emptyAvailEnv, unitAvailEnv, availEnvElts,
plusAvailEnv, groupAvails, warnUnusedImports,
warnUnusedLocalBinds, warnUnusedModules,
- lookupSrcName, addImplicitFVs,
+ lookupSrcName, getImplicitStmtFVs, getImplicitModuleFVs, rnSyntaxNames,
newGlobalName, unQualInScope,, ubiquitousNames
)
import Module ( Module, ModuleName, WhereFrom(..),
import NameEnv
import NameSet
import RdrName ( foldRdrEnv, isQual )
-import PrelNames ( SyntaxMap, pRELUDE_Name )
+import PrelNames ( SyntaxMap, vanillaSyntaxMap, pRELUDE_Name )
import ErrUtils ( dumpIfSet, dumpIfSet_dyn, showPass,
printErrorsAndWarnings, errorsFound )
import Bag ( bagToList )
doDump [] stmt [] `thenRn_` returnRn (print_unqual, Nothing)
else
- let filtered_fvs = fvs `delListFromNameSet` rdrEnvElts local_env in
-
-- Add implicit free vars, and close decls
- addImplicitFVs rdr_env Nothing filtered_fvs
- `thenRn` \ (slurp_fvs, syntax_map) ->
- slurpImpDecls slurp_fvs `thenRn` \ decls ->
+ getImplicitStmtFVs `thenRn` \ implicit_fvs ->
+ let
+ filtered_fvs = fvs `delListFromNameSet` rdrEnvElts local_env
+ source_fvs = implicit_fvs `plusFV` filtered_fvs
+ in
+ slurpImpDecls source_fvs `thenRn` \ decls ->
doDump binders stmt decls `thenRn_`
- returnRn (print_unqual, Just (binders, (syntax_map, stmt, decls)))
+ returnRn (print_unqual, Just (binders, (vanillaSyntaxMap, stmt, decls)))
where
doc = text "context for compiling expression"
else
-- SLURP IN ALL THE NEEDED DECLARATIONS
- addImplicitFVs gbl_env (Just (mod_name, rn_local_decls))
- source_fvs `thenRn` \ (slurp_fvs, sugar_map) ->
- traceRn (text "Source FVs:" <+> fsep (map ppr (nameSetToList slurp_fvs))) `thenRn_`
- slurpImpDecls slurp_fvs `thenRn` \ rn_imp_decls ->
+ -- Find out what re-bindable names to use for desugaring
+ getImplicitModuleFVs mod_name rn_local_decls `thenRn` \ implicit_fvs ->
+ rnSyntaxNames gbl_env source_fvs `thenRn` \ (source_fvs1, sugar_map) ->
+ let
+ export_fvs = availsToNameSet export_avails
+ source_fvs2 = source_fvs1 `plusFV` export_fvs
+ -- The export_fvs make the exported names look just as if they
+ -- occurred in the source program. For the reasoning, see the
+ -- comments with RnIfaces.mkImportInfo
+ -- It also helps reportUnusedNames, which of course must not complain
+ -- that 'f' isn't mentioned if it is mentioned in the export list
+
+ source_fvs3 = implicit_fvs `plusFV` source_fvs2
+ -- It's important to do the "plus" this way round, so that
+ -- when compiling the prelude, locally-defined (), Bool, etc
+ -- override the implicit ones.
+ in
+ traceRn (text "Source FVs:" <+> fsep (map ppr (nameSetToList source_fvs3))) `thenRn_`
+ slurpImpDecls source_fvs3 `thenRn` \ rn_imp_decls ->
rnDump rn_imp_decls rn_local_decls `thenRn_`
-- GENERATE THE VERSION/USAGE INFO
- mkImportInfo mod_name imports `thenRn` \ my_usages ->
+ mkImportInfo mod_name imports `thenRn` \ my_usages ->
-- BUILD THE MODULE INTERFACE
let
-- REPORT UNUSED NAMES, AND DEBUG DUMP
reportUnusedNames mod_iface print_unqualified
imports global_avail_env
- source_fvs export_avails rn_imp_decls `thenRn_`
+ source_fvs2 rn_imp_decls `thenRn_`
+ -- NB: source_fvs2: include exports (else we get bogus
+ -- warnings of unused things) but not implicit FVs.
returnRn (print_unqualified, Just (is_exported, mod_iface, (sugar_map, final_decls)))
where
-> [RdrNameImportDecl]
-> AvailEnv
-> NameSet -- Used in this module
- -> Avails -- Exported by this module
-> [RenamedHsDecl]
-> RnMG ()
reportUnusedNames my_mod_iface unqual imports avail_env
- source_fvs export_avails imported_decls
+ used_names imported_decls
= warnUnusedModules unused_imp_mods `thenRn_`
warnUnusedLocalBinds bad_locals `thenRn_`
warnUnusedImports bad_imp_names `thenRn_`
this_mod = mi_module my_mod_iface
gbl_env = mi_globals my_mod_iface
- -- The export_fvs make the exported names look just as if they
- -- occurred in the source program.
- export_fvs = availsToNameSet export_avails
- used_names = source_fvs `plusFV` export_fvs
-
-- Now, a use of C implies a use of T,
-- if C was brought into scope by T(..) or T(C)
really_used_names = used_names `unionNameSets`
import HscTypes ( ModIface(..) )
import HsSyn
-import RnHsSyn ( RenamedHsDecl )
import RdrHsSyn ( RdrNameIE )
import RdrName ( RdrName, rdrNameModule, rdrNameOcc, isQual, isUnqual, isOrig,
mkRdrUnqual, mkRdrQual, qualifyRdrName, lookupRdrEnv, foldRdrEnv
%* *
%*********************************************************
-@addImplicitFVs@ forces the renamer to slurp in some things which aren't
+@getXImplicitFVs@ forces the renamer to slurp in some things which aren't
mentioned explicitly, but which might be needed by the type checker.
\begin{code}
-addImplicitFVs :: GlobalRdrEnv
- -> Maybe (ModuleName, [RenamedHsDecl]) -- Nothing when compling an expression
- -> FreeVars -- Free in the source
- -> RnMG (FreeVars, SyntaxMap) -- Augmented source free vars
-
-addImplicitFVs gbl_env maybe_mod source_fvs
- = -- Find out what re-bindable names to use for desugaring
- rnSyntaxNames gbl_env source_fvs `thenRn` \ (source_fvs1, sugar_map) ->
-
- -- Find implicit FVs thade
- extra_implicits maybe_mod `thenRn` \ extra_fvs ->
-
- let
- implicit_fvs = ubiquitousNames `plusFV` extra_fvs
- slurp_fvs = implicit_fvs `plusFV` source_fvs1
- -- It's important to do the "plus" this way round, so that
- -- when compiling the prelude, locally-defined (), Bool, etc
- -- override the implicit ones.
- in
- returnRn (slurp_fvs, sugar_map)
-
- where
- extra_implicits Nothing -- Compiling a statement
- = returnRn (mkFVs [printName, bindIOName, returnIOName, failIOName])
+getImplicitStmtFVs -- Compiling a statement
+ = returnRn (mkFVs [printName, bindIOName, returnIOName, failIOName]
+ `plusFV` ubiquitousNames)
-- These are all needed implicitly when compiling a statement
-- See TcModule.tc_stmts
- extra_implicits (Just (mod_name, decls)) -- Compiling a module
- = lookupOrigNames deriv_occs `thenRn` \ deriving_names ->
- returnRn (deriving_names `plusFV` implicit_main)
- where
+getImplicitModuleFVs mod_name decls -- Compiling a module
+ = lookupOrigNames deriv_occs `thenRn` \ deriving_names ->
+ returnRn (deriving_names `plusFV` implicit_main `plusFV` ubiquitousNames)
+ where
-- Add occurrences for IO or PrimIO
implicit_main | mod_name == mAIN_Name
|| mod_name == pREL_MAIN_Name = unitFV ioTyConName
%* *
%*********************************************************
-mkImportInof figures out what the ``usage information'' for this
+mkImportInfo figures out what the ``usage information'' for this
moudule is; that is, what it must record in its interface file as the
things it uses.
We produce a line for every module B below the module, A, currently being
compiled:
import B <n> ;
-to record the fact that A does import B indireclty. This is used to decide
+to record the fact that A does import B indirectly. This is used to decide
to look to look for B.hi rather than B.hi-boot when compiling a module that
imports A. This line says that A imports B, but uses nothing in it.
So we'll get an early bale-out when compiling A if B's version changes.
+The usage information records:
+
+\begin{itemize}
+\item (a) anything reachable from its body code
+\item (b) any module exported with a @module Foo@
+\item (c) anything reachable from an exported item
+\end{itemize}
+
+Why (b)? Because if @Foo@ changes then this module's export list
+will change, so we must recompile this module at least as far as
+making a new interface file --- but in practice that means complete
+recompilation.
+
+Why (c)? Consider this:
+\begin{verbatim}
+ module A( f, g ) where | module B( f ) where
+ import B( f ) | f = h 3
+ g = ... | h = ...
+\end{verbatim}
+
+Here, @B.f@ isn't used in A. Should we nevertheless record @B.f@ in
+@A@'s usages? Our idea is that we aren't going to touch A.hi if it is
+*identical* to what it was before. If anything about @B.f@ changes
+than anyone who imports @A@ should be recompiled in case they use
+@B.f@ (they'll get an early exit if they don't). So, if anything
+about @B.f@ changes we'd better make sure that something in A.hi
+changes, and the convenient way to do that is to record the version
+number @B.f@ in A.hi in the usage list. If B.f changes that'll force a
+complete recompiation of A, which is overkill but it's the only way to
+write a new, slightly different, A.hi.
+
+But the example is tricker. Even if @B.f@ doesn't change at all,
+@B.h@ may do so, and this change may not be reflected in @f@'s version
+number. But with -O, a module that imports A must be recompiled if
+@B.h@ changes! So A must record a dependency on @B.h@. So we treat
+the occurrence of @B.f@ in the export list *just as if* it were in the
+code of A, and thereby haul in all the stuff reachable from it.
+
+ *** Conclusion: if A mentions B.f in its export list,
+ behave just as if A mentioned B.f in its source code,
+ and slurp in B.f and all its transitive closure ***
+
+[NB: If B was compiled with -O, but A isn't, we should really *still*
+haul in all the unfoldings for B, in case the module that imports A *is*
+compiled with -O. I think this is the case.]
+
\begin{code}
mkImportInfo :: ModuleName -- Name of this module
-> [ImportDecl n] -- The import decls
import_info0 = foldModuleEnv mk_imp_info [] pit
import_info1 = foldModuleEnv mk_imp_info import_info0 hit
- import_info = [ (mod_name, orphans, is_boot, NothingAtAll)
- | (mod_name, (orphans, is_boot)) <- fmToList (iImpModInfo ifaces) ] ++
- import_info1
+ import_info = not_even_opened_imports ++ import_info1
+
+ -- Recall that iImpModInfo describes modules that have been mentioned
+ -- in the import lists of interfaces we have opened, but which we have
+ -- not even opened when compiling this module
+ not_even_opened_imports = [ (mod_name, orphans, is_boot, NothingAtAll)
+ | (mod_name, (orphans, is_boot)) <- fmToList (iImpModInfo ifaces) ]
+
mk_imp_info :: ModIface -> [ImportVersion Name] -> [ImportVersion Name]
mk_imp_info iface so_far
| import_all_mod -- Case (a) and (b); the import-all part
= if is_home_pkg_mod then
go_for_it (Specifically mod_vers (Just export_vers) [] rules_vers)
+ -- Since the module isn't in the mv_map, presumably we
+ -- didn't actually import anything at all from it
else
go_for_it (Everything mod_vers)
projects / ghc-hetmet.git / commitdiff