[Git][ghc/ghc][wip/fabu/T25014-mistakenly-accepted-parent] Apply 12 suggestion(s) to 2 file(s)

[Fabricio Nascimento (@fabu)]

Fabricio Nascimento pushed to branch wip/fabu/T25014-mistakenly-accepted-parent at Glasgow Haskell Compiler / GHC


Commits:
d6590865 by Fabricio Nascimento at 2024-07-29T10:23:44+00:00
Apply 12 suggestion(s) to 2 file(s)

Co-authored-by: sheaf <sam.derbyshire at gmail.com>
- - - - -


2 changed files:

- compiler/GHC/Rename/Env.hs
- compiler/GHC/Tc/Gen/Export.hs


Changes:

=====================================
compiler/GHC/Rename/Env.hs
=====================================
@@ -691,7 +691,7 @@ parent than it was declared, for example PatternSynonyms (see [Typing Pattern
 Synonym Exports]).
 
 Another difference is in the presence of ambiguous names. Because we are strict
-on the parent, we won't report a name clash in the example bellow (see #24452),
+on the parent, we won't report a name clash in the example below (see #24452),
 as it would lead to a confusing error.
 
   module Ambiguous where
@@ -734,7 +734,6 @@ lookupInstanceDeclarationSubBndr warn_if_deprec parent doc rdr_name =
           return $ Left (UnknownSubordinate doc)
         AmbiguousOccurrence _ ->
           return $ Left (UnknownSubordinate doc)
-{-# INLINEABLE lookupInstanceDeclarationSubBndr #-}
 
 -- For details, see Note [Renaming children on export lists]
 lookupChildExportListSubBndr :: DeprecationWarnings
@@ -760,7 +759,6 @@ lookupChildExportListSubBndr warn_if_deprec parent rdr_name lookup_method = do
     success_found_child warn_if_deprec g = do
       addUsedGRE warn_if_deprec g
       return $ FoundChild g
-{-# INLINEABLE lookupChildExportListSubBndr #-}
 
 {- Note [Picking and disambiguating children candidates]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -781,7 +779,7 @@ parent matches can cause #25014.
     import Ambig2 (T(MkT))
 
 Even when we don't find matching parents, we need to consider matching names
-without a parent, for example for pattern synonyms bellow.
+without a parent, for example for pattern synonyms below.
 
   module M (Maybe (Empty)) where
     class Empty a where
@@ -813,16 +811,17 @@ pick_matching_gres parent rdr_name lookup_method = do
     traceTc "pick_matching_gres original_gres:" (ppr original_gres)
     return (picked_gres, original_gres)
   where
+    See Note [Renaming child GREs] for what's happening here
     pick_gres :: [GlobalRdrElt] -> DisambigInfo
     pick_gres gres
-        | length matching_parent_gres == 1 =
-          MatchingParentOccurrence (head matching_parent_gres)
+        | [gre] <- matching_parent_gres =
+          MatchingParentOccurrence gre
         | length no_parent_gres == 1 =
           NoParentOccurrence (head no_parent_gres)
         | null no_parent_gres && null matching_parent_gres =
           NoOccurrence
-        | not $ null matching_parent_gres =
-          AmbiguousOccurrence (NE.fromList matching_parent_gres)
+        | gre:gres <- matching_parent_gres =
+          AmbiguousOccurrence (gre NE.:| gres)
         | otherwise =
           -- no_parent_gres won't be empty due to the conditions above
           AmbiguousOccurrence (NE.fromList no_parent_gres)
@@ -853,7 +852,7 @@ When GHC does not find a matching name on GREs after disambiguation
 `Not in scope: ...` (NoOccurence). In some cases we can offer a better error
 by looking at the original GRE matches before disambiguation and attempt to
 surface problems that could have caused ghc to not being able to find the
-correct identifier.
+correct identifier. This is what error_no_occurrence_after_disambiguation does.
 
 1. For example where the name exists for a different parent.
 
@@ -907,10 +906,10 @@ error_incorrect_parent parent gres = return $ IncorrectParent parent (NE.head gr
 
 
 {- Note [Disambiguating GREs by parent]
-
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 Names can occur on GRE with or without Parent. When renaming an identifier
 for example the `foo` on export `A (foo)` on the export list of the program
-bellow, we have the following types of matches:
+below, we have the following types of matches:
 
   {-# LANGUAGE DuplicateRecordFields #-}
   module Matches (A (foo, Pat, bar)) where


=====================================
compiler/GHC/Tc/Gen/Export.hs
=====================================
@@ -691,7 +691,7 @@ in a children export list under a parent.
     pattern Px{x} <- Point x _
 
 
-To makes matter more complicate.
+To makes matter more complicated:
 1. Some type constructors are parsed as variables (-.->) for example.
 2. All data constructors are parsed as type constructors
 3. When there is ambiguity, we default type constructors to data
@@ -700,10 +700,12 @@ constructors.
 4. Pattern synonyms are very flexible in which parents they can be exported with
 (see [Typing Pattern Synonym Exports]).
 
-The strategy for renaming, is to first establish all the possible namespaces
-that an identifier might be in, then for each namespace in turn,
-tries to find the correct identifier there returning the
-first positive result or the first terminating error.
+We proceed in two steps:
+
+  1. We look up GREs, handling the possible NameSpaces to look up in.
+     See Note [Configurable GRE lookup priority].
+  2. We refine by using the GRE parent information.
+     See Note [Renaming child GREs].
 
 For more details see
 [Renaming the LHS on type class Instances],



View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/d6590865e8ef662c029393a9b2ab5412576877d9

-- 
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/d6590865e8ef662c029393a9b2ab5412576877d9
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