[GHC] #13237: Extend TH with addModCStub

[GHC]

#13237: Extend TH with addModCStub
-------------------------------------+-------------------------------------
        Reporter:                    |                Owner:
  facundo.dominguez                  |  facundo.dominguez
            Type:  feature request   |               Status:  patch
        Priority:  normal            |            Milestone:  8.2.1
       Component:  Template Haskell  |              Version:  8.0.1
      Resolution:                    |             Keywords:  inline-c
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D3106
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by nh2):

 One question about the implementation:

 Do we have to be careful with recompilation avoidance / reproducible
 builds / interface hashes here? E.g. if the `String` passed to
 `addModCStub` is different between two builds, should that invalidate any
 modules further down? Or could, through recursive tracing of `include`s,
 the behaviour of a module change when the module is loaded from
 TemplateHaskell, so that e.g. the entire preprocessor-expanded C code
 should make its way into an interface hash?

 (Note I haven't actually analysed if it's possible for the generated C
 code to be used in TemplateHaskell later in the same compilation pass,
 just some ideas that went through my head.)

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13237#comment:9>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler