[mac] Teach dump_syms to handle additional zerofill sections

src/common/mac/macho_reader.cc

 // Copyright (c) 2010, Google Inc.
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
@@ skipping 463 matching lines @@
         >> dummy32
         >> section.flags
         >> dummy32
         >> dummy32;
     if (section.bits_64)
       cursor >> dummy32;
     if (!cursor) {
       reporter_->SectionsMissing(segment.name);
       return false;
     }
-    if ((section.flags & SECTION_TYPE) == S_ZEROFILL) {
+    const uint32_t section_type = section.flags & SECTION_TYPE;
+    if (section_type == S_ZEROFILL || section_type == S_THREAD_LOCAL_ZEROFILL ||
+            section_type == S_GB_ZEROFILL) {
       // Zero-fill sections have a size, but no contents.
       section.contents.start = section.contents.end = NULL;
     } else if (segment.contents.start == NULL &&
                segment.contents.end == NULL) {
       // Mach-O files in .dSYM bundles have the contents of the loaded
       // segments removed, and their file offsets and file sizes zeroed
       // out.  However, the sections within those segments still have
       // non-zero sizes.  There's no reason to call MisplacedSectionData in
       // this case; the caller may just need the section's load
       // address. But do set the contents' limits to NULL, for safety.
@@ skipping 33 matching lines @@
 
 bool Reader::MapSegmentSections(const Segment &segment,
                                 SectionMap *section_map) const {
   section_map->clear();
   SectionMapper mapper(section_map);
   return WalkSegmentSections(segment, &mapper);
 }
 
 }  // namespace mach_o
 }  // namespace google_breakpad