Add write barriers when setting Tasks' scope field.

src/codegen.cpp

@@ -9334,6 +9334,7 @@ static jl_llvm_functions_t
                 Value *scope_ptr = get_scope_field(ctx);
                 LoadInst *current_scope = ctx.builder.CreateAlignedLoad(ctx.types().T_prjlvalue, scope_ptr, ctx.types().alignof_ptr);
                 StoreInst *scope_store = ctx.builder.CreateAlignedStore(scope_boxed, scope_ptr, ctx.types().alignof_ptr);
+                emit_write_barrier(ctx, get_current_task(ctx), scope_boxed);
                 jl_aliasinfo_t::fromTBAA(ctx, ctx.tbaa().tbaa_gcframe).decorateInst(current_scope);
                 jl_aliasinfo_t::fromTBAA(ctx, ctx.tbaa().tbaa_gcframe).decorateInst(scope_store);
                 // GC preserve the scope, since it is not rooted in the `jl_handler_t *`

src/interpreter.c

@@ -545,6 +545,7 @@ static jl_value_t *eval_body(jl_array_t *stmts, interpreter_state *s, size_t ip,
                 // replaced later
                 JL_GC_PUSH1(&scope);
                 ct->scope = scope;
+                jl_gc_wb(ct, ct->scope);
                 if (!jl_setjmp(__eh.eh_ctx, 0)) {
                     ct->eh = &__eh;
                     eval_body(stmts, s, next_ip, toplevel);

src/rtutils.c

@@ -296,6 +296,7 @@ JL_DLLEXPORT void jl_eh_restore_state(jl_task_t *ct, jl_handler_t *eh)
     ct->eh = eh->prev;
     ct->gcstack = eh->gcstack;
     ct->scope = eh->scope;
+    jl_gc_wb(ct, ct->scope);
     small_arraylist_t *locks = &ptls->locks;
     int unlocks = locks->len > eh->locks_len;
     if (unlocks) {
@@ -335,6 +336,7 @@ JL_DLLEXPORT void jl_eh_restore_state_noexcept(jl_task_t *ct, jl_handler_t *eh)
 {
     assert(ct->gcstack == eh->gcstack && "Incorrect GC usage under try catch");
     ct->scope = eh->scope;
+    jl_gc_wb(ct, ct->scope);
     ct->eh = eh->prev;
     ct->ptls->defer_signal = eh->defer_signal; // optional, but certain try-finally (in stream.jl) may be slightly harder to write without this
 }

src/task.c

@@ -1108,6 +1108,7 @@ JL_DLLEXPORT jl_task_t *jl_new_task(jl_function_t *start, jl_value_t *completion
     jl_atomic_store_relaxed(&t->_isexception, 0);
     // Inherit scope from parent task
     t->scope = ct->scope;
+    jl_gc_wb(t, ct->scope);
     // Fork task-local random state from parent
     jl_rng_split(t->rngState, ct->rngState);
     // there is no active exception handler available on this stack yet