Bug in simplifyDifferentiation.

When generating auxiliary relations for differentiation and delay
operators, we incorrectly added the prefix to the fully qualified
relation name instead of the local component of the name.  As a result,
the compiler crashed when such relations were declared anywhere other
than the main module.

CHANGELOG.md

@@ -14,6 +14,11 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 - [C API tutorial](doc/c_tutorial/c_tutorial.rst), kindly contributed by @smadaminov.
 
+### Bug fix
+
+- Compiler crashed when differentiation or delay operators were applied to
+  relations declared outside of the main module of the program.
+
 ## [0.37.0] - Feb 15, 2021
 
 ### Language improvements

src/Language/DifferentialDatalog/Compile.hs

@@ -624,7 +624,11 @@ simplifyDelayedRels d =
            delayed_rels d'
     where
     mk_delayed_rel_name :: (String, Delay) -> String
-    mk_delayed_rel_name (rel, del) = "__" ++ show (delayDelay del) ++ "_" ++ rel
+    mk_delayed_rel_name (rel, del) = scoped rel_scope $ "__" ++ show (delayDelay del) ++ "_" ++ rel_name
+        where
+        rel_scope = nameScope rel
+        rel_name = nameLocalStr rel
+
     -- Find all delayed rels in the program, replacing each occurrence
     -- of 'R-n' with '__n_R'.
     (delayed_rels, d') = runState
@@ -682,7 +686,10 @@ simplifyDifferentiation d =
            diff_rels d'
     where
     mk_diff_rel_name :: String -> String
-    mk_diff_rel_name rname = "__diff_" ++ rname
+    mk_diff_rel_name rname = scoped rel_scope $ "__diff_" ++ rel_name
+        where
+        rel_scope = nameScope rname
+        rel_name = nameLocalStr rname
     -- Find all differentiated rels in the program, replacing each occurrence
     -- of 'R'' with '__diff_R'.
     (diff_rels, d') = runState

src/Language/DifferentialDatalog/Module.hs

@@ -143,7 +143,6 @@ stdImports = map stdImport stdLibs
 parseDatalogProgram :: [FilePath] -> Bool -> String -> FilePath -> ExceptT String IO ([DatalogModule], DatalogProgram, M.Map ModuleName (Doc, Doc, Doc))
 parseDatalogProgram roots import_std fdata fname = do
     roots' <- lift $ nub <$> mapM canonicalizePath roots
-    -- TODO: parseDatalogProgram should return ExceptT.
     prog <- parseDatalogString fdata fname
     let prog' = if import_std
                    then prog { progImports = stdImports ++ progImports prog }

src/Language/DifferentialDatalog/Parse.hs

@@ -58,7 +58,7 @@ import Language.DifferentialDatalog.Ops
 import Language.DifferentialDatalog.Error
 import {-# SOURCE #-} Language.DifferentialDatalog.Expr
 
--- parse a string containing a datalog program and produce the intermediate representation
+-- parse a string containing a DDlog program and produce the intermediate representation.
 parseDatalogString :: String -> String -> ExceptT String IO DatalogProgram
 parseDatalogString program file = do
   case parse datalogGrammar file program of

test/datalog_tests/modules.dl

@@ -2,6 +2,8 @@ import foolib::lib
 import foolib::ns1::m1 as m1
 import foolib::ns1::m2 as m2
 import redist
+// Make sure we can compile streaming code that lives in a module.
+import streams
 
 input relation Rmain(f1: Tlib, f2: m1::T1)
 output relation Rout(f1: bool, f2: bigint)

test/datalog_tests/test-stream.sh

@@ -2,7 +2,7 @@
 
 set -e
 
-./run-test.sh stream release
+./run-test.sh streams release
 
 run_test() {
     echo Running mem leak test for $1 iterations.
@@ -13,7 +13,7 @@ run_test() {
         insert Chunk(\"{\\\"fild\\\": $i}\"),
         commit dump_changes;"
     done) |
-        /usr/bin/time -o stream_mem -f "%M" ./stream_ddlog/target/release/stream_cli -w 4 --no-store > stream_mem.dump
+        /usr/bin/time -o stream_mem -f "%M" ./streams_ddlog/target/release/streams_cli -w 4 --no-store > stream_mem.dump
 }
 
 run_memleak_test() {
@@ -50,7 +50,7 @@ run_stream_query_test() {
         done
         echo "commit dump_changes;"
     done) > stream_bench.dat
-    /usr/bin/time ./stream_ddlog/target/release/stream_cli -w $3 --no-store < stream_bench.dat > stream_stream_queries.dump
+    /usr/bin/time ./streams_ddlog/target/release/streams_cli -w $3 --no-store < stream_bench.dat > stream_stream_queries.dump
 
 }
 
@@ -82,7 +82,7 @@ run_rel_query_test() {
         echo "commit dump_changes;"
 
     done) > stream_bench.dat
-    /usr/bin/time ./stream_ddlog/target/release/stream_cli -w $3 --no-store < stream_bench.dat > stream_rel_queries.dump
+    /usr/bin/time ./streams_ddlog/target/release/streams_cli -w $3 --no-store < stream_bench.dat > stream_rel_queries.dump
 
 }