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|
(module
(type $struct (struct i32))
(type $extendedstruct (struct i32 f64))
(type $bytes (array (mut i8)))
(import "fuzzing-support" "log-i32" (func $log (param i32)))
(func "structs"
(local $x (ref null $struct))
(local $y (ref null $struct))
(local.set $x
(struct.new_default_with_rtt $struct
(rtt.canon $struct)
)
)
;; The value is initialized to 0
;; Note: -Oz will optimize all these to constants thanks to Precompute
(call $log
(struct.get $struct 0 (local.get $x))
)
;; Assigning a value works
(struct.set $struct 0
(local.get $x)
(i32.const 42)
)
(call $log
(struct.get $struct 0 (local.get $x))
)
;; References are references, so writing to one's value affects the other's
(local.set $y (local.get $x))
(struct.set $struct 0
(local.get $y)
(i32.const 100)
)
(call $log
(struct.get $struct 0 (local.get $x))
)
(call $log
(struct.get $struct 0 (local.get $y))
)
)
(func "arrays"
(local $x (ref null $bytes))
(local.set $x
(array.new_with_rtt $bytes
(rtt.canon $bytes)
(i32.const 50) ;; size
(i32.const 42) ;; value to splat into the array
)
)
;; The length should be 50
(call $log
(array.len $bytes (local.get $x))
)
;; The value should be 42
(call $log
(array.get_u $bytes (local.get $x) (i32.const 10))
)
;; Write a value that will be truncated into an i8
(array.set $bytes (local.get $x) (i32.const 10) (i32.const 0xff80))
;; The value should be 0x80 (-128 or 128 depending on signed/unsigned)
(call $log
(array.get_u $bytes (local.get $x) (i32.const 10))
)
(call $log
(array.get_s $bytes (local.get $x) (i32.const 10))
)
;; Other items than the one at index 10 are unaffected.
(call $log
(array.get_s $bytes (local.get $x) (i32.const 20))
)
)
(func "rtts"
(local $x (rtt $struct))
(local $y (rtt $extendedstruct))
(local $z (rtt $extendedstruct))
(local $any anyref)
(local.set $x (rtt.canon $struct))
(local.set $y (rtt.sub $extendedstruct (local.get $x)))
(local.set $z (rtt.canon $extendedstruct))
;; Casting null returns null.
(call $log (ref.is_null
(ref.cast $struct (ref.null $struct) (local.get $x))
))
;; Testing null returns 0.
(call $log
(ref.test $struct (ref.null $struct) (local.get $x))
)
;; Testing something completely wrong (struct vs array) returns 0.
(call $log
(ref.test $struct
(array.new_with_rtt $bytes
(rtt.canon $bytes)
(i32.const 10)
(i32.const 20)
)
(local.get $x)
)
)
;; Testing a thing with the same RTT returns 1.
(call $log
(ref.test $struct
(struct.new_default_with_rtt $struct
(local.get $x)
)
(local.get $x)
)
)
;; A bad downcast returns 0: we create a struct, which is not a extendedstruct.
(call $log
(ref.test $extendedstruct
(struct.new_default_with_rtt $struct
(local.get $x)
)
(local.get $z)
)
)
;; Create a extendedstruct with RTT y, and upcast statically to anyref.
(local.set $any
(struct.new_default_with_rtt $extendedstruct
(local.get $y)
)
)
;; Casting to y, the exact same RTT, works.
(call $log
(ref.test $extendedstruct
(local.get $any)
(local.get $y)
)
)
;; Casting to z, another RTT of the same data type, fails.
(call $log
(ref.test $extendedstruct
(local.get $any)
(local.get $z)
)
)
;; Casting to x, the parent of y, works.
(call $log
(ref.test $struct
(local.get $any)
(local.get $x)
)
)
)
(func "br_on_cast"
(local $any anyref)
;; create a simple $struct, store it in an anyref
(local.set $any
(struct.new_default_with_rtt $struct (rtt.canon $struct))
)
(drop
(block $block (result ($ref $struct))
(drop
(block $extendedblock (result (ref $extendedstruct))
(drop
;; second, try to cast our simple $struct to what it is, which will work
(br_on_cast $block $struct
;; first, try to cast our simple $struct to an extended, which will fail
(br_on_cast $extendedblock $extendedstruct
(local.get $any) (rtt.canon $extendedstruct)
)
(rtt.canon $struct)
)
)
(call $log (i32.const -1)) ;; we should never get here
(return)
)
)
(call $log (i32.const -2)) ;; we should never get here either
(return)
)
)
(call $log (i32.const 3)) ;; we should get here
(drop
(block $never (result (ref $extendedstruct))
;; an untaken br_on_cast, with unreachable rtt - so we cannot use the
;; RTT in binaryen IR to find the cast type.
(br_on_cast $never $extendedstruct (ref.null $struct) (unreachable))
(unreachable)
)
)
)
)
|
