FIR: introduce ILLEGAL_SUSPEND_FUNCTION_CALL & PROPERTY_ACCESS diagnostics

compiler/fir/checkers/checkers-component-generator/src/org/jetbrains/kotlin/fir/checkers/generator/diagnostics/FirDiagnosticsList.kt

@@ -1182,6 +1182,15 @@ object DIAGNOSTICS_LIST : DiagnosticList("FirErrors") {
 
         val OPERATOR_RENAMED_ON_IMPORT by error<KtImportDirective>(PositioningStrategy.IMPORT_LAST_NAME)
     }
+
+    val SUSPEND by object : DiagnosticGroup("Suspend errors") {
+        val ILLEGAL_SUSPEND_FUNCTION_CALL by error<PsiElement>(PositioningStrategy.REFERENCED_NAME_BY_QUALIFIED) {
+            parameter<Symbol>("suspendCallable")
+        }
+        val ILLEGAL_SUSPEND_PROPERTY_ACCESS by error<PsiElement>(PositioningStrategy.REFERENCED_NAME_BY_QUALIFIED) {
+            parameter<Symbol>("suspendCallable")
+        }
+    }
 }
 
 private val exposedVisibilityDiagnosticInit: DiagnosticBuilder.() -> Unit = {

compiler/fir/checkers/gen/org/jetbrains/kotlin/fir/analysis/diagnostics/FirErrors.kt

@@ -607,4 +607,8 @@ object FirErrors {
     val CONFLICTING_IMPORT by error1<KtImportDirective, Name>(SourceElementPositioningStrategies.IMPORT_LAST_NAME)
     val OPERATOR_RENAMED_ON_IMPORT by error0<KtImportDirective>(SourceElementPositioningStrategies.IMPORT_LAST_NAME)
 
+    // Suspend errors
+    val ILLEGAL_SUSPEND_FUNCTION_CALL by error1<PsiElement, FirBasedSymbol<*>>(SourceElementPositioningStrategies.REFERENCED_NAME_BY_QUALIFIED)
+    val ILLEGAL_SUSPEND_PROPERTY_ACCESS by error1<PsiElement, FirBasedSymbol<*>>(SourceElementPositioningStrategies.REFERENCED_NAME_BY_QUALIFIED)
+
 }

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

@@ -41,7 +41,8 @@ object CommonExpressionCheckers : ExpressionCheckers() {
             FirSealedClassConstructorCallChecker,
             FirUninitializedEnumChecker,
             FirFunInterfaceConstructorReferenceChecker,
-            FirReifiedChecker
+            FirReifiedChecker,
+            FirSuspendCallChecker,
         )
 
     override val functionCallCheckers: Set<FirFunctionCallChecker>

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/expression/FirSuspendCallChecker.kt

@@ -0,0 +1,63 @@
+/*
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.fir.analysis.checkers.expression
+
+import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
+import org.jetbrains.kotlin.fir.analysis.diagnostics.DiagnosticReporter
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
+import org.jetbrains.kotlin.fir.analysis.diagnostics.reportOn
+import org.jetbrains.kotlin.fir.declarations.*
+import org.jetbrains.kotlin.fir.declarations.utils.isSuspend
+import org.jetbrains.kotlin.fir.expressions.FirQualifiedAccessExpression
+import org.jetbrains.kotlin.fir.references.FirResolvedCallableReference
+import org.jetbrains.kotlin.fir.references.FirResolvedNamedReference
+import org.jetbrains.kotlin.fir.resolve.inference.isSuspendFunctionType
+import org.jetbrains.kotlin.fir.symbols.SymbolInternals
+import org.jetbrains.kotlin.fir.symbols.ensureResolved
+import org.jetbrains.kotlin.fir.symbols.impl.FirCallableSymbol
+import org.jetbrains.kotlin.fir.types.coneType
+import org.jetbrains.kotlin.resolve.calls.checkers.COROUTINE_CONTEXT_1_2_20_FQ_NAME
+import org.jetbrains.kotlin.resolve.calls.checkers.COROUTINE_CONTEXT_1_2_30_FQ_NAME
+import org.jetbrains.kotlin.resolve.calls.checkers.COROUTINE_CONTEXT_1_3_FQ_NAME
+
+object FirSuspendCallChecker : FirQualifiedAccessExpressionChecker() {
+    private val SUSPEND_PROPERTIES_FQ_NAMES = setOf(
+        COROUTINE_CONTEXT_1_2_20_FQ_NAME, COROUTINE_CONTEXT_1_2_30_FQ_NAME, COROUTINE_CONTEXT_1_3_FQ_NAME
+    )
+
+    @OptIn(SymbolInternals::class)
+    override fun check(expression: FirQualifiedAccessExpression, context: CheckerContext, reporter: DiagnosticReporter) {
+        val reference = expression.calleeReference as? FirResolvedNamedReference ?: return
+        if (reference is FirResolvedCallableReference) return
+        val symbol = reference.resolvedSymbol as? FirCallableSymbol ?: return
+        symbol.ensureResolved(FirResolvePhase.STATUS)
+        val fir = symbol.fir as? FirMemberDeclaration ?: return
+        when (fir) {
+            is FirSimpleFunction -> if (!fir.isSuspend) return
+            is FirProperty -> if (symbol.callableId.asSingleFqName() !in SUSPEND_PROPERTIES_FQ_NAMES) return
+            else -> return
+        }
+        val enclosingSuspendFunction = findEnclosingSuspendFunction(context)
+        if (enclosingSuspendFunction == null) {
+            when (fir) {
+                is FirSimpleFunction -> reporter.reportOn(expression.source, FirErrors.ILLEGAL_SUSPEND_FUNCTION_CALL, symbol, context)
+                is FirProperty -> reporter.reportOn(expression.source, FirErrors.ILLEGAL_SUSPEND_PROPERTY_ACCESS, symbol, context)
+                else -> {
+                }
+            }
+        }
+    }
+
+    private fun findEnclosingSuspendFunction(context: CheckerContext): FirFunction? {
+        return context.containingDeclarations.lastOrNull {
+            when (it) {
+                is FirAnonymousFunction -> it.typeRef.coneType.isSuspendFunctionType(context.session)
+                is FirSimpleFunction -> it.isSuspend
+                else -> false
+            }
+        } as? FirFunction
+    }
+}

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/diagnostics/FirDefaultErrorMessages.kt

@@ -191,6 +191,8 @@ import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.HAS_NEXT_FUNCTION
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.ILLEGAL_CONST_EXPRESSION
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.ILLEGAL_KOTLIN_VERSION_STRING_VALUE
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.ILLEGAL_SELECTOR
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.ILLEGAL_SUSPEND_FUNCTION_CALL
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.ILLEGAL_SUSPEND_PROPERTY_ACCESS
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.ILLEGAL_UNDERSCORE
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.IMPLEMENTATION_BY_DELEGATION_IN_EXPECT_CLASS
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.INAPPLICABLE_CANDIDATE
@@ -1477,6 +1479,18 @@ class FirDefaultErrorMessages {
             )
             map.put(OPERATOR_RENAMED_ON_IMPORT, "Operator renamed to a different operator on import")
 
+            // Suspend
+            map.put(
+                ILLEGAL_SUSPEND_FUNCTION_CALL,
+                "Suspend function ''{0}'' should be called only from a coroutine or another suspend function",
+                SYMBOL
+            )
+            map.put(
+                ILLEGAL_SUSPEND_PROPERTY_ACCESS,
+                "Suspend property ''{0}'' should be accessed only from a coroutine or suspend function",
+                SYMBOL
+            )
+
             // Extended checkers group
             map.put(REDUNDANT_VISIBILITY_MODIFIER, "Redundant visibility modifier")
             map.put(REDUNDANT_MODALITY_MODIFIER, "Redundant modality modifier")