[lldb] Fix version string when using LLDB_REVISION but not LLDB_REPOSITORY

[rupprecht]

Summary

lldb's format string (line one) is:
lldb version $clang_version ($lldb_repo revision $lldb_revision)

When only using $lldb_revision and not $lldb_repo, this might look like:
lldb version 11 ( revision 12345)
which looks pretty ugly.

Aside: I'm not sure we really need all the different versions since we've moved to the monorepo layout -- I don't think anyone is using different llvm/clang/lldb revisions, are they? We could likely tidy this up further if we knew how people consumed the output of lldb --version.

[labath]

Aside: I'm not sure we really need all the different versions since we've moved to the monorepo layout -- I don't think anyone is using different llvm/clang/lldb revisions, are they?

The standalone build of lldb (and clang) still works, and there are people that use it (some distros build their packages this way, and it's the "official" build method in the swift fork afaik). So, in theory one could build lldb+clang+llvm from three different revisions (but I hope noone actually does that).

[JDevlieghere]

In D74859#1884159, @labath wrote:

Aside: I'm not sure we really need all the different versions since we've moved to the monorepo layout -- I don't think anyone is using different llvm/clang/lldb revisions, are they?

The standalone build of lldb (and clang) still works, and there are people that use it (some distros build their packages this way, and it's the "official" build method in the swift fork afaik). So, in theory one could build lldb+clang+llvm from three different revisions (but I hope noone actually does that).

Yup, Swift uses the standalone build.

lldb/source/lldb.cpp

if (g_version_str.empty()) {
     g_version_str += CLANG_VERSION_STRING;
 
     const char *lldb_repo = GetLLDBRepository();
     const char *lldb_rev = GetLLDBRevision();
     if (lldb_repo || lldb_rev) {
       g_version_str += " (";
       if (lldb_repo)
         g_version_str += lldb_repo;
+      if (lldb_repo && lldb_rev)
+        g_version_str += " ";
       if (lldb_rev) {
-        g_version_str += " revision ";
+        g_version_str += "revision ";
         g_version_str += lldb_rev;
       }
       g_version_str += ")";
     }
 
     std::string clang_rev(clang::getClangRevision());
     if (clang_rev.length() > 0) {
       g_version_str += "\n  clang revision ";