Feature/mixin quantifiers (#2643)

* Refactor: Split MemberInfo and MemberReference.

Mixin MemberInfo strings are only tangentially related to concrete MemberReferences. We also introduce a MemberMatcher superinterface for resolving things.

* Refactor: Parse MemberInfos properly and represent Quantifiers.

* Fix: Handle all cases properly in AmbiguousReferenceInspection.

Really nothing is "ambiguous" (except perhaps to the reader), it's just that Mixin's default behaviour of matching the first method in a given class is unexpected, but I'll leave the terminology for now. Adding any explicit quantifier suppresses this inspection, including `{1}` if that's really what's desired.

Additionally, adding a wildcard is almost never the correct fix. Choosing one of the available descriptors is what should be offered instead, but I'll leave that too for now.

* New: Handle maximum values in quantifiers.

* Fix: Fix incorrect filter stats emptiness check.

Causes targets not to show as unresolved when they should.

* New: Handle minimum values in quantifiers.

* Fix: Account for individual Mixin `method` strings contributing multiple methods.

* Fix: Don't report injector signature issues in methods where we find no targets.

* Move insn resolution failure message to field in failure class, and add message for min quantifier not satisfied

---------

Co-authored-by: joe <burtonjae@hotmail.co.uk>

Author: LlamaLad7

mixin-test-data/src/main/java/com/demonwav/mcdev/mixintestdata/ambiguousReference/MixedIn.java

@@ -3,7 +3,7 @@
  *
  * https://mcdev.io/
  *
- * Copyright (C) 2025 minecraft-dev
+ * Copyright (C) 2026 minecraft-dev
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published
@@ -29,4 +29,7 @@ public void method(String string) {
 
     public void uniqueMethod(String string) {
     }
+
+    public void uniqueDescMethod(int i) {
+    }
 }

src/main/kotlin/platform/mixin/action/CopyMixinTargetReferenceAction.kt

@@ -3,7 +3,7 @@
  *
  * https://mcdev.io/
  *
- * Copyright (C) 2025 minecraft-dev
+ * Copyright (C) 2026 minecraft-dev
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published
@@ -21,7 +21,6 @@
 package com.demonwav.mcdev.platform.mixin.action
 
 import com.demonwav.mcdev.platform.mixin.handlers.injectionPoint.QualifiedMember
-import com.demonwav.mcdev.platform.mixin.reference.toMixinString
 import com.demonwav.mcdev.util.findReferencedMember
 import com.demonwav.mcdev.util.getQualifiedMemberReference
 import com.demonwav.mcdev.util.qualifiedMemberReference

src/main/kotlin/platform/mixin/expression/MEDefinitionFoldingBuilder.kt

@@ -3,7 +3,7 @@
  *
  * https://mcdev.io/
  *
- * Copyright (C) 2025 minecraft-dev
+ * Copyright (C) 2026 minecraft-dev
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published
@@ -24,6 +24,7 @@ import com.demonwav.mcdev.platform.mixin.MixinModuleType
 import com.demonwav.mcdev.platform.mixin.folding.MixinFoldingSettings
 import com.demonwav.mcdev.platform.mixin.reference.target.FieldDefinitionReference
 import com.demonwav.mcdev.platform.mixin.reference.target.MethodDefinitionReference
+import com.demonwav.mcdev.platform.mixin.util.MemberInfo
 import com.demonwav.mcdev.platform.mixin.util.MixinConstants
 import com.demonwav.mcdev.util.MemberReference
 import com.intellij.lang.ASTNode
@@ -49,8 +50,8 @@ class MEDefinitionFoldingBuilder : CustomFoldingBuilder() {
         val psi = node.psi
         if (psi is PsiLiteralExpression) {
             val value = psi.value as? String ?: return "..."
-            val memberReference = MemberReference.parse(value) ?: return "..."
-            return memberReference.presentableText
+            val memberInfo = MemberInfo.parse(value) ?: return "..."
+            return MemberReference(memberInfo.name ?: "*", memberInfo.descriptor, memberInfo.owner).presentableText
         }
         return "..."
     }
@@ -108,7 +109,7 @@ class MEDefinitionFoldingBuilder : CustomFoldingBuilder() {
             if (FieldDefinitionReference.ELEMENT_PATTERN.accepts(expression) ||
                 MethodDefinitionReference.ELEMENT_PATTERN.accepts(expression)
             ) {
-                if (MemberReference.parse(expression.value as String) != null) {
+                if (MemberInfo.parse(expression.value as String) != null) {
                     descriptors.add(FoldingDescriptor(expression.node, expression.textRange))
                 }
             }

src/main/kotlin/platform/mixin/expression/MEExpressionMatchUtil.kt

@@ -3,7 +3,7 @@
  *
  * https://mcdev.io/
  *
- * Copyright (C) 2025 minecraft-dev
+ * Copyright (C) 2026 minecraft-dev
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published
@@ -24,8 +24,8 @@ import com.demonwav.mcdev.platform.mixin.handlers.InjectorAnnotationHandler
 import com.demonwav.mcdev.platform.mixin.handlers.MixinAnnotationHandler
 import com.demonwav.mcdev.platform.mixin.handlers.injectionPoint.CollectVisitor
 import com.demonwav.mcdev.platform.mixin.util.LocalInfo
+import com.demonwav.mcdev.platform.mixin.util.MemberInfo
 import com.demonwav.mcdev.platform.mixin.util.MixinConstants
-import com.demonwav.mcdev.util.MemberReference
 import com.demonwav.mcdev.util.computeStringArray
 import com.demonwav.mcdev.util.constantStringValue
 import com.demonwav.mcdev.util.descriptor
@@ -172,7 +172,7 @@ object MEExpressionMatchUtil {
 
             val fields = annotation.findDeclaredAttributeValue("field")?.computeStringArray() ?: emptyList()
             for (field in fields) {
-                val fieldRef = MemberReference.parse(field) ?: continue
+                val fieldRef = MemberInfo.parse(field) ?: continue
                 pool.addMember(
                     definitionId,
                     SimpleMemberDefinition {
@@ -183,7 +183,7 @@ object MEExpressionMatchUtil {
 
             val methods = annotation.findDeclaredAttributeValue("method")?.computeStringArray() ?: emptyList()
             for (method in methods) {
-                val methodRef = MemberReference.parse(method) ?: continue
+                val methodRef = MemberInfo.parse(method) ?: continue
                 pool.addMember(
                     definitionId,
                     object : SimpleMemberDefinition {

src/main/kotlin/platform/mixin/expression/MESourceMatchContext.kt

@@ -3,7 +3,7 @@
  *
  * https://mcdev.io/
  *
- * Copyright (C) 2025 minecraft-dev
+ * Copyright (C) 2026 minecraft-dev
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published
@@ -21,7 +21,7 @@
 package com.demonwav.mcdev.platform.mixin.expression
 
 import com.demonwav.mcdev.platform.mixin.util.LocalInfo
-import com.demonwav.mcdev.util.MemberReference
+import com.demonwav.mcdev.platform.mixin.util.MemberInfo
 import com.intellij.openapi.project.Project
 import com.intellij.psi.PsiElement
 
@@ -32,8 +32,8 @@ class MESourceMatchContext(val project: Project) {
     val captures: List<PsiElement> get() = capturesInternal
 
     private val types = mutableMapOf<String, MutableList<String>>()
-    private val fields = mutableMapOf<String, MutableList<MemberReference>>()
-    private val methods = mutableMapOf<String, MutableList<MemberReference>>()
+    private val fields = mutableMapOf<String, MutableList<MemberInfo>>()
+    private val methods = mutableMapOf<String, MutableList<MemberInfo>>()
     private val localInfos = mutableMapOf<String, MutableList<LocalInfo>>()
 
     init {
@@ -57,15 +57,15 @@ class MESourceMatchContext(val project: Project) {
         types.getOrPut(key, ::mutableListOf) += desc
     }
 
-    fun getFields(key: String): List<MemberReference> = fields[key] ?: emptyList()
+    fun getFields(key: String): List<MemberInfo> = fields[key] ?: emptyList()
 
-    fun addField(key: String, field: MemberReference) {
+    fun addField(key: String, field: MemberInfo) {
         fields.getOrPut(key, ::mutableListOf) += field
     }
 
-    fun getMethods(key: String): List<MemberReference> = methods[key] ?: emptyList()
+    fun getMethods(key: String): List<MemberInfo> = methods[key] ?: emptyList()
 
-    fun addMethod(key: String, method: MemberReference) {
+    fun addMethod(key: String, method: MemberInfo) {
         methods.getOrPut(key, ::mutableListOf) += method
     }
 

src/main/kotlin/platform/mixin/folding/MixinTargetDescriptorFoldingBuilder.kt

@@ -3,7 +3,7 @@
  *
  * https://mcdev.io/
  *
- * Copyright (C) 2025 minecraft-dev
+ * Copyright (C) 2026 minecraft-dev
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published
@@ -51,7 +51,7 @@ class MixinTargetDescriptorFoldingBuilder : CustomFoldingBuilder() {
 
     override fun getLanguagePlaceholderText(node: ASTNode, range: TextRange): String? {
         val element = node.psi
-        return TargetReference.resolveTarget(element)?.let { formatElement(it) }
+        return TargetReference.resolveTargets(element).singleOrNull()?.let { formatElement(it) }
     }
 
     private fun formatElement(element: PsiElement): String? {

src/main/kotlin/platform/mixin/handlers/InjectorAnnotationHandler.kt

@@ -68,9 +68,9 @@ abstract class InjectorAnnotationHandler : MixinAnnotationHandler {
             (actualTarget to actualTarget.methods)
         }
 
-        return targetClassMethods.mapNotNull { (selector, pair) ->
+        return targetClassMethods.flatMap { (selector, pair) ->
             val (clazz, methods) = pair
-            methods.firstNotNullOfOrNull { method ->
+            methods.mapNotNull { method ->
                 if (selector.matchMethod(method, clazz)) {
                     MethodTargetMember(clazz, method)
                 } else {
@@ -88,9 +88,9 @@ abstract class InjectorAnnotationHandler : MixinAnnotationHandler {
         }
 
         return resolveTarget(annotation, targetClass).map { targetMember ->
-            val targetMethod = targetMember as? MethodTargetMember ?: return@map InsnResolutionInfo.Failure()
+            val targetMethod = targetMember as? MethodTargetMember ?: return@map InsnResolutionInfo.Failure(AtResolver.DEFAULT_UNRESOLVED_MESSAGE)
             isUnresolved(annotation, targetClass, targetMethod.classAndMethod.method) ?: return@isUnresolved null
-        }.reduceOrNull(InsnResolutionInfo.Failure::combine) ?: InsnResolutionInfo.Failure()
+        }.reduceOrNull(InsnResolutionInfo.Failure::combine) ?: InsnResolutionInfo.Failure(AtResolver.DEFAULT_UNRESOLVED_MESSAGE)
     }
 
     open fun getAtKey(annotation: PsiAnnotation): String = "at"
@@ -101,7 +101,7 @@ abstract class InjectorAnnotationHandler : MixinAnnotationHandler {
         targetMethod: MethodNode,
     ): InsnResolutionInfo.Failure? {
         return annotation.findAttributeValue(getAtKey(annotation))?.findAnnotations()
-            .ifNullOrEmpty { return InsnResolutionInfo.Failure() }!!
+            .ifNullOrEmpty { return InsnResolutionInfo.Failure(AtResolver.DEFAULT_UNRESOLVED_MESSAGE) }!!
             .firstNotNullOfOrNull { AtResolver(it, targetClass, targetMethod).isUnresolved() }
     }
 
@@ -170,10 +170,6 @@ abstract class InjectorAnnotationHandler : MixinAnnotationHandler {
 
     open val allowedInsnDescription = "all instructions"
 
-    override fun createUnresolvedMessage(annotation: PsiAnnotation): String? {
-        return "Cannot resolve any target instructions in target class"
-    }
-
     open fun canAlwaysBeStatic(method: PsiMethod): Boolean {
         return true
     }

src/main/kotlin/platform/mixin/handlers/MixinAnnotationHandler.kt

@@ -52,7 +52,7 @@ interface MixinAnnotationHandler {
     fun resolveTarget(annotation: PsiAnnotation, targetClass: ClassNode): List<MixinTargetMember>
 
     fun isUnresolved(annotation: PsiAnnotation): InsnResolutionInfo.Failure? {
-        val containingClass = annotation.findContainingClass() ?: return InsnResolutionInfo.Failure()
+        val containingClass = annotation.findContainingClass() ?: return null // no containing mixin, don't show unresolved error
         return containingClass.mixinTargets
             .mapNotNull { isUnresolved(annotation, it) }
             .reduceOrNull(InsnResolutionInfo.Failure::combine)
@@ -67,8 +67,6 @@ interface MixinAnnotationHandler {
 
     fun resolveForNavigation(annotation: PsiAnnotation, targetClass: ClassNode): List<PsiElement>
 
-    fun createUnresolvedMessage(annotation: PsiAnnotation): String?
-
     /**
      * Returns true if we don't actually know the implementation of the annotation, and we're just making
      * a guess. Prevents unresolved errors but still attempts navigation

src/main/kotlin/platform/mixin/handlers/MixinMemberAnnotationHandler.kt

@@ -28,7 +28,7 @@ import org.objectweb.asm.tree.ClassNode
 interface MixinMemberAnnotationHandler : MixinAnnotationHandler {
     override fun isUnresolved(annotation: PsiAnnotation, targetClass: ClassNode): InsnResolutionInfo.Failure? {
         return if (resolveTarget(annotation, targetClass).isEmpty()) {
-            InsnResolutionInfo.Failure()
+            createUnresolvedMessage(annotation)?.let(InsnResolutionInfo<Nothing>::Failure)
         } else {
             null
         }
@@ -39,4 +39,6 @@ interface MixinMemberAnnotationHandler : MixinAnnotationHandler {
         val targets = resolveTarget(annotation, targetClass)
         return targets.mapNotNull { it.findSourceElement(project, annotation.resolveScope, canDecompile = true) }
     }
+
+    fun createUnresolvedMessage(annotation: PsiAnnotation): String?
 }

src/main/kotlin/platform/mixin/handlers/injectionPoint/AtResolver.kt

@@ -36,9 +36,11 @@ import com.demonwav.mcdev.platform.mixin.util.findSourceClass
 import com.demonwav.mcdev.platform.mixin.util.findSourceElement
 import com.demonwav.mcdev.platform.mixin.util.isClinit
 import com.demonwav.mcdev.platform.mixin.util.memberReference
+import com.demonwav.mcdev.util.Quantifier
 import com.demonwav.mcdev.util.computeStringArray
 import com.demonwav.mcdev.util.constantStringValue
 import com.demonwav.mcdev.util.constantValue
+import com.demonwav.mcdev.util.countIsAtLeast
 import com.demonwav.mcdev.util.descriptor
 import com.demonwav.mcdev.util.equivalentTo
 import com.demonwav.mcdev.util.findMethods
@@ -174,6 +176,8 @@ class AtResolver(
                 else -> 0
             }
         }
+
+        const val DEFAULT_UNRESOLVED_MESSAGE = "Cannot resolve any instructions in target"
     }
 
     fun isUnresolved(): InsnResolutionInfo.Failure? {
@@ -190,14 +194,24 @@ class AtResolver(
         )
         if (collectVisitor == null) {
             // syntax error in target
-            val stringValue = targetAttr?.constantStringValue ?: return InsnResolutionInfo.Failure()
+            val stringValue = targetAttr?.constantStringValue ?: return InsnResolutionInfo.Failure(DEFAULT_UNRESOLVED_MESSAGE)
             return if (isMiscDynamicSelector(at.project, stringValue)) {
                 null
             } else {
-                InsnResolutionInfo.Failure()
+                InsnResolutionInfo.Failure(DEFAULT_UNRESOLVED_MESSAGE)
+            }
+        }
+        return when (val result = collectVisitor.visit(targetMethod)) {
+            is InsnResolutionInfo.Failure -> result
+            is InsnResolutionInfo.Success -> {
+                val minMatches = collectVisitor.quantifier.min(Quantifier.Context.INSTRUCTION).coerceAtLeast(1)
+                if (result.results.countIsAtLeast(minMatches)) {
+                    null
+                } else {
+                    InsnResolutionInfo.Failure("Quantifier requires at least $minMatches matches")
+                }
             }
         }
-        return collectVisitor.visit(targetMethod) as? InsnResolutionInfo.Failure
     }
 
     fun resolveInstructions(
@@ -207,12 +221,12 @@ class AtResolver(
     }
 
     fun getInstructionResolutionInfo(mode: CollectVisitor.Mode = CollectVisitor.Mode.RESOLUTION): InsnResolutionInfo<*> {
-        val injectionPoint = getInjectionPoint(at) ?: return InsnResolutionInfo.Failure()
+        val injectionPoint = getInjectionPoint(at) ?: return InsnResolutionInfo.Failure(DEFAULT_UNRESOLVED_MESSAGE)
         val targetAttr = at.findAttributeValue("target")
         val target = targetAttr?.let { parseMixinSelector(it) }
 
         val collectVisitor = injectionPoint.createCollectVisitor(at, target, getTargetClass(target), mode)
-            ?: return InsnResolutionInfo.Failure()
+            ?: return InsnResolutionInfo.Failure(DEFAULT_UNRESOLVED_MESSAGE)
 
         return collectVisitor.visit(targetMethod)
     }
@@ -311,13 +325,19 @@ class AtResolver(
 
 sealed class InsnResolutionInfo<out T : PsiElement>(val results: Sequence<CollectVisitor.Result<T>>) {
     class Success<T : PsiElement>(results: Sequence<CollectVisitor.Result<T>>) : InsnResolutionInfo<T>(results)
-    class Failure(val filterStats: Map<String, Int> = emptyMap()) : InsnResolutionInfo<Nothing>(emptySequence()) {
+    class Failure(val messages: Set<String>, val filterStats: Map<String, Int>) : InsnResolutionInfo<Nothing>(emptySequence()) {
+        constructor(message: String, filterStats: Map<String, Int> = emptyMap()) : this(linkedSetOf(message), filterStats)
+
         infix fun combine(other: Failure): Failure {
+            val messages = linkedSetOf<String>()
+            messages += this.messages
+            messages += other.messages
+
             val result = LinkedHashMap(this.filterStats)
             for ((key, value) in other.filterStats) {
                 result[key] = (result[key] ?: 0) + value
             }
-            return Failure(result)
+            return Failure(messages, result)
         }
     }
 }