Add RTS option to supress tix file

libraries/base/GHC/RTS/Flags.hsc

@@ -387,6 +387,13 @@ data ParFlags = ParFlags
              , Generic -- ^ @since 4.15.0.0
              )
 
+-- | Parameters pertaining to Haskell program coverage (HPC)
+data HpcFlags = HpcFlags
+    { emitTixFile :: Bool
+    }
+    deriving (Show
+             , Generic
+             )
 -- | Parameters of the runtime system
 --
 -- @since 4.8.0.0
@@ -400,6 +407,7 @@ data RTSFlags = RTSFlags
     , traceFlags      :: TraceFlags
     , tickyFlags      :: TickyFlags
     , parFlags        :: ParFlags
+    , hpcFlags        :: HpcFlags
     } deriving ( Show -- ^ @since 4.8.0.0
                , Generic -- ^ @since 4.15.0.0
                )
@@ -417,6 +425,7 @@ getRTSFlags =
            <*> getTraceFlags
            <*> getTickyFlags
            <*> getParFlags
+           <*> getHpcFlags
 
 peekFilePath :: Ptr () -> IO (Maybe FilePath)
 peekFilePath ptr
@@ -488,6 +497,10 @@ getParFlags = do
     <*> (toBool <$>
           (#{peek PAR_FLAGS, setAffinity} ptr :: IO CBool))
 
+
+getHpcFlags :: IO HpcFlags
+getHpcFlags = error "TODO: Implement getHpcFlags"
+
 getConcFlags :: IO ConcFlags
 getConcFlags = do
   let ptr = (#ptr RTS_FLAGS, ConcFlags) rtsFlagsPtr

rts/Hpc.c

@@ -394,7 +394,7 @@ exitHpc(void) {
 #else
   bool is_subprocess = false;
 #endif
-  if (!is_subprocess) {
+  if (!is_subprocess && RtsFlags.HpcFlags.emitTixFile) {
     FILE *f = __rts_fopen(tixFilename,"w+");
     writeTix(f);
   }

rts/RtsFlags.c

@@ -294,6 +294,7 @@ void initRtsFlagsDefaults(void)
     RtsFlags.TickyFlags.showTickyStats   = false;
     RtsFlags.TickyFlags.tickyFile        = NULL;
 #endif
+    RtsFlags.HpcFlags.emitTixFile        = true;
 }
 
 static const char *
@@ -1040,6 +1041,11 @@ error = true;
                         RtsFlags.GcFlags.nonmovingDenseAllocatorCount = threshold;
                       }
                   }
+                  else if (strequal("emit-tix-file=false",
+                              &rts_argv[arg][2])) {
+                       OPTION_UNSAFE;
+                       RtsFlags.HpcFlags.emitTixFile = false;
+                  }
 #if defined(THREADED_RTS)
 #if defined(mingw32_HOST_OS)
                   else if (!strncmp("io-manager-threads",

rts/include/rts/Flags.h

@@ -281,6 +281,12 @@ typedef struct _PAR_FLAGS {
   bool           setAffinity;    /* force thread affinity with CPUs */
 } PAR_FLAGS;
 
+/* See Note [Synchronization of flags and base APIs] */
+typedef struct _HPC_FLAGS {
+  bool           emitTixFile;    /* Whether the RTS should write a tix
+                                    file at the end of execution */
+} HPC_FLAGS;
+
 /* See Note [Synchronization of flags and base APIs] */
 typedef struct _TICKY_FLAGS {
     bool showTickyStats;
@@ -301,6 +307,7 @@ typedef struct _RTS_FLAGS {
     TRACE_FLAGS       TraceFlags;
     TICKY_FLAGS       TickyFlags;
     PAR_FLAGS         ParFlags;
+    HPC_FLAGS         HpcFlags;
 } RTS_FLAGS;
 
 #if defined(COMPILING_RTS_MAIN)