[llvm] ddba329 - [ADT] Clean up FoldingSet.* (NFC) (#216619)

[via llvm-commits]

Author: Kazu Hirata
Date: 2026-08-16T20:29:57-07:00
New Revision: ddba329a3e54c349533dbefbae92513f4d20a638

URL: https://github.com/llvm/llvm-project/commit/ddba329a3e54c349533dbefbae92513f4d20a638
DIFF: https://github.com/llvm/llvm-project/commit/ddba329a3e54c349533dbefbae92513f4d20a638.diff

LOG: [ADT] Clean up FoldingSet.* (NFC) (#216619)

This patch cleans up minor issues in FoldingSet.*.

- FoldingSetBase::NodeID never existed in the history of FoldingSet.
  The comment should refer to FoldingSetNodeID instead.

- GetBucketPtr lost the first line of its doc comment on February 4,
  2008 in commit e2887863563f, leaving only "testing.".

- ImmutableSetTest.cpp was relying on FoldingSet.h to include
  ArrayRef.h.

Other changes should be self-explanatory.

Assisted-by: Antigravity

Added: 
    

Modified: 
    llvm/include/llvm/ADT/FoldingSet.h
    llvm/lib/Support/FoldingSet.cpp
    llvm/unittests/ADT/ImmutableSetTest.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/ADT/FoldingSet.h b/llvm/include/llvm/ADT/FoldingSet.h
index 72edc3aac21fb..52ee163cb739c 100644
--- a/llvm/include/llvm/ADT/FoldingSet.h
+++ b/llvm/include/llvm/ADT/FoldingSet.h
@@ -16,7 +16,6 @@
 #ifndef LLVM_ADT_FOLDINGSET_H
 #define LLVM_ADT_FOLDINGSET_H
 
-#include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/Hashing.h"
 #include "llvm/ADT/STLForwardCompat.h"
 #include "llvm/ADT/SmallVector.h"
@@ -46,7 +45,7 @@ namespace llvm {
 /// FoldingSetNode.  The node class must also define a Profile method used to
 /// establish the unique bits of data for the node.  The Profile method is
 /// passed a FoldingSetNodeID object which is used to gather the bits.  Just
-/// call one of the Add* functions defined in the FoldingSetBase::NodeID class.
+/// call one of the Add* functions defined in the FoldingSetNodeID class.
 /// NOTE: That the folding set does not own the nodes and it is the
 /// responsibility of the user to dispose of the nodes.
 ///
@@ -328,11 +327,11 @@ class FoldingSetBase {
   unsigned size() const { return NumNodes; }
 
   /// Returns true if there are no nodes in the folding set.
-  bool empty() const { return NumNodes == 0; }
+  [[nodiscard]] bool empty() const { return NumNodes == 0; }
 
   /// Returns the number of nodes permitted in the folding set
   /// before a rebucket operation is performed.
-  unsigned capacity() {
+  unsigned capacity() const {
     // We allow a load factor of up to 2.0,
     // so that means our capacity is NumBuckets * 2
     return NumBuckets * 2;
@@ -458,7 +457,7 @@ template <class Derived, class T> class FoldingSetImpl : public FoldingSetBase {
   /// won't cause a rebucket operation. reserve is permitted to allocate more
   /// space than requested by EltCount.
   void reserve(unsigned EltCount) {
-    return FoldingSetBase::reserve(EltCount, Derived::getFoldingSetInfo());
+    FoldingSetBase::reserve(EltCount, Derived::getFoldingSetInfo());
   }
 
   /// Remove a node from the folding set, returning true if one
@@ -670,7 +669,7 @@ template <class T, class VectorT = SmallVector<T *, 8>> class FoldingSetVector {
   unsigned size() const { return Set.size(); }
 
   /// Returns true if there are no nodes in the folding set.
-  bool empty() const { return Set.empty(); }
+  [[nodiscard]] bool empty() const { return Set.empty(); }
 };
 
 //===----------------------------------------------------------------------===//

diff  --git a/llvm/lib/Support/FoldingSet.cpp b/llvm/lib/Support/FoldingSet.cpp
index ab85d0539ced3..4aec40116a6f5 100644
--- a/llvm/lib/Support/FoldingSet.cpp
+++ b/llvm/lib/Support/FoldingSet.cpp
@@ -162,6 +162,7 @@ static FoldingSetBase::Node *GetNextPtr(void *NextInBucketPtr) {
   return static_cast<FoldingSetBase::Node *>(NextInBucketPtr);
 }
 
+/// GetBucketPtr - Provides a casting of a bucket pointer for isNode
 /// testing.
 static void **GetBucketPtr(void *NextInBucketPtr) {
   intptr_t Ptr = reinterpret_cast<intptr_t>(NextInBucketPtr);

diff  --git a/llvm/unittests/ADT/ImmutableSetTest.cpp b/llvm/unittests/ADT/ImmutableSetTest.cpp
index 8c2eb355cc63f..c79e5b545b57c 100644
--- a/llvm/unittests/ADT/ImmutableSetTest.cpp
+++ b/llvm/unittests/ADT/ImmutableSetTest.cpp
@@ -7,6 +7,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/ADT/ImmutableSet.h"
+#include "llvm/ADT/ArrayRef.h"
 #include "gtest/gtest.h"
 #include <algorithm>
 #include <numeric>