Added setting for suppressing child process errors (#337)

Author: Damtev

utbot-framework-api/src/main/kotlin/org/utbot/framework/UtSettings.kt

@@ -274,6 +274,14 @@ object UtSettings {
         DEFAULT_CONCRETE_EXECUTION_TIMEOUT_IN_CHILD_PROCESS_MS
     )
 
+    /**
+     * Determines whether should errors from a child process be written to a log file or suppressed.
+     * Note: being enabled, this option can highly increase disk usage when using ContestEstimator.
+     *
+     * False by default (for saving disk space).
+     */
+    var logConcreteExecutionErrors by getBooleanProperty(false)
+
     /**
      * Number of branch instructions using for clustering executions in the test minimization phase.
      */

utbot-instrumentation/src/main/kotlin/org/utbot/instrumentation/process/ChildProcessRunner.kt

@@ -1,5 +1,6 @@
 package org.utbot.instrumentation.process
 
+import mu.KotlinLogging
 import org.utbot.common.bracket
 import org.utbot.common.debug
 import org.utbot.common.firstOrNullResourceIS
@@ -9,11 +10,11 @@ import org.utbot.common.pid
 import org.utbot.common.scanForResourcesContaining
 import org.utbot.common.utBotTempDirectory
 import org.utbot.framework.JdkPathService
+import org.utbot.framework.UtSettings
 import org.utbot.instrumentation.Settings
 import org.utbot.instrumentation.agent.DynamicClassTransformer
 import java.io.File
 import java.nio.file.Paths
-import mu.KotlinLogging
 
 private val logger = KotlinLogging.logger {}
 private var processSeqN = 0
@@ -30,19 +31,24 @@ class ChildProcessRunner {
                 debugCmd + listOf("-javaagent:$jarFile", "-ea", "-jar", "$jarFile")
     }
 
-    lateinit var errorLogFile: File
+    var errorLogFile: File = NULL_FILE
 
     fun start(): Process {
         logger.debug { "Starting child process: ${cmds.joinToString(" ")}" }
         processSeqN++
 
-        val dir = File(utBotTempDirectory.toFile(), ERRORS_FILE_PREFIX)
-        dir.mkdirs()
-        errorLogFile = File(dir, "${hashCode()}-${processSeqN}.log")
+        if (UtSettings.logConcreteExecutionErrors) {
+            UT_BOT_TEMP_DIR.mkdirs()
+            errorLogFile = File(UT_BOT_TEMP_DIR, "${hashCode()}-${processSeqN}.log")
+        }
 
         val processBuilder = ProcessBuilder(cmds).redirectError(errorLogFile)
         return processBuilder.start().also {
-            logger.debug { "Process started with PID=${it.pid} , error log: ${errorLogFile.absolutePath}" }
+            logger.debug { "Process started with PID=${it.pid}" }
+
+            if (UtSettings.logConcreteExecutionErrors) {
+                logger.debug { "Child process error log: ${errorLogFile.absolutePath}" }
+            }
         }
     }
 
@@ -53,6 +59,16 @@ class ChildProcessRunner {
 
         private const val DEBUG_RUN_CMD = "-agentlib:jdwp=transport=dt_socket,server=y,suspend=y,quiet=y,address=5005"
 
+        private val UT_BOT_TEMP_DIR: File = File(utBotTempDirectory.toFile(), ERRORS_FILE_PREFIX)
+
+        private val NULL_FILE_PATH: String = if (System.getProperty("os.name").startsWith("Windows")) {
+            "NUL"
+        } else {
+            "/dev/null"
+        }
+
+        private val NULL_FILE = File(NULL_FILE_PATH)
+
         /**
          * * Firstly, searches for utbot-instrumentation jar in the classpath.
          *