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|
module PprCmmZ
( pprCmmGraphLikeCmm
)
where
import BlockId
import Cmm
import CmmExpr
import ForeignCall
import PprCmm
import Outputable
import qualified ZipCfgCmmRep as G
import qualified ZipCfg as Z
import CmmZipUtil
import Maybe
import UniqSet
import FastString
----------------------------------------------------------------
-- | The purpose of this function is to print a Cmm zipper graph "as if it were"
-- a Cmm program. The objective is dodgy, so it's unsurprising parts of the
-- code are dodgy as well.
pprCmmGraphLikeCmm :: G.CmmGraph -> SDoc
pprCmmGraphLikeCmm g = vcat (swallow blocks)
where blocks = Z.postorder_dfs g
swallow :: [G.CmmBlock] -> [SDoc]
swallow [] = []
swallow (Z.Block id t : rest) = tail id [] Nothing t rest
tail id prev' out (Z.ZTail (G.CopyOut conv args) t) rest =
if isJust out then panic "multiple CopyOut nodes in one basic block"
else
tail id (prev') (Just (conv, args)) t rest
tail id prev' out (Z.ZTail m t) rest = tail id (mid m : prev') out t rest
tail id prev' out (Z.ZLast Z.LastExit) rest = exit id prev' out rest
tail id prev' out (Z.ZLast (Z.LastOther l)) rest = last id prev' out l rest
mid (G.CopyIn _ [] _) = text "// proc point (no parameters)"
mid m@(G.CopyIn {}) = ppr m <+> text "(proc point)"
mid m = ppr m
block' id prev'
| id == Z.lg_entry g, entry_has_no_pred =
vcat (text "<entry>" : reverse prev')
| otherwise = hang (ppr id <> colon) 4 (vcat (reverse prev'))
last id prev' out l n =
let endblock stmt = block' id (stmt : prev') : swallow n in
case l of
G.LastBranch tgt ->
case n of
Z.Block id' t : bs
| tgt == id', unique_pred id'
-> tail id prev' out t bs -- optimize out redundant labels
_ -> endblock (ppr $ CmmBranch tgt)
l@(G.LastCondBranch expr tid fid) ->
let ft id = text "// fall through to " <> ppr id in
case n of
Z.Block id' t : bs
| id' == fid, isNothing out ->
tail id (ft fid : ppr (CmmCondBranch expr tid) : prev') Nothing t bs
| id' == tid, Just e' <- maybeInvertCmmExpr expr, isNothing out->
tail id (ft tid : ppr (CmmCondBranch e' fid) : prev') Nothing t bs
_ -> endblock $ with_out out l
l@(G.LastJump {}) -> endblock $ with_out out l
l@(G.LastReturn {}) -> endblock $ with_out out l
l@(G.LastSwitch {}) -> endblock $ with_out out l
l@(G.LastCall _ Nothing) -> endblock $ with_out out l
l@(G.LastCall tgt (Just k))
| Z.Block id' (Z.ZTail (G.CopyIn _ ress srt) t) : bs <- n,
Just (conv, args) <- out,
id' == k ->
let call = CmmCall tgt' ress args (CmmSafe srt) CmmMayReturn
tgt' = CmmCallee tgt (cconv_of_conv conv)
ppcall = ppr call <+> parens (text "ret to" <+> ppr k)
in if unique_pred k then
tail id (ppcall : prev') Nothing t bs
else
endblock (ppcall)
| Z.Block id' t : bs <- n, id' == k, unique_pred k,
Just (conv, args) <- out,
Just (ress, srt) <- findCopyIn t ->
let call = CmmCall tgt' ress args (CmmSafe srt) CmmMayReturn
tgt' = CmmCallee tgt (cconv_of_conv conv)
delayed =
ptext (sLit "// delayed CopyIn follows previous call")
in tail id (delayed : ppr call : prev') Nothing t bs
| otherwise -> endblock $ with_out out l
findCopyIn (Z.ZTail (G.CopyIn _ ress srt) _) = Just (ress, srt)
findCopyIn (Z.ZTail _ t) = findCopyIn t
findCopyIn (Z.ZLast _) = Nothing
exit id prev' out n = -- highly irregular (assertion violation?)
let endblock stmt = block' id (stmt : prev') : swallow n in
case out of Nothing -> endblock (text "// <exit>")
Just (conv, args) -> endblock (ppr (G.CopyOut conv args) $$
text "// <exit>")
preds = zipPreds g
entry_has_no_pred = case lookupBlockEnv preds (Z.lg_entry g) of
Nothing -> True
Just s -> isEmptyUniqSet s
single_preds =
let add b single =
let id = Z.blockId b
in case lookupBlockEnv preds id of
Nothing -> single
Just s -> if sizeUniqSet s == 1 then
extendBlockSet single id
else single
in Z.fold_blocks add emptyBlockSet g
unique_pred id = elemBlockSet id single_preds
cconv_of_conv (G.ConventionStandard conv _) = conv
cconv_of_conv (G.ConventionPrivate {}) = CmmCallConv -- XXX totally bogus
with_out :: Maybe (G.Convention, CmmActuals) -> G.Last -> SDoc
with_out Nothing l = ptext (sLit "??no-arguments??") <+> ppr l
with_out (Just (conv, args)) l = last l
where last (G.LastCall e k) =
hcat [ptext (sLit "... = foreign "),
doubleQuotes(ppr conv), space,
ppr_target e, parens ( commafy $ map ppr args ),
ptext (sLit " \"safe\""),
case k of Nothing -> ptext (sLit " never returns")
Just _ -> empty,
semi ]
last (G.LastReturn) = ppr (CmmReturn args)
last (G.LastJump e) = ppr (CmmJump e args)
last l = ppr (G.CopyOut conv args) $$ ppr l
ppr_target (CmmLit lit) = pprLit lit
ppr_target fn' = parens (ppr fn')
commafy xs = hsep $ punctuate comma xs
|
