snapshot: preserve the uncommitted Canary instrumentation (not authored here)

Working-tree snapshot taken 2026-07-28 so this work is not lost. To be clear
about provenance: NONE of this was written in the session that committed it —
it is pre-existing uncommitted work on phase-a-tracing, last committed 2026-07-09,
from the xenia-rs decoder/deadlock investigation. It is recorded verbatim, not
reviewed and not tested.

Contents: 24 tracked modifications (ppc_emit_memory, xex_module, object_table,
shim_utils, xboxkrnl threading/rtl, xevent/xobject/xthread, memory) plus the
untracked probe sources audit_68_host_mem_watch, audit_69_event_signal_watch,
audit_70_semaphore_release_watch, phase_b_snapshot, and cmake/toolchains.

Deliberately excluded: build-cross/ (51 GB of build output) and
vkd3d-proton.cache. Note third_party/snappy is a submodule pointer change whose
target may not be pushed anywhere, so this branch is a preservation record rather
than a guaranteed-buildable tree.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

cmake/toolchains/xwin-case-symlinks.py

@@ -0,0 +1,126 @@
+#!/usr/bin/env python3
+"""Scan xenia source for #include directives and ensure case-aliases exist
+in xwin's flat SDK/CRT include dirs. xwin's default splat adds lowercase
+aliases for headers that ship with uppercase names (e.g. Windows.h),
+but does NOT add aliases in the reverse direction. xenia (and its
+third_party deps) include some headers using historical Microsoft casing
+(<ObjBase.h>, <Psapi.h>) that don't match the lowercase filenames the
+SDK ships with. This helper creates the missing symlinks.
+
+Idempotent: re-running is safe.
+"""
+from __future__ import annotations
+import os
+import re
+import sys
+from pathlib import Path
+
+INCLUDE_RE = re.compile(r'^\s*#\s*include\s*<([A-Za-z][A-Za-z0-9_/.\-]*\.h)>',
+                        re.MULTILINE)
+
+SOURCE_ROOTS = [
+    "src",
+    "third_party/SDL2/src",
+    "third_party/SDL2/include",
+    "third_party/discord-rpc/src",
+    "third_party/fmt",
+    "third_party/imgui",
+]
+
+SOURCE_EXTS = {".h", ".hpp", ".inc", ".c", ".cc", ".cpp", ".cxx"}
+
+
+def collect_includes(repo_root: Path) -> set[str]:
+    """Return set of all <foo.h>-style include targets found in source."""
+    seen: set[str] = set()
+    for root in SOURCE_ROOTS:
+        base = repo_root / root
+        if not base.exists():
+            continue
+        for path in base.rglob("*"):
+            if path.suffix.lower() not in SOURCE_EXTS:
+                continue
+            try:
+                txt = path.read_text(encoding="utf-8", errors="ignore")
+            except OSError:
+                continue
+            for m in INCLUDE_RE.finditer(txt):
+                seen.add(m.group(1))
+    return seen
+
+
+def index_dir(d: Path) -> dict[str, str]:
+    """Return mapping lowercased-basename -> actual basename for files in d."""
+    if not d.is_dir():
+        return {}
+    idx: dict[str, str] = {}
+    for entry in d.iterdir():
+        idx.setdefault(entry.name.lower(), entry.name)
+    return idx
+
+
+def fix_dir(target_dir: Path, want: set[str]) -> tuple[int, int, list[str]]:
+    """For each header name in `want` (basename only), create a symlink to
+    the case-folded sibling if the exact case doesn't exist. Returns
+    (created, already_ok, missing-from-sdk)."""
+    if not target_dir.is_dir():
+        return 0, 0, []
+    idx = index_dir(target_dir)
+    created = 0
+    already_ok = 0
+    missing: list[str] = []
+    for name in want:
+        # Only look at single-segment names; subdir/foo.h handled separately
+        if "/" in name:
+            continue
+        actual = idx.get(name.lower())
+        if actual is None:
+            missing.append(name)
+            continue
+        if actual == name:
+            already_ok += 1
+            continue
+        link = target_dir / name
+        if link.exists() or link.is_symlink():
+            already_ok += 1
+            continue
+        try:
+            link.symlink_to(actual)
+            created += 1
+        except OSError as e:
+            print(f"  ! failed to symlink {link} -> {actual}: {e}",
+                  file=sys.stderr)
+    return created, already_ok, missing
+
+
+def main() -> int:
+    if len(sys.argv) != 3:
+        print("usage: xwin-case-symlinks.py <xenia-canary-root> <xwin-splat-dir>",
+              file=sys.stderr)
+        return 2
+    repo_root = Path(sys.argv[1]).resolve()
+    xwin_root = Path(sys.argv[2]).resolve()
+    if not (xwin_root / "crt" / "include").exists():
+        print(f"error: {xwin_root}/crt/include missing", file=sys.stderr)
+        return 1
+    want = collect_includes(repo_root)
+    print(f"Collected {len(want)} unique #include <...> targets")
+    sdk_dirs = [
+        xwin_root / "crt" / "include",
+        xwin_root / "sdk" / "include" / "ucrt",
+        xwin_root / "sdk" / "include" / "um",
+        xwin_root / "sdk" / "include" / "shared",
+        xwin_root / "sdk" / "include" / "winrt",
+    ]
+    total_created = 0
+    for d in sdk_dirs:
+        created, ok, _missing = fix_dir(d, want)
+        if created:
+            print(f"  {d}: created {created} case-symlinks")
+        total_created += created
+    print(f"Done: created {total_created} case-symlinks total")
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())