profiling: Look in RHS of rules for cost centre tickswip/t19894

There are some obscure situations where the RHS of a rule can contain a
tick which is not mentioned anywhere else in the program. If this
happens you end up with an obscure linker error. The solution is quite
simple, traverse the RHS of rules to also look for ticks. It turned out
to be easier to implement if the traversal was moved into CoreTidy
rather than at the start of code generation because there we still had
easy access to the rules.

./StreamD.o(.text+0x1b9f2): error: undefined reference to 'StreamK_mkStreamFromStream_HPC_cc'
./MArray.o(.text+0xbe83): error: undefined reference to 'StreamK_mkStreamFromStream_HPC_cc'
Main.o(.text+0x6fdb): error: undefined reference to 'StreamK_mkStreamFromStream_HPC_cc'

1 files changed, 5 insertions, 4 deletions

diff --git a/compiler/GHC/Driver/Main.hs b/compiler/GHC/Driver/Main.hs
index 3c6bacdf6a..d49a2eb87c 100644
--- a/compiler/GHC/Driver/Main.hs
+++ b/compiler/GHC/Driver/Main.hs
@@ -1567,6 +1567,7 @@ hscGenHardCode hsc_env cgguts location output_filename = do
                     -- From now on, we just use the bits we need.
                     cg_module   = this_mod,
                     cg_binds    = core_binds,
+                    cg_ccs      = local_ccs,
                     cg_tycons   = tycons,
                     cg_foreign  = foreign_stubs0,
                     cg_foreign_files = foreign_files,
@@ -1583,7 +1584,7 @@ hscGenHardCode hsc_env cgguts location output_filename = do
         -------------------
         -- PREPARE FOR CODE GENERATION
         -- Do saturation and convert to A-normal form
-        (prepd_binds, local_ccs) <- {-# SCC "CorePrep" #-}
+        (prepd_binds) <- {-# SCC "CorePrep" #-}
                        corePrepPgm hsc_env this_mod location
                                    core_binds data_tycons
 
@@ -1596,7 +1597,7 @@ hscGenHardCode hsc_env cgguts location output_filename = do
                    (myCoreToStg logger dflags (hsc_IC hsc_env) this_mod location prepd_binds)
 
         let cost_centre_info =
-              (S.toList local_ccs ++ caf_ccs, caf_cc_stacks)
+              (local_ccs ++ caf_ccs, caf_cc_stacks)
             platform = targetPlatform dflags
             prof_init
               | sccProfilingEnabled dflags = profilingInitCode platform this_mod cost_centre_info
@@ -1662,7 +1663,7 @@ hscInteractive hsc_env cgguts location = do
     -------------------
     -- PREPARE FOR CODE GENERATION
     -- Do saturation and convert to A-normal form
-    (prepd_binds, _) <- {-# SCC "CorePrep" #-}
+    prepd_binds <- {-# SCC "CorePrep" #-}
                    corePrepPgm hsc_env this_mod location core_binds data_tycons
 
     (stg_binds, _infotable_prov, _caf_ccs__caf_cc_stacks)
@@ -1978,7 +1979,7 @@ hscParsedDecls hsc_env decls = runInteractiveHsc hsc_env $ do
 
     {- Prepare For Code Generation -}
     -- Do saturation and convert to A-normal form
-    (prepd_binds, _) <- {-# SCC "CorePrep" #-}
+    prepd_binds <- {-# SCC "CorePrep" #-}
       liftIO $ corePrepPgm hsc_env this_mod iNTERACTIVELoc core_binds data_tycons
 
     (stg_binds, _infotable_prov, _caf_ccs__caf_cc_stacks)