From b37feb58dd2b1e9fe3ebd455aa74c0e9adb2997a Mon Sep 17 00:00:00 2001
From: Andrew Noyes <andrew@weaselab.dev>
Date: Mon, 11 Nov 2024 21:40:05 -0800
Subject: [PATCH] Require musttail and preserve_none for interleaved

---
 ConflictSet.cpp | 88 ++++++++++++++++++++++++-------------------------
 1 file changed, 44 insertions(+), 44 deletions(-)

diff --git a/ConflictSet.cpp b/ConflictSet.cpp
index b82e748..9a80685 100644
--- a/ConflictSet.cpp
+++ b/ConflictSet.cpp
@@ -3183,6 +3183,12 @@ Node *firstGeqPhysical(Node *n, const TrivialSpan key) {
 #define PRESERVE_NONE
 #endif
 
+#if __has_attribute(musttail) && __has_attribute(preserve_none)
+constexpr bool kEnableInterleaved = true;
+#else
+constexpr bool kEnableInterleaved = false;
+#endif
+
 namespace check {
 
 typedef PRESERVE_NONE void (*Continuation)(struct Job *, struct Context *);
@@ -4969,51 +4975,50 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
     check::Context context;
     context.readContext.impl = this;
 
-#if __has_attribute(musttail)
-    if (count == 1) {
-      useSequential(reads, result, count, context);
-    } else {
-      constexpr int kConcurrent = 16;
-      check::Job inProgress[kConcurrent];
-      context.count = count;
-      context.oldestVersionFullPrecision = oldestVersionFullPrecision;
-      context.root = root;
-      context.queries = reads;
-      context.results = result;
-      int64_t started = std::min(kConcurrent, count);
-      context.started = started;
-      for (int i = 0; i < started; i++) {
-        inProgress[i].init(reads + i, result + i, root,
-                           oldestVersionFullPrecision);
-      }
-      for (int i = 0; i < started - 1; i++) {
-        inProgress[i].next = inProgress + i + 1;
-      }
-      for (int i = 1; i < started; i++) {
-        inProgress[i].prev = inProgress + i - 1;
-      }
-      inProgress[0].prev = inProgress + started - 1;
-      inProgress[started - 1].next = inProgress;
+    if constexpr (kEnableInterleaved) {
+      if (count == 1) {
+        useSequential(reads, result, count, context);
+      } else {
+        constexpr int kConcurrent = 16;
+        check::Job inProgress[kConcurrent];
+        context.count = count;
+        context.oldestVersionFullPrecision = oldestVersionFullPrecision;
+        context.root = root;
+        context.queries = reads;
+        context.results = result;
+        int64_t started = std::min(kConcurrent, count);
+        context.started = started;
+        for (int i = 0; i < started; i++) {
+          inProgress[i].init(reads + i, result + i, root,
+                             oldestVersionFullPrecision);
+        }
+        for (int i = 0; i < started - 1; i++) {
+          inProgress[i].next = inProgress + i + 1;
+        }
+        for (int i = 1; i < started; i++) {
+          inProgress[i].prev = inProgress + i - 1;
+        }
+        inProgress[0].prev = inProgress + started - 1;
+        inProgress[started - 1].next = inProgress;
 
-      // Kick off the sequence of tail calls that finally returns once all jobs
-      // are done
-      inProgress->continuation(inProgress, &context);
+        // Kick off the sequence of tail calls that finally returns once all
+        // jobs are done
+        inProgress->continuation(inProgress, &context);
 
 #ifndef NDEBUG
-      Arena arena;
-      auto *results2 = new (arena) Result[count];
-      check::Context context2;
-      context2.readContext.impl = this;
-      useSequential(reads, results2, count, context2);
-      assert(memcmp(result, results2, count) == 0);
-      assert(context.readContext == context2.readContext);
+        Arena arena;
+        auto *results2 = new (arena) Result[count];
+        check::Context context2;
+        context2.readContext.impl = this;
+        useSequential(reads, results2, count, context2);
+        assert(memcmp(result, results2, count) == 0);
+        assert(context.readContext == context2.readContext);
 #endif
+      }
+    } else {
+      useSequential(reads, result, count, context);
     }
 
-#else
-    useSequential(reads, result, count, context);
-#endif
-
     for (int i = 0; i < count; ++i) {
       assert(reads[i].readVersion >= 0);
       assert(reads[i].readVersion <= newestVersionFullPrecision);
@@ -5186,11 +5191,6 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
     assert(allPointWrites || sorted);
 #endif
 
-#if __has_attribute(musttail)
-    constexpr bool kEnableInterleaved = true;
-#else
-    constexpr bool kEnableInterleaved = false;
-#endif
     if (kEnableInterleaved && count > 1) {
       interleavedWrites(writes, count, InternalVersionT(writeVersion));
     } else {