Don't call FIRConfiguration setLoggerLevel: before FIRApp exists.

Instead, cache the value, and call setLoggerLevel later, after the iOS FIRApp instance is created.

Author: jonsimantov

app/src/app_ios.h

@@ -17,12 +17,16 @@
 #ifndef FIREBASE_APP_SRC_APP_IOS_H_
 #define FIREBASE_APP_SRC_APP_IOS_H_
 #include "FIRApp.h"
+#include "FIRConfiguration.h"
 #include "app/src/util_ios.h"
 
 namespace firebase {
 
 namespace internal {
 OBJ_C_PTR_WRAPPER_NAMED(AppInternal, FIRApp);
+
+void SetFirConfigurationLoggerLevel(FIRLoggerLevel level);
+
 }  // namespace internal
 
 }  // namespace firebase

app/src/app_ios.mm

@@ -133,6 +133,10 @@ static void PlatformOptionsToAppOptions(FIROptions* platform_options, AppOptions
   return platform_app;
 }
 
+// Settings cached by SetFirConfigurationLoggerLevel if App wasn't already initialized.
+static bool g_delayed_fir_configuration_logger_level_set = false;
+static FIRLoggerLevel g_delayed_fir_configuration_logger_level = FIRLoggerLevelWarning;
+
 // Create an iOS FIRApp instance.
 static FIRApp* CreatePlatformApp(const AppOptions& options, const char* name) {
   __block FIRApp* platform_app = nil;
@@ -155,6 +159,14 @@ static void PlatformOptionsToAppOptions(FIROptions* platform_options, AppOptions
             [FIRApp configureWithName:@(name) options:platform_options];
           }
           platform_app = GetPlatformAppByName(name);
+	  // If the logger level was cached due to logging happening prior to
+	  // App's initialization, apply the delayed setting now, when FIRApp
+	  // is guaranteed to exist and we are in the main thread.
+	  if (g_delayed_fir_configuration_logger_level_set) {
+	    g_delayed_fir_configuration_logger_level_set = false;
+	    [[FIRConfiguration sharedInstance]
+	      setLoggerLevel:g_delayed_fir_configuration_logger_level];
+	  }
         } @catch (NSException* e) {
           LogError("Unable to configure Firebase app (%s)",
                    util::NSStringToString(e.reason).c_str());
@@ -276,4 +288,19 @@ static void PlatformOptionsToAppOptions(FIROptions* platform_options, AppOptions
 
 FIRApp* App::GetPlatformApp() const { return internal_->get(); }
 
+void SetFirConfigurationLoggerLevel(FIRLoggerLevel level) {
+  // Check if a FIRApp has been created. FIRApp.allApps will return a
+  // list of all FIRApps, or nil if no FIRApp has been created yet.
+  if (FIRApp.allApps != nil) {
+    // FIRApp has already been initialized, it's safe to set this
+    // value now.
+    [[FIRConfiguration sharedInstance] setLoggerLevel:level];
+  } else {
+    // FIRApp has not yet been initialized. Cache this value to set
+    // later, in CreatePlatformApp().
+    g_delayed_fir_configuration_logger_level = level;
+    g_delayed_fir_configuration_logger_level_set = true;
+  }
+}
+
 }  // namespace firebase

app/src/log_ios.mm

@@ -20,6 +20,7 @@
 
 #import "FIRConfiguration.h"
 
+#include "app/src/app_ios.h"
 #include "app/src/include/firebase/internal/common.h"
 
 #include <stdarg.h>
@@ -61,7 +62,7 @@ void LogInitialize() {
 // Set the platform specific SDK log level.
 void LogSetPlatformLevel(LogLevel level) {
   assert(level < FIREBASE_ARRAYSIZE(kCppToIOSLogLevel));
-  [[FIRConfiguration sharedInstance] setLoggerLevel:kCppToIOSLogLevel[level]];
+  firebase::internal::SetFirConfigurationLoggerLevel(kCppToIOSLogLevel[level]);
 }
 
 // Log a firebase message.