tree fcd693e51cd9f4572c1b129183482c453928d313
parent ee69009f3590748aac4db17c0f9774252326d6cb
author Zonr Chang <zonr.net@gmail.com> 1334208583 +0800
committer Shih-wei Liao <sliao@google.com> 1335351817 -0700

Introduce RSInfo and its reader/extractor/writer.

This commit only adds files that implements RSInfo class and DOES
NOT switch to use it.

RSInfo defines the new file format to cache the metadata and
RS-specific information from the source bitcode.

It's the replacement of the old "MC cache" whose name is ambiguous
and some fields within that are deprecated after legacy JIT was
removed.

Reader of RSInfo reads information from the file we called "RS info
file." It will replace MCCacheReader.

Extractor of RSInfo extracts information from the metadata section of
the source bitcode. It will replace MetadataExtractor.

Writer of RSInfo serializes a RSInfo object to a file such that
we can load it quickly using RSInfo reader later. It will replace
MCCacheWriter.

RSInfo unifies the interfaces to get the RS-specific information
such as #rs_export_var supplied by the developers either from file
(RS info file) or from the source bitcode. Later commit will prove
that.

RSInfo uses signature ("\0rsinfo\n") which is different from the
old MC cache ("\0bcc").

The version (MCO_VERSION in bcc_mccache.h) is increased by 1 in this
commit since we remove res_type in MCO_Dependency. RSInfo inherits
the version number comes from old MC cache therefore its version
number starts with 3.