Allow plugins to access "dead code"
GHC removes dead-bindings quite early in the compilation process, which makes perfect sense from a pure compilation point of view. But with user-plugins, some of the dead-bindings can be interesting: They might be properties or other code that instructs the plugin to do a certain action, even if the binding isn't otherwise used anywhere else or exported. (Think of embedded properties.)
Here's a discussion about the issue, where SimonPJ asked for a ticket to be filed: http://mail.haskell.org/pipermail/ghc-devs/2015-December/010708.html
It appears the desugarer removes some of the dead-code. One option could be to stop the desugarer from doing that, and leaving it to the later optimizer passes so plugins can still see all the bindings (if they run early enough), or require the user to put in an "KeepAlive" pragma on bindings that she cares about. While keeping all-dead code in the desugarer would be the simplest thing to do, requiring the user to put in a pragma isn't a terrible solution either.
Trac metadata
| Trac field | Value |
|---|---|
| Version | 7.10.2 |
| Type | FeatureRequest |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | Compiler |
| Test case | |
| Differential revisions | |
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