Refactor stack trace builder

- omit common stack frames of cause and suppressed exceptions
- reuse stringbuilder when building lines

(cherry picked from commit c777783a584af0090e8d423802ea86fc3bdb082b)

runtime/src/main/kotlin/kotlin/Throwable.kt

@@ -27,7 +27,7 @@ public open class Throwable(open val message: String?, open val cause: Throwable
     constructor() : this(null, null)
 
     @get:ExportForCppRuntime("Kotlin_Throwable_getStackTrace")
-    private val stackTrace = getCurrentStackTrace()
+    private val stackTrace: NativePtrArray = getCurrentStackTrace()
 
     private val stackTraceStrings: Array<String> by lazy {
         getStackTraceStrings(stackTrace).freeze()
@@ -45,40 +45,83 @@ public open class Throwable(open val message: String?, open val cause: Throwable
     /**
      * Prints the [detailed description][Throwable.stackTraceToString] of this throwable to the standard output.
      */
-    public fun printStackTrace(): Unit = dumpStackTrace("", "", { println(it) }, mutableSetOf())
+    public fun printStackTrace(): Unit = ExceptionTraceBuilder(this).print()
 
-    internal fun dumpStackTrace(): String = buildString {
-        dumpStackTrace("", "", { appendln(it) }, mutableSetOf())
-    }
+    internal fun dumpStackTrace(): String = ExceptionTraceBuilder(this).build()
 
-    private fun Throwable.dumpStackTrace(indent: String, qualifier: String, writeln: (String) -> Unit, visited: MutableSet<Throwable>) {
-        this.dumpSelfTrace(indent, qualifier, writeln, visited) || return
+    private class ExceptionTraceBuilder(private val top: Throwable) {
+        private val target = StringBuilder()
+        private var printOut = false
+        private val visited = mutableSetOf<Throwable>()
 
-        var cause = this.cause
-        while (cause != null) {
-            // TODO: should skip common stack frames
-            cause.dumpSelfTrace(indent, "Caused by: ", writeln, visited)
-            cause = cause.cause
+        fun build(): String {
+            top.dumpFullTrace("", "")
+            return target.toString()
         }
-    }
 
-    private fun Throwable.dumpSelfTrace(indent: String, qualifier: String, writeln: (String) -> Unit, visited: MutableSet<Throwable>): Boolean {
-        if (!visited.add(this)) {
-            writeln(indent + qualifier + "[CIRCULAR REFERENCE, SEE ABOVE: $this]")
-            return false
+        fun print() {
+            printOut = true
+            top.dumpFullTrace("", "")
         }
-        writeln(indent + qualifier + this.toString())
-        for (element in stackTraceStrings) {
-            writeln("$indent\tat $element")
-        }
-        val suppressed = suppressedExceptionsList
-        if (!suppressed.isNullOrEmpty()) {
-            val suppressedIndent = indent + '\t'
-            for (s in suppressed) {
-                s.dumpStackTrace(suppressedIndent, "Suppressed: ", writeln, visited)
+
+        private fun StringBuilder.endln() {
+            if (printOut) {
+                println(this)
+                clear()
+            } else {
+                appendln()
             }
         }
-        return true
+
+        private fun Throwable.dumpFullTrace(indent: String, qualifier: String) {
+            this.dumpSelfTrace(indent, qualifier) || return
+
+            var cause = this.cause
+            while (cause != null) {
+                cause.dumpSelfTrace(indent, "Caused by: ")
+                cause = cause.cause
+            }
+        }
+
+        private fun Throwable.dumpSelfTrace(indent: String, qualifier: String): Boolean {
+            if (!visited.add(this)) {
+                target.append(indent).append(qualifier).append("[CIRCULAR REFERENCE, SEE ABOVE: ").append(this).append("]").endln()
+                return false
+            }
+            target.append(indent).append(qualifier).append(this).endln()
+            // leave 1 common frame to ease matching with the top exception stack
+            val commonFrames = (commonStackFrames() - 1).coerceAtLeast(0)
+            for (frameIndex in 0 until stackTraceStrings.size - commonFrames) {
+                val element = stackTraceStrings[frameIndex]
+                target.append(indent).append("    at ").append(element).endln()
+            }
+            if (commonFrames > 0) {
+                target.append(indent).append("    ... and ").append(commonFrames).append(" more common stack frames skipped").endln()
+            }
+            val suppressed = suppressedExceptionsList
+            if (!suppressed.isNullOrEmpty()) {
+                val suppressedIndent = indent + "    "
+                for (s in suppressed) {
+                    s.dumpFullTrace(suppressedIndent, "Suppressed: ")
+                }
+            }
+            return true
+        }
+
+        private fun Throwable.commonStackFrames(): Int {
+            if (top === this) return 0
+            val topStack = top.stackTrace
+            val topSize = topStack.size
+            val thisStack = this.stackTrace
+            val thisSize = thisStack.size
+            val maxSize = minOf(topSize, thisSize)
+            var frame = 0
+            while (frame < maxSize) {
+                if (thisStack[thisSize - 1 - frame] != topStack[topSize - 1 - frame]) break
+                frame++
+            }
+            return frame
+        }
     }