logfile.diff

diff --git a/atom/app/atom_main_delegate.cc b/atom/app/atom_main_delegate.cc
index e1318eb6d..537667389 100644
--- a/atom/app/atom_main_delegate.cc
+++ b/atom/app/atom_main_delegate.cc
@@ -25,6 +25,7 @@
 #include "base/logging.h"
 #include "base/mac/bundle_locations.h"
 #include "base/path_service.h"
+#include "base/strings/string_number_conversions.h"
 #include "chrome/common/chrome_paths.h"
 #include "content/public/common/content_switches.h"
 #include "electron/buildflags/buildflags.h"
@@ -128,6 +129,8 @@ bool AtomMainDelegate::BasicStartupComplete(int* exit_code) {
   auto* command_line = base::CommandLine::ForCurrentProcess();
 
   logging::LoggingSettings settings;
+  logging::LogSeverity log_severity = logging::LOG_INFO;
+
 #if defined(OS_WIN)
   // On Windows the terminal returns immediately, so we add a new line to
   // prevent output in the same line as the prompt.
@@ -146,18 +149,32 @@ bool AtomMainDelegate::BasicStartupComplete(int* exit_code) {
   settings.logging_dest = logging::LOG_TO_SYSTEM_DEBUG_LOG;
 #endif  // !defined(OS_WIN)
 
-  // Only enable logging when --enable-logging is specified.
-  auto env = base::Environment::Create();
+  const auto log_file = command_line->GetSwitchValuePath(::switches::kLogFile);
+  const auto log_level = command_line->GetSwitchValueNative(::switches::kLoggingLevel);
+  const auto env = base::Environment::Create();
+
+  // No logging unless requested by the user
   if (!command_line->HasSwitch(::switches::kEnableLogging) &&
-      !env->HasVar("ELECTRON_ENABLE_LOGGING")) {
+      !env->HasVar("ELECTRON_ENABLE_LOGGING") &&
+      log_file.empty() && log_level.empty()) {
     settings.logging_dest = logging::LOG_NONE;
-    logging::SetMinLogLevel(logging::LOG_NUM_SEVERITIES);
+    log_severity = logging::LOG_NUM_SEVERITIES;
   }
 
-  logging::InitLogging(settings);
+  // If the user specified a log file, use it
+  if (!log_file.empty()) {
+    settings.logging_dest = logging::LOG_TO_FILE;
+    settings.log_file = log_file.value().c_str();
+  }
 
-  // Logging with pid and timestamp.
-  logging::SetLogItems(true, false, true, false);
+  // If the user specified a log level, use it
+  if (!log_level.empty() && !base::StringToInt(log_level, &log_severity)) {
+    std::cerr << "Invalid log level: " << log_level << std::endl;
+  }
+
+  logging::SetLogItems(true/*pid*/, false, true/*timestamp*/, false);
+  logging::SetMinLogLevel(log_severity);
+  logging::InitLogging(settings);
 
   // Enable convient stack printing. This is enabled by default in non-official
   // builds.