[GHC] #13366: addCStub doesn't allow control over compiler flags or source file file

[GHC]

#13366: addCStub doesn't allow control over compiler flags or source file file
-------------------------------------+-------------------------------------
        Reporter:  bgamari           |                Owner:  (none)
            Type:  feature request   |               Status:  closed
        Priority:  high              |            Milestone:  8.2.1
       Component:  Compiler          |              Version:  8.0.1
      Resolution:  fixed             |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D3280
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by alpmestan):

 The `T13366` test fails on master from yesterday, when executed with the
 `ghci` way:

 {{{
 =====> T13366(ghci) 1 of 1 [0, 0, 0]
 cd "./th/T13366.run" && "/home/alp/ghc/inplace/test   spaces/ghc-stage2"
 T13366.hs -dcore-lint -dcmm-lint -no-user-package-db -rtsopts -fno-warn-
 missed-specialisations -fshow-warning-groups -fdiagnostics-color=never
 -fno-diagnostics-show-caret -dno-debug-output -XTemplateHaskell -package
 template-haskell --interactive -v0 -ignore-dot-ghci -fno-ghci-history +RTS
 -I0.1 -RTS -lstdc++ -v0< T13366.genscript
 Actual stderr output differs from expected:
 diff -uw "/dev/null" "./th/T13366.run/T13366.run.stderr.normalised"
 --- /dev/null   2018-03-07 13:03:27.344000000 +0100
 +++ ./th/T13366.run/T13366.run.stderr.normalised        2018-03-08
 14:49:20.583965000 +0100
 @@ -0,0 +1,13 @@
 +ghc: ^^ Could not load 'fcxx', dependency unresolved. See top entry
 above.
 +
 +
 +ByteCodeLink: can't find label
 +During interactive linking, GHCi couldn't find the following symbol:
 +  fcxx
 +This may be due to you not asking GHCi to load extra object files,
 +archives or DLLs needed by your current session.  Restart GHCi,
 specifying
 +the missing library using the -L/path/to/object/dir and -lmissinglibname
 +flags, or simply by naming the relevant files on the GHCi command line.
 +Alternatively, this link failure might indicate a bug in GHCi.
 +If you suspect the latter, please send a bug report to:
 +  glasgow-haskell-bugs at haskell.org
 *** unexpected failure for T13366(ghci)
 }}}

 where the aforementionned symbol is defined in a snippet of C++ code that
 TH adds to the build through `addForeignFile`:

 {{{#!hs
 foreign import ccall fcxx :: Int -> IO Int

 do addForeignFile LangCxx $ unlines
      [ "#include <iostream>"
      , "extern \"C\" {"
      , "  int fcxx(int x) {"
      , "    std::cout << \"calling fcxx(\" << x << \")\" << std::endl;"
      , "    std::cout.flush();"
      , "    return A_MACRO + x;"
      , "  }"
      , "}"
      ]
    return []
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13366#comment:14>
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