wasm-tools 1.255.0

CLI tools for interoperating with WebAssembly files
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120

;; RUN: wast --assert default --snapshot tests/snapshots % -f stack-switching

(assert_invalid
  (module
    (type $ft (func))
    (type $ct (cont $ft))

    (type $tag_ft (func (param i32)))
    (tag $t (type $tag_ft))

    (func
      block $label
        (resume $ct (on $t switch) (ref.null $ct))
        unreachable
      end
    )
  )
  "type mismatch: switch tag does not match continuation")

(assert_invalid
  (module
    (type $ft (func))
    (type $ct (cont $ft))

    (type $tag_ft (func (result i32)))
    (tag $t (type $tag_ft))

    (func
      block $label
        (resume $ct (on $t switch) (ref.null $ct))
        unreachable
      end
    )
  )
  "type mismatch: switch tag does not match continuation")

(assert_invalid
  (module
    (type $ft (func (result i64)))
    (type $ct (cont $ft))

    (type $tag_ft (func (result i32)))
    (tag $t (type $tag_ft))

    (func
      block $label
        (resume $ct (on $t switch) (ref.null $ct))
        unreachable
      end
    )
  )
  "type mismatch: switch tag does not match continuation")

(module
  (type $ft (func (result i32)))
  (type $ct (cont $ft))

  (type $tag_ft (func (result i32)))
  (tag $t (type $tag_ft))

  (func
    block $label
      (resume $ct (on $t switch) (ref.null $ct))
      unreachable
    end
  )
)

(assert_invalid
  (module
    (type $ft (func (result nullfuncref)))
    (type $ct (cont $ft))

    (type $tag_ft (func (result funcref)))
    (tag $t (type $tag_ft))

    (func
      block $label
        (resume $ct (on $t switch) (ref.null $ct))
        unreachable
      end
    )
  )
  "type mismatch: switch tag does not match continuation")

;; The switch tag's results must be *equivalent* to the continuation's results,
;; not merely a subtype. Here the tag results `[nullfuncref]` are a strict
;; subtype of the continuation results `[funcref]`, so this must be rejected.
(assert_invalid
  (module
    (type $ft (func (result funcref)))
    (type $ct (cont $ft))

    (type $tag_ft (func (result nullfuncref)))
    (tag $t (type $tag_ft))

    (func
      block $label
        (resume $ct (on $t switch) (ref.null $ct))
        unreachable
      end
    )
  )
  "type mismatch: switch tag does not match continuation")

;; Equivalent reference-type results (both `[funcref]`) are accepted.
(module
  (type $ft (func (result funcref)))
  (type $ct (cont $ft))

  (type $tag_ft (func (result funcref)))
  (tag $t (type $tag_ft))

  (func
    block $label
      (resume $ct (on $t switch) (ref.null $ct))
      unreachable
    end
  )
)