wasm-split: Handle RefFuncs (#6513)

When we have a ref.func that refers to the secondary module then make a trampoline
that calls it directly. The trampoline's call is then fixed up like all direct calls to the
secondary module.

2 files changed, 160 insertions, 0 deletions

diff --git a/test/lit/wasm-split/passive.wast b/test/lit/wasm-split/passive.wast
new file mode 100644
index 000000000..a72dcada5
--- /dev/null
+++ b/test/lit/wasm-split/passive.wast
@@ -0,0 +1,54 @@
+;; NOTE: Assertions have been generated by update_lit_checks.py --all-items and should not be edited.
+
+;; RUN: wasm-split %s --split-funcs=second-in-table -g -o1 %t.1.wasm -o2 %t.2.wasm -all
+;; RUN: wasm-dis %t.1.wasm | filecheck %s --check-prefix PRIMARY
+;; RUN: wasm-dis %t.2.wasm | filecheck %s --check-prefix SECONDARY
+
+(module
+ (type $func-array (array (mut funcref)))
+
+ ;; PRIMARY:      (type $0 (func))
+
+ ;; PRIMARY:      (import "placeholder" "0" (func $placeholder_0))
+
+ ;; PRIMARY:      (table $table 3 funcref)
+ (table $table 3 funcref)
+
+ ;; Workaround for https://github.com/WebAssembly/binaryen/issues/6572 - we
+ ;; error without an active segment.
+ (elem (i32.const 0))
+
+ ;; PRIMARY:      (elem $0 (i32.const 0) $placeholder_0)
+
+ ;; PRIMARY:      (elem $passive func $in-table $1)
+ (elem $passive func $in-table $second-in-table)
+
+ ;; PRIMARY:      (export "table" (table $table))
+
+ ;; PRIMARY:      (func $in-table
+ ;; PRIMARY-NEXT:  (nop)
+ ;; PRIMARY-NEXT: )
+ (func $in-table
+  ;; This is in a passive segment, but it is in the main module so we need no
+  ;; special handling.
+ )
+
+ ;; SECONDARY:      (type $0 (func))
+
+ ;; SECONDARY:      (import "primary" "table" (table $table 3 funcref))
+
+ ;; SECONDARY:      (elem $0 (i32.const 0) $second-in-table)
+
+ ;; SECONDARY:      (func $second-in-table
+ ;; SECONDARY-NEXT:  (nop)
+ ;; SECONDARY-NEXT: )
+ (func $second-in-table
+  ;; This is in a passive segment, and it is in the secondary module, so we will
+  ;; handle it by adding a trampoline from the segment as a new function "$1".
+ )
+)
+;; PRIMARY:      (func $1
+;; PRIMARY-NEXT:  (call_indirect (type $0)
+;; PRIMARY-NEXT:   (i32.const 0)
+;; PRIMARY-NEXT:  )
+;; PRIMARY-NEXT: )
diff --git a/test/lit/wasm-split/ref.func.wast b/test/lit/wasm-split/ref.func.wast
new file mode 100644
index 000000000..f7832dcf4
--- /dev/null
+++ b/test/lit/wasm-split/ref.func.wast
@@ -0,0 +1,106 @@
+;; NOTE: Assertions have been generated by update_lit_checks.py --all-items and should not be edited.
+
+;; RUN: wasm-split %s --split-funcs=second,second-in-table -g -o1 %t.1.wasm -o2 %t.2.wasm -all
+;; RUN: wasm-dis %t.1.wasm | filecheck %s --check-prefix PRIMARY
+;; RUN: wasm-dis %t.2.wasm | filecheck %s --check-prefix SECONDARY
+
+;; Test that we handle ref.func operations properly as we split out $second.
+;; ref.funcs that refer to the other module must be fixed up to refer to
+;; something in the same module, that then trampolines to the other.
+(module
+ ;; PRIMARY:      (type $0 (func))
+
+ ;; PRIMARY:      (import "placeholder" "1" (func $placeholder_1))
+
+ ;; PRIMARY:      (import "placeholder" "2" (func $placeholder_2))
+
+ ;; PRIMARY:      (global $glob1 (ref func) (ref.func $prime))
+
+ ;; PRIMARY:      (global $glob2 (ref func) (ref.func $2))
+
+ ;; PRIMARY:      (table $table 3 3 funcref)
+ (table $table 1 1 funcref)
+
+ (global $glob1 (ref func) (ref.func $prime))
+
+ (global $glob2 (ref func) (ref.func $second))
+
+ ;; PRIMARY:      (elem $elem (i32.const 0) $in-table $placeholder_1 $placeholder_2)
+ (elem $elem (i32.const 0) $in-table $second-in-table)
+
+ ;; PRIMARY:      (export "prime" (func $prime))
+
+ ;; PRIMARY:      (export "table" (table $table))
+
+ ;; PRIMARY:      (export "global" (global $glob1))
+
+ ;; PRIMARY:      (export "global_3" (global $glob2))
+
+ ;; PRIMARY:      (func $prime
+ ;; PRIMARY-NEXT:  (drop
+ ;; PRIMARY-NEXT:   (ref.func $prime)
+ ;; PRIMARY-NEXT:  )
+ ;; PRIMARY-NEXT:  (drop
+ ;; PRIMARY-NEXT:   (ref.func $2)
+ ;; PRIMARY-NEXT:  )
+ ;; PRIMARY-NEXT: )
+ (func $prime
+  (drop
+   (ref.func $prime)
+  )
+  (drop
+   (ref.func $second)
+  )
+ )
+
+ ;; SECONDARY:      (type $0 (func))
+
+ ;; SECONDARY:      (import "primary" "table" (table $table 3 3 funcref))
+
+ ;; SECONDARY:      (import "primary" "global" (global $glob1 (ref func)))
+
+ ;; SECONDARY:      (import "primary" "global_3" (global $glob2 (ref func)))
+
+ ;; SECONDARY:      (import "primary" "prime" (func $prime))
+
+ ;; SECONDARY:      (elem $0 (i32.const 1) $second-in-table $second)
+
+ ;; SECONDARY:      (func $second
+ ;; SECONDARY-NEXT:  (drop
+ ;; SECONDARY-NEXT:   (ref.func $prime)
+ ;; SECONDARY-NEXT:  )
+ ;; SECONDARY-NEXT:  (drop
+ ;; SECONDARY-NEXT:   (ref.func $second)
+ ;; SECONDARY-NEXT:  )
+ ;; SECONDARY-NEXT: )
+ (func $second
+  (drop
+   (ref.func $prime)
+  )
+  (drop
+   (ref.func $second)
+  )
+ )
+
+ ;; PRIMARY:      (func $in-table
+ ;; PRIMARY-NEXT:  (nop)
+ ;; PRIMARY-NEXT: )
+ (func $in-table
+  ;; This empty function is in the table. Just being present in the table is not
+  ;; enough of a reason for us to make a trampoline, even though in our IR the
+  ;; table is a list of ref.funcs.
+ )
+
+ ;; SECONDARY:      (func $second-in-table
+ ;; SECONDARY-NEXT:  (nop)
+ ;; SECONDARY-NEXT: )
+ (func $second-in-table
+  ;; As above, but in the secondary module. We still don't need a trampoline
+  ;; (but we will get a placeholder, as all split-out functions do).
+ )
+)
+;; PRIMARY:      (func $2
+;; PRIMARY-NEXT:  (call_indirect (type $0)
+;; PRIMARY-NEXT:   (i32.const 2)
+;; PRIMARY-NEXT:  )
+;; PRIMARY-NEXT: )