[FIR] Add contracts to FIR renderer

compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirRenderer.kt

@@ -10,12 +10,14 @@ import org.jetbrains.kotlin.builtins.functions.FunctionClassDescriptor
 import org.jetbrains.kotlin.descriptors.Visibilities
 import org.jetbrains.kotlin.descriptors.Visibility
 import org.jetbrains.kotlin.descriptors.annotations.AnnotationUseSiteTarget
+import org.jetbrains.kotlin.fir.contracts.FirContractDescription
+import org.jetbrains.kotlin.fir.contracts.FirRawContractDescription
+import org.jetbrains.kotlin.fir.contracts.FirResolvedContractDescription
+import org.jetbrains.kotlin.fir.contracts.description.ConeContractRenderer
+import org.jetbrains.kotlin.fir.contracts.impl.FirEmptyContractDescription
 import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.expressions.*
-import org.jetbrains.kotlin.fir.expressions.impl.FirElseIfTrueCondition
-import org.jetbrains.kotlin.fir.expressions.impl.FirExpressionStub
-import org.jetbrains.kotlin.fir.expressions.impl.FirNoReceiverExpression
-import org.jetbrains.kotlin.fir.expressions.impl.FirUnitExpression
+import org.jetbrains.kotlin.fir.expressions.impl.*
 import org.jetbrains.kotlin.fir.references.*
 import org.jetbrains.kotlin.fir.symbols.AbstractFirBasedSymbol
 import org.jetbrains.kotlin.fir.symbols.ConeClassLikeLookupTag
@@ -157,6 +159,14 @@ class FirRenderer(builder: StringBuilder, private val mode: RenderMode = RenderM
         }
         print(": ")
         callableDeclaration.returnTypeRef.accept(this)
+        callableDeclaration.renderContractDescription()
+    }
+
+    private fun FirDeclaration.renderContractDescription() {
+        val contractDescription = (this as? FirContractDescriptionOwner)?.contractDescription ?: return
+        pushIndent()
+        contractDescription.accept(this@FirRenderer)
+        popIndent()
     }
 
     private fun Visibility.asString(effectiveVisibility: FirEffectiveVisibility? = null): String {
@@ -310,12 +320,12 @@ class FirRenderer(builder: StringBuilder, private val mode: RenderMode = RenderM
         }
     }
 
-    fun renderInBraces(f: () -> Unit) {
-        println(" {")
+    fun renderInBraces(leftBrace: String = "{", rightBrace: String = "}", f: () -> Unit) {
+        println(" $leftBrace")
         pushIndent()
         f()
         popIndent()
-        println("}")
+        println(rightBrace)
     }
 
     fun renderSupertypes(regularClass: FirRegularClass) {
@@ -423,6 +433,7 @@ class FirRenderer(builder: StringBuilder, private val mode: RenderMode = RenderM
         propertyAccessor.valueParameters.renderParameters()
         print(": ")
         propertyAccessor.returnTypeRef.accept(this)
+        propertyAccessor.renderContractDescription()
         propertyAccessor.body?.renderBody()
     }
 
@@ -1116,4 +1127,27 @@ class FirRenderer(builder: StringBuilder, private val mode: RenderMode = RenderM
     override fun visitErrorNamedReference(errorNamedReference: FirErrorNamedReference) {
         visitNamedReference(errorNamedReference)
     }
+
+    override fun visitRawContractDescription(rawContractDescription: FirRawContractDescription) {
+        newLine()
+        print("[Contract description]")
+        renderInBraces("<", ">") {
+            rawContractDescription.contractCall.accept(this)
+            newLine()
+        }
+    }
+
+    override fun visitResolvedContractDescription(resolvedContractDescription: FirResolvedContractDescription) {
+        newLine()
+        println("[R|Contract description]")
+        renderInBraces("<", ">") {
+            for (effect in resolvedContractDescription.effects) {
+                println(buildString { effect.accept(ConeContractRenderer(this), null) })
+            }
+        }
+    }
+
+    override fun visitContractDescription(contractDescription: FirContractDescription) {
+        require(contractDescription is FirEmptyContractDescription)
+    }
 }