#14298: Let Template Haskell dynamically add something with which to link -------------------------------------+------------------------------------- Reporter: harpocrates | Owner: (none) Type: feature request | Status: new Priority: normal | Milestone: Component: Template Haskell | Version: 8.2.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by bgamari):
That said, my understanding of `-c` is that it shouldn't work on any module that uses TH from another module.
That isn't quite true. TH will work perfectly well in single-shot mode. However, as usual, the user must guarantee that any needed modules are compiled for whatever way GHC will want to load to evaluate splices. For instance, {{{ $ pwd /opt/exp/ghc/ghc-landing/testsuite/tests/th $ ghc -c TH_NestedSplices_Lib.hs -dynamic-too -fforce-recomp $ ghc -c TH_NestedSplices.hs -fforce-recomp }}} It's important that this behavior be preserved since Cabal is slowly moving towards using single-shot mode to improve module-level build parallelism.
About the API, I would prefer: {{{ addForeignObject :: ByteString -> Q () }}}
The interface in comment:6 sounds plausible. The worry that I have with just allowing the user to specify an object file path as in the original proposal is that it makes it seem as though they can safely `addForeignObject` the same object file from multiple modules. However, this is not safe as they will encounter conflicting symbol errors when they attempt to link the final object. Of course, we could in principle document our way out of this issue. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14298#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler