\section[HscTypes]{Types for the per-module compiler}
\begin{code}
-module HscTypes ( TyThing(..), GlobalSymbolTable, OrigNameEnv, AvailEnv,
- WhetherHasOrphans, ImportVersion, ExportItem,
- PersistentRenamerState(..), IsBootInterface, Avails, DeclsMap,
- IfaceInsts, IfaceRules, DeprecationEnv, ModDetails(..),
- InstEnv, lookupTypeEnv )
-where
+module HscTypes (
+ ModDetails(..), GlobalSymbolTable,
+
+ TyThing(..), lookupTypeEnv,
+
+ WhetherHasOrphans, ImportVersion, ExportItem,
+ PersistentRenamerState(..), IsBootInterface, Avails, DeclsMap,
+ IfaceInsts, IfaceRules, DeprecationEnv, OrigNameEnv, AvailEnv,
+
+ InstEnv,
+
+ -- Provenance
+ Provenance(..), ImportReason(..), PrintUnqualified,
+ pprProvenance, hasBetterProv
+
+ ) where
#include "HsVersions.h"
= ModDetails {
moduleId :: Module,
moduleExports :: Avails, -- What it exports
+ mdVersion :: VersionInfo,
moduleEnv :: GlobalRdrEnv, -- Its top level environment
fixityEnv :: NameEnv Fixity,
Simple lookups in the symbol table.
\begin{code}
-lookupFixityEnv :: SymbolTable -> Name -> Fixity
+lookupFixityEnv :: SymbolTable -> Name -> Maybe Fixity
-- Returns defaultFixity if there isn't an explicit fixity
lookupFixityEnv tbl name
= case lookupModuleEnv tbl (nameModule name) of
- Nothing -> defaultFixity
- Just details -> case lookupNameEnv (fixityEnv details) name of
- Just fixity -> fixity
- Nothing -> defaultFixity
+ Nothing -> Nothing
+ Just details -> lookupNameEnv (fixityEnv details) name
\end{code}
but they are mostly elaborated elsewhere
\begin{code}
-type DeprecationEnv = NameEnv DeprecTxt -- Give reason for deprecation
+data VersionInfo
+ = VersionInfo {
+ modVers :: Version,
+ fixVers :: Version,
+ ruleVers :: Version,
+ declVers :: NameEnv Version
+ }
-type GlobalRdrEnv = RdrNameEnv [Name] -- The list is because there may be name clashes
- -- These only get reported on lookup,
- -- not on construction
+type DeprecationEnv = NameEnv DeprecTxt -- Give reason for deprecation
type InstEnv = UniqFM ClsInstEnv -- Maps Class to instances for that class
type ClsInstEnv = [(TyVarSet, [Type], DFunId)] -- The instances for a particular class
-- 'Everything' means there was a "module M" in
-- this module's export list, so we just have to go by M's version,
-- not the list of (name,version) pairs
-
\end{code}
prsInsts :: IfaceInsts,
prsRules :: IfaceRules
}
+\end{code}
+
+The OrigNameEnv makes sure that there is just one Unique assigned for
+each original name; i.e. (module-name, occ-name) pair. The Name is
+always stored as a Global, and has the SrcLoc of its binding location.
+Actually that's not quite right. When we first encounter the original
+name, we might not be at its binding site (e.g. we are reading an
+interface file); so we give it 'noSrcLoc' then. Later, when we find
+its binding site, we fix it up.
+
+Exactly the same is true of the Module stored in the Name. When we first
+encounter the occurrence, we may not know the details of the module, so
+we just store junk. Then when we find the binding site, we fix it up.
+\begin{code}
data OrigNameEnv
- = Orig { origNames :: FiniteMap (Module,OccName) Name, -- Ensures that one original name gets one unique
- origIParam :: FiniteMap OccName Name -- Ensures that one implicit parameter name gets one unique
+ = Orig { origNames :: FiniteMap (ModuleName,OccName) Name, -- Ensures that one original name gets one unique
+ origIParam :: FiniteMap OccName Name -- Ensures that one implicit parameter name gets one unique
}
+\end{code}
-type DeclsMap = NameEnv (Version, AvailInfo, Bool, (Module, RdrNameHsDecl))
- -- A DeclsMap contains a binding for each Name in the declaration
- -- including the constructors of a type decl etc.
- -- The Bool is True just for the 'main' Name.
+
+A DeclsMap contains a binding for each Name in the declaration
+including the constructors of a type decl etc. The Bool is True just
+for the 'main' Name.
+
+\begin{code}
+type DeclsMap = NameEnv (AvailInfo, Bool, (Module, RdrNameHsDecl))
type IfaceInsts = Bag GatedDecl
type IfaceRules = Bag GatedDecl
\end{code}
+%************************************************************************
+%* *
+\subsection{Provenance and export info}
+%* *
+%************************************************************************
+
+The GlobalRdrEnv gives maps RdrNames to Names. There is a separate
+one for each module, corresponding to that module's top-level scope.
+
+\begin{code}
+type GlobalRdrEnv = RdrNameEnv [(Name,Provenance)] -- The list is because there may be name clashes
+ -- These only get reported on lookup,
+ -- not on construction
+\end{code}
+
+The "provenance" of something says how it came to be in scope.
+
+\begin{code}
+data Provenance
+ = LocalDef -- Defined locally
+
+ | NonLocalDef -- Defined non-locally
+ ImportReason
+ PrintUnqualified
+
+data ImportReason
+ = UserImport Module SrcLoc Bool -- Imported from module M on line L
+ -- Note the M may well not be the defining module
+ -- for this thing!
+ -- The Bool is true iff the thing was named *explicitly* in the import spec,
+ -- rather than being imported as part of a group; e.g.
+ -- import B
+ -- import C( T(..) )
+ -- Here, everything imported by B, and the constructors of T
+ -- are not named explicitly; only T is named explicitly.
+ -- This info is used when warning of unused names.
+
+ | ImplicitImport -- Imported implicitly for some other reason
+
+
+type PrintUnqualified = Bool -- True <=> the unqualified name of this thing is
+ -- in scope in this module, so print it
+ -- unqualified in error messages
+\end{code}
+
+\begin{code}
+hasBetterProv :: Provenance -> Provenance -> Bool
+-- Choose
+-- a local thing over an imported thing
+-- a user-imported thing over a non-user-imported thing
+-- an explicitly-imported thing over an implicitly imported thing
+hasBetterProv LocalDef _ = True
+hasBetterProv (NonLocalDef (UserImport _ _ True) _) _ = True
+hasBetterProv (NonLocalDef (UserImport _ _ _ ) _) (NonLocalDef ImplicitImport _) = True
+hasBetterProv _ _ = False
+
+pprNameProvenance :: Name -> Provenance -> SDoc
+pprProvenance name LocalDef = ptext SLIT("defined at") <+> ppr (nameSrcLoc name)
+pprProvenance name (NonLocalDef why _) = sep [ppr_reason why,
+ nest 2 (parens (ppr_defn (nameSrcLoc name)))]
+
+ppr_reason ImplicitImport = ptext SLIT("implicitly imported")
+ppr_reason (UserImport mod loc _) = ptext SLIT("imported from") <+> ppr mod <+> ptext SLIT("at") <+> ppr loc
+
+ppr_defn loc | isGoodSrcLoc loc = ptext SLIT("at") <+> ppr loc
+ | otherwise = empty
+\end{code}
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