Updates from code review comments.

tests/test_table.cc

@@ -62,8 +62,7 @@ void test_strtable(const vector<std::string>& keys, uint32_t num_to_insert) {
       upb_strtable_next(&iter)) {
     const char *key = upb_strtable_iter_key(&iter);
     std::string tmp(key, strlen(key));
-    std::string tmp2(key, upb_strtable_iter_keylength(&iter));
-    ASSERT(tmp == tmp2);
+    ASSERT(strlen(key) == upb_strtable_iter_keylength(&iter));
     std::set<std::string>::iterator i = all.find(tmp);
     ASSERT(i != all.end());
     all.erase(i);

upb/refcounted.c

@@ -726,6 +726,18 @@ static void freeobj(upb_refcounted *o) {
 bool upb_refcounted_init(upb_refcounted *r,
                          const struct upb_refcounted_vtbl *vtbl,
                          const void *owner) {
+#ifndef NDEBUG
+  // Endianness check.  This is unrelated to upb_refcounted, it's just a
+  // convenient place to put the check that we can be assured will run for
+  // basically every program using upb.
+  const int x = 1;
+#ifdef UPB_BIG_ENDIAN
+  assert(*(char*)&x != 1);
+#else
+  assert(*(char*)&x == 1);
+#endif
+#endif
+
   r->next = r;
   r->vtbl = vtbl;
   r->individual_count = 0;

upb/table.int.h

@@ -158,10 +158,14 @@ FUNCS(fptr,     fptr,         upb_func*,    UPB_CTYPE_FPTR);
 // length into a byte-wise string representation, so code generation needs to
 // help it along.
 //
-// "len1" is the low byte and len4 is the high byte.  For big endian we'll need
-// to define a version of this that flips it around.
+// "len1" is the low byte and len4 is the high byte.
+#ifdef UPB_BIG_ENDIAN
+#define UPB_TABKEY_STR(len1, len2, len3, len4, strval) \
+    (uintptr_t)(len4 len3 len2 len1 strval)
+#else
 #define UPB_TABKEY_STR(len1, len2, len3, len4, strval) \
     (uintptr_t)(len1 len2 len3 len4 strval)
+#endif
 
 // Either:
 //   1. an actual integer key, or

upb/upb.h

@@ -25,6 +25,12 @@
 #define UPB_INLINE static inline
 #endif
 
+// Define this manually if you're on big endian and your compiler doesn't
+// provide these preprocessor symbols.
+#if defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
+#define UPB_BIG_ENDIAN
+#endif
+
 // For use in C/C++ source files (not headers), forces inlining within the file.
 #ifdef __GNUC__
 #define UPB_FORCEINLINE inline __attribute__((always_inline))