MachOImageSymbolTableReader: permit indirect symbols to exist among external defined symbols

snapshot/mac/mach_o_image_reader_test.cc

 // Copyright 2014 The Crashpad Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 375 matching lines @@
 // Only external defined symbols are considered, other types of symbols are
 // excluded because LookUpExternalDefinedSymbol() only deals with external
 // defined symbols.
 void ExpectSymbol(const Nlist* entry,
                   const char* name,
                   const MachOImageReader* actual_image) {
   SCOPED_TRACE(name);
 
   uint32_t entry_type = entry->n_type & N_TYPE;
   if ((entry->n_type & N_STAB) == 0 && (entry->n_type & N_PEXT) == 0 &&
-      entry_type != N_UNDF && entry_type != N_PBUD &&
+      (entry_type == N_ABS || entry_type == N_SECT) &&
       (entry->n_type & N_EXT) == 1) {
-    // Note that this catches more symbols than MachOImageSymbolTableReader
-    // does. This test looks for all external defined symbols, but the
-    // implementation excludes indirect (N_INDR) symbols. This is intentional,
-    // because indirect symbols are currently not seen in the wild, but if they
-    // begin to be used more widely, this test is expected to catch them so that
-    // a decision can be made regarding whether support ought to be implemented.
     mach_vm_address_t actual_address;
     ASSERT_TRUE(
         actual_image->LookUpExternalDefinedSymbol(name, &actual_address));
 
     // Since the nlist interface was used to read the symbol, use it to compute
     // the symbol address too. This isn’t perfect, and it should be possible in
     // theory to use dlsym() to get the expected address of a symbol. In
     // practice, dlsym() is difficult to use when only a MachHeader* is
     // available as in this function, as opposed to a void* opaque handle. It is
     // possible to get a void* handle by using dladdr() to find the file name
@@ skipping 217 matching lines @@
       image_reader.UUID(&actual_uuid);
       EXPECT_EQ(expected_uuid, actual_uuid);
     }
   }
 #endif
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace crashpad