[odb-users] Strange Problems Building ODB Compiler From Source

[Boris Kolpackov]

Brian Coggins <becoggins at hotmail.com> writes:

> $ odb --database sqlite test.h
> 
> clang: error: unknown argument: '-fplugin-arg-odb-svc-path=/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1'

Ok, this suggests that for some reason ODB is using g++ instead of
g++-8. On Mac OS g++ is an alias for clang++.

Now we need to understand why. Could you run the following for me
and send the beginning of the output (or upload the whole log
somewhere):

$ cd odb-gcc-8/odb-2.5.0-b.13
$ b clean
$ b --verbose=5

I am particularly interested in these lines (shown with values from
my Linux box):

trace: reset: original host: 'x86_64-linux-gnu'
trace: reset: canonical host: 'x86_64-linux-gnu'; class: linux

cxx ...
  cxx        g++-7@/usr/bin/g++-7
  id         gcc
  version    7.2.0 (Ubuntu 7.2.0-1ubuntu1~16.04)
  ...
  target     x86_64-linux-gnu

As well as the g++ compilation command line that shows the -DODB_GXX_NAME
option.

Also, if you want to try and debug this, the relevant place to look is
odb-gcc-8/odb-2.5.0-b.13/buildfile, lines that reference gxx_name. You
could, for example, try to print the host/target triplets by adding the
following lines:

info $cxx.target
info $build.host