Remove CallStack CPP guards in GHC 8.4

GHC 7.10.1 didn't support CallStack, while its successors did. Yet in post-8.0 master (which needs to be buildable with the 7.10 series, including 7.10.1) references to CallStack have begun to sneak in to GHC.

The first instance of this was 9d33adb6 but there will likely be more. I've fixed in this instance in D1812 by adding #if guards. These should be removed in GHC 8.2.

Trac metadata

Trac field	Value
Version	7.10.3
Type	Task
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture

changed milestone to %8.2.1

changed weight to 5

added Ttask Trac import labels

Actually, the first instance was in 80d7ce80 - that also broke the build for me because the guard incorrectly said >= 710 instead of > 710.

mentioned in commit ede055eb

rwbarton astutely points out that MIN_VERSION_GLASGOW_HASKELL, which is used in the above commit (which was merged to ghc-8.0 as well), was only introduced in ghc 7.10. Looks like we'll need to revert to __GLASGOW_HASKELL__ in ghc-8.0.

Trac metadata

Trac field	Value
Version	7.10.3 → 8.0.1-rc1

Does 8.2 need to be able to build with 7.10.1? If so then we can't remove these CPP guards entirely until 8.4.

This is an honest question, by the way. I don't know whether our policy is that 8.2 should be buildable by every 7.10.* release, or some 7.10.* release, or perhaps the last 7.10.* release. If we somehow released a compiler that was completely incapable of bootstrapping GHC, it would be a serious problem for the "every" policy. Is this policy written down somewhere?

changed title from Remove CallStack CPP guards in GHC 8.2 to Remove CallStack CPP guards in GHC 8.4

changed milestone to %8.4.1

I think we should be conservative here; the cost of keeping the CPP is relatively small compared to the inconvenience of worrying about which 7.10 releases we can/can't build with. Bumping to 8.4.

changed milestone to %8.6.1

This ticket won't be resolved in 8.4; remilestoning for 8.6. Do holler if you are affected by this or would otherwise like to work on it.

closed

changed milestone to %8.4.1

This was carried out in c13720c8.

Trac metadata

Trac field	Value
Resolution	Unresolved → ResolvedFixed

added Pnormal label