!>
+
+const val compareInt5 = INT < 2
+const val compareInt6 = INT <= 3
+const val compareInt7 = INT > 4
+const val compareInt8 = INT >= 5
+
+const val compareLong1 = <!CONST_VAL_WITH_NON_CONST_INITIALIZER!>1L < 2L<!>
+const val compareLong2 = <!CONST_VAL_WITH_NON_CONST_INITIALIZER!>1L <= 3L<!>
+const val compareLong3 = <!CONST_VAL_WITH_NON_CONST_INITIALIZER!>1L > 4L<!>
+const val compareLong4 = <!CONST_VAL_WITH_NON_CONST_INITIALIZER!>1L >= 5L<!>
+
+const val compareLong5 = LONG < 2L
+const val compareLong6 = LONG <= 3L
+const val compareLong7 = LONG > 4L
+const val compareLong8 = LONG >= 5L

compiler/testData/diagnostics/tests/modifiers/const/equals_before.fir.kt

@@ -0,0 +1,46 @@
+// !LANGUAGE: -IntrinsicConstEvaluation
+
+const val equalsBoolean1 = <!CONST_VAL_WITH_NON_CONST_INITIALIZER!>true.equals(true)<!>
+const val equalsBoolean2 = false != true
+const val equalsBoolean3 = <!CONST_VAL_WITH_NON_CONST_INITIALIZER!>false.equals(1)<!>
+const val equalsBoolean4 = <!EQUALITY_NOT_APPLICABLE!>false == 1<!>
+
+const val equalsChar1 = <!CONST_VAL_WITH_NON_CONST_INITIALIZER!>'1'.equals('2')<!>
+const val equalsChar2 = '2' == '2'
+const val equalsChar3 = <!CONST_VAL_WITH_NON_CONST_INITIALIZER!>'1'.equals(1)<!>
+const val equalsChar4 = <!EQUALITY_NOT_APPLICABLE!>'1' == 1<!>
+
+const val equalsByte1 = <!CONST_VAL_WITH_NON_CONST_INITIALIZER!>1.toByte().equals(2.toByte())<!>
+const val equalsByte2 = 2.toByte() == 2.toByte()
+const val equalsByte3 = <!CONST_VAL_WITH_NON_CONST_INITIALIZER!>1.toByte().equals("1")<!>
+const val equalsByte4 = <!EQUALITY_NOT_APPLICABLE!>1.toByte() == "1"<!>
+
+const val equalsShort1 = <!CONST_VAL_WITH_NON_CONST_INITIALIZER!>1.toShort().equals(2.toShort())<!>
+const val equalsShort2 = 2.toShort() == 2.toShort()
+const val equalsShort3 = <!CONST_VAL_WITH_NON_CONST_INITIALIZER!>1.toShort().equals("1")<!>
+const val equalsShort4 = <!EQUALITY_NOT_APPLICABLE!>1.toShort() == "1"<!>
+
+const val equalsInt1 = <!CONST_VAL_WITH_NON_CONST_INITIALIZER!>1.equals(2)<!>
+const val equalsInt2 = 2 == 2
+const val equalsInt3 = <!CONST_VAL_WITH_NON_CONST_INITIALIZER!>1.equals("1")<!>
+const val equalsInt4 = <!EQUALITY_NOT_APPLICABLE!>1 == "1"<!>
+
+const val equalsLong1 = <!CONST_VAL_WITH_NON_CONST_INITIALIZER!>1L.equals(2L)<!>
+const val equalsLong2 = 2L == 2L
+const val equalsLong3 = <!CONST_VAL_WITH_NON_CONST_INITIALIZER!>1L.equals("1")<!>
+const val equalsLong4 = <!EQUALITY_NOT_APPLICABLE!>1L == "1"<!>
+
+const val equalsFloat1 = <!CONST_VAL_WITH_NON_CONST_INITIALIZER!>1.0f.equals(2.0f)<!>
+const val equalsFloat2 = 2.0f == 2.0f
+const val equalsFloat3 = <!CONST_VAL_WITH_NON_CONST_INITIALIZER!>1.0f.equals("1")<!>
+const val equalsFloat4 = <!EQUALITY_NOT_APPLICABLE!>1.0f == "1"<!>
+
+const val equalsDoable1 = <!CONST_VAL_WITH_NON_CONST_INITIALIZER!>1.0.equals(2.0)<!>
+const val equalsDoable2 = 2.0 == 2.0
+const val equalsDoable3 = <!CONST_VAL_WITH_NON_CONST_INITIALIZER!>1.0.equals("1")<!>
+const val equalsDoable4 = <!EQUALITY_NOT_APPLICABLE!>1.0 == "1"<!>
+
+const val equalsString1 = <!CONST_VAL_WITH_NON_CONST_INITIALIZER!>"someStr".equals("123")<!>
+const val equalsString2 = "someStr" == "otherStr"
+const val equalsString3 = <!CONST_VAL_WITH_NON_CONST_INITIALIZER!>"someStr".equals(1)<!>
+const val equalsString4 = <!EQUALITY_NOT_APPLICABLE!>"someStr" == 1<!>

compiler/testData/diagnostics/tests/modifiers/const/equals_before.kt

@@ -1,4 +1,3 @@
-// FIR_IDENTICAL
 // !LANGUAGE: -IntrinsicConstEvaluation
 
 const val equalsBoolean1 = <!CONST_VAL_WITH_NON_CONST_INITIALIZER!>true.equals(true)<!>

compiler/testData/diagnostics/tests/nonConstNotCall.fir.kt

@@ -0,0 +1,3 @@
+// ISSUE: KT-55196
+
+const val bb: Boolean = !false // Red in K1, green in K2

compiler/testData/diagnostics/tests/nonConstNotCall.kt

@@ -1,4 +1,3 @@
-// FIR_IDENTICAL
 // ISSUE: KT-55196
 
 const val bb: Boolean = <!CONST_VAL_WITH_NON_CONST_INITIALIZER!>!false<!> // Red in K1, green in K2

compiler/testData/diagnostics/testsWithJsStdLibAndBackendCompilation/jsCode/compileTimeStringWithIntrinConstCall.fir.kt

@@ -74,10 +74,10 @@ fun testArithmeticOperations() {
 }
 
 fun testLogicOperations() {
-    js("{ var a = ${<!JSCODE_ARGUMENT_NON_CONST_EXPRESSION!>!true<!>}; }")
-    js("{ var a = ${<!JSCODE_ARGUMENT_NON_CONST_EXPRESSION!>true or false<!>}; }")
+    js("{ var a = ${!true}; }")
+    js("{ var a = ${true or false}; }")
     js("{ var a = ${true || false}; }")
-    js("{ var a = ${<!JSCODE_ARGUMENT_NON_CONST_EXPRESSION!>true and false<!>}; }")
+    js("{ var a = ${true and false}; }")
     js("{ var a = ${true && false}; }")
 
     js("{ var a = ${TRUE && false}; }")
@@ -85,14 +85,14 @@ fun testLogicOperations() {
 }
 
 fun testEq() {
-    js("{ var a = ${<!JSCODE_ARGUMENT_NON_CONST_EXPRESSION!>1 == 1<!>}; }")
+    js("{ var a = ${1 == 1}; }")
     js(<!JSCODE_CAN_NOT_VERIFY_JAVASCRIPT!>"{ var a = ${<!JSCODE_ARGUMENT_NON_CONST_EXPRESSION!>1U == 1U<!>}; }"<!>)
     js(<!JSCODE_CAN_NOT_VERIFY_JAVASCRIPT!>"{ var a = ${<!JSCODE_ARGUMENT_NON_CONST_EXPRESSION!>UONE == 1U<!>}; }"<!>)
     js("{ var a = ${"FOO" == STR}; }")
     js("{ var a = ${TRUE == null}; }")
     js("{ var a = ${STR == null}; }")
 
-    js("{ var a = ${<!JSCODE_ARGUMENT_NON_CONST_EXPRESSION!>1 != 1<!>}; }")
+    js("{ var a = ${1 != 1}; }")
     js(<!JSCODE_CAN_NOT_VERIFY_JAVASCRIPT!>"{ var a = ${<!JSCODE_ARGUMENT_NON_CONST_EXPRESSION!>1U != 1U<!>}; }"<!>)
     js(<!JSCODE_CAN_NOT_VERIFY_JAVASCRIPT!>"{ var a = ${<!JSCODE_ARGUMENT_NON_CONST_EXPRESSION!>UONE != 1U<!>}; }"<!>)
     js("{ var a = ${"FOO" != STR}; }")

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java

@@ -23951,6 +23951,12 @@ public class DiagnosticTestGenerated extends AbstractDiagnosticTest {
                     runTest("compiler/testData/diagnostics/tests/modifiers/const/arrayInAnnotationArgumentType.kt");
                 }
 
+                @Test
+                @TestMetadata("compare.kt")
+                public void testCompare() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/modifiers/const/compare.kt");
+                }
+
                 @Test
                 @TestMetadata("constInteraction.kt")
                 public void testConstInteraction() throws Exception {