Copying the following files AS-IS from google.glog r141:

base/third_party/symbolize/symbolize.h

 // Copyright (c) 2006, 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 87 matching lines @@
 // success. Otherwise, returns false.
 bool GetSectionHeaderByName(int fd, const char *name, size_t name_len,
                             ElfW(Shdr) *out);
 
 _END_GOOGLE_NAMESPACE_
 
 #endif  /* __ELF__ */
 
 _START_GOOGLE_NAMESPACE_
 
+// Restrictions on the callbacks that follow:
+//  - The callbacks must not use heaps but only use stacks.
+//  - The callbacks must be async-signal-safe.
+
 // Installs a callback function, which will be called right before a symbol name
 // is printed. The callback is intended to be used for showing a file name and a
 // line number preceding a symbol name.
 // "fd" is a file descriptor of the object file containing the program
 // counter "pc". The callback function should write output to "out"
 // and return the size of the output written. On error, the callback
 // function should return -1.
 typedef int (*SymbolizeCallback)(int fd, void *pc, char *out, size_t out_size,
                                  uint64 relocation);
 void InstallSymbolizeCallback(SymbolizeCallback callback);
 
+// Installs a callback function, which will be called instead of
+// OpenObjectFileContainingPcAndGetStartAddress.  The callback is expected
+// to searches for the object file (from /proc/self/maps) that contains
+// the specified pc.  If found, sets |start_address| to the start address
+// of where this object file is mapped in memory, sets the module base
+// address into |base_address|, copies the object file name into
+// |out_file_name|, and attempts to open the object file.  If the object
+// file is opened successfully, returns the file descriptor.  Otherwise,
+// returns -1.  |out_file_name_size| is the size of the file name buffer
+// (including the null-terminator).
+typedef int (*SymbolizeOpenObjectFileCallback)(uint64_t pc,
+                                               uint64_t &start_address,
+                                               uint64_t &base_address,
+                                               char *out_file_name,
+                                               int out_file_name_size);
+void InstallSymbolizeOpenObjectFileCallback(
+    SymbolizeOpenObjectFileCallback callback);
+
 _END_GOOGLE_NAMESPACE_
 
 #endif
 
 _START_GOOGLE_NAMESPACE_
 
 // Symbolizes a program counter.  On success, returns true and write the
 // symbol name to "out".  The symbol name is demangled if possible
 // (supports symbols generated by GCC 3.x or newer).  Otherwise,
 // returns false.
 bool Symbolize(void *pc, char *out, int out_size);
 
 _END_GOOGLE_NAMESPACE_
 
 #endif  // BASE_SYMBOLIZE_H_