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| author | Ben Gamari <ben@smart-cactus.org> | 2022-05-23 23:00:32 -0400 |
|---|---|---|
| committer | Douglas Wilson <douglas.wilson@gmail.com> | 2022-06-16 17:02:48 +0100 |
| commit | 4d2db4a5547e88fb42ee74fa9d19566887ef4ac7 (patch) | |
| tree | ccd53c2a1a90f5e3554532f15c4cb0c484342e8a /rts | |
| parent | 49837c7f0ccb2971823d297c0fa0aea0c47a0487 (diff) | |
| download | haskell-wip/T21622.tar.gz | |
ghc-heap: Don't Box NULL pointerswip/T21622
Previously we could construct a `Box` of a NULL pointer from the `link`
field of `StgWeak`. Now we take care to avoid ever introducing such
pointers in `collect_pointers` and ensure that the `link` field is
represented as a `Maybe` in the `Closure` type.
Fixes #21622
Diffstat (limited to 'rts')
| -rw-r--r-- | rts/Heap.c | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/rts/Heap.c b/rts/Heap.c index 09beb9a8d2..0594a46b0b 100644 --- a/rts/Heap.c +++ b/rts/Heap.c @@ -224,13 +224,18 @@ StgWord collect_pointers(StgClosure *closure, StgClosure *ptrs[]) { ptrs[nptrs++] = (StgClosure *)((StgTSO *)closure)->bq; break; - case WEAK: - ptrs[nptrs++] = (StgClosure *)((StgWeak *)closure)->cfinalizers; - ptrs[nptrs++] = (StgClosure *)((StgWeak *)closure)->key; - ptrs[nptrs++] = (StgClosure *)((StgWeak *)closure)->value; - ptrs[nptrs++] = (StgClosure *)((StgWeak *)closure)->finalizer; - ptrs[nptrs++] = (StgClosure *)((StgWeak *)closure)->link; + case WEAK: { + StgWeak *w = (StgWeak *)closure; + ptrs[nptrs++] = (StgClosure *) w->cfinalizers; + ptrs[nptrs++] = (StgClosure *) w->key; + ptrs[nptrs++] = (StgClosure *) w->value; + ptrs[nptrs++] = (StgClosure *) w->finalizer; + // link may be NULL which is not a valid GC pointer + if (w->link) { + ptrs[nptrs++] = (StgClosure *) w->link; + } break; + } default: fprintf(stderr,"closurePtrs: Cannot handle type %s yet\n", |