Fix unreachable prefix in instruction printing (#2265)

When a memory instruction's type is unreachable, i.e., one of its
child expressions is unreachable, the instruction will be printed like
`unreachable.load`, which is invalid text format.

This prints unreachable prefix instruction types as `i32` to just make
them pass the parser. It is OK because they are not reachable anyway.
Also this removes printing of `?` in atomic.rmw instruction printing.

7 files changed, 75 insertions, 4 deletions

diff --git a/test/passes/alignment-lowering.txt b/test/passes/alignment-lowering.txt
index dd8d8ca9c..61066dc54 100644
--- a/test/passes/alignment-lowering.txt
+++ b/test/passes/alignment-lowering.txt
@@ -437,7 +437,7 @@
    )
   )
   (drop
-   (unreachable.load offset=100
+   (i32.load offset=100
     (unreachable)
    )
   )
diff --git a/test/passes/flatten.txt b/test/passes/flatten.txt
index 7cfd1e6a7..5fc0a1032 100644
--- a/test/passes/flatten.txt
+++ b/test/passes/flatten.txt
@@ -679,7 +679,7 @@
    (drop
     (unreachable)
    )
-   (unreachable.load
+   (i32.load
     (unreachable)
    )
    (unreachable)
@@ -1183,7 +1183,7 @@
     (i32.const 22)
     (block
      (unreachable)
-     (unreachable.load
+     (i32.load
       (unreachable)
      )
      (drop
diff --git a/test/passes/remove-unused-brs.txt b/test/passes/remove-unused-brs.txt
index 790d943c3..0cfa94f6c 100644
--- a/test/passes/remove-unused-brs.txt
+++ b/test/passes/remove-unused-brs.txt
@@ -984,7 +984,7 @@
      (i32.const 607395945)
     )
     (br_if $label$1
-     (unreachable.load offset=3 align=1
+     (i32.load offset=3 align=1
       (select
        (call $untaken-brs-might-prevent-block-removal
         (f32.const 1.4904844647389837e-07)
diff --git a/test/unreachable-instr-type.wast b/test/unreachable-instr-type.wast
new file mode 100644
index 000000000..220347f0f
--- /dev/null
+++ b/test/unreachable-instr-type.wast
@@ -0,0 +1,28 @@
+(module
+  (memory (shared 1 1))
+  (func $test
+    (f32.load (unreachable))
+
+    (f32.store
+      (unreachable)
+      (f32.const 0)
+    )
+
+    (i64.atomic.rmw.add
+      (unreachable)
+      (i64.const 0)
+    )
+
+    (i64.atomic.rmw.cmpxchg
+      (unreachable)
+      (i64.const 0)
+      (i64.const 1)
+    )
+
+    (i64.atomic.wait
+      (unreachable)
+      (i64.const 0)
+      (i64.const 0)
+    )
+  )
+)
diff --git a/test/unreachable-instr-type.wast.from-wast b/test/unreachable-instr-type.wast.from-wast
new file mode 100644
index 000000000..2e3a87b49
--- /dev/null
+++ b/test/unreachable-instr-type.wast.from-wast
@@ -0,0 +1,27 @@
+(module
+ (type $FUNCSIG$v (func))
+ (memory $0 (shared 1 1))
+ (func $test (; 0 ;) (type $FUNCSIG$v)
+  (i32.load
+   (unreachable)
+  )
+  (f32.store
+   (unreachable)
+   (f32.const 0)
+  )
+  (i32.atomic.rmw.add
+   (unreachable)
+   (i64.const 0)
+  )
+  (i32.atomic.rmw.cmpxchg
+   (unreachable)
+   (i64.const 0)
+   (i64.const 1)
+  )
+  (i64.atomic.wait
+   (unreachable)
+   (i64.const 0)
+   (i64.const 0)
+  )
+ )
+)
diff --git a/test/unreachable-instr-type.wast.fromBinary b/test/unreachable-instr-type.wast.fromBinary
new file mode 100644
index 000000000..32838581a
--- /dev/null
+++ b/test/unreachable-instr-type.wast.fromBinary
@@ -0,0 +1,8 @@
+(module
+ (type $0 (func))
+ (memory $0 (shared 1 1))
+ (func $test (; 0 ;) (type $0)
+  (unreachable)
+ )
+)
+
diff --git a/test/unreachable-instr-type.wast.fromBinary.noDebugInfo b/test/unreachable-instr-type.wast.fromBinary.noDebugInfo
new file mode 100644
index 000000000..16237ef69
--- /dev/null
+++ b/test/unreachable-instr-type.wast.fromBinary.noDebugInfo
@@ -0,0 +1,8 @@
+(module
+ (type $0 (func))
+ (memory $0 (shared 1 1))
+ (func $0 (; 0 ;) (type $0)
+  (unreachable)
+ )
+)
+