Opened 17 months ago

Last modified 12 months ago

#7430 new bug

GHC API reports CPP errors in confusing ways

Reported by: MikolajKonarski Owned by:
Priority: normal Milestone: 7.8.3
Component: GHC API Version: 7.6.1
Keywords: Cc:
Operating System: Linux Architecture: Unknown/Multiple
Type of failure: Other Difficulty: Unknown
Test Case: Blocked By:
Blocking: Related Tickets:

Description

When there is a CPP error, the GHC API provides a normal error message (such as in case of type errors), e.g.,

error: missing binary operator before token "("

but it does not say it's a CPP error. In addition (and unlike for type errors), GHC API throws an exception, e.g.,

phase `C pre-processor' failed (exitcode = 1)

which states the error comes from CPP, but is otherwise uninformative and not tied in any way to the normal error message.

Ideally, all the information would be in the error message and the exception that disrupts the normal control flow would not be thrown.

Here's how to reproduce this: in the following repo (uh, just realised it's a rather large repo)

https://github.com/Mikolaj/ghc/tree/CPPrunGhc

run

ghc --make GhcRun.hs -package ghc-7.6.1

and then

./GhcRun

You should get

Normal error message:
Severity: SevError  SrcSpan: RealSrcSpan (SrcSpanPoint {srcSpanFile = "Ticks.hs", srcSpanLine = 1, srcSpanCol = 0})  MsgDoc:  error: missing binary operator before token "("

Exception:
GhcRun: phase `C pre-processor' failed (exitcode = 1)

Attachments (2)

GhcRun.hs (2.3 KB) - added by MikolajKonarski 17 months ago.
Ticks.hs (42 bytes) - added by MikolajKonarski 17 months ago.

Download all attachments as: .zip

Change History (4)

Changed 17 months ago by MikolajKonarski

Changed 17 months ago by MikolajKonarski

comment:1 Changed 17 months ago by MikolajKonarski

Attached the source files. Just make sure you run GhcRun? in the same directory that Ticks.hs resides.

comment:2 Changed 12 months ago by igloo

  • Difficulty set to Unknown
  • Milestone set to 7.8.1

Thanks for the report.

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