Added an option (-i) to have dump_syms output header information only.

src/tools/linux/dump_syms/dump_syms.cc

 // Copyright (c) 2011, 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 21 matching lines @@
 #include <unistd.h>
 
 #include <cstring>
 #include <iostream>
 #include <string>
 #include <vector>
 
 #include "common/linux/dump_symbols.h"
 
 using google_breakpad::WriteSymbolFile;
+using google_breakpad::WriteSymbolFileHeader;
 
 int usage(const char* self) {
   fprintf(stderr, "Usage: %s [OPTION] <binary-with-debugging-info> "
           "[directories-for-debug-file]\n\n", self);
   fprintf(stderr, "Options:\n");
+  fprintf(stderr, "  -i:   Output module header information only.\n");
   fprintf(stderr, "  -c    Do not generate CFI section\n");
   fprintf(stderr, "  -r    Do not handle inter-compilation unit references\n");
   fprintf(stderr, "  -v    Print all warnings to stderr\n");
   return 1;
 }
 
 int main(int argc, char **argv) {
   if (argc < 2)
     return usage(argv[0]);
-
+  bool header_only = false;
   bool cfi = true;
   bool handle_inter_cu_refs = true;
   bool log_to_stderr = false;
   int arg_index = 1;
   while (arg_index < argc && strlen(argv[arg_index]) > 0 &&
          argv[arg_index][0] == '-') {
-    if (strcmp("-c", argv[arg_index]) == 0) {
+    if (strcmp("-i", argv[arg_index]) == 0) {
+      header_only = true;
+    } else if (strcmp("-c", argv[arg_index]) == 0) {
       cfi = false;
     } else if (strcmp("-r", argv[arg_index]) == 0) {
       handle_inter_cu_refs = false;
     } else if (strcmp("-v", argv[arg_index]) == 0) {
       log_to_stderr = true;
     } else {
+      printf("2.4 %s\n", argv[arg_index]);
       return usage(argv[0]);
     }
     ++arg_index;
   }
   if (arg_index == argc)
     return usage(argv[0]);
-
   // Save stderr so it can be used below.
   FILE* saved_stderr = fdopen(dup(fileno(stderr)), "w");
   if (!log_to_stderr) {
     if (freopen(_PATH_DEVNULL, "w", stderr)) {
       // If it fails, not a lot we can (or should) do.
       // Add this brace section to silence gcc warnings.
     }
   }
-
   const char* binary;
   std::vector<string> debug_dirs;
   binary = argv[arg_index];
   for (int debug_dir_index = arg_index + 1;
        debug_dir_index < argc;
        ++debug_dir_index) {
     debug_dirs.push_back(argv[debug_dir_index]);
   }
 
-  SymbolData symbol_data = cfi ? ALL_SYMBOL_DATA : NO_CFI;
-  google_breakpad::DumpOptions options(symbol_data, handle_inter_cu_refs);
-  if (!WriteSymbolFile(binary, debug_dirs, options, std::cout)) {
-    fprintf(saved_stderr, "Failed to write symbol file.\n");
-    return 1;
+  if (header_only) {
+    if (!WriteSymbolFileHeader(binary, std::cout)) {
+      fprintf(saved_stderr, "Failed to process file.\n");
+      return 1;
+    }
+  } else {
+    SymbolData symbol_data = cfi ? ALL_SYMBOL_DATA : NO_CFI;
+    google_breakpad::DumpOptions options(symbol_data, handle_inter_cu_refs);
+    if (!WriteSymbolFile(binary, debug_dirs, options, std::cout)) {
+      fprintf(saved_stderr, "Failed to write symbol file.\n");
+      return 1;
+    }
   }
 
   return 0;
 }