X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FbasicTypes%2FBasicTypes.lhs;h=82a446bbade39d4a92a96ec166644c998174e586;hb=fda89b29c748c6cd2fe1fdb477d5c0e8f7d32b90;hp=d19f0bd9a01deb3722eb33175a9c3159be7323db;hpb=5f34bb74bf3c7e051bce8ad343ac4bbbc11f62cd;p=ghc-hetmet.git

diff --git a/ghc/compiler/basicTypes/BasicTypes.lhs b/ghc/compiler/basicTypes/BasicTypes.lhs
index d19f0bd..82a446b 100644
--- a/ghc/compiler/basicTypes/BasicTypes.lhs
+++ b/ghc/compiler/basicTypes/BasicTypes.lhs
@@ -19,7 +19,7 @@ module BasicTypes(
 	SYN_IE(Version), SYN_IE(Arity),
 	SYN_IE(Module), moduleString, pprModule,
 	Fixity(..), FixityDirection(..),
-	NewOrData(..)
+	NewOrData(..), IfaceFlavour(..)
    ) where
 
 IMP_Ubiq()
@@ -67,6 +67,38 @@ pprModule :: PprStyle -> Module -> Doc
 pprModule sty m = ptext m
 \end{code}
 
+%************************************************************************
+%*									*
+\subsection[IfaceFlavour]{IfaceFlavour}
+%*									*
+%************************************************************************
+
+The IfaceFlavour type is used mainly in an imported Name's Provenance
+to say whether the name comes from a regular .hi file, or whether it comes
+from a hand-written .hi-boot file.  This is important, because it has to be 
+propagated.  Suppose
+
+	C.hs imports B
+	B.hs imports A
+	A.hs imports C {-# SOURCE -#} ( f )
+
+Then in A.hi we may mention C.f, in an inlining.  When compiling B we *must not* 
+read C.f's details from C.hi, even if the latter happens to exist from an earlier
+compilation run.  So we use the name "C!f" in A.hi, and when looking for an interface
+file with details of C!f we look in C.hi-boot.  The "!" stuff is recorded in the
+IfaceFlavour in the Name of C.f in A. 
+
+Not particularly beautiful, but it works.
+
+\begin{code}
+data IfaceFlavour = HiFile		-- The interface was read from a standard interface file
+		  | HiBootFile		-- ... or from a handwritten "hi-boot" interface file
+
+instance Text IfaceFlavour where	-- Just used in debug prints of lex tokens
+  showsPrec n HiFile     s = s
+  showsPrec n HiBootFile s = "!" ++ s
+\end{code}
+
 
 %************************************************************************
 %*									*