11 import qualified ZipCfgCmmRep as G
12 import qualified ZipCfg as Z
18 ----------------------------------------------------------------
19 -- | The purpose of this function is to print a Cmm zipper graph "as if it were"
20 -- a Cmm program. The objective is dodgy, so it's unsurprising parts of the
21 -- code are dodgy as well.
23 pprCmmGraphLikeCmm :: G.CmmGraph -> SDoc
24 pprCmmGraphLikeCmm g = vcat (swallow blocks)
25 where blocks = Z.postorder_dfs g
26 swallow :: [G.CmmBlock] -> [SDoc]
28 swallow (Z.Block id t : rest) = tail id [] Nothing t rest
29 tail id prev' out (Z.ZTail m t) rest = tail id (mid m : prev') out t rest
30 tail id prev' out (Z.ZLast (Z.LastOther l)) rest = last id prev' out l rest
31 tail id prev' _ (Z.ZLast Z.LastExit) rest = exit id prev' rest
34 | id == Z.lg_entry g, entry_has_no_pred =
35 vcat (text "<entry>" : reverse prev')
36 | otherwise = hang (ppr id <> colon) 4 (vcat (reverse prev'))
37 last id prev' out l n =
38 let endblock stmt = block' id (stmt : prev') : swallow n in
43 | tgt == id', unique_pred id'
44 -> tail id prev' out t bs -- optimize out redundant labels
45 _ -> endblock (ppr $ CmmBranch tgt)
46 l@(G.LastCondBranch expr tid fid) ->
47 let ft id = text "// fall through to " <> ppr id in
50 | id' == fid, isNothing out ->
51 tail id (ft fid : ppr (CmmCondBranch expr tid) : prev') Nothing t bs
52 | id' == tid, Just e' <- maybeInvertCmmExpr expr, isNothing out->
53 tail id (ft tid : ppr (CmmCondBranch e' fid) : prev') Nothing t bs
54 _ -> endblock $ with_out out l
55 l@(G.LastSwitch {}) -> endblock $ with_out out l
56 l@(G.LastCall _ _ _ _ _) -> endblock $ with_out out l
57 exit id prev' n = -- highly irregular (assertion violation?)
58 let endblock stmt = block' id (stmt : prev') : swallow n in
59 endblock (text "// <exit>")
61 entry_has_no_pred = case lookupBlockEnv preds (Z.lg_entry g) of
63 Just s -> isEmptyBlockSet s
67 in case lookupBlockEnv preds id of
69 Just s -> if sizeBlockSet s == 1 then
70 extendBlockSet single id
72 in Z.fold_blocks add emptyBlockSet g
73 unique_pred id = elemBlockSet id single_preds
75 with_out :: Maybe (G.Convention, CmmActuals) -> G.Last -> SDoc
76 with_out Nothing l = ptext (sLit "??no-arguments??") <+> ppr l
77 with_out (Just (conv, args)) l = last l
78 where last (G.LastCall e k _ _ _) =
79 hcat [ptext (sLit "... = foreign "),
80 doubleQuotes(ppr conv), space,
81 ppr_target e, parens ( commafy $ map ppr args ),
82 ptext (sLit " \"safe\""),
83 text " returns to " <+> ppr k,
86 ppr_target (CmmLit lit) = pprLit lit
87 ppr_target fn' = parens (ppr fn')
88 commafy xs = hsep $ punctuate comma xs