diff --git a/compiler/GHC/Driver/Make.hs b/compiler/GHC/Driver/Make.hs index bac99883e2c5ea792560ff0c543fc3a8ece8f319..6b69d3606dbbe03d9a518a09e9ead483d3c813f1 100644 --- a/compiler/GHC/Driver/Make.hs +++ b/compiler/GHC/Driver/Make.hs @@ -608,7 +608,7 @@ createBuildPlan mod_graph maybe_top_mod = -- Now perform another toposort but just with these nodes and relevant hs-boot files. -- The result should be acyclic, if it's not, then there's an unresolved cycle in the graph. mresolved_cycle = collapseSCC (topSortWithBoot nodes) - in acyclic ++ [maybe (UnresolvedCycle nodes) ResolvedCycle mresolved_cycle] ++ toBuildPlan sccs [] + in acyclic ++ [either UnresolvedCycle ResolvedCycle mresolved_cycle] ++ toBuildPlan sccs [] (mg, lookup_node) = moduleGraphNodes False (mgModSummaries' mod_graph) trans_deps_map = allReachable mg (mkNodeKey . node_payload) @@ -639,12 +639,12 @@ createBuildPlan mod_graph maybe_top_mod = get_boot_module m = case m of ModuleNode _ ms | HsSrcFile <- ms_hsc_src ms -> lookupModuleEnv boot_modules (ms_mod ms); _ -> Nothing -- Any cycles should be resolved now - collapseSCC :: [SCC ModuleGraphNode] -> Maybe [(Either ModuleGraphNode ModuleGraphNodeWithBootFile)] + collapseSCC :: [SCC ModuleGraphNode] -> Either [ModuleGraphNode] [(Either ModuleGraphNode ModuleGraphNodeWithBootFile)] -- Must be at least two nodes, as we were in a cycle - collapseSCC [AcyclicSCC node1, AcyclicSCC node2] = Just [toNodeWithBoot node1, toNodeWithBoot node2] + collapseSCC [AcyclicSCC node1, AcyclicSCC node2] = Right [toNodeWithBoot node1, toNodeWithBoot node2] collapseSCC (AcyclicSCC node : nodes) = (toNodeWithBoot node :) <$> collapseSCC nodes -- Cyclic - collapseSCC _ = Nothing + collapseSCC nodes = Left (flattenSCCs nodes) toNodeWithBoot :: ModuleGraphNode -> Either ModuleGraphNode ModuleGraphNodeWithBootFile toNodeWithBoot mn = diff --git a/testsuite/tests/driver/T24196/T24196.stderr b/testsuite/tests/driver/T24196/T24196.stderr new file mode 100644 index 0000000000000000000000000000000000000000..af11bbe0e1fc56843d16f80f9db182d3a29d960b --- /dev/null +++ b/testsuite/tests/driver/T24196/T24196.stderr @@ -0,0 +1,4 @@ +Module graph contains a cycle: + module ‘T24196A’ (./T24196A.hs-boot) + imports module ‘T24196B’ (T24196B.hs) + which imports module ‘T24196A’ (./T24196A.hs-boot) diff --git a/testsuite/tests/driver/T24196/T24196A.hs b/testsuite/tests/driver/T24196/T24196A.hs new file mode 100644 index 0000000000000000000000000000000000000000..231f8f6e6871a673b77f5e3b32f3930986aa2ef5 --- /dev/null +++ b/testsuite/tests/driver/T24196/T24196A.hs @@ -0,0 +1 @@ +module T24196A where diff --git a/testsuite/tests/driver/T24196/T24196A.hs-boot b/testsuite/tests/driver/T24196/T24196A.hs-boot new file mode 100644 index 0000000000000000000000000000000000000000..6b036443f35c59b66bfb16d378ded3a5f473d060 --- /dev/null +++ b/testsuite/tests/driver/T24196/T24196A.hs-boot @@ -0,0 +1,3 @@ +module T24196A where + +import T24196B diff --git a/testsuite/tests/driver/T24196/T24196B.hs b/testsuite/tests/driver/T24196/T24196B.hs new file mode 100644 index 0000000000000000000000000000000000000000..b6de161446d04a4c3bc8980cc10e23c21fbf11f4 --- /dev/null +++ b/testsuite/tests/driver/T24196/T24196B.hs @@ -0,0 +1,3 @@ +module T24196B where + +import {-# SOURCE #-} T24196A diff --git a/testsuite/tests/driver/T24196/all.T b/testsuite/tests/driver/T24196/all.T new file mode 100644 index 0000000000000000000000000000000000000000..c5519da4886cba02e19cd91c7c63c7e346057e35 --- /dev/null +++ b/testsuite/tests/driver/T24196/all.T @@ -0,0 +1 @@ +test('T24196', extra_files(['T24196A.hs','T24196A.hs-boot','T24196B.hs']), multimod_compile_fail, ['T24196B',''])