Make GHCi & TH work when the compiler is built with -prof

Summary:
Amazingly, there were zero changes to the byte code generator and very
few changes to the interpreter - mainly because we've used good
abstractions that hide the differences between profiling and
non-profiling.  So that bit was pleasantly straightforward, but there
were a pile of other wibbles to get the whole test suite through.

Note that a compiler built with -prof is now like one built with
-dynamic, in that to use TH you have to build the code the same way.
For dynamic, we automatically enable -dynamic-too when TH is required,
but we don't have anything equivalent for profiling, so you have to
explicitly use -prof when building code that uses TH with a profiled
compiler.  For this reason Cabal won't work with TH.  We don't expect
to ship a profiled compiler, so I think that's OK.

Test Plan: validate with GhcProfiled=YES in validate.mk

Reviewers: goldfire, bgamari, rwbarton, austin, hvr, erikd, ezyang

Reviewed By: ezyang

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D1407

GHC Trac Issues: #4837, #545

1 files changed, 7 insertions, 6 deletions

diff --git a/compiler/codeGen/StgCmmProf.hs b/compiler/codeGen/StgCmmProf.hs
index a7384c725b..efad805120 100644
--- a/compiler/codeGen/StgCmmProf.hs
+++ b/compiler/codeGen/StgCmmProf.hs
@@ -321,14 +321,15 @@ dynLdvInit dflags =     -- (era << LDV_SHIFT) | LDV_STATE_CREATE
 -- Initialise the LDV word of a new closure
 --
 ldvRecordCreate :: CmmExpr -> FCode ()
-ldvRecordCreate closure = do dflags <- getDynFlags
-                             emit $ mkStore (ldvWord dflags closure) (dynLdvInit dflags)
+ldvRecordCreate closure = do
+  dflags <- getDynFlags
+  emit $ mkStore (ldvWord dflags closure) (dynLdvInit dflags)
 
 --
--- Called when a closure is entered, marks the closure as having been "used".
--- The closure is not an 'inherently used' one.
--- The closure is not IND or IND_OLDGEN because neither is considered for LDV
--- profiling.
+-- | Called when a closure is entered, marks the closure as having
+-- been "used".  The closure is not an "inherently used" one.  The
+-- closure is not @IND@ or @IND_OLDGEN@ because neither is considered
+-- for LDV profiling.
 --
 ldvEnterClosure :: ClosureInfo -> CmmReg -> FCode ()
 ldvEnterClosure closure_info node_reg = do