Build and test both C++ loggers where possible (#595)

* Rename FIREBASE_BINARY_DIR to FIREBASE_INSTALL_DIR

  Make this consistent with the outer superbuild and also make the
  association with CMAKE_INSTALL_PREFIX more obvious.

* Build and test log_stdio separate from the rest of util

  This is in preparation for adding a test for log_apple

* Build and test log_apple under CMake

  Also add notes about how FIRLogger's debug mode can break this test

* Refactor log_apple to cut down duplicate switch statements

  There's also a slight reduction in final binary size.

1 files changed, 10 insertions, 0 deletions

diff --git a/Firestore/core/test/firebase/firestore/util/log_test.cc b/Firestore/core/test/firebase/firestore/util/log_test.cc
index 09b2c08..46cbc4e 100644
--- a/Firestore/core/test/firebase/firestore/util/log_test.cc
+++ b/Firestore/core/test/firebase/firestore/util/log_test.cc
@@ -22,6 +22,16 @@ namespace firebase {
 namespace firestore {
 namespace util {
 
+// When running against the log_apple.mm implementation (backed by FIRLogger)
+// this test can fail if debug_mode gets persisted in the user defaults. Check
+// for defaults getting in your way with
+//
+//   defaults read firebase_firestore_util_log_apple_test
+//
+// You can fix it with:
+//
+//   defaults write firebase_firestore_util_log_apple_test \
+//       /google/firebase/debug_mode NO
 TEST(Log, SetAndGet) {
   LogSetLevel(kLogLevelVerbose);