Skip to content

[Wasm R2R] Report tracked GC vars as untracked in GC info #129100

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
AndyAyersMS merged 1 commit into from
Jun 7, 2026
+14 −2
Merged

[Wasm R2R] Report tracked GC vars as untracked in GC info #129100

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
8 changes: 8 additions & 0 deletions src/coreclr/jit/codegencommon.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -3799,6 +3799,14 @@ void CodeGen::genCheckUseBlockInit()
JITDUMP("must init a tracked V%02u because it a struct with a GC ref\n", varNum);
mustInitThisVar = true;
}
#ifdef TARGET_WASM
else if (hasGCPtr)
{
// On wasm all GC vars are reported as untracked, so the slot must be zero-inited.
JITDUMP("must init V%02u because wasm reports tracked GC vars as untracked\n", varNum);
mustInitThisVar = true;
}
#endif
else
{
// We are done with tracked or GC vars, now look at untracked vars without GC refs.
Expand Down
8 changes: 6 additions & 2 deletions src/coreclr/jit/gcencode.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -4134,7 +4134,9 @@ void GCInfo::gcMakeRegPtrTable(
// If it is pinned, it must be an untracked local.
assert(!varDsc->lvPinned || !varDsc->lvTracked);

if (varDsc->lvTracked || !varDsc->lvOnFrame)
// When noTrackedGCSlots is true (e.g. on wasm) tracked on-frame GC vars
// must be reported here as untracked, since gcVarPtrList is not populated.
if ((varDsc->lvTracked && !noTrackedGCSlots) || !varDsc->lvOnFrame)
{
continue;
}
Expand All @@ -4161,7 +4163,9 @@ void GCInfo::gcMakeRegPtrTable(
}
else
{
if (varDsc->lvIsRegArg && varDsc->lvTracked)
// When noTrackedGCSlots is true (e.g. on wasm) tracked register args
// must fall through and be reported as untracked.
if (varDsc->lvIsRegArg && varDsc->lvTracked && !noTrackedGCSlots)
{
// If this register-passed arg is tracked, then
// it has been allocated space near the other
Expand Down
Loading