Make infix modifier diagnostic message more informative (KT-12589)

(cherry picked from commit 2744309)

compiler/frontend/src/org/jetbrains/kotlin/diagnostics/Errors.java

@@ -621,7 +621,7 @@ public interface Errors {
     DiagnosticFactory1<PsiElement, String> INVALID_CHARACTERS = DiagnosticFactory1.create(ERROR);
 
     DiagnosticFactory1<PsiElement, String> INAPPLICABLE_OPERATOR_MODIFIER = DiagnosticFactory1.create(ERROR);
-    DiagnosticFactory0<PsiElement> INAPPLICABLE_INFIX_MODIFIER = DiagnosticFactory0.create(ERROR);
+    DiagnosticFactory1<PsiElement, String> INAPPLICABLE_INFIX_MODIFIER = DiagnosticFactory1.create(ERROR);
 
     DiagnosticFactory2<PsiElement, FunctionDescriptor, String> OPERATOR_MODIFIER_REQUIRED = DiagnosticFactory2.create(ERROR);
     DiagnosticFactory2<KtOperationReferenceExpression, FunctionDescriptor, String> INFIX_MODIFIER_REQUIRED = DiagnosticFactory2.create(ERROR);

compiler/frontend/src/org/jetbrains/kotlin/diagnostics/rendering/DefaultErrorMessages.java

@@ -379,7 +379,7 @@ public class DefaultErrorMessages {
         MAP.put(INVALID_CHARACTERS, "Name {0}", STRING);
 
         MAP.put(INAPPLICABLE_OPERATOR_MODIFIER, "''operator'' modifier is inapplicable on this function: {0}", STRING);
-        MAP.put(INAPPLICABLE_INFIX_MODIFIER, "'infix' modifier is inapplicable on this function");
+        MAP.put(INAPPLICABLE_INFIX_MODIFIER, "'infix' modifier is inapplicable on this function: {0}", STRING);
 
         MAP.put(OPERATOR_MODIFIER_REQUIRED, "''operator'' modifier is required on ''{0}'' in ''{1}''", NAME, STRING);
         MAP.put(INFIX_MODIFIER_REQUIRED, "''infix'' modifier is required on ''{0}'' in ''{1}''", NAME, STRING);

compiler/frontend/src/org/jetbrains/kotlin/resolve/InfixModifierChecker.kt

@@ -22,7 +22,8 @@ import org.jetbrains.kotlin.diagnostics.DiagnosticSink
 import org.jetbrains.kotlin.diagnostics.Errors
 import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.psi.KtDeclaration
-import org.jetbrains.kotlin.resolve.descriptorUtil.hasDefaultValue
+import org.jetbrains.kotlin.util.CheckResult
+import org.jetbrains.kotlin.util.InfixChecks
 
 class InfixModifierChecker : SimpleDeclarationChecker {
 
@@ -36,17 +37,9 @@ class InfixModifierChecker : SimpleDeclarationChecker {
         if (!functionDescriptor.isInfix) return
         val modifier = declaration.modifierList?.getModifier(KtTokens.INFIX_KEYWORD) ?: return
 
-        if (!isApplicable(functionDescriptor)) {
+        val checkResult = InfixChecks.check(functionDescriptor)
-            diagnosticHolder.report(Errors.INAPPLICABLE_INFIX_MODIFIER.on(modifier))
+        if (checkResult !is CheckResult.IllegalSignature) return
-        }
+
+        diagnosticHolder.report(Errors.INAPPLICABLE_INFIX_MODIFIER.on(modifier, checkResult.error))
     }
-
-    private fun isApplicable(descriptor: FunctionDescriptor): Boolean {
-        if (descriptor.dispatchReceiverParameter == null && descriptor.extensionReceiverParameter == null) return false
-        if (descriptor.valueParameters.size != 1) return false
-
-        val singleParameter = descriptor.valueParameters.first()
-        return !singleParameter.hasDefaultValue() && singleParameter.varargElementType == null
-    }
-
 }

compiler/frontend/src/org/jetbrains/kotlin/resolve/OperatorModifierChecker.kt

@@ -55,7 +55,7 @@ object OperatorModifierChecker {
         if (!functionDescriptor.isOperator) return
         val modifier = declaration.modifierList?.getModifier(KtTokens.OPERATOR_KEYWORD) ?: return
 
-        val checkResult = OperatorChecks.checkOperator(functionDescriptor)
+        val checkResult = OperatorChecks.check(functionDescriptor)
         if (checkResult.isSuccess) {
             if (functionDescriptor.name in COROUTINE_OPERATOR_NAMES
                     && !languageFeatureSettings.supportsFeature(LanguageFeature.Coroutines)) {

compiler/testData/diagnostics/tests/InfixModifierApplicability.kt

@@ -3,20 +3,25 @@
 class Pair<A, B>(val a: A, val b: B)
 infix fun <A, B> A.to(that: B): Pair<A, B> = Pair(this, that)
 
-infix fun String.o1(o: String) = o
+// OK
-<!INAPPLICABLE_INFIX_MODIFIER!>infix<!> fun String.o2(o: String, o2: String? = null) = o
+infix fun String.ok1(o: String) {}
-<!INAPPLICABLE_INFIX_MODIFIER!>infix<!> fun String.o3(o: String = "", o2: String? = null) = o
+class OkTest {
+    infix fun ok2(o: String) {}
+    infix fun String.ok3(o: String) {}
+}
 
-<!INAPPLICABLE_INFIX_MODIFIER!>infix<!> fun w1() {}
+// Errors
-<!INAPPLICABLE_INFIX_MODIFIER!>infix<!> fun w2(s: String) {}
+<!INAPPLICABLE_INFIX_MODIFIER(must have a single value parameter)!>infix<!> fun String.e1(o: String, o2: String? = null) = o
-<!INAPPLICABLE_INFIX_MODIFIER!>infix<!> fun String.w3() {}
+<!INAPPLICABLE_INFIX_MODIFIER(must have a single value parameter)!>infix<!> fun String.e2(o: String = "", o2: String? = null) = o
-<!INAPPLICABLE_INFIX_MODIFIER!>infix<!> fun String.w4(a: Int, b: Int) {}
+
-<!INAPPLICABLE_INFIX_MODIFIER!>infix<!> fun w5(a: Int, b: Int) {}
+<!INAPPLICABLE_INFIX_MODIFIER(must be a member of an extension function)!>infix<!> fun e3() {}
+<!INAPPLICABLE_INFIX_MODIFIER(must be a member of an extension function)!>infix<!> fun e4(s: String) {}
+<!INAPPLICABLE_INFIX_MODIFIER(must have a single value parameter)!>infix<!> fun String.e5() {}
+<!INAPPLICABLE_INFIX_MODIFIER(must have a single value parameter)!>infix<!> fun String.e6(a: Int, b: Int) {}
+<!INAPPLICABLE_INFIX_MODIFIER(must be a member of an extension function)!>infix<!> fun e7(a: Int, b: Int) {}
 
 class Example {
-    infix fun c1(s: String) {}
+    <!INAPPLICABLE_INFIX_MODIFIER(must have a single value parameter)!>infix<!> fun e8(s: String, a: Int = 0) {}
-    <!INAPPLICABLE_INFIX_MODIFIER!>infix<!> fun c2(s: String, a: Int = 0) {}
+    <!INAPPLICABLE_INFIX_MODIFIER(must have a single value parameter)!>infix<!> fun e9(s: String, a: Int) {}
-
+    <!INAPPLICABLE_INFIX_MODIFIER(must have a single value parameter)!>infix<!> fun e10() {}
-    <!INAPPLICABLE_INFIX_MODIFIER!>infix<!> fun cw1(s: String, a: Int) {}
-    <!INAPPLICABLE_INFIX_MODIFIER!>infix<!> fun sw2() {}
 }

compiler/testData/diagnostics/tests/InfixModifierApplicability.txt

@@ -1,26 +1,34 @@
 package
 
-public infix fun w1(): kotlin.Unit
+public infix fun e3(): kotlin.Unit
-public infix fun w2(/*0*/ s: kotlin.String): kotlin.Unit
+public infix fun e4(/*0*/ s: kotlin.String): kotlin.Unit
-public infix fun w5(/*0*/ a: kotlin.Int, /*1*/ b: kotlin.Int): kotlin.Unit
+public infix fun e7(/*0*/ a: kotlin.Int, /*1*/ b: kotlin.Int): kotlin.Unit
-public infix fun kotlin.String.o1(/*0*/ o: kotlin.String): kotlin.String
+public infix fun kotlin.String.e1(/*0*/ o: kotlin.String, /*1*/ o2: kotlin.String? = ...): kotlin.String
-public infix fun kotlin.String.o2(/*0*/ o: kotlin.String, /*1*/ o2: kotlin.String? = ...): kotlin.String
+public infix fun kotlin.String.e2(/*0*/ o: kotlin.String = ..., /*1*/ o2: kotlin.String? = ...): kotlin.String
-public infix fun kotlin.String.o3(/*0*/ o: kotlin.String = ..., /*1*/ o2: kotlin.String? = ...): kotlin.String
+public infix fun kotlin.String.e5(): kotlin.Unit
+public infix fun kotlin.String.e6(/*0*/ a: kotlin.Int, /*1*/ b: kotlin.Int): kotlin.Unit
+public infix fun kotlin.String.ok1(/*0*/ o: kotlin.String): kotlin.Unit
 public infix fun </*0*/ A, /*1*/ B> A.to(/*0*/ that: B): Pair<A, B>
-public infix fun kotlin.String.w3(): kotlin.Unit
-public infix fun kotlin.String.w4(/*0*/ a: kotlin.Int, /*1*/ b: kotlin.Int): kotlin.Unit
 
 public final class Example {
     public constructor Example()
-    public final infix fun c1(/*0*/ s: kotlin.String): kotlin.Unit
+    public final infix fun e10(): kotlin.Unit
-    public final infix fun c2(/*0*/ s: kotlin.String, /*1*/ a: kotlin.Int = ...): kotlin.Unit
+    public final infix fun e8(/*0*/ s: kotlin.String, /*1*/ a: kotlin.Int = ...): kotlin.Unit
-    public final infix fun cw1(/*0*/ s: kotlin.String, /*1*/ a: kotlin.Int): kotlin.Unit
+    public final infix fun e9(/*0*/ s: kotlin.String, /*1*/ a: kotlin.Int): kotlin.Unit
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
-    public final infix fun sw2(): kotlin.Unit
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 }
 
+public final class OkTest {
+    public constructor OkTest()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public final infix fun ok2(/*0*/ o: kotlin.String): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+    public final infix fun kotlin.String.ok3(/*0*/ o: kotlin.String): kotlin.Unit
+}
+
 public final class Pair</*0*/ A, /*1*/ B> {
     public constructor Pair</*0*/ A, /*1*/ B>(/*0*/ a: A, /*1*/ b: B)
     public final val a: A

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/java/descriptors/JavaMethodDescriptor.java

@@ -87,7 +87,7 @@ public class JavaMethodDescriptor extends SimpleFunctionDescriptorImpl implement
         SimpleFunctionDescriptorImpl descriptor = super.initialize(
                 receiverParameterType, dispatchReceiverParameter, typeParameters, unsubstitutedValueParameters,
                 unsubstitutedReturnType, modality, visibility);
-        setOperator(OperatorChecks.INSTANCE.checkOperator(descriptor).isSuccess());
+        setOperator(OperatorChecks.INSTANCE.check(descriptor).isSuccess());
         return descriptor;
     }
 

core/descriptors/src/org/jetbrains/kotlin/util/modifierChecks.kt

@@ -68,11 +68,11 @@ interface Check {
 }
 
 sealed class MemberKindCheck(override val description: String) : Check {
-    object MemberOrExtension : MemberKindCheck("must be a member or an extension") {
+    object MemberOrExtension : MemberKindCheck("must be a member or an extension function") {
         override fun check(functionDescriptor: FunctionDescriptor) =
                 functionDescriptor.isExtension || functionDescriptor.containingDeclaration is ClassDescriptor
     }
-    object Member : MemberKindCheck("must be a member") {
+    object Member : MemberKindCheck("must be a member function") {
         override fun check(functionDescriptor: FunctionDescriptor) = functionDescriptor.containingDeclaration is ClassDescriptor
     }
 }
@@ -92,6 +92,13 @@ sealed class ValueParameterCountCheck(override val description: String) : Check
     }
 }
 
+private object HasDispatchOrExtensionReceiverParameter : Check {
+    override val description = "must be a member of an extension function"
+    override fun check(functionDescriptor: FunctionDescriptor): Boolean {
+        return functionDescriptor.dispatchReceiverParameter != null || functionDescriptor.extensionReceiverParameter != null
+    }
+}
+
 private object NoDefaultAndVarargsCheck : Check {
     override val description = "should not have varargs or parameters with default values"
     override fun check(functionDescriptor: FunctionDescriptor) =
@@ -120,7 +127,7 @@ sealed class ReturnsCheck(val name: String, val type: KotlinBuiltIns.() -> Kotli
     object ReturnsUnit : ReturnsCheck("Unit", { unitType })
 }
 
-private class Checks private constructor(
+internal class Checks private constructor(
         val name: Name?,
         val regex: Regex?,
         val nameList: Collection<Name>?,
@@ -150,6 +157,8 @@ private class Checks private constructor(
         return CheckResult.SuccessCheck
     }
 
+    constructor(vararg checks: Check, additionalChecks: FunctionDescriptor.() -> String? = { null })
+            : this(null, null, null, additionalChecks, *checks)
     constructor(name: Name, vararg checks: Check, additionalChecks: FunctionDescriptor.() -> String? = { null })
             : this(name, null, null, additionalChecks, *checks)
     constructor(regex: Regex, vararg checks: Check, additionalChecks: FunctionDescriptor.() -> String? = { null })
@@ -158,10 +167,23 @@ private class Checks private constructor(
             : this(null, null, nameList, additionalChecks, *checks)
 }
 
-object OperatorChecks {
+abstract class AbstractModifierChecks {
-    private inline fun ensure(cond: Boolean, msg: () -> String) = if (!cond) msg() else null
+    abstract internal val checks: List<Checks>
+    
+    inline fun ensure(cond: Boolean, msg: () -> String) = if (!cond) msg() else null
 
-    private val CHECKS = listOf(
+    fun check(functionDescriptor: FunctionDescriptor): CheckResult {
+        for (check in checks) {
+            if (!check.isApplicable(functionDescriptor)) continue
+            return check.checkAll(functionDescriptor)
+        }
+
+        return CheckResult.IllegalFunctionName
+    }
+}
+
+object OperatorChecks : AbstractModifierChecks() {
+    override val checks = listOf(
             Checks(GET, MemberOrExtension, ValueParameterCountCheck.AtLeast(1)),
             Checks(SET, MemberOrExtension, ValueParameterCountCheck.AtLeast(2)) {
                 val lastIsOk = valueParameters.lastOrNull()?.let { !it.hasDefaultValue() && it.varargElementType == null } ?: false
@@ -212,15 +234,11 @@ object OperatorChecks {
             "Second parameter should be Continuation<Nothing>"
         }
     }
-
-    fun checkOperator(functionDescriptor: FunctionDescriptor): CheckResult {
-        for (check in CHECKS) {
-            if (!check.isApplicable(functionDescriptor)) continue
-            return check.checkAll(functionDescriptor)
-        }
-
-        return CheckResult.IllegalFunctionName
-    }
 }
 
-fun FunctionDescriptor.isValidOperator() = isOperator && OperatorChecks.checkOperator(this).isSuccess
+object InfixChecks : AbstractModifierChecks() {
+    override val checks = listOf(
+            Checks(HasDispatchOrExtensionReceiverParameter, SingleValueParameter, NoDefaultAndVarargsCheck))
+}
+
+fun FunctionDescriptor.isValidOperator() = isOperator && OperatorChecks.check(this).isSuccess

idea/src/org/jetbrains/kotlin/idea/intentions/AddOperatorModifierIntention.kt

@@ -28,7 +28,7 @@ class AddOperatorModifierIntention : SelfTargetingRangeIntention<KtNamedFunction
     override fun applicabilityRange(element: KtNamedFunction): TextRange? {
         val nameIdentifier = element.nameIdentifier ?: return null
         val functionDescriptor = element.resolveToDescriptor() as? FunctionDescriptor ?: return null
-        if (functionDescriptor.isOperator || !OperatorChecks.checkOperator(functionDescriptor).isSuccess) return null
+        if (functionDescriptor.isOperator || !OperatorChecks.check(functionDescriptor).isSuccess) return null
         return nameIdentifier.textRange
     }
 

idea/src/org/jetbrains/kotlin/idea/intentions/conventionNameCalls/ReplaceContainsIntention.kt

@@ -51,7 +51,7 @@ class ReplaceContainsIntention : SelfTargetingRangeIntention<KtDotQualifiedExpre
         if (!element.isReceiverExpressionWithValue()) return null
 
         val functionDescriptor = getFunctionDescriptor(element) ?: return null
-        if (!functionDescriptor.isOperator || !OperatorChecks.checkOperator(functionDescriptor).isSuccess) return null
+        if (!functionDescriptor.isOperator || !OperatorChecks.check(functionDescriptor).isSuccess) return null
 
         return element.callExpression!!.calleeExpression!!.textRange
     }

idea/testData/intentions/conventionNameCalls/replaceGetOrSet/topLevelFun.kt

@@ -1,5 +1,5 @@
 // IS_APPLICABLE: false
-// ERROR: 'operator' modifier is inapplicable on this function: must be a member or an extension
+// ERROR: 'operator' modifier is inapplicable on this function: must be a member or an extension function
 
 package p
 

idea/testData/intentions/toInfixCall/multipleArguments.kt

@@ -1,5 +1,5 @@
 // IS_APPLICABLE: false
-// ERROR: 'infix' modifier is inapplicable on this function
+// ERROR: infix modifier is inapplicable on this function: must have a single value parameter
 interface Foo {
     infix fun foo(a: Int, b: Int)
 }

idea/testData/intentions/toInfixCall/namedArgument.kt

@@ -1,5 +1,5 @@
 // IS_APPLICABLE: false
-// ERROR: 'infix' modifier is inapplicable on this function
+// ERROR: infix modifier is inapplicable on this function: must have a single value parameter
 fun foo(x: Foo) {
     x.<caret>foo(bar = x)
 }

idea/testData/intentions/toInfixCall/noExplicitReceiver.kt

@@ -1,4 +1,4 @@
 // IS_APPLICABLE: false
-// ERROR: 'infix' modifier is inapplicable on this function
+// ERROR: infix modifier is inapplicable on this function: must be a member of an extension function
 infix fun id(s: String) = s
 val x = <caret>id("0").get(0)

idea/testData/intentions/toInfixCall/packageFunctionCall.kt

@@ -1,5 +1,5 @@
 // IS_APPLICABLE: false
-// ERROR: 'infix' modifier is inapplicable on this function
+// ERROR: infix modifier is inapplicable on this function: must be a member of an extension function
 package ppp
 
 infix fun foo(p: String){}

idea/testData/intentions/toInfixCall/secondParameterLabeled.kt

@@ -1,5 +1,5 @@
 // IS_APPLICABLE: false
-// ERROR: 'infix' modifier is inapplicable on this function
+// ERROR: infix modifier is inapplicable on this function: must have a single value parameter
 
 class Foo {
     infix fun foo(x: Int = 0, y: Int = 0) {

idea/testData/intentions/toInfixCall/simpleArgumentAndFunctionLiteralArgument.kt

@@ -1,5 +1,5 @@
 // IS_APPLICABLE: false
-// ERROR: 'infix' modifier is inapplicable on this function
+// ERROR: infix modifier is inapplicable on this function: must have a single value parameter
 
 fun foo(x: Foo) {
     x.<caret>foo(1) { it * 2 }

idea/testData/intentions/toInfixCall/singlePackageFunctionCall.kt

@@ -1,6 +1,6 @@
 // WITH_RUNTIME
 // IS_APPLICABLE: false
-// ERROR: 'infix' modifier is inapplicable on this function
+// ERROR: infix modifier is inapplicable on this function: must be a member of an extension function
 
 package demo
 

idea/testData/quickfix/deprecatedSymbolUsage/infixCall.kt

@@ -1,5 +1,5 @@
 // "Replace with 'newFun(p, this)'" "true"
-// ERROR: 'infix' modifier is inapplicable on this function
+// ERROR: infix modifier is inapplicable on this function: must be a member of an extension function
 
 @Deprecated("", ReplaceWith("newFun(p, this)"))
 infix fun String.oldFun(p: Int) {

idea/testData/quickfix/deprecatedSymbolUsage/infixCall.kt.after

@@ -1,5 +1,5 @@
 // "Replace with 'newFun(p, this)'" "true"
-// ERROR: 'infix' modifier is inapplicable on this function
+// ERROR: infix modifier is inapplicable on this function: must be a member of an extension function
 
 @Deprecated("", ReplaceWith("newFun(p, this)"))
 infix fun String.oldFun(p: Int) {