diff options
Diffstat (limited to 'compiler/GHC/Driver/Make.hs')
| -rw-r--r-- | compiler/GHC/Driver/Make.hs | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/compiler/GHC/Driver/Make.hs b/compiler/GHC/Driver/Make.hs index efaefd84f5..1968bfa954 100644 --- a/compiler/GHC/Driver/Make.hs +++ b/compiler/GHC/Driver/Make.hs @@ -591,11 +591,18 @@ createBuildPlan mod_graph maybe_top_mod = (mg, lookup_node) = moduleGraphNodes False (mgModSummaries' mod_graph) trans_deps_map = allReachable mg (mkNodeKey . node_payload) + -- Compute the intermediate modules between a file and its hs-boot file. + -- See Step 2a in Note [Upsweep] boot_path mn uid = map (summaryNodeSummary . expectJust "toNode" . lookup_node) $ Set.toList $ + -- Don't include the boot module itself Set.delete (NodeKey_Module (key IsBoot)) $ - expectJust "boot_path" (M.lookup (NodeKey_Module (key NotBoot)) trans_deps_map) - `Set.difference` (expectJust "boot_path" (M.lookup (NodeKey_Module (key IsBoot)) trans_deps_map)) + -- Keep intermediate dependencies: as per Step 2a in Note [Upsweep], these are + -- the transitive dependencies of the non-boot file which transitively depend + -- on the boot file. + Set.filter (\nk -> nodeKeyUnitId nk == uid -- Cheap test + && (NodeKey_Module (key IsBoot)) `Set.member` expectJust "dep_on_boot" (M.lookup nk trans_deps_map)) $ + expectJust "not_boot_dep" (M.lookup (NodeKey_Module (key NotBoot)) trans_deps_map) where key ib = ModNodeKeyWithUid (GWIB mn ib) uid @@ -894,8 +901,13 @@ Step 1: Topologically sort the module graph without hs-boot files. This returns Step 2: For each cycle, topologically sort the modules in the cycle *with* the relevant hs-boot files. This should result in an acyclic build plan if the hs-boot files are sufficient to resolve the cycle. Step 2a: For each module in the cycle, if the module has a boot file then compute the - modules on the path between it and the hs-boot file. This information is - stored in ModuleGraphNodeWithBoot. + modules on the path between it and the hs-boot file. + These are the intermediate modules which: + (1) are (transitive) dependencies of the non-boot module, and + (2) have the boot module as a (transitive) dependency. + In particular, all such intermediate modules must appear in the same unit as + the module under consideration, as module cycles cannot cross unit boundaries. + This information is stored in ModuleGraphNodeWithBoot. The `[BuildPlan]` is then interpreted by the `interpretBuildPlan` function. |