Commit 3c452d0d authored by Zejun Wu's avatar Zejun Wu Committed by Ben Gamari

Fix rare undefined asm temp end label error in x86

Summary:
Encountered assembly error due to undefined label `.LcaDcU_info_end` for
following code generated by `pprFrameProc`:

```
.Lsat_sa8fp{v}_info_fde_end:
  .long .Lblock{v caDcU}_info_fde_end-.Lblock{v caDcU}_info_fde
.Lblock{v caDcU}_info_fde:
  .long _nbHlD-.Lsection_frame
  .quad block{v caDcU}_info-1
  .quad .Lblock{v caDcU}_info_end-block{v caDcU}_info+1
  .byte 1
```

This diff fixed the error.

Test Plan:
  ./validate

Also the case where we used to have assembly error is now fixed.
Unfortunately, I have limited insight here and cannot get a small enough repro
or test case for this.

Ben says:

> I think I see: Previously we only produced end symbols for the info
> tables of top-level procedures. However, blocks within a procedure may
> also have info tables, we will dutifully generate debug information for
> and consequently we get undefined symbols.

Reviewers: simonmar, scpmw, last_g, bgamari

Reviewed By: bgamari

Subscribers: rwbarton, carter

Differential Revision: https://phabricator.haskell.org/D5246
parent d8495549
......@@ -115,8 +115,6 @@ pprNatCmmDecl proc@(CmmProc top_info lbl _ (ListGraph blocks)) =
<+> char '-'
<+> ppr (mkDeadStripPreventer info_lbl)
else empty) $$
(if debugLevel dflags > 0
then ppr (mkAsmTempEndLabel info_lbl) <> char ':' else empty) $$
pprSizeDecl info_lbl
-- | Output the ELF .size directive.
......@@ -130,20 +128,23 @@ pprSizeDecl lbl
pprBasicBlock :: LabelMap CmmStatics -> NatBasicBlock Instr -> SDoc
pprBasicBlock info_env (BasicBlock blockid instrs)
= sdocWithDynFlags $ \dflags ->
maybe_infotable $$
maybe_infotable dflags $
pprLabel asmLbl $$
vcat (map pprInstr instrs) $$
(if debugLevel dflags > 0
then ppr (mkAsmTempEndLabel asmLbl) <> char ':' else empty)
where
asmLbl = blockLbl blockid
maybe_infotable = case mapLookup blockid info_env of
Nothing -> empty
Just (Statics info_lbl info) ->
maybe_infotable dflags c = case mapLookup blockid info_env of
Nothing -> c
Just (Statics infoLbl info) ->
pprAlignForSection Text $$
infoTableLoc $$
vcat (map pprData info) $$
pprLabel info_lbl
pprLabel infoLbl $$
c $$
(if debugLevel dflags > 0
then ppr (mkAsmTempEndLabel infoLbl) <> char ':' else empty)
-- Make sure the info table has the right .loc for the block
-- coming right after it. See [Note: Info Offset]
infoTableLoc = case instrs of
......
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