Log stack traces for PHP warnings etc (#14961)

* Allow stack traces to be logged to file for PHP warnings

* Use debug_backtrace() to generate an abbreviated stack trace

* Change trace format, fix LogTest

* smaller trace by not including unimportant doc root 

makes it also easier for users to share the trace since they don't need to remove any paths

* Update ErrorHandler.php

3 files changed, 36 insertions, 11 deletions

diff --git a/plugins/Monolog/Formatter/LineMessageFormatter.php b/plugins/Monolog/Formatter/LineMessageFormatter.php
index 306838d34d..f8e1dbc99f 100644
--- a/plugins/Monolog/Formatter/LineMessageFormatter.php
+++ b/plugins/Monolog/Formatter/LineMessageFormatter.php
@@ -61,16 +61,32 @@ class LineMessageFormatter implements FormatterInterface
 
     private function formatMessage($class, $message, $date, $record)
     {
+        $trace = isset($record['context']['trace']) ? self::formatTrace($record['context']['trace']) : '';
         $message = str_replace(
-            array('%tag%', '%message%', '%datetime%', '%level%'),
-            array($class, $message, $date, $record['level_name']),
+            array('%tag%', '%message%', '%datetime%', '%level%', '%trace%'),
+            array($class, $message, $date, $record['level_name'], $trace),
             $this->logMessageFormat
         );
 
-        $message .= "\n";
+        $message = trim($message) . "\n";
         return $message;
     }
 
+    private static function formatTrace(array $trace, $numLevels = 10)
+    {
+        $strTrace = '';
+        for ($i = 0; $i < $numLevels; $i++) {
+            $level = $trace[$i];
+            if (isset($level['file'], $level['line'])) {
+                $levelTrace = '#' . $i . (str_replace(PIWIK_DOCUMENT_ROOT, '', $level['file'])) . '(' . $level['line'] . ')';
+            } else {
+                $levelTrace = '[internal function]: ' . $level['class'] . $level['type'] . $level['function'] . '()';
+            }
+            $strTrace .= $levelTrace . ",";
+        }
+        return trim($strTrace, ",");
+    }
+
     public function formatBatch(array $records)
     {
         foreach ($records as $key => $record) {
diff --git a/plugins/Monolog/config/config.php b/plugins/Monolog/config/config.php
index 18e07c5c33..9d48f603cc 100644
--- a/plugins/Monolog/config/config.php
+++ b/plugins/Monolog/config/config.php
@@ -97,16 +97,13 @@ return array(
         ->constructor(DI\get('log.file.filename'), DI\get('log.level.file'))
         ->method('setFormatter', DI\get('log.lineMessageFormatter.file')),
 
-    'log.lineMessageFormatter.file' => DI\object('Piwik\Plugins\Monolog\Formatter\LineMessageFormatter')
-        ->constructorParameter('allowInlineLineBreaks', false),
-
     'Piwik\Plugins\Monolog\Handler\DatabaseHandler' => DI\object()
         ->constructor(DI\get('log.level.database'))
-        ->method('setFormatter', DI\get('Piwik\Plugins\Monolog\Formatter\LineMessageFormatter')),
+        ->method('setFormatter', DI\get('log.lineMessageFormatter')),
 
     'Piwik\Plugins\Monolog\Handler\WebNotificationHandler' => DI\object()
         ->constructor(DI\get('log.level.screen'))
-        ->method('setFormatter', DI\get('Piwik\Plugins\Monolog\Formatter\LineMessageFormatter')),
+        ->method('setFormatter', DI\get('log.lineMessageFormatter')),
 
     'log.level' => DI\factory(function (ContainerInterface $c) {
         if ($c->has('ini.log.log_level')) {
@@ -175,16 +172,27 @@ return array(
         return $logPath;
     }),
 
-    'Piwik\Plugins\Monolog\Formatter\LineMessageFormatter' => DI\object()
-        ->constructor(DI\get('log.format')),
+    'log.lineMessageFormatter' => DI\object('Piwik\Plugins\Monolog\Formatter\LineMessageFormatter')
+        ->constructor(DI\get('log.short.format')),
 
-    'log.format' => DI\factory(function (ContainerInterface $c) {
+    'log.lineMessageFormatter.file' => DI\object('Piwik\Plugins\Monolog\Formatter\LineMessageFormatter')
+        ->constructor(DI\get('log.trace.format'))
+        ->constructorParameter('allowInlineLineBreaks', false),
+
+    'log.short.format' => DI\factory(function (ContainerInterface $c) {
         if ($c->has('ini.log.string_message_format')) {
             return $c->get('ini.log.string_message_format');
         }
         return '%level% %tag%[%datetime%] %message%';
     }),
 
+    'log.trace.format' => DI\factory(function (ContainerInterface $c) {
+        if ($c->has('ini.log.string_message_format_trace')) {
+            return $c->get('ini.log.string_message_format_trace');
+        }
+        return '%level% %tag%[%datetime%] %message% %trace%';
+    }),
+
     'archiving.performance.handlers' => function (ContainerInterface $c) {
         $logFile = trim($c->get('ini.Debug.archive_profiling_log'));
         if (empty($logFile)) {
diff --git a/plugins/Monolog/tests/Integration/LogTest.php b/plugins/Monolog/tests/Integration/LogTest.php
index 69d84379fc..0f2c32ec84 100644
--- a/plugins/Monolog/tests/Integration/LogTest.php
+++ b/plugins/Monolog/tests/Integration/LogTest.php
@@ -257,6 +257,7 @@ class LogTest extends IntegrationTestCase
             'ini.log.log_writers' => array($backend),
             'ini.log.log_level' => $level,
             'ini.log.string_message_format' => self::STRING_MESSAGE_FORMAT,
+            'ini.log.string_message_format_trace' => self::STRING_MESSAGE_FORMAT,
             'ini.log.logger_file_path' => self::getLogFileLocation(),
             'Psr\Log\LoggerInterface' => \DI\get('Monolog\Logger'),
             'Tests.log.allowAllHandlers' => true,