Fix linker interaction between Template Haskell and HPC (#9762)

Summary:
I'm not really happy about perpetuating the hackish fix for #8696,
but at least in the context of building with -fhpc, the performance
cost should be negligible.

I'm suspicious about PlainModuleInitLabel and the Windows stuff too,
but I don't know what it does / can't test it (respectively) so I'll
leave those alone for now.

Hopefully out-of-process TH will save us from these hacks some day.

The test is an adaptation of T8696. It's a bit more awkward since
I couldn't think of a way to get cross-module tickbox references
without optimizations (inlining), but ghci doesn't permit -O for
some reason.

Test Plan: harbormaster; validate

Reviewers: austin

Reviewed By: austin

Subscribers: carter, thomie

Differential Revision: https://phabricator.haskell.org/D583

GHC Trac Issues: #9762

Conflicts:
	testsuite/tests/ghci/scripts/all.T

7 files changed, 21 insertions, 2 deletions

diff --git a/compiler/cmm/CLabel.hs b/compiler/cmm/CLabel.hs
index 603f2130e0..ebf902f149 100644
--- a/compiler/cmm/CLabel.hs
+++ b/compiler/cmm/CLabel.hs
@@ -897,7 +897,7 @@ labelDynamic dflags this_pkg this_mod lbl =
 
    PlainModuleInitLabel m -> not (gopt Opt_Static dflags) && this_pkg /= (modulePackageKey m)
 
-   HpcTicksLabel m        -> not (gopt Opt_Static dflags) && this_pkg /= (modulePackageKey m)
+   HpcTicksLabel m        -> not (gopt Opt_Static dflags) && this_mod /= m
 
    -- Note that DynamicLinkerLabels do NOT require dynamic linking themselves.
    _                 -> False
diff --git a/testsuite/tests/ghci/scripts/Makefile b/testsuite/tests/ghci/scripts/Makefile
index 873de43d09..1ccd62f3b1 100644
--- a/testsuite/tests/ghci/scripts/Makefile
+++ b/testsuite/tests/ghci/scripts/Makefile
@@ -44,3 +44,6 @@ T9367:
 	'$(TEST_HC)' $(TEST_HC_OPTS) --interactive -v0 -ignore-dot-ghci                   < T9367.script > T9367-raw.run.stdout
 	cmp T9367-raw.run.stdout T9367-raw.stdout
 
+.PHONY: T9762_prep
+T9762_prep:
+	'$(TEST_HC)' $(TEST_HC_OPTS) -O -fhpc -dynamic T9762B.hs
diff --git a/testsuite/tests/ghci/scripts/T9762.script b/testsuite/tests/ghci/scripts/T9762.script
new file mode 100644
index 0000000000..c41dbfd1c6
--- /dev/null
+++ b/testsuite/tests/ghci/scripts/T9762.script
@@ -0,0 +1,3 @@
+:load T9762A T9762B
+T9762A.a
+T9762B.b
diff --git a/testsuite/tests/ghci/scripts/T9762.stdout b/testsuite/tests/ghci/scripts/T9762.stdout
new file mode 100644
index 0000000000..b94473479c
--- /dev/null
+++ b/testsuite/tests/ghci/scripts/T9762.stdout
@@ -0,0 +1,2 @@
+3
+4
diff --git a/testsuite/tests/ghci/scripts/T9762A.hs b/testsuite/tests/ghci/scripts/T9762A.hs
new file mode 100644
index 0000000000..cd386edc26
--- /dev/null
+++ b/testsuite/tests/ghci/scripts/T9762A.hs
@@ -0,0 +1,5 @@
+module T9762A (a) where
+-- By marking a INLINE, we create a reference from B to A's tickboxes.
+{-# INLINE a #-}
+a :: Int
+a = 3
diff --git a/testsuite/tests/ghci/scripts/T9762B.hs b/testsuite/tests/ghci/scripts/T9762B.hs
new file mode 100644
index 0000000000..387d0e2761
--- /dev/null
+++ b/testsuite/tests/ghci/scripts/T9762B.hs
@@ -0,0 +1,4 @@
+module T9762B (b) where
+import T9762A (a)
+b :: Int
+b = a+1
diff --git a/testsuite/tests/ghci/scripts/all.T b/testsuite/tests/ghci/scripts/all.T
index a78068a452..c8462c181f 100755
--- a/testsuite/tests/ghci/scripts/all.T
+++ b/testsuite/tests/ghci/scripts/all.T
@@ -193,4 +193,6 @@ test('T9086b', normal, ghci_script, ['T9086b.script'])
 test('T9140', combined_output, ghci_script, ['T9140.script'])
 test('T9658', normal, ghci_script, ['T9658.script'])
 test('T9293', normal, ghci_script_without_flag('-fno-warn-tabs'), ['T9293.script'])
-test('T9881', normal, ghci_script, ['T9881.script'])
\ No newline at end of file
+test('T9762', [pre_cmd('$MAKE -s --no-print-directory T9762_prep')],
+     ghci_script, ['T9762.script'])
+test('T9881', normal, ghci_script, ['T9881.script'])