Add initial script to generate relaxed atomics spec test (WebAssembly#8220)

Part of WebAssembly#8165. test/spec/relaxed-atomics2.wast was generated by the
script. Binary tests will be added in the next PR.

Will add missing instructions e.g. load8, i64 instructions, etc once the
approach looks good.

The ruff warning for E741 probably isn't triggering anymore, but I chose
to disable it because it disallows variables named `l` because it could
be confused with `I` which I think isn't relevant in text editors.

Author: stevenfontanella

.ruff.toml

@@ -31,6 +31,7 @@ ignore = [
   "B011", # https://docs.astral.sh/ruff/rules/assert-false/
   "B023", # https://docs.astral.sh/ruff/rules/function-uses-loop-variable/
   "E501", # https://docs.astral.sh/ruff/rules/line-too-long/
+  "E741", # https://docs.astral.sh/ruff/rules/ambiguous-variable-name/
   "PERF401", # https://docs.astral.sh/ruff/rules/manual-list-comprehension/
   "PLR0912", # https://docs.astral.sh/ruff/rules/too-many-branches/
   "PLR0913", # https://docs.astral.sh/ruff/rules/too-many-arguments/

scripts/test/generate-atomic-spec-test.py

@@ -0,0 +1,98 @@
+import enum
+from dataclasses import dataclass
+from enum import Enum
+
+# Workaround for python <3.10, escape characters can't appear in f-strings.
+# Although we require 3.10 in some places, the formatter complains without this.
+newline = "\n"
+
+
+def indent(s):
+    return "\n".join(f"  {line}" if line else "" for line in s.split("\n"))
+
+
+class ValueType(Enum):
+    i32 = enum.auto()
+    i64 = enum.auto()
+
+
+class Ordering(Enum):
+    seqcst = 0
+    acqrel = 1
+
+
+@dataclass
+class Template:
+    str: str
+    value_type: object
+    args: int
+
+
+templates = [
+    Template(str="(drop (i32.atomic.load %(memarg)s%(args)s))", value_type=ValueType.i32, args=1),
+    Template(str="(drop (i64.atomic.load %(memarg)s%(args)s))", value_type=ValueType.i64, args=1),
+    Template(str="(i32.atomic.store %(memarg)s%(args)s)", value_type=ValueType.i32, args=2),
+    Template(str="(i64.atomic.store %(memarg)s%(args)s)", value_type=ValueType.i64, args=2),
+]
+
+
+def statement(template, mem_idx: str | None, ordering: Ordering | None):
+    """Return a statement exercising the op in `template` e.g. (i32.atomic.store 1 acqrel (i64.const 42) (i32.const 42))"""
+    memargs = []
+    if mem_idx is not None:
+        memargs.append(mem_idx)
+    if ordering is not None:
+        memargs.append(ordering.name)
+
+    memarg_str = " ".join(memargs) + " " if memargs else ""
+    idx_type = ValueType.i64 if mem_idx == "1" else ValueType.i32 if mem_idx == "0" else ValueType.i32
+
+    # The first argument (the memory location) must match the memory that we're indexing. Other arguments match the op (e.g. i32 for i32.atomic.load).
+    args = [f"({idx_type.name}.const 42)"] + [f"({template.value_type.name}.const 42)" for _ in range(template.args - 1)]
+    return template.str % {"memarg": memarg_str, "args": " ".join(args)}
+
+
+def func():
+    """Return a func exercising all ops in `templates` e.g.
+      (func $test-all-ops
+        (drop (i32.atomic.load (i32.const 42)))
+        (drop (i32.atomic.load acqrel (i32.const 42)))
+        ...
+      )
+    """
+    statements = [statement(template, mem_idx, ordering) for template in templates for mem_idx in [None, "0", "1"] for ordering in [None, Ordering.acqrel, Ordering.seqcst]]
+    return f''';; Memory index must come before memory ordering if present.
+;; Both immediates are optional; an ommitted memory ordering will be treated as seqcst.
+(func $test-all-ops
+{indent(newline.join(statements))}
+)'''
+
+
+def text_test():
+    """Return a (module ...) that exercises all ops in `templates`."""
+    return f'''(module
+  (memory i32 1 1)
+  (memory i64 1 1)
+
+{indent(func())}
+)'''
+
+
+def invalid_text_test():
+    return '''(assert_invalid (module
+  (memory 1 1 shared)
+
+  (func $i32load (drop (i32.load acqrel (i32.const 51))))
+) "Can't set memory ordering for non-atomic i32.load")'''
+
+
+def main():
+    print(";; Generated by scripts/test/generate-atomic-spec-test.py. Do not edit manually.")
+    print()
+    print(text_test())
+    print()
+    print(invalid_text_test())
+
+
+if __name__ == "__main__":
+    main()

test/spec/relaxed-atomics.wast

@@ -1,3 +1,5 @@
+;; TODO: replace this with the script generated by scripts/test/generate-atomic-spec-test.py
+
 (module
   (memory 1 1 shared)
   (memory 1 1 shared)

test/spec/relaxed-atomics2.wast

@@ -0,0 +1,53 @@
+;; Generated by scripts/test/generate-atomic-spec-test.py. Do not edit manually.
+
+(module
+  (memory i32 1 1)
+  (memory i64 1 1)
+
+  ;; Memory index must come before memory ordering if present.
+  ;; Both immediates are optional; an ommitted memory ordering will be treated as seqcst.
+  (func $test-all-ops
+    (drop (i32.atomic.load (i32.const 42)))
+    (drop (i32.atomic.load acqrel (i32.const 42)))
+    (drop (i32.atomic.load seqcst (i32.const 42)))
+    (drop (i32.atomic.load 0 (i32.const 42)))
+    (drop (i32.atomic.load 0 acqrel (i32.const 42)))
+    (drop (i32.atomic.load 0 seqcst (i32.const 42)))
+    (drop (i32.atomic.load 1 (i64.const 42)))
+    (drop (i32.atomic.load 1 acqrel (i64.const 42)))
+    (drop (i32.atomic.load 1 seqcst (i64.const 42)))
+    (drop (i64.atomic.load (i32.const 42)))
+    (drop (i64.atomic.load acqrel (i32.const 42)))
+    (drop (i64.atomic.load seqcst (i32.const 42)))
+    (drop (i64.atomic.load 0 (i32.const 42)))
+    (drop (i64.atomic.load 0 acqrel (i32.const 42)))
+    (drop (i64.atomic.load 0 seqcst (i32.const 42)))
+    (drop (i64.atomic.load 1 (i64.const 42)))
+    (drop (i64.atomic.load 1 acqrel (i64.const 42)))
+    (drop (i64.atomic.load 1 seqcst (i64.const 42)))
+    (i32.atomic.store (i32.const 42) (i32.const 42))
+    (i32.atomic.store acqrel (i32.const 42) (i32.const 42))
+    (i32.atomic.store seqcst (i32.const 42) (i32.const 42))
+    (i32.atomic.store 0 (i32.const 42) (i32.const 42))
+    (i32.atomic.store 0 acqrel (i32.const 42) (i32.const 42))
+    (i32.atomic.store 0 seqcst (i32.const 42) (i32.const 42))
+    (i32.atomic.store 1 (i64.const 42) (i32.const 42))
+    (i32.atomic.store 1 acqrel (i64.const 42) (i32.const 42))
+    (i32.atomic.store 1 seqcst (i64.const 42) (i32.const 42))
+    (i64.atomic.store (i32.const 42) (i64.const 42))
+    (i64.atomic.store acqrel (i32.const 42) (i64.const 42))
+    (i64.atomic.store seqcst (i32.const 42) (i64.const 42))
+    (i64.atomic.store 0 (i32.const 42) (i64.const 42))
+    (i64.atomic.store 0 acqrel (i32.const 42) (i64.const 42))
+    (i64.atomic.store 0 seqcst (i32.const 42) (i64.const 42))
+    (i64.atomic.store 1 (i64.const 42) (i64.const 42))
+    (i64.atomic.store 1 acqrel (i64.const 42) (i64.const 42))
+    (i64.atomic.store 1 seqcst (i64.const 42) (i64.const 42))
+  )
+)
+
+(assert_invalid (module
+  (memory 1 1 shared)
+
+  (func $i32load (drop (i32.load acqrel (i32.const 51))))
+) "Can't set memory ordering for non-atomic i32.load")