[project @ 2005-05-02 13:08:38 by simonpj]

In the :i command for ghci, load the interface files for
the home module of every in-scope type or class. That way
we are sure to see all their instance declarations.

	MERGE TO STABLE branch

diff --git a/ghc/compiler/iface/LoadIface.lhs b/ghc/compiler/iface/LoadIface.lhs
index 15217b8..70e09c9 100644 (file)
--- a/ghc/compiler/iface/LoadIface.lhs
+++ b/ghc/compiler/iface/LoadIface.lhs
@@ -5,8 +5,8 @@
 
 \begin{code}
 module LoadIface (
-       loadHomeInterface, loadInterface, loadWiredInHomeIface, 
-       loadSrcInterface, loadOrphanModules, 
+       loadInterface, loadHomeInterface, loadWiredInHomeIface, 
+       loadSrcInterface, loadSysInterface, loadOrphanModules, 
        findAndReadIface, readIface,    -- Used when reading the module's old interface
        loadDecls, ifaceStats, discardDeclPrags,
        initExternalPackageState

diff --git a/ghc/compiler/typecheck/TcRnDriver.lhs b/ghc/compiler/typecheck/TcRnDriver.lhs
index 44964ec..09ac7b4 100644 (file)
--- a/ghc/compiler/typecheck/TcRnDriver.lhs
+++ b/ghc/compiler/typecheck/TcRnDriver.lhs
@@ -87,8 +87,8 @@ import HsSyn          ( HsStmtContext(..), Stmt(..), HsExpr(..), HsBindGroup(..),
                          collectLStmtsBinders, mkSimpleMatch, nlVarPat,
                          placeHolderType, noSyntaxExpr )
 import RdrName         ( GlobalRdrEnv, mkGlobalRdrEnv, GlobalRdrElt(..),
-                         Provenance(..), ImportSpec(..),
-                         lookupLocalRdrEnv, extendLocalRdrEnv )
+                         Provenance(..), ImportSpec(..), globalRdrEnvElts,
+                         unQualOK, lookupLocalRdrEnv, extendLocalRdrEnv )
 import RnSource                ( addTcgDUs )
 import TcHsSyn         ( mkHsLet, zonkTopLExpr, zonkTopBndrs )
 import TcHsType                ( kcHsType )
@@ -102,16 +102,16 @@ import RnTypes            ( rnLHsType )
 import Inst            ( tcGetInstEnvs )
 import InstEnv         ( classInstances, instEnvElts )
 import RnExpr          ( rnStmts, rnLExpr )
-import LoadIface       ( loadSrcInterface )
+import LoadIface       ( loadSrcInterface, loadSysInterface )
 import IfaceSyn                ( IfaceDecl(..), IfaceClassOp(..), IfaceConDecl(..), 
                          IfaceExtName(..), IfaceConDecls(..), 
                          tyThingToIfaceDecl )
 import IfaceType       ( IfaceType, toIfaceType, 
                          interactiveExtNameFun )
 import IfaceEnv                ( lookupOrig, ifaceExportNames )
-import Module          ( lookupModuleEnv )
+import Module          ( lookupModuleEnv, moduleSetElts, mkModuleSet )
 import RnEnv           ( lookupOccRn, dataTcOccs, lookupFixityRn )
-import Id              ( isImplicitId, setIdType, globalIdDetails, mkExportedLocalId )
+import Id              ( isImplicitId, setIdType, globalIdDetails )
 import MkId            ( unsafeCoerceId )
 import DataCon         ( dataConTyCon )
 import TyCon           ( tyConName )
@@ -121,7 +121,7 @@ import SrcLoc               ( interactiveSrcLoc, unLoc )
 import Kind            ( Kind )
 import Var             ( globaliseId )
 import Name            ( nameOccName, nameModule )
-import OccName         ( occNameUserString )
+import OccName         ( occNameUserString, isTcOcc )
 import NameEnv         ( delListFromNameEnv )
 import PrelNames       ( iNTERACTIVE, ioTyConName, printName, itName, 
                          bindIOName, thenIOName, returnIOName )
@@ -1228,6 +1228,12 @@ tcRnGetInfo hsc_env ictxt rdr_name
   = initTcPrintErrors hsc_env iNTERACTIVE $ 
     setInteractiveContext hsc_env ictxt $ do {
 
+       -- Load the interface for all unqualified types and classes
+       -- That way we will find all the instance declarations
+       -- (Packages have not orphan modules, and we assume that
+       --  in the home package all relevant modules are loaded.)
+    loadUnqualIfaces ictxt ;
+
     good_names <- lookup_rdr_name rdr_name ;
 
        -- And lookup up the entities, avoiding duplicates, which arise
@@ -1301,6 +1307,21 @@ toIfaceDecl ext_nm thing
                        ClassOpId cls      -> AClass cls
                        other              -> AnId id
     munge other_thing = other_thing
+
+loadUnqualIfaces :: InteractiveContext -> TcM ()
+-- Load the home module for everything that is in scope unqualified
+-- This is so that we can accurately report the instances for 
+-- something
+loadUnqualIfaces ictxt
+  = initIfaceTcRn $
+    mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
+  where
+    unqual_mods = [ nameModule name
+                 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
+                   let name = gre_name gre,
+                   isTcOcc (nameOccName name),  -- Types and classes only
+                   unQualOK gre ]               -- In scope unqualified
+    doc = ptext SLIT("Need interface for module whose export(s) are in scope unqualified")
 #endif /* GHCI */
 \end{code}