Diagnostics on 'infix' (declaration&use site)

compiler/testData/diagnostics/tests/Infix.kt

@@ -0,0 +1,26 @@
+class Pair<out A, out B>(val first: A, val second: B)
+
+class Example {
+    infix fun to(other: Example) = Pair(this, other)
+    fun toNonInfix(other: Example) = Pair(this, other)
+}
+
+infix fun Example.toExt(other: Example) = Pair(this, other)
+fun Example.toExtNonInfix(other: Example) = Pair(this, other)
+
+fun Example.withLambda(f: () -> Unit) = Pair(this, f)
+
+fun test() {
+    Example() to Example()
+    Example() <!INFIX_MODIFIER_REQUIRED!>toNonInfix<!> Example()
+    Example().toNonInfix(Example())
+
+    val a = Example()
+    val b = Example()
+
+    a toExt b
+    a <!INFIX_MODIFIER_REQUIRED!>toExtNonInfix<!> b
+    a.toExtNonInfix(b)
+
+    a <!INFIX_MODIFIER_REQUIRED!>withLambda<!> { }
+}

compiler/testData/diagnostics/tests/Infix.txt

@@ -0,0 +1,24 @@
+package
+
+public fun test(): kotlin.Unit
+public infix fun Example.toExt(/*0*/ other: Example): Pair<Example, Example>
+public fun Example.toExtNonInfix(/*0*/ other: Example): Pair<Example, Example>
+public fun Example.withLambda(/*0*/ f: () -> kotlin.Unit): Pair<Example, () -> kotlin.Unit>
+
+public final class Example {
+    public constructor Example()
+    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 to(/*0*/ other: Example): Pair<Example, Example>
+    public final fun toNonInfix(/*0*/ other: Example): Pair<Example, Example>
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class Pair</*0*/ out A, /*1*/ out B> {
+    public constructor Pair</*0*/ out A, /*1*/ out B>(/*0*/ first: A, /*1*/ second: B)
+    public final val first: A
+    public final val second: B
+    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 open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/tests/InfixModifierApplicability.kt

@@ -0,0 +1,21 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
+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
+infix fun String.o2(o: String, o2: String? = null) = o
+
+<!INAPPLICABLE_INFIX_MODIFIER!>infix<!> fun w1() {}
+<!INAPPLICABLE_INFIX_MODIFIER!>infix<!> fun w2(s: String) {}
+<!INAPPLICABLE_INFIX_MODIFIER!>infix<!> fun String.w3() {}
+<!INAPPLICABLE_INFIX_MODIFIER!>infix<!> fun String.w4(a: Int, b: Int) {}
+<!INAPPLICABLE_INFIX_MODIFIER!>infix<!> fun w5(a: Int, b: Int) {}
+
+class Example {
+    infix fun c1(s: String) {}
+    infix fun c2(s: String, a: Int = 0) {}
+
+    <!INAPPLICABLE_INFIX_MODIFIER!>infix<!> fun cw1(s: String, a: Int) {}
+    <!INAPPLICABLE_INFIX_MODIFIER!>infix<!> fun sw2() {}
+}

compiler/testData/diagnostics/tests/InfixModifierApplicability.txt

@@ -0,0 +1,30 @@
+package
+
+public infix fun w1(): kotlin.Unit
+public infix fun w2(/*0*/ s: kotlin.String): kotlin.Unit
+public infix fun w5(/*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.o2(/*0*/ o: kotlin.String, /*1*/ o2: kotlin.String? = ...): kotlin.String
+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 c2(/*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 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 Pair</*0*/ A, /*1*/ B> {
+    public constructor Pair</*0*/ A, /*1*/ B>(/*0*/ a: A, /*1*/ b: B)
+    public final val a: A
+    public final val b: B
+    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 open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}