Subzero: Embed the revision string into translated output.

pydir/crosstest.py

 #!/usr/bin/env python2
 
 import argparse
 import os
 import subprocess
 import sys
 import tempfile
 
 import targets
 from szbuild import LinkNonsfi
@@ skipping 147 matching lines @@
                       '-o=' + obj_sz,
                       asm_sz])
 
         # Each separately translated Subzero object file contains its own
         # definition of the __Sz_block_profile_info profiling symbol.  Avoid
         # linker errors (multiply defined symbol) by making all copies weak.
         # (This could also be done by Subzero if it supported weak symbol
         # definitions.)  This approach should be OK because cross tests are
         # currently the only situation where multiple translated files are
         # linked into the executable, but when PNaCl supports shared nexe
-        # libraries, this would need to change.
+        # libraries, this would need to change.  (Note: the same issue applies
+        # to the __Sz_revision symbol.)
         shellcmd(['{bin}/{objcopy}'.format(bin=bindir, objcopy=GetObjcopyCmd()),
                   '--weaken-symbol=__Sz_block_profile_info',
+                  '--weaken-symbol=__Sz_revision',
                   '--strip-symbol=nacl_tp_tdb_offset',
                   '--strip-symbol=nacl_tp_tls_offset',
                   obj_sz])
         objs.append(obj_sz)
         shellcmd(['{bin}/pnacl-llc'.format(bin=bindir),
                   '-arm-enable-dwarf-eh=1',
                   '-mtriple=' + triple,
                   '-externalize',
                   '-filetype=obj',
                   '-bitcode-format=llvm',
                   '-o=' + obj_llc,
                   bitcode] + llc_flags)
         shellcmd(['{bin}/{objcopy}'.format(bin=bindir, objcopy=GetObjcopyCmd()),
-                  '--weaken-symbol=__Sz_block_profile_info',
                   '--strip-symbol=nacl_tp_tdb_offset',
                   '--strip-symbol=nacl_tp_tls_offset',
                   obj_llc])
         objs.append(obj_llc)
 
     # Add szrt_sb_${target}.o or szrt_native_${target}.o.
     if not args.nonsfi:
         objs.append((
                 '{root}/toolchain_build/src/subzero/build/runtime/' +
                 'szrt_{sb}_' + args.target + '.o'
@@ skipping 64 matching lines @@
     objs.append(obj_llc)
     if args.nonsfi:
         LinkNonsfi(objs, os.path.join(args.dir, args.output), args.target)
     elif args.sandbox:
         LinkSandbox(objs, os.path.join(args.dir, args.output), args.target)
     else:
         LinkNative(objs, os.path.join(args.dir, args.output), args.target)
 
 if __name__ == '__main__':
     main()