Improved supportability (#941)

* Reverted references of ELASTIC_APM_EMPTY_STRING_VIEW back to makeEmptyStringView()

since ELASTIC_APM_EMPTY_STRING_VIEW is added in a later PR

* Fixed incorrect merge

* Added INTERNAL_CHECKS_LEVEL to OptionNames.php

* Added maxNumberOfStackFrames as parameter to 

LoggableStackTrace::buildForCurrent instead having hardcoded

* Removed static from constructConfigManagerMetadata to have on stack trace

* Log stack trace on failed ASSERT in native part

* Set g_elasticApmDirectLogLevel* to default values so that they can be used even before configuration is parsed

src/ElasticApm/Impl/Config/OptionNames.php

@@ -44,6 +44,7 @@ final class OptionNames
     public const ENABLED = 'enabled';
     public const ENVIRONMENT = 'environment';
     public const HOSTNAME = 'hostname';
+    public const INTERNAL_CHECKS_LEVEL = 'internal_checks_level';
     public const LOG_LEVEL = 'log_level';
     public const LOG_LEVEL_SYSLOG = 'log_level_syslog';
     public const LOG_LEVEL_STDERR = 'log_level_stderr';

src/ElasticApm/Impl/Log/LoggableStackTrace.php

@@ -36,12 +36,15 @@ final class LoggableStackTrace
 {
     public const STACK_TRACE_KEY = 'stacktrace';
 
+    public const MAX_NUMBER_OF_STACK_FRAMES = 100;
+
     /**
      * @param int $numberOfStackFramesToSkip
+     * @param int $maxNumberOfStackFrames
      *
      * @return ClassicFormatStackTraceFrame[]
      */
-    public static function buildForCurrent(int $numberOfStackFramesToSkip): array
+    public static function buildForCurrent(int $numberOfStackFramesToSkip, int $maxNumberOfStackFrames = self::MAX_NUMBER_OF_STACK_FRAMES): array
     {
         /**
          * @param string $key
@@ -58,7 +61,7 @@ public static function buildForCurrent(int $numberOfStackFramesToSkip): array
             null /* <- loggerFactory */,
             $numberOfStackFramesToSkip + 1 /* <- offset */,
             DEBUG_BACKTRACE_IGNORE_ARGS /* <- options */,
-            100 /* limit */
+            $maxNumberOfStackFrames /* <- limit */
         );
         $result = [];
 

src/ext/ConfigManager.c

@@ -1569,7 +1569,6 @@ void destructConfigManagerMetadata( ConfigMetadata* cfgManagerMeta )
     ELASTIC_APM_ZERO_STRUCT( cfgManagerMeta );
 }
 
-static
 ResultCode constructConfigManagerMetadata( ConfigMetadata* cfgManagerMeta )
 {
     ELASTIC_APM_ASSERT_VALID_PTR( cfgManagerMeta );

src/ext/elastic_apm_assert.c

@@ -60,6 +60,15 @@ void vElasticApmAssertFailed(
                     , msgPrintfFmt
                     , msgPrintfFmtArgs );
 
+    void* stackTraceAddresses[ maxCaptureStackTraceDepth ];
+    size_t stackTraceAddressesCount = 0;
+    stackTraceAddressesCount = ELASTIC_APM_CAPTURE_STACK_TRACE( &(stackTraceAddresses[ 0 ]), ELASTIC_APM_STATIC_ARRAY_SIZE( stackTraceAddresses ) );
+
+    char txtOutStreamBuf[ ELASTIC_APM_TEXT_OUTPUT_STREAM_ON_STACK_BUFFER_SIZE * 10 ];
+    TextOutputStream txtOutStream = ELASTIC_APM_TEXT_OUTPUT_STREAM_FROM_STATIC_BUFFER( txtOutStreamBuf );
+
+    ELASTIC_APM_FORCE_LOG_CRITICAL( "Stack trace:\n%s", streamStackTrace( &( stackTraceAddresses[ 0 ] ), stackTraceAddressesCount, /* linePrefix: */ "\t", &txtOutStream ) );
+
     elasticApmAbort();
 }
 

src/ext/log.c

@@ -35,9 +35,9 @@
 #define ELASTIC_APM_CURRENT_LOG_CATEGORY ELASTIC_APM_LOG_CATEGORY_LOG
 
 #ifndef PHP_WIN32
-LogLevel g_elasticApmDirectLogLevelSyslog = logLevel_off;
+LogLevel g_elasticApmDirectLogLevelSyslog = logLevel_info;
 #endif // #ifndef PHP_WIN32
-LogLevel g_elasticApmDirectLogLevelStderr = logLevel_off;
+LogLevel g_elasticApmDirectLogLevelStderr = logLevel_error;
 
 String logLevelNames[numberOfLogLevels] =
         {