BUILD_DESC_FROM_UNKNOWN in src/version.cpp

[MarkPfennig]

version.cpp currently applies one of three version suffixes

• -BUILD_SUFFIX, when building from an untagged commit
• -gtag-dirty, when building from an archive
• -unk, when building from a currently tagged commit/release

It seems rather strange that the 'ideal' build, a new tagged release cross compiled in gitian, would result in a suffix of 'unknown' using BUILD_DESC_FROM_UNKNOWN.

Perhaps BUILD_DESC_FROM_UNKNOWN would be better suited to builds where the source is unknown, with no suffix applied to tag matching release builds.

Does that make sense?

Details

If you tag a for a release, then build it, the output of share/genbuild.sh will be something like:

#define BUILD_DESC "v0.9.2.2"
#define BUILD_DATE "2014-08-21 05:44:34 +0100"

Then if you follow the logic in src/version.cpp you will find

#ifndef BUILD_DESC
#    ifdef BUILD_SUFFIX
#        define BUILD_DESC BUILD_DESC_WITH_SUFFIX(CLIENT_VERSION_MAJOR, CLIENT_VERSION_MINOR, CLIENT_VERSION_REVISION, CLIENT_VERSION_BUILD, BUILD_SUFFIX)
#    elif defined(GIT_COMMIT_ID)
#        define BUILD_DESC BUILD_DESC_FROM_COMMIT(CLIENT_VERSION_MAJOR, CLIENT_VERSION_MINOR, CLIENT_VERSION_REVISION, CLIENT_VERSION_BUILD, GIT_COMMIT_ID)
#    else
#        define BUILD_DESC BUILD_DESC_FROM_UNKNOWN(CLIENT_VERSION_MAJOR, CLIENT_VERSION_MINOR, CLIENT_VERSION_REVISION, CLIENT_VERSION_BUILD)
#    endif
#endif

In english: If there's a tagged clean release, with no dirty suffix, and not a downloaded archive, then say it is from an unknown source.

[theuni]

Gitian builds are generated from the official (deterministic) source tarballs, which include the "git archive'd" version.cpp. Git replaces some place-holders with real info (deterministic, since it's based on a tag's hash). So real releases hit the GIT_COMMIT_ID path rather than the else path.

For instance, from my current working tree:
make dist
untar that
check bitcoin-* folder, src/version.cpp
Mine looks like this:

#define GIT_ARCHIVE 1
#ifdef GIT_ARCHIVE
#    define GIT_COMMIT_ID "36d51b8"
#    define GIT_COMMIT_DATE "Thu, 21 Aug 2014 00:00:06 -0400"
#endif

[MarkPfennig]

Very simple code that achieves the same thing, and handles four uses rather than three:

#ifndef BUILD_DESC
#    ifdef BUILD_SUFFIX // any commit
#        define BUILD_DESC BUILD_DESC_WITH_SUFFIX(CLIENT_VERSION_MAJOR, CLIENT_VERSION_MINOR, CLIENT_VERSION_REVISION, CLIENT_VERSION_BUILD, BUILD_SUFFIX)
#    elif defined(GIT_COMMIT_ID) // archive release
#        define BUILD_DESC BUILD_DESC_FROM_COMMIT(CLIENT_VERSION_MAJOR, CLIENT_VERSION_MINOR, CLIENT_VERSION_REVISION, CLIENT_VERSION_BUILD, GIT_COMMIT_ID)
#    else // tagged commit
#        define BUILD_DESC BUILD_DESC_FROM_TAG(CLIENT_VERSION_MAJOR, CLIENT_VERSION_MINOR, CLIENT_VERSION_REVISION, CLIENT_VERSION_BUILD)
#    endif
#else // unknown source
#  define BUILD_DESC BUILD_DESC_FROM_UNKNOWN(CLIENT_VERSION_MAJOR, CLIENT_VERSION_MINOR, CLIENT_VERSION_REVISION, CLIENT_VERSION_BUILD)
#endif

[theuni]

What problem are you trying to solve?