Fixes #1169

src/Cryptol/ModuleSystem/Renamer.hs

@@ -161,8 +161,10 @@ renameModule' thisNested env mpath m =
          allImps   = openLoop allNested env openDs imps
 
      (inScope,decls') <-
-        shadowNames allImps $
+        shadowNames' CheckNone allImps $
         shadowNames' CheckOverlap env $
+                          -- maybe we should allow for a warning
+                          -- if a local name shadows an imported one?
         do inScope <- getNamingEnv
            ds      <- renameTopDecls' (allNested,mpath) (mDecls m)
            pure (inScope, ds)

src/Cryptol/ModuleSystem/Renamer/Monad.hs

@@ -250,10 +250,16 @@ checkEnv check (NamingEnv lenv) r rw0
 
   where
   newEnv         = NamingEnv newMap
-  (rwFin,newMap) = Map.mapAccumWithKey doNS rw0 lenv
+  (rwFin,newMap) = Map.mapAccumWithKey doNS rw0 lenv  -- lenv 1 ns at a time
   doNS rw ns     = Map.mapAccumWithKey (step ns) rw
 
-  step ns acc k xs = (acc', [head xs])
+  -- namespace, current state, k : parse name, xs : possible entities for k
+  step ns acc k xs = (acc', case check of
+                              CheckNone -> xs
+                              _         -> [head xs]
+                              -- we've already reported an overlap error,
+                              -- so resolve arbitrarily to  the first entry
+                      )
     where
     acc' = acc
       { rwWarnings =

tests/modsys/T15.icry

@@ -0,0 +1 @@
+:module T15::B

tests/modsys/T15.icry.stdout

@@ -0,0 +1,4 @@
+Loading module Cryptol
+Loading module Cryptol
+Loading module T15::A
+Loading module T15::B

tests/modsys/T15/A.cry

@@ -0,0 +1,5 @@
+module T15::A where
+
+update = 0x02
+
+

tests/modsys/T15/B.cry

@@ -0,0 +1,3 @@
+module T15::B where
+
+import T15::A

tests/modsys/T16.icry

@@ -0,0 +1 @@
+:module T16::B

tests/modsys/T16.icry.stdout

@@ -0,0 +1,9 @@
+Loading module Cryptol
+Loading module Cryptol
+Loading module T16::A
+Loading module T16::B
+
+[error] at ./T16/B.cry:5:5--5:11
+    Multiple definitions for symbol: update
+    (at Cryptol:846:11--846:17, update)
+    (at ./T16/A.cry:3:1--3:7, T16::A::update)

tests/modsys/T16/A.cry

@@ -0,0 +1,5 @@
+module T16::A where
+
+update = 0x02
+
+

tests/modsys/T16/B.cry

@@ -0,0 +1,5 @@
+module T16::B where
+
+import T16::A
+
+f = update

tests/modsys/T17.icry

@@ -0,0 +1 @@
+:module T17::B

tests/modsys/T17.icry.stdout

@@ -0,0 +1,5 @@
+Loading module Cryptol
+Loading module Cryptol
+Loading module T17::A
+Loading module T17::A1
+Loading module T17::B

tests/modsys/T17/A.cry

@@ -0,0 +1,5 @@
+module T17::A where
+
+u = 0x02
+
+

tests/modsys/T17/A1.cry

@@ -0,0 +1,5 @@
+module T17::A1 where
+
+u = 0x03
+
+

tests/modsys/T17/B.cry

@@ -0,0 +1,4 @@
+module T17::B where
+
+import T17::A
+import T17::A1

tests/modsys/T18.icry

@@ -0,0 +1 @@
+:module T18::B

tests/modsys/T18.icry.stdout

@@ -0,0 +1,10 @@
+Loading module Cryptol
+Loading module Cryptol
+Loading module T18::A
+Loading module T18::A1
+Loading module T18::B
+
+[error] at ./T18/B.cry:6:5--6:6
+    Multiple definitions for symbol: u
+    (at ./T18/A.cry:3:1--3:2, T18::A::u)
+    (at ./T18/A1.cry:3:1--3:2, T18::A1::u)

tests/modsys/T18/A.cry

@@ -0,0 +1,5 @@
+module T18::A where
+
+u = 0x02
+
+

tests/modsys/T18/A1.cry

@@ -0,0 +1,5 @@
+module T18::A1 where
+
+u = 0x03
+
+

tests/modsys/T18/B.cry

@@ -0,0 +1,6 @@
+module T18::B where
+
+import T18::A
+import T18::A1
+
+f = u

tests/modsys/nested/T15.icry.stdout

@@ -1,15 +1,6 @@
 Loading module Cryptol
 Loading module Cryptol
 Loading module T15
-[warning] at T15.cry:5:13--5:14
-    This binding for `A` shadows the existing binding at
-    T15.cry:3:11--3:12
-[warning] at T15.cry:7:15--7:16
-    This binding for `A` shadows the existing binding at
-    T15.cry:5:13--5:14
-[warning] at T15.cry:7:15--7:16
-    This binding for `A::A` shadows the existing binding at
-    T15.cry:5:13--5:14
 Showing a specific instance of polymorphic result:
   * Using 'Integer' for 1st type argument of 'T15::A::A::y'
 2