[GHC] #7478: setSessionDynFlags does not always work

[GHC]

#7478: setSessionDynFlags does not always work
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        Reporter:  edsko             |                   Owner:
            Type:  bug               |                  Status:  new
        Priority:  high              |               Milestone:  7.12.1
       Component:  Compiler          |                 Version:  7.7
      Resolution:                    |                Keywords:
Operating System:  Unknown/Multiple  |            Architecture:
 Type of failure:  None/Unknown      |  Unknown/Multiple
      Blocked By:                    |               Test Case:  ghc-
 Related Tickets:                    |  api/T7478
                                     |                Blocking:
                                     |  Differential Revisions:
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Comment (by bherzog):

 A better solution is the following, I think:

 Have `defaultFlags` include `Opt_Static` in its result if
 `pc_DYNAMIC_BY_DEFAULT` is False.

 Reasoning: comment:17 shows that `ways` and `generalFlags` need to be
 coordinated wrt. dynamic/static linking: `generalFlags` needs to contain
 `Opt_Static` exactly when `ways` does not contain `WayDyn`. The values of
 both fields are derived from the settings passed to `defaultDynFlags`. In
 particular, `ways` will either be `[WayDyn]` or `[]`, depending on whether
 `pc_DYNAMIC_BY_DEFAULT` is True or False respectively. Therefore,
 `defaultFlags` should include `Opt_Static` in its result if
 `pc_DYNAMIC_BY_DEFAULT` is False.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7478#comment:18>
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