rts/IPE: Share module_name within a Node

This allows us to shave a 64-bit word off of the packed IPE entry size.

compiler/GHC/StgToCmm/InfoTableProv.hs

@@ -83,9 +83,10 @@ emitIpeBufferListNode this_mod ents = do
         platform = stgToCmmPlatform cfg
         int n    = mkIntCLit platform n
 
-        (cg_ipes, strtab) = flip runState emptyStringTable $ do
+        ((cg_ipes, module_name), strtab) = flip runState emptyStringTable $ do
           module_name <- lookupStringTable $ ST.pack $ renderWithContext ctx (ppr this_mod)
-          mapM (toCgIPE platform ctx module_name) ents
+          cg_ipes <- mapM (toCgIPE platform ctx) ents
+          return (cg_ipes, module_name)
 
         tables :: [CmmStatic]
         tables = map (CmmStaticLit . CmmLabel . ipeInfoTablePtr) cg_ipes
@@ -136,6 +137,9 @@ emitIpeBufferListNode this_mod ents = do
 
             -- 'string_table_size' field (decompressed size)
           , int $ BS.length uncompressed_strings
+
+            -- 'module_name' field
+          , CmmInt (fromIntegral module_name) W32
           ]
 
     -- Emit the list of info table pointers
@@ -173,10 +177,8 @@ toIpeBufferEntries byte_order cg_ipes =
       , ipeClosureDesc cg_ipe
       , ipeTypeDesc cg_ipe
       , ipeLabel cg_ipe
-      , ipeModuleName cg_ipe
       , ipeSrcFile cg_ipe
       , ipeSrcSpan cg_ipe
-      , 0 -- padding
       ]
 
     word32Builder :: Word32 -> BSB.Builder
@@ -184,8 +186,8 @@ toIpeBufferEntries byte_order cg_ipes =
       BigEndian    -> BSB.word32BE
       LittleEndian -> BSB.word32LE
 
-toCgIPE :: Platform -> SDocContext -> StrTabOffset -> InfoProvEnt -> State StringTable CgInfoProvEnt
-toCgIPE platform ctx module_name ipe = do
+toCgIPE :: Platform -> SDocContext -> InfoProvEnt -> State StringTable CgInfoProvEnt
+toCgIPE platform ctx ipe = do
     table_name <- lookupStringTable $ ST.pack $ renderWithContext ctx (pprCLabel platform (infoTablePtr ipe))
     closure_desc <- lookupStringTable $ ST.pack $ show (infoProvEntClosureType ipe)
     type_desc <- lookupStringTable $ ST.pack $ infoTableType ipe
@@ -205,7 +207,6 @@ toCgIPE platform ctx module_name ipe = do
                            , ipeClosureDesc = closure_desc
                            , ipeTypeDesc = type_desc
                            , ipeLabel = label
-                           , ipeModuleName = module_name
                            , ipeSrcFile = src_file
                            , ipeSrcSpan = src_span
                            }
@@ -216,7 +217,6 @@ data CgInfoProvEnt = CgInfoProvEnt
                                , ipeClosureDesc :: !StrTabOffset
                                , ipeTypeDesc :: !StrTabOffset
                                , ipeLabel :: !StrTabOffset
-                               , ipeModuleName :: !StrTabOffset
                                , ipeSrcFile :: !StrTabOffset
                                , ipeSrcSpan :: !StrTabOffset
                                }

rts/IPE.c

@@ -108,7 +108,7 @@ static InfoProvEnt ipeBufferEntryToIpe(const IpeBufferListNode *node, uint32_t i
                 .closure_desc = &strings[ent->closure_desc],
                 .ty_desc = &strings[ent->ty_desc],
                 .label = &strings[ent->label],
-                .module = &strings[ent->module_name],
+                .module = &strings[node->module_name],
                 .src_file = &strings[ent->src_file],
                 .src_span = &strings[ent->src_span]
             }

rts/include/rts/IPE.h

@@ -56,10 +56,8 @@ typedef struct {
     StringIdx closure_desc;
     StringIdx ty_desc;
     StringIdx label;
-    StringIdx module_name;
     StringIdx src_file;
     StringIdx src_span;
-    uint32_t _padding;
 } IpeBufferEntry;
 
 GHC_STATIC_ASSERT(sizeof(IpeBufferEntry) % (WORD_SIZE_IN_BITS / 8) == 0, "sizeof(IpeBufferEntry) must be a multiple of the word size");
@@ -83,6 +81,9 @@ typedef struct IpeBufferListNode_ {
 
     const char *string_table;
     StgWord string_table_size; // decompressed size
+
+    // Shared by all entries
+    StringIdx module_name;
 } IpeBufferListNode;
 
 void registerInfoProvList(IpeBufferListNode *node);

testsuite/tests/rts/ipe/ipeEventLog.stderr

-7f5278bc0740: IPE: table_name table_name_000, closure_desc closure_desc_000, ty_desc ty_desc_000, label label_000, module module_000, srcloc src_file_000:src_span_000
-7f5278bc0740: IPE: table_name table_name_001, closure_desc closure_desc_001, ty_desc ty_desc_001, label label_001, module module_001, srcloc src_file_001:src_span_001
-7f5278bc0740: IPE: table_name table_name_002, closure_desc closure_desc_002, ty_desc ty_desc_002, label label_002, module module_002, srcloc src_file_002:src_span_002
-7f5278bc0740: IPE: table_name table_name_003, closure_desc closure_desc_003, ty_desc ty_desc_003, label label_003, module module_003, srcloc src_file_003:src_span_003
-7f5278bc0740: IPE: table_name table_name_004, closure_desc closure_desc_004, ty_desc ty_desc_004, label label_004, module module_004, srcloc src_file_004:src_span_004
-7f5278bc0740: IPE: table_name table_name_005, closure_desc closure_desc_005, ty_desc ty_desc_005, label label_005, module module_005, srcloc src_file_005:src_span_005
-7f5278bc0740: IPE: table_name table_name_006, closure_desc closure_desc_006, ty_desc ty_desc_006, label label_006, module module_006, srcloc src_file_006:src_span_006
-7f5278bc0740: IPE: table_name table_name_007, closure_desc closure_desc_007, ty_desc ty_desc_007, label label_007, module module_007, srcloc src_file_007:src_span_007
-7f5278bc0740: IPE: table_name table_name_008, closure_desc closure_desc_008, ty_desc ty_desc_008, label label_008, module module_008, srcloc src_file_008:src_span_008
-7f5278bc0740: IPE: table_name table_name_009, closure_desc closure_desc_009, ty_desc ty_desc_009, label label_009, module module_009, srcloc src_file_009:src_span_009
-7f5278bc0740: IPE: table_name table_name_000, closure_desc closure_desc_000, ty_desc ty_desc_000, label label_000, module module_000, srcloc src_file_000:src_span_000
-7f5278bc0740: IPE: table_name table_name_001, closure_desc closure_desc_001, ty_desc ty_desc_001, label label_001, module module_001, srcloc src_file_001:src_span_001
-7f5278bc0740: IPE: table_name table_name_002, closure_desc closure_desc_002, ty_desc ty_desc_002, label label_002, module module_002, srcloc src_file_002:src_span_002
-7f5278bc0740: IPE: table_name table_name_003, closure_desc closure_desc_003, ty_desc ty_desc_003, label label_003, module module_003, srcloc src_file_003:src_span_003
-7f5278bc0740: IPE: table_name table_name_004, closure_desc closure_desc_004, ty_desc ty_desc_004, label label_004, module module_004, srcloc src_file_004:src_span_004
-7f5278bc0740: IPE: table_name table_name_005, closure_desc closure_desc_005, ty_desc ty_desc_005, label label_005, module module_005, srcloc src_file_005:src_span_005
-7f5278bc0740: IPE: table_name table_name_006, closure_desc closure_desc_006, ty_desc ty_desc_006, label label_006, module module_006, srcloc src_file_006:src_span_006
-7f5278bc0740: IPE: table_name table_name_007, closure_desc closure_desc_007, ty_desc ty_desc_007, label label_007, module module_007, srcloc src_file_007:src_span_007
-7f5278bc0740: IPE: table_name table_name_008, closure_desc closure_desc_008, ty_desc ty_desc_008, label label_008, module module_008, srcloc src_file_008:src_span_008
-7f5278bc0740: IPE: table_name table_name_009, closure_desc closure_desc_009, ty_desc ty_desc_009, label label_009, module module_009, srcloc src_file_009:src_span_009
+7ffff7a4d740: IPE: table_name table_name_000, closure_desc closure_desc_000, ty_desc ty_desc_000, label label_000, module module_000, srcloc src_file_000:src_span_000
+7ffff7a4d740: IPE: table_name table_name_001, closure_desc closure_desc_001, ty_desc ty_desc_001, label label_001, module module_000, srcloc src_file_001:src_span_001
+7ffff7a4d740: IPE: table_name table_name_002, closure_desc closure_desc_002, ty_desc ty_desc_002, label label_002, module module_000, srcloc src_file_002:src_span_002
+7ffff7a4d740: IPE: table_name table_name_003, closure_desc closure_desc_003, ty_desc ty_desc_003, label label_003, module module_000, srcloc src_file_003:src_span_003
+7ffff7a4d740: IPE: table_name table_name_004, closure_desc closure_desc_004, ty_desc ty_desc_004, label label_004, module module_000, srcloc src_file_004:src_span_004
+7ffff7a4d740: IPE: table_name table_name_005, closure_desc closure_desc_005, ty_desc ty_desc_005, label label_005, module module_000, srcloc src_file_005:src_span_005
+7ffff7a4d740: IPE: table_name table_name_006, closure_desc closure_desc_006, ty_desc ty_desc_006, label label_006, module module_000, srcloc src_file_006:src_span_006
+7ffff7a4d740: IPE: table_name table_name_007, closure_desc closure_desc_007, ty_desc ty_desc_007, label label_007, module module_000, srcloc src_file_007:src_span_007
+7ffff7a4d740: IPE: table_name table_name_008, closure_desc closure_desc_008, ty_desc ty_desc_008, label label_008, module module_000, srcloc src_file_008:src_span_008
+7ffff7a4d740: IPE: table_name table_name_009, closure_desc closure_desc_009, ty_desc ty_desc_009, label label_009, module module_000, srcloc src_file_009:src_span_009
+7ffff7a4d740: IPE: table_name table_name_000, closure_desc closure_desc_000, ty_desc ty_desc_000, label label_000, module module_000, srcloc src_file_000:src_span_000
+7ffff7a4d740: IPE: table_name table_name_001, closure_desc closure_desc_001, ty_desc ty_desc_001, label label_001, module module_000, srcloc src_file_001:src_span_001
+7ffff7a4d740: IPE: table_name table_name_002, closure_desc closure_desc_002, ty_desc ty_desc_002, label label_002, module module_000, srcloc src_file_002:src_span_002
+7ffff7a4d740: IPE: table_name table_name_003, closure_desc closure_desc_003, ty_desc ty_desc_003, label label_003, module module_000, srcloc src_file_003:src_span_003
+7ffff7a4d740: IPE: table_name table_name_004, closure_desc closure_desc_004, ty_desc ty_desc_004, label label_004, module module_000, srcloc src_file_004:src_span_004
+7ffff7a4d740: IPE: table_name table_name_005, closure_desc closure_desc_005, ty_desc ty_desc_005, label label_005, module module_000, srcloc src_file_005:src_span_005
+7ffff7a4d740: IPE: table_name table_name_006, closure_desc closure_desc_006, ty_desc ty_desc_006, label label_006, module module_000, srcloc src_file_006:src_span_006
+7ffff7a4d740: IPE: table_name table_name_007, closure_desc closure_desc_007, ty_desc ty_desc_007, label label_007, module module_000, srcloc src_file_007:src_span_007
+7ffff7a4d740: IPE: table_name table_name_008, closure_desc closure_desc_008, ty_desc ty_desc_008, label label_008, module module_000, srcloc src_file_008:src_span_008
+7ffff7a4d740: IPE: table_name table_name_009, closure_desc closure_desc_009, ty_desc ty_desc_009, label label_009, module module_000, srcloc src_file_009:src_span_009

testsuite/tests/rts/ipe/ipeEventLog_fromMap.stderr

-7f86c4be8740: created capset 0 of type 2
-7f86c4be8740: created capset 1 of type 3
-7f86c4be8740: cap 0: initialised
-7f86c4be8740: assigned cap 0 to capset 0
-7f86c4be8740: assigned cap 0 to capset 1
-7f86c4be8740: cap 0: created thread 1[""]
-7f86c4be8740: cap 0: running thread 1[""] (ThreadRunGHC)
-7f86c4be8740: cap 0: thread 1[""] stopped (stack overflow, size 109)
-7f86c4be8740: cap 0: running thread 1[""] (ThreadRunGHC)
-7f86c4be8740: cap 0: created thread 2[""]
-7f86c4be8740: cap 0: thread 2 has label IOManager on cap 0
-7f86c4be8740: cap 0: thread 1[""] stopped (yielding)
-7f86b67fc640: cap 0: running thread 2["IOManager on cap 0"] (ThreadRunGHC)
-7f86b67fc640: cap 0: thread 2["IOManager on cap 0"] stopped (yielding)
-7f86c4be8740: cap 0: running thread 1[""] (ThreadRunGHC)
-7f86c4be8740: cap 0: created thread 3[""]
-7f86c4be8740: cap 0: thread 3 has label TimerManager
-7f86c4be8740: cap 0: thread 1[""] stopped (finished)
-7f86c4be8740: IPE: table_name table_name_009, closure_desc closure_desc_009, ty_desc ty_desc_009, label label_009, module module_009, srcloc src_file_009:src_span_009
-7f86c4be8740: IPE: table_name table_name_008, closure_desc closure_desc_008, ty_desc ty_desc_008, label label_008, module module_008, srcloc src_file_008:src_span_008
-7f86c4be8740: IPE: table_name table_name_007, closure_desc closure_desc_007, ty_desc ty_desc_007, label label_007, module module_007, srcloc src_file_007:src_span_007
-7f86c4be8740: IPE: table_name table_name_006, closure_desc closure_desc_006, ty_desc ty_desc_006, label label_006, module module_006, srcloc src_file_006:src_span_006
-7f86c4be8740: IPE: table_name table_name_005, closure_desc closure_desc_005, ty_desc ty_desc_005, label label_005, module module_005, srcloc src_file_005:src_span_005
-7f86c4be8740: IPE: table_name table_name_004, closure_desc closure_desc_004, ty_desc ty_desc_004, label label_004, module module_004, srcloc src_file_004:src_span_004
-7f86c4be8740: IPE: table_name table_name_003, closure_desc closure_desc_003, ty_desc ty_desc_003, label label_003, module module_003, srcloc src_file_003:src_span_003
-7f86c4be8740: IPE: table_name table_name_002, closure_desc closure_desc_002, ty_desc ty_desc_002, label label_002, module module_002, srcloc src_file_002:src_span_002
-7f86c4be8740: IPE: table_name table_name_001, closure_desc closure_desc_001, ty_desc ty_desc_001, label label_001, module module_001, srcloc src_file_001:src_span_001
-7f86c4be8740: IPE: table_name table_name_000, closure_desc closure_desc_000, ty_desc ty_desc_000, label label_000, module module_000, srcloc src_file_000:src_span_000
-7f86c4be8740: IPE: table_name table_name_009, closure_desc closure_desc_009, ty_desc ty_desc_009, label label_009, module module_009, srcloc src_file_009:src_span_009
-7f86c4be8740: IPE: table_name table_name_008, closure_desc closure_desc_008, ty_desc ty_desc_008, label label_008, module module_008, srcloc src_file_008:src_span_008
-7f86c4be8740: IPE: table_name table_name_007, closure_desc closure_desc_007, ty_desc ty_desc_007, label label_007, module module_007, srcloc src_file_007:src_span_007
-7f86c4be8740: IPE: table_name table_name_006, closure_desc closure_desc_006, ty_desc ty_desc_006, label label_006, module module_006, srcloc src_file_006:src_span_006
-7f86c4be8740: IPE: table_name table_name_005, closure_desc closure_desc_005, ty_desc ty_desc_005, label label_005, module module_005, srcloc src_file_005:src_span_005
-7f86c4be8740: IPE: table_name table_name_004, closure_desc closure_desc_004, ty_desc ty_desc_004, label label_004, module module_004, srcloc src_file_004:src_span_004
-7f86c4be8740: IPE: table_name table_name_003, closure_desc closure_desc_003, ty_desc ty_desc_003, label label_003, module module_003, srcloc src_file_003:src_span_003
-7f86c4be8740: IPE: table_name table_name_002, closure_desc closure_desc_002, ty_desc ty_desc_002, label label_002, module module_002, srcloc src_file_002:src_span_002
-7f86c4be8740: IPE: table_name table_name_001, closure_desc closure_desc_001, ty_desc ty_desc_001, label label_001, module module_001, srcloc src_file_001:src_span_001
-7f86c4be8740: IPE: table_name table_name_000, closure_desc closure_desc_000, ty_desc ty_desc_000, label label_000, module module_000, srcloc src_file_000:src_span_000
-7f86c4be8740: cap 0: created thread 4[""]
-7f86b67fc640: cap 0: running thread 2["IOManager on cap 0"] (ThreadRunGHC)
-7f86b67fc640: cap 0: thread 2["IOManager on cap 0"] stopped (suspended while making a foreign call)
-7f86b5ffb640: cap 0: running thread 3["TimerManager"] (ThreadRunGHC)
-7f86b5ffb640: cap 0: thread 3["TimerManager"] stopped (suspended while making a foreign call)
-7f86c4be8740: cap 0: running thread 4[""] (ThreadRunGHC)
-7f86c4be8740: cap 0: thread 4[""] stopped (yielding)
-7f86c4be8740: cap 0: running thread 4[""] (ThreadRunGHC)
-7f86c4be8740: cap 0: thread 4[""] stopped (finished)
-7f86b57fa640: cap 0: requesting sequential GC
-7f86b57fa640: cap 0: starting GC
-7f86b57fa640: cap 0: GC working
-7f86b57fa640: cap 0: GC idle
-7f86b57fa640: cap 0: GC done
-7f86b57fa640: cap 0: GC idle
-7f86b57fa640: cap 0: GC done
-7f86b57fa640: cap 0: GC idle
-7f86b57fa640: cap 0: GC done
-7f86b57fa640: cap 0: Memory Return (Current: 6) (Needed: 8) (Returned: 0)
-7f86b57fa640: cap 0: all caps stopped for GC
-7f86b57fa640: cap 0: finished GC
-7f86b5ffb640: cap 0: running thread 3["TimerManager"] (ThreadRunGHC)
-7f86b5ffb640: cap 0: thread 3["TimerManager"] stopped (finished)
-7f86b67fc640: cap 0: running thread 2["IOManager on cap 0"] (ThreadRunGHC)
-7f86b67fc640: cap 0: thread 2["IOManager on cap 0"] stopped (finished)
-7f86c4be8740: removed cap 0 from capset 0
-7f86c4be8740: removed cap 0 from capset 1
-7f86c4be8740: cap 0: shutting down
-7f86c4be8740: deleted capset 0
-7f86c4be8740: deleted capset 1
+7ffff7a4d740: IPE: table_name table_name_009, closure_desc closure_desc_009, ty_desc ty_desc_009, label label_009, module module_000, srcloc src_file_009:src_span_009
+7ffff7a4d740: IPE: table_name table_name_008, closure_desc closure_desc_008, ty_desc ty_desc_008, label label_008, module module_000, srcloc src_file_008:src_span_008
+7ffff7a4d740: IPE: table_name table_name_007, closure_desc closure_desc_007, ty_desc ty_desc_007, label label_007, module module_000, srcloc src_file_007:src_span_007
+7ffff7a4d740: IPE: table_name table_name_006, closure_desc closure_desc_006, ty_desc ty_desc_006, label label_006, module module_000, srcloc src_file_006:src_span_006
+7ffff7a4d740: IPE: table_name table_name_005, closure_desc closure_desc_005, ty_desc ty_desc_005, label label_005, module module_000, srcloc src_file_005:src_span_005
+7ffff7a4d740: IPE: table_name table_name_004, closure_desc closure_desc_004, ty_desc ty_desc_004, label label_004, module module_000, srcloc src_file_004:src_span_004
+7ffff7a4d740: IPE: table_name table_name_003, closure_desc closure_desc_003, ty_desc ty_desc_003, label label_003, module module_000, srcloc src_file_003:src_span_003
+7ffff7a4d740: IPE: table_name table_name_002, closure_desc closure_desc_002, ty_desc ty_desc_002, label label_002, module module_000, srcloc src_file_002:src_span_002
+7ffff7a4d740: IPE: table_name table_name_001, closure_desc closure_desc_001, ty_desc ty_desc_001, label label_001, module module_000, srcloc src_file_001:src_span_001
+7ffff7a4d740: IPE: table_name table_name_000, closure_desc closure_desc_000, ty_desc ty_desc_000, label label_000, module module_000, srcloc src_file_000:src_span_000
+7ffff7a4d740: IPE: table_name table_name_009, closure_desc closure_desc_009, ty_desc ty_desc_009, label label_009, module module_000, srcloc src_file_009:src_span_009
+7ffff7a4d740: IPE: table_name table_name_008, closure_desc closure_desc_008, ty_desc ty_desc_008, label label_008, module module_000, srcloc src_file_008:src_span_008
+7ffff7a4d740: IPE: table_name table_name_007, closure_desc closure_desc_007, ty_desc ty_desc_007, label label_007, module module_000, srcloc src_file_007:src_span_007
+7ffff7a4d740: IPE: table_name table_name_006, closure_desc closure_desc_006, ty_desc ty_desc_006, label label_006, module module_000, srcloc src_file_006:src_span_006
+7ffff7a4d740: IPE: table_name table_name_005, closure_desc closure_desc_005, ty_desc ty_desc_005, label label_005, module module_000, srcloc src_file_005:src_span_005
+7ffff7a4d740: IPE: table_name table_name_004, closure_desc closure_desc_004, ty_desc ty_desc_004, label label_004, module module_000, srcloc src_file_004:src_span_004
+7ffff7a4d740: IPE: table_name table_name_003, closure_desc closure_desc_003, ty_desc ty_desc_003, label label_003, module module_000, srcloc src_file_003:src_span_003
+7ffff7a4d740: IPE: table_name table_name_002, closure_desc closure_desc_002, ty_desc ty_desc_002, label label_002, module module_000, srcloc src_file_002:src_span_002
+7ffff7a4d740: IPE: table_name table_name_001, closure_desc closure_desc_001, ty_desc ty_desc_001, label label_001, module module_000, srcloc src_file_001:src_span_001
+7ffff7a4d740: IPE: table_name table_name_000, closure_desc closure_desc_000, ty_desc ty_desc_000, label label_000, module module_000, srcloc src_file_000:src_span_000

testsuite/tests/rts/ipe/ipeMap.c

@@ -53,6 +53,8 @@ HaskellObj shouldFindOneIfItHasBeenRegistered(Capability *cap) {
     StringTable st;
     init_string_table(&st);
 
+    node->module_name = add_string(&st, "TheModule");
+
     HaskellObj fortyTwo = UNTAG_CLOSURE(rts_mkInt(cap, 42));
     node->next = NULL;
     node->compressed = 0;
@@ -71,7 +73,7 @@ HaskellObj shouldFindOneIfItHasBeenRegistered(Capability *cap) {
     assertStringsEqual(result.prov.closure_desc, "closure_desc_042");
     assertStringsEqual(result.prov.ty_desc, "ty_desc_042");
     assertStringsEqual(result.prov.label, "label_042");
-    assertStringsEqual(result.prov.module, "module_042");
+    assertStringsEqual(result.prov.module, "TheModule");
     assertStringsEqual(result.prov.src_file, "src_file_042");
     assertStringsEqual(result.prov.src_span, "src_span_042");
 
@@ -88,6 +90,8 @@ void shouldFindTwoIfTwoHaveBeenRegistered(Capability *cap,
     StringTable st;
     init_string_table(&st);
 
+    node->module_name = add_string(&st, "TheModule");
+
     HaskellObj twentyThree = UNTAG_CLOSURE(rts_mkInt8(cap, 23));
     node->next = NULL;
     node->compressed = 0;

testsuite/tests/rts/ipe/ipe_lib.c

@@ -48,11 +48,6 @@ IpeBufferEntry makeAnyProvEntry(Capability *cap, StringTable *st, int i) {
     snprintf(label, labelLength, "label_%03i", i);
     provEnt.label = add_string(st, label);
 
-    unsigned int moduleLength = strlen("module_") + 3 /* digits */ + 1 /* null character */;
-    char *module = malloc(sizeof(char) * moduleLength);
-    snprintf(module, moduleLength, "module_%03i", i);
-    provEnt.module_name = add_string(st, module);
-
     unsigned int srcFileLength = strlen("src_file_") + 3 /* digits */ + 1 /* null character */;
     char *srcFile = malloc(sizeof(char) * srcFileLength);
     snprintf(srcFile, srcFileLength, "src_file_%03i", i);
@@ -77,6 +72,11 @@ IpeBufferListNode *makeAnyProvEntries(Capability *cap, int start, int end) {
     StringTable st;
     init_string_table(&st);
 
+    unsigned int moduleLength = strlen("module_") + 3 /* digits */ + 1 /* null character */;
+    char *module = malloc(sizeof(char) * moduleLength);
+    snprintf(module, moduleLength, "module_%03i", start);
+    node->module_name = add_string(&st, module);
+
     // Make the entries and fill the buffers
     for (int i=start; i < end; i++) {
         HaskellObj closure = rts_mkInt(cap, 42);