commit 9a18cc1a127ef2d675532926f714fc62ba0bd881
author Evan Brown <ezb@google.com> Tue Sep 17 11:20:11 2024 -0700
committer Copybara-Service <copybara-worker@google.com> Tue Sep 17 11:21:27 2024 -0700
tree 712b199332297f427715bd0f814afe31fb0fc76d
parent 857fa4fa31a5c63611782b3eda81f60260488573

Add an explicit tag for non-SOO CommonFields (removing default ctor) and add a small optimization for early return in AssertNotDebugCapacity.

PiperOrigin-RevId: 675640181
Change-Id: I5ab4cc6eaa0b54932ed70e42ed654f912cf1b099

absl/container/internal/raw_hash_set.cc

diff --git a/absl/container/internal/raw_hash_set.cc b/absl/container/internal/raw_hash_set.cc
index 1cae038..e8a5432 100644
--- a/absl/container/internal/raw_hash_set.cc
+++ b/absl/container/internal/raw_hash_set.cc
@@ -338,7 +338,7 @@
     c.infoz().RecordClearedReservation();
     c.infoz().RecordStorageChanged(0, soo_enabled ? SooCapacity() : 0);
     (*policy.dealloc)(c, policy);
-    c = soo_enabled ? CommonFields{soo_tag_t{}} : CommonFields{};
+    c = soo_enabled ? CommonFields{soo_tag_t{}} : CommonFields{non_soo_tag_t{}};
   }
 }
 

absl/container/internal/raw_hash_set.h

diff --git a/absl/container/internal/raw_hash_set.h b/absl/container/internal/raw_hash_set.h
index b09f22d..3cb9422 100644
--- a/absl/container/internal/raw_hash_set.h
+++ b/absl/container/internal/raw_hash_set.h
@@ -1245,6 +1245,8 @@
 struct soo_tag_t {};
 // Sentinel type to indicate SOO CommonFields construction with full size.
 struct full_soo_tag_t {};
+// Sentinel type to indicate non-SOO CommonFields construction.
+struct non_soo_tag_t {};
 // Sentinel value to indicate non-SOO construction for moved-from values.
 struct moved_from_non_soo_tag_t {};
 // Sentinel value to indicate an uninitialized CommonFields for use in swapping.
@@ -1330,10 +1332,11 @@
 // of this state to helper functions as a single argument.
 class CommonFields : public CommonFieldsGenerationInfo {
  public:
-  CommonFields() : capacity_(0), size_(0), heap_or_soo_(EmptyGroup()) {}
   explicit CommonFields(soo_tag_t) : capacity_(SooCapacity()), size_(0) {}
   explicit CommonFields(full_soo_tag_t)
       : capacity_(SooCapacity()), size_(size_t{1} << HasInfozShift()) {}
+  explicit CommonFields(non_soo_tag_t)
+      : capacity_(0), size_(0), heap_or_soo_(EmptyGroup()) {}
   // For non-SOO moved-from values, we only need to initialize capacity_.
   explicit CommonFields(moved_from_non_soo_tag_t) : capacity_(0) {}
   // For use in swapping.
@@ -1349,7 +1352,8 @@
 
   template <bool kSooEnabled>
   static CommonFields CreateDefault() {
-    return kSooEnabled ? CommonFields{soo_tag_t{}} : CommonFields{};
+    return kSooEnabled ? CommonFields{soo_tag_t{}}
+                       : CommonFields{non_soo_tag_t{}};
   }
   template <bool kSooEnabled>
   static CommonFields CreateMovedFrom() {
@@ -3932,6 +3936,10 @@
 
   // Asserts that the capacity is not a sentinel invalid value.
   void AssertNotDebugCapacity() const {
+    if (ABSL_PREDICT_TRUE(capacity() <
+                          InvalidCapacity::kAboveMaxValidCapacity)) {
+      return;
+    }
     assert(capacity() != InvalidCapacity::kReentrance &&
            "Reentrant container access during element construction/destruction "
            "is not allowed.");