[FIR] Fix the TODO in FirConflictsHelpers

According to https://github.com/Kotlin/KEEP/blob/master/proposals/enhancing-main-convention.md#rules-and-semantics, only main function without args may avoid `CONFLICTING_OVERLOADS`, but since the jps/jps-plugin/testData/incremental/withJava/other/mainRedeclaration test dates back to 2015, this is not the current behavior.
2023-06-28 11:52:22 +03:00
parent 3014c7b353
commit 8541143d6f
5 changed files with 69 additions and 9 deletions
@@ -6,15 +6,22 @@
 package org.jetbrains.kotlin.fir.analysis.checkers

 import org.jetbrains.kotlin.KtFakeSourceElementKind
+import org.jetbrains.kotlin.builtins.StandardNames
 import org.jetbrains.kotlin.descriptors.ClassKind
 import org.jetbrains.kotlin.diagnostics.DiagnosticReporter
 import org.jetbrains.kotlin.diagnostics.reportOn
 import org.jetbrains.kotlin.fir.*
 import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
+import org.jetbrains.kotlin.fir.analysis.checkers.declaration.FirMethodOfAnyImplementedInInterfaceChecker.appendRepresentation
+import org.jetbrains.kotlin.fir.analysis.checkers.declaration.FirMethodOfAnyImplementedInInterfaceChecker.appendRepresentationAfterCallableId
+import org.jetbrains.kotlin.fir.analysis.checkers.declaration.FirMethodOfAnyImplementedInInterfaceChecker.appendRepresentationBeforeCallableId
 import org.jetbrains.kotlin.fir.analysis.checkers.declaration.FirNameConflictsTracker
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
 import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.declarations.impl.FirOuterClassTypeParameterRef
+import org.jetbrains.kotlin.fir.declarations.impl.FirResolvedDeclarationStatusImpl.Companion.DEFAULT_STATUS_FOR_STATUSLESS_DECLARATIONS
+import org.jetbrains.kotlin.fir.declarations.impl.FirResolvedDeclarationStatusImpl.Companion.DEFAULT_STATUS_FOR_SUSPEND_MAIN_FUNCTION
+import org.jetbrains.kotlin.fir.declarations.impl.modifiersRepresentation
 import org.jetbrains.kotlin.fir.resolve.providers.firProvider
 import org.jetbrains.kotlin.fir.scopes.impl.FirPackageMemberScope
 import org.jetbrains.kotlin.fir.symbols.FirBasedSymbol
@@ -22,9 +29,9 @@ import org.jetbrains.kotlin.fir.symbols.SymbolInternals
 import org.jetbrains.kotlin.fir.symbols.impl.FirCallableSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirClassLikeSymbol
 import org.jetbrains.kotlin.fir.symbols.lazyResolveToPhase
-import org.jetbrains.kotlin.fir.types.*
 import org.jetbrains.kotlin.fir.util.ListMultimap
 import org.jetbrains.kotlin.fir.visitors.FirVisitorVoid
+import org.jetbrains.kotlin.name.CallableId
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.utils.SmartSet

@@ -32,6 +39,34 @@ internal class FirDefaultDeclarationPresenter : FirDeclarationPresenter

 private val NO_NAME_PROVIDED = Name.special("<no name provided>")

+private val MAIN_FUNCTION_SHAPES = setOf(
+    "<>[]():kotlin/Unit",
+    "<>[](kotlin/Array<kotlin/String,>,):kotlin/Unit",
+    "<>[](vararg kotlin/String,):kotlin/Unit",
+)
+
+val DEFAULT_STATUS_FOR_NORMAL_MAIN_FUNCTION = DEFAULT_STATUS_FOR_STATUSLESS_DECLARATIONS
+
+private val FirSimpleFunction.hasMainFunctionStatus
+    get() = when (status.modifiersRepresentation) {
+        DEFAULT_STATUS_FOR_NORMAL_MAIN_FUNCTION.modifiersRepresentation,
+        DEFAULT_STATUS_FOR_SUSPEND_MAIN_FUNCTION.modifiersRepresentation -> true
+        else -> false
+    }
+
+private val CallableId.isTopLevel get() = className == null
+
+private val FirSimpleFunction.representsMainFunctionAllowingConflictingOverloads
+    get(): Boolean = when {
+        name != StandardNames.MAIN || !symbol.callableId.isTopLevel || !hasMainFunctionStatus -> false
+        else -> buildString {
+            appendRepresentationBeforeCallableId(this@representsMainFunctionAllowingConflictingOverloads)
+            appendRepresentationAfterCallableId(this@representsMainFunctionAllowingConflictingOverloads)
+            append(':')
+            appendRepresentation(returnTypeRef)
+        } in MAIN_FUNCTION_SHAPES
+    }
+
 // - see testEnumValuesValueOf.
 // it generates a static function that has
 // the same signature as the function defined
@@ -211,12 +246,11 @@ class FirDeclarationInspector {

    private fun areCompatibleMainFunctions(
        declaration1: FirDeclaration, file1: FirFile, declaration2: FirDeclaration, file2: FirFile?
-    ): Boolean {
-        // TODO: proper main function detector
-        if (declaration1 !is FirSimpleFunction || declaration2 !is FirSimpleFunction) return false
-        if (declaration1.name.asString() != "main" || declaration2.name.asString() != "main") return false
-        return file1 != file2
-    }
+    ) = file1 != file2
+            && declaration1 is FirSimpleFunction
+            && declaration2 is FirSimpleFunction
+            && declaration1.representsMainFunctionAllowingConflictingOverloads
+            && declaration2.representsMainFunctionAllowingConflictingOverloads

    private fun collectExternalConflict(
        declaration: FirDeclaration,
@@ -158,7 +158,7 @@ interface FirDeclarationPresenter {
        }
    }

-    fun represent(it: FirSimpleFunction) = buildString {
+    fun StringBuilder.appendRepresentationBeforeCallableId(it: FirSimpleFunction) {
        it.contextReceivers.forEach {
            appendRepresentation(it)
            append(',')
@@ -175,7 +175,9 @@ interface FirDeclarationPresenter {
        }
        append(']')
        appendOperatorTag(it)
-        appendRepresentation(it.symbol.callableId)
+    }
+
+    fun StringBuilder.appendRepresentationAfterCallableId(it: FirSimpleFunction) {
        append('(')
        it.valueParameters.forEach {
            appendRepresentation(it)
@@ -184,6 +186,12 @@ interface FirDeclarationPresenter {
        append(')')
    }

+    fun represent(it: FirSimpleFunction) = buildString {
+        appendRepresentationBeforeCallableId(it)
+        appendRepresentation(it.symbol.callableId)
+        appendRepresentationAfterCallableId(it)
+    }
+
    fun represent(it: FirTypeAlias) = buildString {
        append('[')
        append(']')
@@ -9,6 +9,7 @@ import org.jetbrains.kotlin.KtSourceElement
 import org.jetbrains.kotlin.descriptors.EffectiveVisibility
 import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.descriptors.Visibility
+import org.jetbrains.kotlin.fir.FirImplementationDetail
 import org.jetbrains.kotlin.fir.FirPureAbstractElement
 import org.jetbrains.kotlin.fir.declarations.FirDeclarationStatus
 import org.jetbrains.kotlin.fir.declarations.impl.FirDeclarationStatusImpl.Modifier.*
@@ -22,6 +23,9 @@ open class FirDeclarationStatusImpl(
    override val source: KtSourceElement? get() = null
    protected var flags: Int = HAS_STABLE_PARAMETER_NAMES.mask

+    @FirImplementationDetail
+    internal val rawFlags get() = flags
+
    operator fun get(modifier: Modifier): Boolean = (flags and modifier.mask) != 0

    operator fun set(modifier: Modifier, value: Boolean) {
@@ -182,3 +186,10 @@ open class FirDeclarationStatusImpl(
        return FirResolvedDeclarationStatusImpl(visibility, modality, effectiveVisibility, flags)
    }
 }
+
+@OptIn(FirImplementationDetail::class)
+val FirDeclarationStatus.modifiersRepresentation: Any
+    get() = when (this) {
+        is FirDeclarationStatusImpl -> rawFlags
+        else -> error("Generating modifier representations for ${this::class.simpleName} is not supported")
+    }
@@ -28,6 +28,11 @@ class FirResolvedDeclarationStatusImpl(
            Modality.FINAL,
            EffectiveVisibility.Public
        ).apply { isSuspend = true }
+        val DEFAULT_STATUS_FOR_SUSPEND_MAIN_FUNCTION = FirResolvedDeclarationStatusImpl(
+            Visibilities.Public,
+            Modality.FINAL,
+            EffectiveVisibility.Public
+        ).apply { isSuspend = true }
    }

    internal constructor(
@@ -36,6 +36,8 @@ object StandardNames {

    @JvmField val NAME = Name.identifier("name")

+    @JvmField val MAIN = Name.identifier("main")
+
    @JvmField val NEXT_CHAR = Name.identifier("nextChar")

    @JvmField val IMPLICIT_LAMBDA_PARAMETER_NAME = Name.identifier("it")