[LifetimeSafety] Disable canonicalization in immutable collections

[usx95]

Disable canonicalization in immutable collections for lifetime analysis.

Modified the LifetimeFactory struct in LifetimeSafety.cpp to explicitly initialize the immutable collection factories with canonicalize=false. This prevents the factories from canonicalizing their data structures, which can improve performance by avoiding unnecessary comparisons and digest computations.

[usx95]

• [LifetimeSafety] Introduce a liveness-based lifetime policy #159991
• [LifetimeSafety] Implement support for lifetimebound attribute #158489
• [LifetimeSafety] Disable canonicalization in immutable collections #159850 👈 (View in Graphite)
• [ImmutableSet] Optimize add/remove operations to avoid redundant tree modifications #159845
• main

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[github-actions]

✅ With the latest revision this PR passed the C/C++ code formatter.

[llvmbot]

@llvm/pr-subscribers-clang-temporal-safety

@llvm/pr-subscribers-clang-analysis

Author: Utkarsh Saxena (usx95)

Changes

Disable canonicalization in immutable collections for lifetime analysis.

Modified the LifetimeFactory struct in LifetimeSafety.cpp to explicitly initialize the immutable collection factories with canonicalize=false. This prevents the factories from canonicalizing their data structures, which can improve performance by avoiding unnecessary comparisons and digest computations.

---

Full diff: https://github.com/llvm/llvm-project/pull/159850.diff

1 Files Affected:

• (modified) clang/lib/Analysis/LifetimeSafety.cpp (+6-3)

diff --git a/clang/lib/Analysis/LifetimeSafety.cpp b/clang/lib/Analysis/LifetimeSafety.cpp
index 0dd5716d93fb6..43cab406a9dc3 100644
--- a/clang/lib/Analysis/LifetimeSafety.cpp
+++ b/clang/lib/Analysis/LifetimeSafety.cpp
@@ -966,9 +966,12 @@ using ExpiredLoanMap = llvm::ImmutableMap<LoanID, const ExpireFact *>;
 /// An object to hold the factories for immutable collections, ensuring
 /// that all created states share the same underlying memory management.
 struct LifetimeFactory {
-  OriginLoanMap::Factory OriginMapFactory;
-  LoanSet::Factory LoanSetFactory;
-  ExpiredLoanMap::Factory ExpiredLoanMapFactory;
+  // Avoid canonicalising
+  OriginLoanMap::Factory OriginMapFactory =
+      OriginLoanMap::Factory(/*canonicalize=*/false);
+  LoanSet::Factory LoanSetFactory = LoanSet::Factory(/*canonicalize=*/false);
+  ExpiredLoanMap::Factory ExpiredLoanMapFactory =
+      ExpiredLoanMap::Factory(/*canonicalize=*/false);
 };
 
 /// Represents the dataflow lattice for loan propagation.