[FIR] Support including flow information when dumping CFG dot file

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/dfa/cfg/ControlFlowGraphRenderer.kt

@@ -10,15 +10,18 @@ package org.jetbrains.kotlin.fir.resolve.dfa.cfg
 import org.jetbrains.kotlin.fir.FirElement
 import org.jetbrains.kotlin.fir.declarations.FirFile
 import org.jetbrains.kotlin.fir.references.FirControlFlowGraphReference
-import org.jetbrains.kotlin.fir.resolve.dfa.FirControlFlowGraphReferenceImpl
+import org.jetbrains.kotlin.fir.render
+import org.jetbrains.kotlin.fir.resolve.dfa.*
+import org.jetbrains.kotlin.fir.symbols.impl.FirCallableSymbol
 import org.jetbrains.kotlin.fir.visitors.FirVisitorVoid
+import org.jetbrains.kotlin.name.CallableId
 import org.jetbrains.kotlin.utils.DFS
 import org.jetbrains.kotlin.utils.Printer
-import java.util.*
 
 class FirControlFlowGraphRenderVisitor(
     builder: StringBuilder,
-    private val renderLevels: Boolean = false
+    private val renderLevels: Boolean = false,
+    private val renderFlow: Boolean = false,
 ) : FirVisitorVoid() {
     companion object {
         private const val EDGE = " -> "
@@ -59,13 +62,33 @@ class FirControlFlowGraphRenderVisitor(
                 color = BLUE
             }
             val attributes = mutableListOf<String>()
-            val label = buildString {
-                append(node.render().replace("\"", ""))
-                if (renderLevels) {
-                    append(" [${node.level}]")
+            if (renderFlow) {
+                // To maintain compatibility with existing CFG renders, only use HTML-like rendering if flow details are enabled.
+                val label = buildString {
+                    append("<TABLE BORDER=\"0\">")
+                    append("<TR><TD><B>")
+                    append(node.render().toHtmlLikeString())
+                    if (renderLevels) {
+                        append(" [${node.level}]")
+                    }
+                    append("</B></TD></TR>")
+                    if (node.flowInitialized) {
+                        append("<TR><TD ALIGN=\"LEFT\" BALIGN=\"LEFT\">")
+                        append(node.renderFlowHtmlLike())
+                        append("</TD></TR>")
+                    }
+                    append("</TABLE>")
                 }
+                attributes += "label=< $label >"
+            } else {
+                val label = buildString {
+                    append(node.render().replace("\"", ""))
+                    if (renderLevels) {
+                        append(" [${node.level}]")
+                    }
+                }
+                attributes += "label=\"$label\""
             }
-            attributes += "label=\"$label\""
 
             when {
                 node.isDead -> "gray"
@@ -142,4 +165,73 @@ class FirControlFlowGraphRenderVisitor(
         popIndent()
         println("}")
     }
+
+    private fun CFGNode<*>.renderFlowHtmlLike(): String {
+        val flow = flow
+        val variables = flow.knownVariables + flow.implications.keys +
+                flow.implications.flatMap { it.value }.map { it.condition.variable } +
+                flow.implications.flatMap { it.value }.map { it.effect.variable }
+        return variables.sorted().joinToString(separator = "<BR/><BR/>") { variable ->
+            buildString {
+                append(variable.renderHtmlLike())
+                if (variable is RealVariable) {
+                    flow.getTypeStatement(variable)?.let {
+                        append("<BR/><B>types</B> ")
+                        append(it.exactType.toHtmlLikeString())
+                    }
+                    flow.implications[flow.unwrapVariable(variable)]?.let {
+                        for (implication in it) {
+                            append("<BR/><B>implication</B> ")
+                            append(implication.toHtmlLikeString())
+                        }
+                    }
+                }
+                flow.implications[variable]?.let {
+                    for (implication in it) {
+                        append("<BR/><B>implication</B> ")
+                        append(implication.toHtmlLikeString())
+                    }
+                }
+            }
+        }
+    }
+
+    private fun DataFlowVariable.renderHtmlLike(): String {
+        val variable = this
+        return buildString {
+            append("<B>")
+            append(variable)
+            append("</B>")
+
+            val callableId = variable.callableId
+            if (variable is RealVariable && callableId != null) {
+                append(" = ")
+                val receivers = listOfNotNull(
+                    variable.identifier.dispatchReceiver?.callableId?.toHtmlLikeString(),
+                    variable.identifier.extensionReceiver?.callableId?.toHtmlLikeString(),
+                )
+                when (receivers.size) {
+                    2 -> append(receivers.joinToString(prefix = "(", postfix = ")."))
+                    1 -> append(receivers.joinToString(postfix = "."))
+                }
+                append(callableId.toHtmlLikeString())
+            }
+            if (variable is SyntheticVariable) {
+                append(" = '")
+                append(variable.fir.render().toHtmlLikeString())
+                append("'")
+            }
+        }
+    }
+
+    private val DataFlowVariable.callableId: CallableId?
+        get() = ((this as? RealVariable)?.identifier?.symbol as? FirCallableSymbol<*>)?.callableId
+
+    /**
+     * Sanitize string for rendering with HTML-like syntax.
+     */
+    private fun Any.toHtmlLikeString(): String = toString()
+        .replace("&", "&amp;")
+        .replace(">", "&gt;")
+        .replace("<", "&lt;")
 }

compiler/fir/semantics/src/org/jetbrains/kotlin/fir/resolve/dfa/DfaVariables.kt

@@ -22,10 +22,12 @@ data class Identifier(
     }
 }
 
-sealed class DataFlowVariable(private val variableIndexForDebug: Int) {
+sealed class DataFlowVariable(private val variableIndexForDebug: Int) : Comparable<DataFlowVariable> {
     final override fun toString(): String {
         return "d$variableIndexForDebug"
     }
+
+    override fun compareTo(other: DataFlowVariable): Int = variableIndexForDebug.compareTo(other.variableIndexForDebug)
 }
 
 enum class PropertyStability(val impliedSmartcastStability: SmartcastStability?) {

compiler/testData/codegen/box/smartCasts/kt44814.kt

@@ -1,8 +1,7 @@
 // ISSUE: KT-44814
 // WITH_STDLIB
 // DUMP_IR
-// DUMP_CFG
-// RENDERER_CFG_LEVELS
+// DUMP_CFG: LEVELS
 
 class FlyweightCapableTreeStructure
 

compiler/testData/diagnostics/tests/script/ComplexScript.kts

@@ -1,6 +1,5 @@
 // FIR_IDENTICAL
-// DUMP_CFG
-// RENDERER_CFG_LEVELS
+// DUMP_CFG: LEVELS
 // !DIAGNOSICS: +UNUSED_PARAMETER
 
 fun foo(x: Int) = 1

compiler/testData/diagnostics/tests/script/NestedInnerClass.fir.kts

@@ -1,7 +1,6 @@
 // !WITH_NEW_INFERENCE
 // documents inconsistency between scripts and classes, see DeclarationScopeProviderImpl
-// DUMP_CFG
-// RENDERER_CFG_LEVELS
+// DUMP_CFG: LEVELS
 
 fun function() = 42
 val property = ""

compiler/testData/diagnostics/tests/script/NestedInnerClass.kts

@@ -1,7 +1,6 @@
 // !WITH_NEW_INFERENCE
 // documents inconsistency between scripts and classes, see DeclarationScopeProviderImpl
-// DUMP_CFG
-// RENDERER_CFG_LEVELS
+// DUMP_CFG: LEVELS
 
 fun function() = 42
 val property = ""

compiler/testData/diagnostics/tests/script/NestedInnerClass.ll.kts

@@ -3,8 +3,7 @@
 // LL_FIR_DIVERGENCE
 // !WITH_NEW_INFERENCE
 // documents inconsistency between scripts and classes, see DeclarationScopeProviderImpl
-// DUMP_CFG
-// RENDERER_CFG_LEVELS
+// DUMP_CFG: LEVELS
 
 fun function() = 42
 val property = ""

compiler/tests-common-new/tests/org/jetbrains/kotlin/test/directives/FirDiagnosticsDirectives.kt

@@ -14,17 +14,16 @@ import org.jetbrains.kotlin.test.frontend.fir.handlers.FirResolvedTypesVerifier
 import org.jetbrains.kotlin.test.frontend.fir.handlers.FirScopeDumpHandler
 
 object FirDiagnosticsDirectives : SimpleDirectivesContainer() {
-    val DUMP_CFG by directive(
+    val DUMP_CFG by stringDirective(
         description = """
             Dumps control flow graphs of all declarations to `testName.dot` file
-            This directive may be applied only to all modules
+            This directive may be applied only to all modules.
+            Syntax: DUMP_CFG(: [OPTIONS])
+            
+            Additional options may be enabled :
+             - ${DumpCfgOption.LEVELS}: Render levels of nodes in CFG dump.
+             - ${DumpCfgOption.FLOW}: Include data analysis variable information in CFG dump for debugging purposes.
         """.trimIndent(),
-        applicability = Global
-    )
-
-    val RENDERER_CFG_LEVELS by directive(
-        description = "Render leves of nodes in CFG dump",
-        applicability = Global
     )
 
     val FIR_DUMP by directive(
@@ -96,6 +95,11 @@ object FirDiagnosticsDirectives : SimpleDirectivesContainer() {
     )
 }
 
+object DumpCfgOption {
+    const val LEVELS = "LEVELS"
+    const val FLOW = "FLOW"
+}
+
 fun TestConfigurationBuilder.configureFirParser(parser: FirParser) {
     defaultDirectives {
         FIR_PARSER with parser

compiler/tests-common-new/tests/org/jetbrains/kotlin/test/frontend/fir/handlers/FirCfgDumpHandler.kt

@@ -6,8 +6,8 @@
 package org.jetbrains.kotlin.test.frontend.fir.handlers
 
 import org.jetbrains.kotlin.fir.resolve.dfa.cfg.FirControlFlowGraphRenderVisitor
+import org.jetbrains.kotlin.test.directives.DumpCfgOption
 import org.jetbrains.kotlin.test.directives.FirDiagnosticsDirectives
-import org.jetbrains.kotlin.test.directives.FirDiagnosticsDirectives.RENDERER_CFG_LEVELS
 import org.jetbrains.kotlin.test.directives.model.DirectivesContainer
 import org.jetbrains.kotlin.test.frontend.fir.FirOutputArtifact
 import org.jetbrains.kotlin.test.model.TestModule
@@ -24,9 +24,12 @@ class FirCfgDumpHandler(testServices: TestServices) : FirAnalysisHandler(testSer
 
     override fun processModule(module: TestModule, info: FirOutputArtifact) {
         if (alreadyDumped || FirDiagnosticsDirectives.DUMP_CFG !in module.directives) return
+        val options = module.directives[FirDiagnosticsDirectives.DUMP_CFG].map { it.uppercase() }
+
         val file = info.mainFirFiles.values.first()
-        val renderLevels = RENDERER_CFG_LEVELS in module.directives
-        file.accept(FirControlFlowGraphRenderVisitor(builder, renderLevels))
+        val renderLevels = DumpCfgOption.LEVELS in options
+        val renderFlow = DumpCfgOption.FLOW in options
+        file.accept(FirControlFlowGraphRenderVisitor(builder, renderLevels, renderFlow))
         alreadyDumped = true
     }