Fix for Trac #15611: Scope errors lie about what modules are imported.

Summary:
For the error message:
    Not in scope X.Y
    Module X does not export Y
    No module named ‘X’ is imported:
there are 2 cases, where we don't show the last "no module named is imported" line:
1. If the module X has been imported.
2. If the module X is the current module. There are 2 subcases:

   2.1 If the unknown module name is in a input source file,
       then we can use the getModule function to get the current module name.

   2.2 If the unknown module name has been entered by the user in GHCi,
       then the getModule function returns something like "interactive:Ghci1",
       and we have to check the current module in the last added entry of
       the HomePackageTable.

Test Plan: make test TESTS="T15611a T15611b"

Reviewers: monoidal, hvr, thomie, dfeuer, bgamari, DavidEichmann

Reviewed By: monoidal, DavidEichmann

Subscribers: rwbarton, carter

GHC Trac Issues: #15611

Differential Revision: https://phabricator.haskell.org/D5284

8 files changed, 10 insertions, 4 deletions

diff --git a/testsuite/tests/rename/should_fail/T15611a.hs b/testsuite/tests/rename/should_fail/T15611a.hs
new file mode 100644
index 0000000000..df1bb2f08c
--- /dev/null
+++ b/testsuite/tests/rename/should_fail/T15611a.hs
@@ -0,0 +1,2 @@
+main :: IO ()
+main = Main.foo
diff --git a/testsuite/tests/rename/should_fail/T15611a.stderr b/testsuite/tests/rename/should_fail/T15611a.stderr
new file mode 100644
index 0000000000..ebeb83b5f2
--- /dev/null
+++ b/testsuite/tests/rename/should_fail/T15611a.stderr
@@ -0,0 +1 @@
+T15611a.hs:2:8: Not in scope: ‘Main.foo’
diff --git a/testsuite/tests/rename/should_fail/T15611b.hs b/testsuite/tests/rename/should_fail/T15611b.hs
new file mode 100644
index 0000000000..0ab721d1d1
--- /dev/null
+++ b/testsuite/tests/rename/should_fail/T15611b.hs
@@ -0,0 +1 @@
+module T15611b where
diff --git a/testsuite/tests/rename/should_fail/T15611b.script b/testsuite/tests/rename/should_fail/T15611b.script
new file mode 100644
index 0000000000..d2b1fb1458
--- /dev/null
+++ b/testsuite/tests/rename/should_fail/T15611b.script
@@ -0,0 +1,2 @@
+:l T15611b
+T15611b.foo
diff --git a/testsuite/tests/rename/should_fail/T15611b.stderr b/testsuite/tests/rename/should_fail/T15611b.stderr
new file mode 100644
index 0000000000..609ab4c041
--- /dev/null
+++ b/testsuite/tests/rename/should_fail/T15611b.stderr
@@ -0,0 +1 @@
+<interactive>:2:1: Not in scope: ‘T15611b.foo’
diff --git a/testsuite/tests/rename/should_fail/T5892b.stderr b/testsuite/tests/rename/should_fail/T5892b.stderr
index 0f93c21f68..d55d0cb8e1 100644
--- a/testsuite/tests/rename/should_fail/T5892b.stderr
+++ b/testsuite/tests/rename/should_fail/T5892b.stderr
@@ -1,4 +1,2 @@
 
-T5892b.hs:11:7: error:
-    Not in scope: ‘T5892b.subForest’
-    No module named ‘T5892b’ is imported.
+T5892b.hs:11:7: error: Not in scope: ‘T5892b.subForest’
diff --git a/testsuite/tests/rename/should_fail/all.T b/testsuite/tests/rename/should_fail/all.T
index 6debe7b917..9ca330f873 100644
--- a/testsuite/tests/rename/should_fail/all.T
+++ b/testsuite/tests/rename/should_fail/all.T
@@ -138,5 +138,7 @@ test('T15539', normal, compile_fail, [''])
 test('T15487', normal, multimod_compile_fail, ['T15487','-v0'])
 test('T15659', normal, compile_fail, [''])
 test('T15607', normal, compile_fail, [''])
+test('T15611a', normal, compile_fail, [''])
+test('T15611b', normal, ghci_script, ['T15611b.script'])
 
 test('ExplicitForAllRules2', normal, compile_fail, [''])
diff --git a/testsuite/tests/rename/should_fail/rnfail034.stderr b/testsuite/tests/rename/should_fail/rnfail034.stderr
index 63e6eb5037..a5219c138b 100644
--- a/testsuite/tests/rename/should_fail/rnfail034.stderr
+++ b/testsuite/tests/rename/should_fail/rnfail034.stderr
@@ -4,4 +4,3 @@ rnfail034.hs:4:11: error: Qualified name in binding position: M.y
 rnfail034.hs:4:26: error:
     Not in scope: ‘M.y’
     Perhaps you meant ‘M.g’ (line 4)
-    No module named ‘M’ is imported.