Limit printing of Literal[s] in a general way (#5792)

Previously we limited printing in a single Literals. But we can have
infinitely recursive GC literals, or just huge graphs even without
infinite recursion where no single Literals is that big (but we still
get exponential blowup). This PR adds a general limit on how much
we print once we start to print a Literal or Literals.

1 files changed, 43 insertions, 0 deletions

diff --git a/test/lit/exec/eh-print.wast b/test/lit/exec/eh-print.wast
new file mode 100644
index 000000000..8f9520e75
--- /dev/null
+++ b/test/lit/exec/eh-print.wast
@@ -0,0 +1,43 @@
+;; NOTE: Assertions have been generated by update_lit_checks.py --output=fuzz-exec and should not be edited.
+
+;; RUN: wasm-opt %s -all --fuzz-exec-before -q -o /dev/null 2>&1 | filecheck %s
+
+(module
+ (tag $A (param (ref $A)))
+ (tag $B (param (ref $B)))
+
+ (type $A (array (field (mut i32))))
+
+ (type $B (struct (field (mut anyref))))
+
+ ;; CHECK:      [fuzz-exec] calling array
+ ;; CHECK-NEXT: [exception thrown: A [ref (type $array.0 (array (mut i32))) (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0[..])]]
+ (func "array" (result (ref $A))
+  ;; Throw a very large array. We should not print all 12K items in it, as that
+  ;; would be very verbose. Instead we stop after a reasonable amount and
+  ;; print [..] for the rest.
+  (throw $A
+   (array.new_default $A
+    (i32.const 12345)
+   )
+  )
+ )
+
+ ;; CHECK:      [fuzz-exec] calling struct
+ ;; CHECK-NEXT: [exception thrown: B [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [ref (type $struct.0 (struct (field (mut anyref)))) [..]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]
+ (func "struct" (result (ref $B))
+  (local $x (ref $B))
+  ;; As above, but now with a recursive struct.
+  (local.set $x
+   (struct.new_default $B)
+  )
+  (struct.set $B 0
+   (local.get $x)
+   (local.get $x)
+  )
+  (throw $B
+   (local.get $x)
+  )
+ )
+)
+