[OTS] TAG() macro for big endian

src/ots.cc

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ots.h"
 
 #include <sys/types.h>
 #include <zlib.h>
 
 #include <algorithm>
@@ skipping 64 matching lines @@
     uint8_t* p = new uint8_t[length];
     hunks_.push_back(p);
     return p;
   }
 
  private:
   std::vector<uint8_t*> hunks_;
 };
 
 // Use a macro instead of a function because gcc 4.4.3 creates static
-// initializers in that case. Note this macro assumes a little-endian system.
+// initializers in that case.
+#if defined(__BIG_ENDIAN__) || defined(_BIG_ENDIAN)

[jfkthame, 2012/04/28 09:10:46]

Unfortunately, this doesn't work as intended on some systems - in the Android
NDK, and (at least some) OpenBSD systems, <endian.h> defines the symbol
_BIG_ENDIAN (with various levels of underscore-decoration) not to mean "this
system is big-endian" but as a magic constant to compare with _BYTE_ORDER. As a
result, the big-endian option here is chosen even on little-endian
architectures.

(See mozilla issue https://bugzilla.mozilla.org/show_bug.cgi?id=747816#c10.)

+#define TAG(d, c, b, a) (a | (b << 8) | (c << 16) | (d << 24))
+#else
 #define TAG(a, b, c, d) (a | (b << 8) | (c << 16) | (d << 24))
+#endif
 
 const struct {
   uint32_t tag;
   bool (*parse)(ots::OpenTypeFile *otf, const uint8_t *data, size_t length);
   bool (*serialise)(ots::OTSStream *out, ots::OpenTypeFile *file);
   bool (*should_serialise)(ots::OpenTypeFile *file);
   void (*free)(ots::OpenTypeFile *file);
   bool required;
 } table_parsers[] = {
   { TAG('m', 'a', 'x', 'p'), ots::ots_maxp_parse, ots::ots_maxp_serialise,
@@ skipping 614 matching lines @@
     va_start(va, format);
     std::vfprintf(stderr, format, va);
     va_end(va);
     std::fprintf(stderr, "\n");
     std::fflush(stderr);
   }
 }
 #endif
 
 }  // namespace ots