Remote GHCi, -fexternal-interpreter

Summary:
(Apologies for the size of this patch, I couldn't make a smaller one
that was validate-clean and also made sense independently)

(Some of this code is derived from GHCJS.)

This commit adds support for running interpreted code (for GHCi and
TemplateHaskell) in a separate process.  The functionality is
experimental, so for now it is off by default and enabled by the flag
-fexternal-interpreter.

Reaosns we want this:

* compiling Template Haskell code with -prof does not require
  building the code without -prof first

* when GHC itself is profiled, it can interpret unprofiled code, and
  the same applies to dynamic linking.  We would no longer need to
  force -dynamic-too with TemplateHaskell, and we can load ordinary
  objects into a dynamically-linked GHCi (and vice versa).

* An unprofiled GHCi can load and run profiled code, which means it
  can use the stack-trace functionality provided by profiling without
  taking the performance hit on the compiler that profiling would
  entail.

Amongst other things; see
https://ghc.haskell.org/trac/ghc/wiki/RemoteGHCi for more details.

Notes on the implementation are in Note [Remote GHCi] in the new
module compiler/ghci/GHCi.hs.  It probably needs more documenting,
feel free to suggest things I could elaborate on.

Things that are not currently implemented for -fexternal-interpreter:

* The GHCi debugger
* :set prog, :set args in GHCi
* `recover` in Template Haskell
* Redirecting stdin/stdout for the external process

These are all doable, I just wanted to get to a working validate-clean
patch first.

I also haven't done any benchmarking yet.  I expect there to be slight hit
to link times for byte code and some penalty due to having to
serialize/deserialize TH syntax, but I don't expect it to be a serious
problem.  There's also lots of low-hanging fruit in the byte code
generator/linker that we could exploit to speed things up.

Test Plan:
* validate
* I've run parts of the test suite with
EXTRA_HC_OPTS=-fexternal-interpreter, notably tests/ghci and tests/th.
There are a few failures due to the things not currently implemented
(see above).

Reviewers: simonpj, goldfire, ezyang, austin, alanz, hvr, niteria, bgamari, gibiansky, luite

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D1562

25 files changed, 136 insertions, 50 deletions

diff --git a/testsuite/tests/annotations/should_run/annrun01.hs b/testsuite/tests/annotations/should_run/annrun01.hs
index 6fd07252cc..0dbd44dd92 100644
--- a/testsuite/tests/annotations/should_run/annrun01.hs
+++ b/testsuite/tests/annotations/should_run/annrun01.hs
@@ -6,7 +6,7 @@ import GHC
 import MonadUtils  ( liftIO )
 import DynFlags    ( defaultFatalMessager, defaultFlushOut )
 import Annotations ( AnnTarget(..), CoreAnnTarget )
-import Serialized  ( deserializeWithData )
+import GHC.Serialized  ( deserializeWithData )
 import Panic
 
 import Config
diff --git a/testsuite/tests/cabal/cabal04/Makefile b/testsuite/tests/cabal/cabal04/Makefile
index 9aaa25f404..6c43dde45d 100644
--- a/testsuite/tests/cabal/cabal04/Makefile
+++ b/testsuite/tests/cabal/cabal04/Makefile
@@ -14,7 +14,7 @@ cabal04:
 	$(MAKE) clean
 	'$(TEST_HC)' -v0 --make Setup
 	$(SETUP) clean
-	$(SETUP) configure --with-ghc='$(TEST_HC)' --ghc-options='$(filter-out -rtsopts,$(TEST_HC_OPTS))' $(VANILLA) $(PROF) $(DYN) --ghc-options='$(ghcThWayFlags)'
+	$(SETUP) configure --with-ghc='$(TEST_HC)' --ghc-options='$(filter-out -rtsopts,$(TEST_HC_OPTS))' $(VANILLA) $(PROF) $(DYN)
 	$(SETUP) build 2> err
 	! grep -v "Creating library file" err
 ifneq "$(CLEANUP)" ""
@@ -23,4 +23,3 @@ endif
 
 clean :
 	$(RM) -r *.o *.hi dist Setup$(exeext) err
-
diff --git a/testsuite/tests/cabal/cabal04/all.T b/testsuite/tests/cabal/cabal04/all.T
index 53d90145ce..b2794a5e10 100644
--- a/testsuite/tests/cabal/cabal04/all.T
+++ b/testsuite/tests/cabal/cabal04/all.T
@@ -20,5 +20,5 @@ else:
 
 test('cabal04',
      normal,
-     run_command, 
+     run_command,
      ['$MAKE -s --no-print-directory cabal04 VANILLA=' + vanilla + ' PROF=' + prof + ' DYN=' + dyn + ' ' + cleanup])
diff --git a/testsuite/tests/ghc-api/T4891/T4891.hs b/testsuite/tests/ghc-api/T4891/T4891.hs
index 854bf62998..b2f8cc464d 100644
--- a/testsuite/tests/ghc-api/T4891/T4891.hs
+++ b/testsuite/tests/ghc-api/T4891/T4891.hs
@@ -35,17 +35,16 @@ doit = do
   dflags' <- getSessionDynFlags
   primPackages <- setSessionDynFlags dflags'
   dflags <- getSessionDynFlags
-  defaultCleanupHandler dflags $ do
-    target <- guessTarget "X.hs" Nothing
-    setTargets [target]
-    load LoadAllTargets
+  target <- guessTarget "X.hs" Nothing
+  setTargets [target]
+  load LoadAllTargets
 
-    () <- chaseConstructor (unsafeCoerce False)
-    () <- chaseConstructor (unsafeCoerce [1,2,3])
-    () <- chaseConstructor (unsafeCoerce (3 :-> 2))
-    () <- chaseConstructor (unsafeCoerce (4 :->. 4))
-    () <- chaseConstructor (unsafeCoerce (4 :->.+ 4))
-    return ()
+  () <- chaseConstructor (unsafeCoerce False)
+  () <- chaseConstructor (unsafeCoerce [1,2,3])
+  () <- chaseConstructor (unsafeCoerce (3 :-> 2))
+  () <- chaseConstructor (unsafeCoerce (4 :->. 4))
+  () <- chaseConstructor (unsafeCoerce (4 :->.+ 4))
+  return ()
 
 chaseConstructor :: (GhcMonad m) => HValue -> m ()
 chaseConstructor !hv = do
diff --git a/testsuite/tests/ghci.debugger/scripts/break006.stderr b/testsuite/tests/ghci.debugger/scripts/break006.stderr
index 16ba5ec004..58faa697c5 100644
--- a/testsuite/tests/ghci.debugger/scripts/break006.stderr
+++ b/testsuite/tests/ghci.debugger/scripts/break006.stderr
@@ -10,7 +10,7 @@
         instance Show Ordering -- Defined in ‘GHC.Show’
         instance Show Integer -- Defined in ‘GHC.Show’
         ...plus 23 others
-        ...plus 13 instance involving out-of-scope typess
+        ...plus 19 instance involving out-of-scope typess
         (use -fprint-potential-instances to see them all)
     • In a stmt of an interactive GHCi command: print it
 
@@ -25,6 +25,6 @@
         instance Show Ordering -- Defined in ‘GHC.Show’
         instance Show Integer -- Defined in ‘GHC.Show’
         ...plus 23 others
-        ...plus 13 instance involving out-of-scope typess
+        ...plus 19 instance involving out-of-scope typess
         (use -fprint-potential-instances to see them all)
     • In a stmt of an interactive GHCi command: print it
diff --git a/testsuite/tests/ghci.debugger/scripts/break011.script b/testsuite/tests/ghci.debugger/scripts/break011.script
index f9ca3fe393..e913a2f240 100644
--- a/testsuite/tests/ghci.debugger/scripts/break011.script
+++ b/testsuite/tests/ghci.debugger/scripts/break011.script
@@ -15,4 +15,7 @@ error "foo"
 :force _exception
 :show bindings
 :force _result
+-- the exception is caught by the withProg/withArgs wrappers, hence 3 :continues
+:continue
+:continue
 :continue
diff --git a/testsuite/tests/ghci.debugger/scripts/break011.stdout b/testsuite/tests/ghci.debugger/scripts/break011.stdout
index dee4d94360..ec0b3e9609 100644
--- a/testsuite/tests/ghci.debugger/scripts/break011.stdout
+++ b/testsuite/tests/ghci.debugger/scripts/break011.stdout
@@ -32,6 +32,18 @@ _exception :: SomeException = SomeException
 *** Exception: foo
 CallStack (from ImplicitParams):
   error, called at ../Test7.hs:2:18 in main:Main
+Stopped at <exception thrown>
+_exception :: e = SomeException
+                    (ErrorCallWithLocation
+                       "foo"
+                       "CallStack (from ImplicitParams):
+  error, called at ../Test7.hs:2:18 in main:Main")
+Stopped at <exception thrown>
+_exception :: e = SomeException
+                    (ErrorCallWithLocation
+                       "foo"
+                       "CallStack (from ImplicitParams):
+  error, called at ../Test7.hs:2:18 in main:Main")
 *** Exception: foo
 CallStack (from ImplicitParams):
   error, called at ../Test7.hs:2:18 in main:Main
diff --git a/testsuite/tests/ghci.debugger/scripts/break013.stdout b/testsuite/tests/ghci.debugger/scripts/break013.stdout
index 4c3d5f3d76..13d203f0b3 100644
--- a/testsuite/tests/ghci.debugger/scripts/break013.stdout
+++ b/testsuite/tests/ghci.debugger/scripts/break013.stdout
@@ -5,7 +5,7 @@ _result :: (Bool, Bool, ()) = _
 a :: Bool = _
 b :: Bool = _
 c :: () = _
-c :: () = _
 b :: Bool = _
+c :: () = _
 a :: Bool = _
 _result :: (Bool, Bool, ()) = _
diff --git a/testsuite/tests/ghci.debugger/scripts/break024.stdout b/testsuite/tests/ghci.debugger/scripts/break024.stdout
index dc3bd73425..548e7a4470 100644
--- a/testsuite/tests/ghci.debugger/scripts/break024.stdout
+++ b/testsuite/tests/ghci.debugger/scripts/break024.stdout
@@ -10,7 +10,9 @@ _exception :: e = _
 _exception = SomeException
                (GHC.IO.Exception.IOError
                   Nothing GHC.IO.Exception.UserError [] "error" Nothing Nothing)
-*** Exception: user error (error)
+Stopped at <exception thrown>
+_exception :: e = SomeException
+                    (GHC.IO.Exception.IOError Nothing GHC.IO.Exception.UserError ....)
 Stopped at <exception thrown>
 _exception :: e = _
 _exception = SomeException
diff --git a/testsuite/tests/ghci.debugger/scripts/print019.stderr b/testsuite/tests/ghci.debugger/scripts/print019.stderr
index fa53d94701..c1dc48bf21 100644
--- a/testsuite/tests/ghci.debugger/scripts/print019.stderr
+++ b/testsuite/tests/ghci.debugger/scripts/print019.stderr
@@ -9,6 +9,6 @@
         instance Show Ordering -- Defined in ‘GHC.Show’
         instance Show TyCon -- Defined in ‘GHC.Show’
         ...plus 30 others
-        ...plus two instance involving out-of-scope typess
+        ...plus 8 instance involving out-of-scope typess
         (use -fprint-potential-instances to see them all)
     • In a stmt of an interactive GHCi command: print it
diff --git a/testsuite/tests/ghci/prog001/prog001-ext.stdout b/testsuite/tests/ghci/prog001/prog001-ext.stdout
new file mode 100644
index 0000000000..eef24c2153
--- /dev/null
+++ b/testsuite/tests/ghci/prog001/prog001-ext.stdout
@@ -0,0 +1,4 @@
+"hello world84"
+"hello world84"
+"hello world84"
+44
diff --git a/testsuite/tests/ghci/prog001/prog001.T b/testsuite/tests/ghci/prog001/prog001.T
index 1ef3c0430c..af221e6fd9 100644
--- a/testsuite/tests/ghci/prog001/prog001.T
+++ b/testsuite/tests/ghci/prog001/prog001.T
@@ -1,5 +1,5 @@
 test('prog001',
      [extra_clean(['C.hs', 'D.hs', 'D.hi', 'D.o']),
-      cmd_prefix('ghciWayFlags=' + config.ghci_way_flags)],
+      cmd_prefix('ghciWayFlags=' + config.ghci_way_flags),
+      unless(opsys('mingw32'),extra_ways(['ghci-ext']))],
      ghci_script, ['prog001.script'])
-
diff --git a/testsuite/tests/ghci/scripts/T10110A.hs b/testsuite/tests/ghci/scripts/T10110A.hs
index 8482e7f673..ab64cfd016 100644
--- a/testsuite/tests/ghci/scripts/T10110A.hs
+++ b/testsuite/tests/ghci/scripts/T10110A.hs
@@ -1,4 +1,5 @@
 module T10110A (a) where
+import Debug.Trace
 {-# NOINLINE a #-}
 a :: Int
 a = 3
diff --git a/testsuite/tests/ghci/scripts/all.T b/testsuite/tests/ghci/scripts/all.T
index 1a664d128d..5c25cf8bb0 100755
--- a/testsuite/tests/ghci/scripts/all.T
+++ b/testsuite/tests/ghci/scripts/all.T
@@ -3,9 +3,13 @@
 test('ghci001', combined_output, ghci_script, ['ghci001.script'])
 test('ghci002', combined_output, ghci_script, ['ghci002.script'])
 test('ghci003', combined_output, ghci_script, ['ghci003.script'])
-test('ghci004', combined_output, ghci_script, ['ghci004.script'])
+test('ghci004', [ combined_output,
+                  unless(opsys('mingw32'),extra_ways(['ghci-ext'])) ],
+                ghci_script, ['ghci004.script'])
 test('ghci005', combined_output, ghci_script, ['ghci005.script'])
-test('ghci006', combined_output, ghci_script, ['ghci006.script'])
+test('ghci006', [ combined_output,
+                  unless(opsys('mingw32'),extra_ways(['ghci-ext'])) ],
+                ghci_script, ['ghci006.script'])
 test('ghci007', combined_output, ghci_script, ['ghci007.script'])
 test('ghci008', combined_output, ghci_script, ['ghci008.script'])
 test('ghci009', combined_output, ghci_script, ['ghci009.script'])
@@ -84,7 +88,7 @@ test('ghci056',
      ],
      ghci_script, ['ghci056.script'])
 
-test('ghci057', normal, ghci_script_without_flag('-fno-warn-tabs'), ['ghci057.script'])
+test('ghci057', extra_hc_opts('-fwarn-tabs'), ghci_script, ['ghci057.script'])
 
 test('T2452', normal, ghci_script, ['T2452.script'])
 test('T2766', normal, ghci_script, ['T2766.script'])
@@ -192,7 +196,7 @@ test('T9181', normal, ghci_script, ['T9181.script'])
 test('T9086b', normal, ghci_script, ['T9086b.script'])
 test('T9140', combined_output, ghci_script, ['T9140.script'])
 test('T9658', normal, ghci_script, ['T9658.script'])
-test('T9293', normal, ghci_script_without_flag('-fno-warn-tabs'), ['T9293.script'])
+test('T9293', extra_hc_opts('-fwarn-tabs'), ghci_script, ['T9293.script'])
 test('T9762',
  [ unless(have_dynamic(),skip)
  , pre_cmd('$MAKE -s --no-print-directory T9762_prep')
diff --git a/testsuite/tests/profiling/should_run/scc003.prof.sample b/testsuite/tests/profiling/should_run/scc003.prof.sample
index e1d0b64464..69633d4c91 100644
--- a/testsuite/tests/profiling/should_run/scc003.prof.sample
+++ b/testsuite/tests/profiling/should_run/scc003.prof.sample
@@ -1,27 +1,35 @@
-	Thu Apr  2 19:44 2015 Time and Allocation Profiling Report  (Final)
+	Tue Dec  8 08:29 2015 Time and Allocation Profiling Report  (Final)
 
-	   scc003 +RTS -p -RTS
+	   scc003 +RTS -hc -p -RTS
 
-	total time  =        0.13 secs   (132 ticks @ 1000 us, 1 processor)
-	total alloc = 195,487,784 bytes  (excludes profiling overheads)
+	total time  =        0.04 secs   (40 ticks @ 1000 us, 1 processor)
+	total alloc =      48,912 bytes  (excludes profiling overheads)
 
-COST CENTRE MODULE  %time %alloc
+COST CENTRE MODULE            %time %alloc
 
-fib         Main    100.0  100.0
+fib         Main              100.0    0.0
+MAIN        MAIN                0.0    1.8
+main        Main                0.0   19.6
+CAF         GHC.Conc.Signal     0.0    1.3
+CAF         GHC.IO.Encoding     0.0    5.9
+CAF         GHC.IO.Handle.FD    0.0   70.6
 
 
-                                                     individual      inherited
-COST CENTRE MODULE                no.     entries  %time %alloc   %time %alloc
+                                                      individual      inherited
+COST CENTRE  MODULE                no.     entries  %time %alloc   %time %alloc
 
-MAIN        MAIN                   99           0    0.0    0.0   100.0  100.0
- CAF        Main                  197           0    0.0    0.0   100.0  100.0
-  main      Main                  198           1    0.0    0.0   100.0  100.0
-   f        Main                  199           1    0.0    0.0   100.0  100.0
-    f.\     Main                  201           1    0.0    0.0    99.2   99.2
-     fib    Main                  202     2692537   99.2   99.2    99.2   99.2
-    fib     Main                  200       21891    0.8    0.8     0.8    0.8
- CAF        GHC.Conc.Signal       179           0    0.0    0.0     0.0    0.0
- CAF        GHC.IO.Encoding       163           0    0.0    0.0     0.0    0.0
- CAF        GHC.IO.Encoding.Iconv 161           0    0.0    0.0     0.0    0.0
- CAF        GHC.IO.Handle.FD      152           0    0.0    0.0     0.0    0.0
- CAF        GHC.IO.Handle.Text    150           0    0.0    0.0     0.0    0.0
+MAIN         MAIN                  105           0    0.0    1.8   100.0  100.0
+ main        Main                  211           0    0.0   18.9     0.0   18.9
+ CAF         GHC.IO.Handle.Text    140           0    0.0    0.2     0.0    0.2
+ CAF         GHC.IO.Handle.FD      138           0    0.0   70.6     0.0   70.6
+ CAF         GHC.IO.Encoding.Iconv 130           0    0.0    0.5     0.0    0.5
+ CAF         GHC.IO.Encoding       128           0    0.0    5.9     0.0    5.9
+ CAF         GHC.Conc.Signal       118           0    0.0    1.3     0.0    1.3
+ CAF         Main                  112           0    0.0    0.0   100.0    0.8
+  main       Main                  210           1    0.0    0.7   100.0    0.8
+   f         Main                  212           1    0.0    0.0   100.0    0.1
+    f.\      Main                  216           1    0.0    0.0   100.0    0.0
+     fib     Main                  217     2692537  100.0    0.0   100.0    0.0
+    f.x'     Main                  213           1    0.0    0.0     0.0    0.0
+     f.(...) Main                  214           1    0.0    0.0     0.0    0.0
+      fib    Main                  215       21891    0.0    0.0     0.0    0.0
diff --git a/testsuite/tests/rts/LinkerUnload.hs b/testsuite/tests/rts/LinkerUnload.hs
index 7e9d1dd38a..9d6b243256 100644
--- a/testsuite/tests/rts/LinkerUnload.hs
+++ b/testsuite/tests/rts/LinkerUnload.hs
@@ -16,5 +16,5 @@ loadPackages = do
     let dflags' = dflags { hscTarget = HscNothing
                          , ghcLink  = LinkInMemory }
     pkgs <- setSessionDynFlags dflags'
-    dflags <- getSessionDynFlags
-    liftIO $ Linker.linkPackages dflags pkgs
+    hsc_env <- getSession
+    liftIO $ Linker.linkPackages hsc_env pkgs
diff --git a/testsuite/tests/rts/T2615.hs b/testsuite/tests/rts/T2615.hs
index 53c2d13ceb..6a81185e9e 100644
--- a/testsuite/tests/rts/T2615.hs
+++ b/testsuite/tests/rts/T2615.hs
@@ -1,4 +1,4 @@
-import ObjLink
+import GHCi.ObjLink
 
 library_name = "libfoo_script_T2615.so" -- this is really a linker script
 
diff --git a/testsuite/tests/th/Makefile b/testsuite/tests/th/Makefile
index 5d2be1eb34..b759a81b67 100644
--- a/testsuite/tests/th/Makefile
+++ b/testsuite/tests/th/Makefile
@@ -20,6 +20,13 @@ TH_spliceE5_prof::
 	'$(TEST_HC)' $(TEST_HC_OPTS) $(HC_OPTS) --make -v0 TH_spliceE5_prof.hs -prof -auto-all -osuf p.o -o $@
 	./$@
 
+# With -fexternal-interpreter, we don't have to build the non-profiled
+# objects first.
+TH_spliceE5_prof_ext::
+	$(RM) TH_spliceE5_prof_ext*.o TH_spliceE5_prof_ext*.hi TH_spliceE5_prof_ext*.p.o
+	'$(TEST_HC)' $(TEST_HC_OPTS) $(HC_OPTS) --make -v0 TH_spliceE5_prof_ext.hs -prof -auto-all -fexternal-interpreter -o $@
+	./$@
+
 .PHONY: TH_Depends
 TH_Depends:
 	$(RM) TH_Depends_external.txt
diff --git a/testsuite/tests/th/TH_Roles2.stderr b/testsuite/tests/th/TH_Roles2.stderr
index e4a9a47858..c44e5b9d9d 100644
--- a/testsuite/tests/th/TH_Roles2.stderr
+++ b/testsuite/tests/th/TH_Roles2.stderr
@@ -5,9 +5,10 @@ TYPE CONSTRUCTORS
     Kind: forall k1. k1 -> *
 COERCION AXIOMS
 Dependent modules: []
-Dependent packages: [array-0.5.1.0, base-4.9.0.0, deepseq-1.4.2.0,
+Dependent packages: [array-0.5.1.0, base-4.9.0.0, binary-0.7.5.0,
+                     bytestring-0.10.7.0, containers-0.5.6.3, deepseq-1.4.2.0,
                      ghc-boot-0.0.0.0, ghc-prim-0.5.0.0, integer-gmp-1.0.0.0,
-                     pretty-1.1.2.0, template-haskell-2.11.0.0]
+                     pretty-1.1.3.2, template-haskell-2.11.0.0]
 
 ==================== Typechecker ====================
 TH_Roles2.$tcT
diff --git a/testsuite/tests/th/TH_finalizer.hs b/testsuite/tests/th/TH_finalizer.hs
new file mode 100644
index 0000000000..f59364edaf
--- /dev/null
+++ b/testsuite/tests/th/TH_finalizer.hs
@@ -0,0 +1,11 @@
+{-# LANGUAGE TemplateHaskell #-}
+
+module ShouldCompile where
+
+import Language.Haskell.TH
+import Language.Haskell.TH.Syntax
+
+$( do
+     addModFinalizer (do b <- getQ; reportWarning (show (b::Maybe Bool)))
+     return [] )
+$( putQ True >> return [] )
diff --git a/testsuite/tests/th/TH_finalizer.stderr b/testsuite/tests/th/TH_finalizer.stderr
new file mode 100644
index 0000000000..e89d434adb
--- /dev/null
+++ b/testsuite/tests/th/TH_finalizer.stderr
@@ -0,0 +1,2 @@
+
+TH_finalizer.hs:1:1: warning: Just True
diff --git a/testsuite/tests/th/TH_spliceE5_prof_ext.hs b/testsuite/tests/th/TH_spliceE5_prof_ext.hs
new file mode 100644
index 0000000000..255b1c5b8d
--- /dev/null
+++ b/testsuite/tests/th/TH_spliceE5_prof_ext.hs
@@ -0,0 +1,14 @@
+module Main where
+
+import TH_spliceE5_prof_ext_Lib
+
+v1 = "foo"
+
+main = putStrLn $(expandVars ["v1","v2"])
+-- The splice expands to refer to both v1 and v2,
+-- and the test checks that we don't dependency-analyse
+-- the program so that one or the other isn't in scope
+-- to the type checker
+
+
+v2 = "bar"
diff --git a/testsuite/tests/th/TH_spliceE5_prof_ext.stdout b/testsuite/tests/th/TH_spliceE5_prof_ext.stdout
new file mode 100644
index 0000000000..323fae03f4
--- /dev/null
+++ b/testsuite/tests/th/TH_spliceE5_prof_ext.stdout
@@ -0,0 +1 @@
+foobar
diff --git a/testsuite/tests/th/TH_spliceE5_prof_ext_Lib.hs b/testsuite/tests/th/TH_spliceE5_prof_ext_Lib.hs
new file mode 100644
index 0000000000..eb598c03d7
--- /dev/null
+++ b/testsuite/tests/th/TH_spliceE5_prof_ext_Lib.hs
@@ -0,0 +1,8 @@
+module TH_spliceE5_prof_ext_Lib where
+
+import Language.Haskell.TH
+
+expandVars :: [String] -> Q Exp
+expandVars s = [| concat $(return (ListE (map f s))) |]
+  where
+    f x = VarE (mkName x)
diff --git a/testsuite/tests/th/all.T b/testsuite/tests/th/all.T
index af8531c8b1..45ee2df13b 100644
--- a/testsuite/tests/th/all.T
+++ b/testsuite/tests/th/all.T
@@ -51,6 +51,14 @@ test('TH_spliceE5_prof',
      run_command,
      ['$MAKE -s --no-print-directory TH_spliceE5_prof'])
 
+test('TH_spliceE5_prof_ext',
+     [req_profiling,
+      omit_ways(['ghci']),
+      extra_clean(['TH_spliceE5_prof_ext_Lib.hi',
+                   'TH_spliceE5_prof_ext_Lib.o'])],
+     run_command,
+     ['$MAKE -s --no-print-directory TH_spliceE5_prof_ext'])
+
 test('TH_spliceD1',
      extra_clean(['TH_spliceD1_Lib.hi', 'TH_spliceD1_Lib.o']),
      multimod_compile_fail,
@@ -370,3 +378,5 @@ test('T10819',
      multimod_compile,
      ['T10819.hs', '-v0 ' + config.ghc_th_way_flags])
 test('T10820', normal, compile_and_run, ['-v0'])
+
+test('TH_finalizer', normal, compile, ['-v0'])