Source code
Revision control
Copy as Markdown
Other Tools
// type $S is too large to fit in an inline WasmGcObject, and the write barrier
// logic must take this into account when storing the (ref $S2) into the last
// field of the object.
const wat = `
(module
(type $S2 (sub (struct)))
(type $S (sub $S2
(struct
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut eqref)))))
(func $main
(struct.set $S 18
(struct.new $S
(i64.const 0)
(i64.const 0)
(i64.const 0)
(i64.const 0)
(i64.const 0)
(i64.const 0)
(i64.const 0)
(i64.const 0)
(i64.const 0)
(i64.const 0)
(i64.const 0)
(i64.const 0)
(i64.const 0)
(i64.const 0)
(i64.const 0)
(i64.const 0)
(i64.const 0)
(i64.const 0)
(ref.null eq))
(struct.new $S2)))
(start $main))
`
wasmEvalText(wat);
// Test subtyping across outline/inline representations works
wasmEvalText(`
(module
(type $inline
(sub (struct
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
)))
(type $outline (sub $inline
(struct
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64))
(field (mut i64)))))
(func $main
(local $outline (ref null $outline))
(local $inline (ref null $inline))
(; create an outline object and acquire multiple views to it ;)
(struct.new $outline
(i64.const 0xFF)
(i64.const 0)
(i64.const 0)
(i64.const 0)
(i64.const 0)
(i64.const 0)
(i64.const 0)
(i64.const 0)
(i64.const 0)
(i64.const 0)
(i64.const 0)
(i64.const 0)
(i64.const 0)
(i64.const 0)
(i64.const 0)
(i64.const 0)
(i64.const 0)
(i64.const 0)
(i64.const 0))
local.tee $outline
local.set $inline
(; clobber the object header ;)
(struct.set $inline 0
local.get $inline
i64.const 0
)
(struct.set $inline 1
local.get $inline
i64.const 0
)
(struct.set $inline 2
local.get $inline
i64.const 0
)
(struct.set $inline 3
local.get $inline
i64.const 0
)
(struct.set $inline 4
local.get $inline
i64.const 0
)
(; try to read a field ;)
(struct.get $outline 0
local.get $outline
)
drop
)
(start $main))
`);