Detect when a C finalizer calls back to Haskell

This is illegal now, after the fix for #1364, but it turns out that
the existing check for dodgy callbacks doesn't catch finalizers
calling back, so we need another test.  This will be particularly
important for 6.10.2, because the behaviour has changed.

1 files changed, 11 insertions, 0 deletions

diff --git a/rts/Weak.c b/rts/Weak.c
index a50a72e59c..17150f6b3c 100644
--- a/rts/Weak.c
+++ b/rts/Weak.c
@@ -22,6 +22,9 @@
 
 StgWeak *weak_ptr_list;
 
+// So that we can detect when a finalizer illegally calls back into Haskell
+rtsBool running_finalizers = rtsFalse;
+
 void
 runCFinalizer(StgVoid *fn, StgVoid *ptr, StgVoid *env, StgWord flag)
 {
@@ -36,6 +39,8 @@ runAllCFinalizers(StgWeak *list)
 {
     StgWeak *w;
 
+    running_finalizers = rtsTrue;
+
     for (w = list; w; w = w->link) {
 	StgArrWords *farr;
 
@@ -47,6 +52,8 @@ runAllCFinalizers(StgWeak *list)
 	                  (StgVoid *)farr->payload[2],
 	                  farr->payload[3]);
     }
+
+    running_finalizers = rtsFalse;
 }
 
 /*
@@ -72,6 +79,8 @@ scheduleFinalizers(Capability *cap, StgWeak *list)
     StgMutArrPtrs *arr;
     nat n;
 
+    running_finalizers = rtsTrue;
+
     // count number of finalizers, and kill all the weak pointers first...
     n = 0;
     for (w = list; w; w = w->link) { 
@@ -105,6 +114,8 @@ scheduleFinalizers(Capability *cap, StgWeak *list)
 	SET_HDR(w, &stg_DEAD_WEAK_info, w->header.prof.ccs);
     }
 	
+    running_finalizers = rtsFalse;
+
     // No finalizers to run?
     if (n == 0) return;