[threads] Fix shared ref.eq and disallow mixed-shareability (#6763)

Update the validator to reject mixed-shareability ref.eq, although this
is still under discussion in
https://github.com/WebAssembly/shared-everything-threads/issues/76. Fix
the implementation of `Literal::operator==` to work properly with shared
i31ref.

2 files changed, 202 insertions, 2 deletions

diff --git a/test/spec/shared-polymorphism.wast b/test/spec/shared-polymorphism.wast
index be8b5e467..5c9d905e7 100644
--- a/test/spec/shared-polymorphism.wast
+++ b/test/spec/shared-polymorphism.wast
@@ -2,8 +2,6 @@
 ;; references.
 (module
   (func (drop (ref.eq (ref.null (shared none)) (ref.null (shared none)))))
-  (func (drop (ref.eq (ref.null (shared none)) (ref.null none))))
-  (func (drop (ref.eq (ref.null none) (ref.null (shared none)))))
 
   (func (param (ref null (shared i31))) (drop (i31.get_s (local.get 0))))
   (func (param (ref null (shared i31))) (drop (i31.get_u (local.get 0))))
diff --git a/test/spec/shared-ref_eq.wast b/test/spec/shared-ref_eq.wast
new file mode 100644
index 000000000..662138ee6
--- /dev/null
+++ b/test/spec/shared-ref_eq.wast
@@ -0,0 +1,202 @@
+(module
+  (type $st (sub (shared (struct))))
+  (type $st' (sub (shared (struct (field i32)))))
+  (type $at (shared (array i8)))
+  (type $st-sub1 (sub $st (shared (struct))))
+  (type $st-sub2 (sub $st (shared (struct))))
+  (type $st'-sub1 (sub $st' (shared (struct (field i32)))))
+  (type $st'-sub2 (sub $st' (shared (struct (field i32)))))
+
+  (table 20 (ref null (shared eq)))
+
+  (func (export "init")
+    (table.set (i32.const 0) (ref.null (shared eq)))
+    (table.set (i32.const 1) (ref.null (shared i31)))
+    (table.set (i32.const 2) (ref.i31_shared (i32.const 7)))
+    (table.set (i32.const 3) (ref.i31_shared (i32.const 7)))
+    (table.set (i32.const 4) (ref.i31_shared (i32.const 8)))
+    (table.set (i32.const 5) (struct.new_default $st))
+    (table.set (i32.const 6) (struct.new_default $st))
+    (table.set (i32.const 7) (array.new_default $at (i32.const 0)))
+    (table.set (i32.const 8) (array.new_default $at (i32.const 0)))
+  )
+
+  (func (export "eq") (param $i i32) (param $j i32) (result i32)
+    (ref.eq (table.get (local.get $i)) (table.get (local.get $j)))
+  )
+)
+
+(invoke "init")
+
+(assert_return (invoke "eq" (i32.const 0) (i32.const 0)) (i32.const 1))
+(assert_return (invoke "eq" (i32.const 0) (i32.const 1)) (i32.const 1))
+(assert_return (invoke "eq" (i32.const 0) (i32.const 2)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 0) (i32.const 3)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 0) (i32.const 4)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 0) (i32.const 5)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 0) (i32.const 6)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 0) (i32.const 7)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 0) (i32.const 8)) (i32.const 0))
+
+(assert_return (invoke "eq" (i32.const 1) (i32.const 0)) (i32.const 1))
+(assert_return (invoke "eq" (i32.const 1) (i32.const 1)) (i32.const 1))
+(assert_return (invoke "eq" (i32.const 1) (i32.const 2)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 1) (i32.const 3)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 1) (i32.const 4)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 1) (i32.const 5)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 1) (i32.const 6)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 1) (i32.const 7)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 1) (i32.const 8)) (i32.const 0))
+
+(assert_return (invoke "eq" (i32.const 2) (i32.const 0)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 2) (i32.const 1)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 2) (i32.const 2)) (i32.const 1))
+(assert_return (invoke "eq" (i32.const 2) (i32.const 3)) (i32.const 1))
+(assert_return (invoke "eq" (i32.const 2) (i32.const 4)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 2) (i32.const 5)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 2) (i32.const 6)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 2) (i32.const 7)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 2) (i32.const 8)) (i32.const 0))
+
+(assert_return (invoke "eq" (i32.const 3) (i32.const 0)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 3) (i32.const 1)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 3) (i32.const 2)) (i32.const 1))
+(assert_return (invoke "eq" (i32.const 3) (i32.const 3)) (i32.const 1))
+(assert_return (invoke "eq" (i32.const 3) (i32.const 4)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 3) (i32.const 5)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 3) (i32.const 6)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 3) (i32.const 7)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 3) (i32.const 8)) (i32.const 0))
+
+(assert_return (invoke "eq" (i32.const 4) (i32.const 0)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 4) (i32.const 1)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 4) (i32.const 2)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 4) (i32.const 3)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 4) (i32.const 4)) (i32.const 1))
+(assert_return (invoke "eq" (i32.const 4) (i32.const 5)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 4) (i32.const 6)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 4) (i32.const 7)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 4) (i32.const 8)) (i32.const 0))
+
+(assert_return (invoke "eq" (i32.const 5) (i32.const 0)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 5) (i32.const 1)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 5) (i32.const 2)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 5) (i32.const 3)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 5) (i32.const 4)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 5) (i32.const 5)) (i32.const 1))
+(assert_return (invoke "eq" (i32.const 5) (i32.const 6)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 5) (i32.const 7)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 5) (i32.const 8)) (i32.const 0))
+
+(assert_return (invoke "eq" (i32.const 6) (i32.const 0)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 6) (i32.const 1)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 6) (i32.const 2)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 6) (i32.const 3)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 6) (i32.const 4)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 6) (i32.const 5)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 6) (i32.const 6)) (i32.const 1))
+(assert_return (invoke "eq" (i32.const 6) (i32.const 7)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 6) (i32.const 8)) (i32.const 0))
+
+(assert_return (invoke "eq" (i32.const 7) (i32.const 0)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 7) (i32.const 1)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 7) (i32.const 2)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 7) (i32.const 3)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 7) (i32.const 4)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 7) (i32.const 5)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 7) (i32.const 6)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 7) (i32.const 7)) (i32.const 1))
+(assert_return (invoke "eq" (i32.const 7) (i32.const 8)) (i32.const 0))
+
+(assert_return (invoke "eq" (i32.const 8) (i32.const 0)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 8) (i32.const 1)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 8) (i32.const 2)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 8) (i32.const 3)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 8) (i32.const 4)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 8) (i32.const 5)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 8) (i32.const 6)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 8) (i32.const 7)) (i32.const 0))
+(assert_return (invoke "eq" (i32.const 8) (i32.const 8)) (i32.const 1))
+
+(assert_invalid
+  (module
+    (func (export "eq") (param $r (ref (shared any))) (result i32)
+      (ref.eq (local.get $r) (local.get $r))
+    )
+  )
+  "type mismatch"
+)
+(assert_invalid
+  (module
+    (func (export "eq") (param $r (ref null (shared any))) (result i32)
+      (ref.eq (local.get $r) (local.get $r))
+    )
+  )
+  "type mismatch"
+)
+(assert_invalid
+  (module
+    (func (export "eq") (param $r (ref null (shared func))) (result i32)
+      (ref.eq (local.get $r) (local.get $r))
+    )
+  )
+  "type mismatch"
+)
+(assert_invalid
+  (module
+    (func (export "eq") (param $r (ref null (shared func))) (result i32)
+      (ref.eq (local.get $r) (local.get $r))
+    )
+  )
+  "type mismatch"
+)
+(assert_invalid
+  (module
+    (func (export "eq") (param $r (ref (shared extern))) (result i32)
+      (ref.eq (local.get $r) (local.get $r))
+    )
+  )
+  "type mismatch"
+)
+(assert_invalid
+  (module
+    (func (export "eq") (param $r (ref null (shared extern))) (result i32)
+      (ref.eq (local.get $r) (local.get $r))
+    )
+  )
+  "type mismatch"
+)
+
+;; Mixed shared / unshared eq
+(assert_invalid
+  (module
+    (func (export "eq") (param $r1 (ref eq)) (param $r2 (ref (shared eq))) (result i32)
+      (ref.eq (local.get $r1) (local.get $r2))
+    )
+  )
+  "type mismatch"
+)
+(assert_invalid
+  (module
+    (func (export "eq") (param $r1 (ref (shared eq))) (param $r2 (ref eq)) (result i32)
+      (ref.eq (local.get $r1) (local.get $r2))
+    )
+  )
+  "type mismatch"
+)
+(assert_invalid
+  (module
+    (func (export "eq") (param $r1 eqref) (param $r2 (ref null (shared eq))) (result i32)
+      (ref.eq (local.get $r1) (local.get $r2))
+    )
+  )
+  "type mismatch"
+)
+(assert_invalid
+  (module
+    (func (export "eq") (param $r1 (ref null (shared eq))) (param $r2 eqref) (result i32)
+      (ref.eq (local.get $r1) (local.get $r2))
+    )
+  )
+  "type mismatch"
+)