+addVersionInfo :: Maybe ModIface -- The old interface, read from M.hi
+ -> ModIface -- The new interface decls
+ -> (ModIface, Maybe SDoc) -- Nothing => no change; no need to write new Iface
+ -- Just mi => Here is the new interface to write
+ -- with correct version numbers
+
+-- NB: the fixities, declarations, rules are all assumed
+-- to be sorted by increasing order of hsDeclName, so that
+-- we can compare for equality
+
+addVersionInfo Nothing new_iface
+-- No old interface, so definitely write a new one!
+ = (new_iface, Just (text "No old interface available"))
+
+addVersionInfo (Just old_iface@(ModIface { mi_version = old_version,
+ mi_decls = old_decls,
+ mi_fixities = old_fixities,
+ mi_deprecs = old_deprecs }))
+ new_iface@(ModIface { mi_decls = new_decls,
+ mi_fixities = new_fixities,
+ mi_deprecs = new_deprecs })
+
+ | no_output_change && no_usage_change
+ = (new_iface, Nothing)
+ -- don't return the old iface because it may not have an
+ -- mi_globals field set to anything reasonable.
+
+ | otherwise -- Add updated version numbers
+ = --pprTrace "completeIface" (ppr (dcl_tycl old_decls))
+ (final_iface, Just pp_diffs)
+
+ where
+ final_iface = new_iface { mi_version = new_version }
+ old_mod_vers = vers_module old_version
+ new_version = VersionInfo { vers_module = bumpVersion no_output_change old_mod_vers,
+ vers_exports = bumpVersion no_export_change (vers_exports old_version),
+ vers_rules = bumpVersion no_rule_change (vers_rules old_version),
+ vers_decls = tc_vers }
+
+ no_output_change = no_tc_change && no_rule_change && no_export_change && no_deprec_change
+ no_usage_change = mi_usages old_iface == mi_usages new_iface
+
+ no_export_change = mi_exports old_iface == mi_exports new_iface -- Kept sorted
+ no_rule_change = dcl_rules old_decls == dcl_rules new_decls -- Ditto
+ no_deprec_change = old_deprecs == new_deprecs
+
+ -- Fill in the version number on the new declarations by looking at the old declarations.
+ -- Set the flag if anything changes.
+ -- Assumes that the decls are sorted by hsDeclName.
+ (no_tc_change, pp_tc_diffs, tc_vers) = diffDecls old_version old_fixities new_fixities
+ (dcl_tycl old_decls) (dcl_tycl new_decls)
+ pp_diffs = vcat [pp_tc_diffs,
+ pp_change no_export_change "Export list",
+ pp_change no_rule_change "Rules",
+ pp_change no_deprec_change "Deprecations",
+ pp_change no_usage_change "Usages"]
+ pp_change True what = empty
+ pp_change False what = text what <+> ptext SLIT("changed")
+
+diffDecls :: VersionInfo -- Old version
+ -> NameEnv Fixity -> NameEnv Fixity -- Old and new fixities
+ -> [RenamedTyClDecl] -> [RenamedTyClDecl] -- Old and new decls
+ -> (Bool, -- True <=> no change
+ SDoc, -- Record of differences
+ NameEnv Version) -- New version map
+
+diffDecls (VersionInfo { vers_module = old_mod_vers, vers_decls = old_decls_vers })
+ old_fixities new_fixities old new
+ = diff True empty emptyNameEnv old new
+ where
+ -- When seeing if two decls are the same,
+ -- remember to check whether any relevant fixity has changed
+ eq_tc d1 d2 = d1 == d2 && all (same_fixity . fst) (tyClDeclNames d1)
+ same_fixity n = lookupNameEnv old_fixities n == lookupNameEnv new_fixities n
+
+ diff ok_so_far pp new_vers [] [] = (ok_so_far, pp, new_vers)
+ diff ok_so_far pp new_vers (od:ods) [] = diff False (pp $$ only_old od) new_vers ods []
+ diff ok_so_far pp new_vers [] (nd:nds) = diff False (pp $$ only_new nd) new_vers_with_new [] nds
+ where
+ new_vers_with_new = extendNameEnv new_vers (tyClDeclName nd) (bumpVersion False old_mod_vers)
+ -- When adding a new item, start from the old module version
+ -- This way, if you have version 4 of f, then delete f, then add f again,
+ -- you'll get version 6 of f, which will (correctly) force recompilation of
+ -- clients
+
+ diff ok_so_far pp new_vers (od:ods) (nd:nds)
+ = case od_name `compare` nd_name of
+ LT -> diff False (pp $$ only_old od) new_vers ods (nd:nds)
+ GT -> diff False (pp $$ only_new nd) new_vers (od:ods) nds
+ EQ | od `eq_tc` nd -> diff ok_so_far pp new_vers ods nds
+ | otherwise -> diff False (pp $$ changed od nd) new_vers_with_diff ods nds
+ where
+ od_name = tyClDeclName od
+ nd_name = tyClDeclName nd
+ new_vers_with_diff = extendNameEnv new_vers nd_name (bumpVersion False old_version)
+ old_version = lookupVersion old_decls_vers od_name
+
+ only_old d = ptext SLIT("Only in old iface:") <+> ppr d
+ only_new d = ptext SLIT("Only in new iface:") <+> ppr d
+ changed od nd = ptext SLIT("Changed in iface: ") <+> ((ptext SLIT("Old:") <+> ppr od) $$
+ (ptext SLIT("New:") <+> ppr nd))
+\end{code}