Rip out object splitting

The splitter is an evil Perl script that processes assembler code.
Its job can be done better by the linker's --gc-sections flag. GHC
passes this flag to the linker whenever -split-sections is passed on
the command line.

This is based on @DemiMarie's D2768.

Fixes Trac #11315
Fixes Trac #9832
Fixes Trac #8964
Fixes Trac #8685
Fixes Trac #8629

1 files changed, 7 insertions, 25 deletions

diff --git a/compiler/nativeGen/AsmCodeGen.hs b/compiler/nativeGen/AsmCodeGen.hs
index 4672415ec5..b866741995 100644
--- a/compiler/nativeGen/AsmCodeGen.hs
+++ b/compiler/nativeGen/AsmCodeGen.hs
@@ -335,7 +335,7 @@ finishNativeGen :: Instruction instr
 finishNativeGen dflags modLoc bufh@(BufHandle _ _ h) us ngs
  = do
         -- Write debug data and finish
-        let emitDw = debugLevel dflags > 0 && not (gopt Opt_SplitObjs dflags)
+        let emitDw = debugLevel dflags > 0
         us' <- if not emitDw then return us else do
           (dwarf, us') <- dwarfGen dflags modLoc us (ngs_debug ngs)
           emitNativeCode dflags bufh dwarf
@@ -406,14 +406,9 @@ cmmNativeGenStream dflags this_mod modLoc ncgImpl h us cmm_stream ngs
                      | otherwise = []
               dbgMap = debugToMap ndbgs
 
-          -- Insert split marker, generate native code
-          let splitObjs = gopt Opt_SplitObjs dflags
-              split_marker = CmmProc mapEmpty mkSplitMarkerLabel [] $
-                             ofBlockList (panic "split_marker_entry") []
-              cmms' | splitObjs  = split_marker : cmms
-                    | otherwise  = cmms
+          -- Generate native code
           (ngs',us') <- cmmNativeGens dflags this_mod modLoc ncgImpl h
-                                             dbgMap us cmms' ngs 0
+                                             dbgMap us cmms ngs 0
 
           -- Link native code information into debug blocks
           -- See Note [What is this unwinding business?] in Debug.
@@ -421,23 +416,10 @@ cmmNativeGenStream dflags this_mod modLoc ncgImpl h us cmm_stream ngs
           dumpIfSet_dyn dflags Opt_D_dump_debug "Debug Infos"
             (vcat $ map ppr ldbgs)
 
-          -- Emit & clear DWARF information when generating split
-          -- object files, as we need it to land in the same object file
-          -- When using split sections, note that we do not split the debug
-          -- info but emit all the info at once in finishNativeGen.
-          (ngs'', us'') <-
-            if debugFlag && splitObjs
-            then do (dwarf, us'') <- dwarfGen dflags modLoc us ldbgs
-                    emitNativeCode dflags h dwarf
-                    return (ngs' { ngs_debug = []
-                                 , ngs_dwarfFiles = emptyUFM
-                                 , ngs_labels = [] },
-                            us'')
-            else return (ngs' { ngs_debug  = ngs_debug ngs' ++ ldbgs
-                              , ngs_labels = [] },
-                         us')
-
-          cmmNativeGenStream dflags this_mod modLoc ncgImpl h us''
+          -- Accumulate debug information for emission in finishNativeGen.
+          let ngs'' = ngs' { ngs_debug = ngs_debug ngs' ++ ldbgs, ngs_labels = [] }
+
+          cmmNativeGenStream dflags this_mod modLoc ncgImpl h us'
               cmm_stream' ngs''
 
 -- | Do native code generation on all these cmms.