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| author | Ryan Scott <ryan.gl.scott@gmail.com> | 2020-10-31 11:41:45 -0400 |
|---|---|---|
| committer | Ryan Scott <ryan.gl.scott@gmail.com> | 2020-10-31 16:01:26 -0400 |
| commit | 13d53c37b1f33b1ca3e6a18289215e861a1a2601 (patch) | |
| tree | ddc3cc0a0bc2d85b68d336039c33d230864bc162 /compiler/GHC/Tc/Module.hs | |
| parent | 08e6993a1b956e6edccdc1cecc7250b724bf79a0 (diff) | |
| download | haskell-wip/T18770.tar.gz | |
Display results of GHC.Core.Lint.lint* functions consistentlywip/T18770
Previously, the functions in `GHC.Core.Lint` used a patchwork of
different ways to display Core Lint errors:
* `lintPassResult` (which is the source of most Core Lint errors) renders
Core Lint errors with a distinctive banner (e.g.,
`*** Core Lint errors : in result of ... ***`) that sets them apart
from ordinary GHC error messages.
* `lintAxioms`, in contrast, uses a completely different code path that
displays Core Lint errors in a rather confusing manner. For example,
the program in #18770 would give these results:
```
Bug.hs:1:1: error:
Bug.hs:12:1: warning:
Non-*-like kind when *-like expected: RuntimeRep
when checking the body of forall: 'TupleRep '[r]
In the coercion axiom Bug.N:T :: []. Bug.T ~_R Any
Substitution: [TCvSubst
In scope: InScope {r}
Type env: [axl :-> r]
Co env: []]
|
1 | {-# LANGUAGE DataKinds #-}
| ^
```
* Further digging reveals that `GHC.IfaceToCore` displays Core Lint
errors for iface unfoldings as though they were a GHC panic. See, for
example, this excerpt from #17723:
```
ghc: panic! (the 'impossible' happened)
(GHC version 8.8.2 for x86_64-unknown-linux):
Iface Lint failure
In interface for Lib
...
```
This patch makes all of these code paths display Core Lint errors and
warnings consistently. I decided to adopt the conventions that
`lintPassResult` currently uses, as they appear to have been around the
longest (and look the best, in my subjective opinion). We now use the
`displayLintResult` function for all three scenarios mentioned above.
For example, here is what the Core Lint error for the program in #18770 looks
like after this patch:
```
[1 of 1] Compiling Bug ( Bug.hs, Bug.o )
*** Core Lint errors : in result of TcGblEnv axioms ***
Bug.hs:12:1: warning:
Non-*-like kind when *-like expected: RuntimeRep
when checking the body of forall: 'TupleRep '[r_axn]
In the coercion axiom N:T :: []. T ~_R Any
Substitution: [TCvSubst
In scope: InScope {r_axn}
Type env: [axn :-> r_axn]
Co env: []]
*** Offending Program ***
axiom N:T :: T = Any -- Defined at Bug.hs:12:1
*** End of Offense ***
<no location info>: error:
Compilation had errors
```
Fixes #18770.
Diffstat (limited to 'compiler/GHC/Tc/Module.hs')
| -rw-r--r-- | compiler/GHC/Tc/Module.hs | 6 |
1 files changed, 1 insertions, 5 deletions
diff --git a/compiler/GHC/Tc/Module.hs b/compiler/GHC/Tc/Module.hs index 94582b00a9..bc12f13423 100644 --- a/compiler/GHC/Tc/Module.hs +++ b/compiler/GHC/Tc/Module.hs @@ -296,11 +296,7 @@ tcRnModuleTcRnM hsc_env mod_sum tcRnSrcDecls explicit_mod_hdr local_decls export_ies ; whenM (goptM Opt_DoCoreLinting) $ - do { let (warns, errs) = lintGblEnv (hsc_dflags hsc_env) tcg_env - ; mapBagM_ (addWarn NoReason) warns - ; mapBagM_ addErr errs - ; failIfErrsM } -- if we have a lint error, we're only - -- going to get in deeper trouble by proceeding + lintGblEnv (hsc_dflags hsc_env) tcg_env ; setGblEnv tcg_env $ do { -- Process the export list |