p

scripts/test/fuzzing.py

@@ -19,10 +19,14 @@
 unfuzzable = [
     # Float16 is still experimental.
     'f16.wast',
-    # TODO: fuzzer and interpreter support for strings
+    # TODO: fuzzer and interpreter support for strings, including limitations
+    #       like the fuzzer not handling (ref extern) imports (there is no way
+    #       to create a replacement value)
     'strings.wast',
     'simplify-locals-strings.wast',
     'string-lowering-instructions.wast',
+    'O2_strings.wast',
+    'O2_O3_strings.wast',
     # TODO: fuzzer and interpreter support for extern conversions
     'extern-conversions.wast',
     # ignore DWARF because it is incompatible with multivalue atm

test/lit/string-builtins.wast

@@ -0,0 +1,28 @@
+;; NOTE: Assertions have been generated by update_lit_checks.py --all-items and should not be edited.
+;; NOTE: This test was ported using port_passes_tests_to_lit.py and could be cleaned up.
+
+;; Run normal -O2, which should lift, optimize, and lower strings, if the
+;; string builtins feature is enabled. We optimize in the last two here.
+
+;; RUN: foreach %s %t wasm-opt -O2                          -S -o - | filecheck %s --check-prefix=MVP
+;; RUN: foreach %s %t wasm-opt -O2 -all                     -S -o - | filecheck %s --check-prefix=ALL
+;; RUN: foreach %s %t wasm-opt -O2 --enable-string-builtins -S -o - | filecheck %s --check-prefix=ESB
+
+(module
+  (type $array16 (array (mut i16)))
+
+  (import "\'" "foo" (global $foo (ref extern)))
+
+  (import "\'" "bar" (global $bar (ref extern)))
+
+  (import "wasm:js-string" "concat" (func $concat (param externref externref) (result (ref extern))))
+
+  (func $string.concat (export "string.concat") (result (ref extern))
+    ;; When we optimize, we concatenate "foo" and "bar" here to "foobar". A new
+    ;; imported global will appear for that, and we will get it here.
+    (call $concat
+      (global.get $foo)
+      (global.get $bar)
+    )
+  )
+)