Sanity check if we pick up an hsig file without -instantiated-with.

Summary:
Previously we would just let compilation proceed along until
we tried to pull up the Module for the hsig file, and get
main:A instead of <A>, and get a mysterious error.  Check
for this earlier!

Fixes #12955.

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

Test Plan: validate

Reviewers: simonpj, austin, bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2815

GHC Trac Issues: #12955

8 files changed, 25 insertions, 8 deletions

diff --git a/testsuite/tests/backpack/reexport/bkpreex02.stderr b/testsuite/tests/backpack/reexport/bkpreex02.stderr
index 44c07c44ff..8ae6714f33 100644
--- a/testsuite/tests/backpack/reexport/bkpreex02.stderr
+++ b/testsuite/tests/backpack/reexport/bkpreex02.stderr
@@ -15,11 +15,11 @@
   [2 of 2] Compiling T                ( r-impl/T.hs, nothing )
 [5 of 5] Processing r
   Instantiating r
-  [1 of 1] Including q[H=r-impl:H, T=r-impl:T]
-    Instantiating q[H=r-impl:H, T=r-impl:T]
+  [1 of 1] Including q[H=r-impl:H,T=r-impl:T]
+    Instantiating q[H=r-impl:H,T=r-impl:T]
     [1 of 2] Including timpl
-    [2 of 2] Including p[H=r-impl:H, T=r-impl:T]
-      Instantiating p[H=r-impl:H, T=r-impl:T]
+    [2 of 2] Including p[H=r-impl:H,T=r-impl:T]
+      Instantiating p[H=r-impl:H,T=r-impl:T]
       [1 of 2] Compiling T[sig]           ( p/T.hsig, nothing )
       [2 of 2] Compiling H[sig]           ( p/H.hsig, nothing )
     [1 of 3] Compiling T[sig]           ( q/T.hsig, nothing )
diff --git a/testsuite/tests/backpack/should_compile/bkp24.stderr b/testsuite/tests/backpack/should_compile/bkp24.stderr
index 73e1f9d6fb..ddafe4150b 100644
--- a/testsuite/tests/backpack/should_compile/bkp24.stderr
+++ b/testsuite/tests/backpack/should_compile/bkp24.stderr
@@ -15,8 +15,8 @@
   Instantiating r
   [1 of 2] Including q[B=b:B]
     Instantiating q[B=b:B]
-    [1 of 2] Including p[A=a:A, B=b:B]
-      Instantiating p[A=a:A, B=b:B]
+    [1 of 2] Including p[A=a:A,B=b:B]
+      Instantiating p[A=a:A,B=b:B]
       [1 of 3] Compiling A[sig]           ( p/A.hsig, bkp24.out/p/p-BVwzUlgOVR6H8V9umpUZ2h/A.o )
       [2 of 3] Compiling B[sig]           ( p/B.hsig, bkp24.out/p/p-BVwzUlgOVR6H8V9umpUZ2h/B.o )
       [3 of 3] Compiling P                ( p/P.hs, bkp24.out/p/p-BVwzUlgOVR6H8V9umpUZ2h/P.o )
diff --git a/testsuite/tests/backpack/should_fail/bkpfail14.stderr b/testsuite/tests/backpack/should_fail/bkpfail14.stderr
index ddfddeeb91..d89e6cab28 100644
--- a/testsuite/tests/backpack/should_fail/bkpfail14.stderr
+++ b/testsuite/tests/backpack/should_fail/bkpfail14.stderr
@@ -15,4 +15,4 @@ bkpfail14.bkp:9:9: error:
       Main module: f :: GHC.Types.Bool
       Hsig file:  f :: GHC.Types.Int
       The two types are different
-    • while checking that QMe implements signature Q in p[Q=QMe, Q2=Q2]
+    • while checking that QMe implements signature Q in p[Q=QMe,Q2=Q2]
diff --git a/testsuite/tests/backpack/should_fail/bkpfail15.stderr b/testsuite/tests/backpack/should_fail/bkpfail15.stderr
index e761cb102e..f32cd6dcf7 100644
--- a/testsuite/tests/backpack/should_fail/bkpfail15.stderr
+++ b/testsuite/tests/backpack/should_fail/bkpfail15.stderr
@@ -14,4 +14,4 @@ bkpfail15.bkp:8:9: error:
       Main module: f :: GHC.Types.Bool
       Hsig file:  f :: GHC.Types.Int
       The two types are different
-    • while checking that q:Q implements signature Q in p[A=<A>, Q=q:Q]
+    • while checking that q:Q implements signature Q in p[A=<A>,Q=q:Q]
diff --git a/testsuite/tests/driver/Makefile b/testsuite/tests/driver/Makefile
index 4e9ef20f41..2dfb41f223 100644
--- a/testsuite/tests/driver/Makefile
+++ b/testsuite/tests/driver/Makefile
@@ -636,3 +636,8 @@ T10923:
 	"$(TEST_HC)" $(TEST_HC_OPTS) -v1 -O0 -c T10923.hs
 	# should NOT output "compilation is NOT required"
 	"$(TEST_HC)" $(TEST_HC_OPTS) -v1 -O -c T10923.hs
+
+.PHONY: T12955
+T12955:
+	! "$(TEST_HC)" $(TEST_HC_OPTS) --make T12955
+	! "$(TEST_HC)" $(TEST_HC_OPTS) --make T12955 -fbuilding-cabal-package
diff --git a/testsuite/tests/driver/T12955.hsig b/testsuite/tests/driver/T12955.hsig
new file mode 100644
index 0000000000..3b674fc497
--- /dev/null
+++ b/testsuite/tests/driver/T12955.hsig
@@ -0,0 +1 @@
+signature T12955 where
diff --git a/testsuite/tests/driver/T12955.stderr b/testsuite/tests/driver/T12955.stderr
new file mode 100644
index 0000000000..acf4000608
--- /dev/null
+++ b/testsuite/tests/driver/T12955.stderr
@@ -0,0 +1,9 @@
+
+T12955.hsig:1:11: error:
+    Unexpected signature: ‘T12955’
+    (Try passing -instantiated-with="T12955=<T12955>"
+     replacing <T12955> as necessary.)
+
+T12955.hsig:1:11: error:
+    Unexpected signature: ‘T12955’
+    (Try adding ‘T12955’ to the ‘signatures’ field in your Cabal file.)
diff --git a/testsuite/tests/driver/all.T b/testsuite/tests/driver/all.T
index 8cd5c2f968..9119c715aa 100644
--- a/testsuite/tests/driver/all.T
+++ b/testsuite/tests/driver/all.T
@@ -499,3 +499,5 @@ test('T10923',
      ['$MAKE -s --no-print-directory T10923'])
 
 test('T12752pass', normal, compile, ['-DSHOULD_PASS=1 -Wcpp-undef'])
+
+test('T12955', normal, run_command, ['$MAKE -s --no-print-directory T12955'])