Enable warnings in the CMake build (#669)

* Enable warnings when building with GCC or clang

* Fix warnings

2 files changed, 3 insertions, 3 deletions

diff --git a/Firestore/core/test/firebase/firestore/util/autoid_test.cc b/Firestore/core/test/firebase/firestore/util/autoid_test.cc
index e55a8e9..079b990 100644
--- a/Firestore/core/test/firebase/firestore/util/autoid_test.cc
+++ b/Firestore/core/test/firebase/firestore/util/autoid_test.cc
@@ -25,8 +25,8 @@ using firebase::firestore::util::CreateAutoId;
 TEST(AutoId, IsSane) {
   for (int i = 0; i < 50; i++) {
     std::string auto_id = CreateAutoId();
-    EXPECT_EQ(20, auto_id.length());
-    for (int pos = 0; pos < 20; pos++) {
+    EXPECT_EQ(20u, auto_id.length());
+    for (size_t pos = 0; pos < 20; pos++) {
       char c = auto_id[pos];
       EXPECT_TRUE(isalpha(c) || isdigit(c))
           << "Should be printable ascii character: '" << c << "' in \""
diff --git a/Firestore/core/test/firebase/firestore/util/string_printf_test.cc b/Firestore/core/test/firebase/firestore/util/string_printf_test.cc
index 76f7cde..085be84 100644
--- a/Firestore/core/test/firebase/firestore/util/string_printf_test.cc
+++ b/Firestore/core/test/firebase/firestore/util/string_printf_test.cc
@@ -64,7 +64,7 @@ TEST(StringPrintf, DontOverwriteErrno) {
 
 TEST(StringPrintf, LargeBuf) {
   // Check that the large buffer is handled correctly.
-  int n = 2048;
+  size_t n = 2048;
   char* buf = new char[n + 1];
   memset(buf, ' ', n);
   buf[n] = 0;