https://github.com/usx95 updated https://github.com/llvm/llvm-project/pull/181216
>From 955cc1732e2a249f33bf2133cdf1c157da4db966 Mon Sep 17 00:00:00 2001 From: Utkarsh Saxena <[email protected]> Date: Thu, 12 Feb 2026 19:28:17 +0000 Subject: [PATCH] invalidations and erase --- .../LifetimeSafety/LifetimeAnnotations.cpp | 26 +++++++++++++++++-- clang/test/Sema/Inputs/lifetime-analysis.h | 1 + .../warn-lifetime-safety-invalidations.cpp | 15 +++++++++++ 3 files changed, 40 insertions(+), 2 deletions(-) diff --git a/clang/lib/Analysis/LifetimeSafety/LifetimeAnnotations.cpp b/clang/lib/Analysis/LifetimeSafety/LifetimeAnnotations.cpp index 01666f4ac271c..67d06f17ffd74 100644 --- a/clang/lib/Analysis/LifetimeSafety/LifetimeAnnotations.cpp +++ b/clang/lib/Analysis/LifetimeSafety/LifetimeAnnotations.cpp @@ -317,12 +317,33 @@ bool isContainerInvalidationMethod(const CXXMethodDecl &MD) { if (!MD.getIdentifier()) return false; + + StringRef MethodName = MD.getName(); + + // Special handling for 'erase': + // It invalidates the whole container (effectively) for contiguous/flat + // storage, but is safe for other iterators in node-based containers. + if (MethodName == "erase") { + static const llvm::StringSet<> NodeBasedContainers = {"map", + "set", + "multimap", + "multiset", + "unordered_map", + "unordered_set", + "unordered_multimap", + "unordered_multiset"}; + + // 'erase' invalidates for non node-based containers (vector, deque, string, + // flat_map). + return !NodeBasedContainers.contains(ContainerName); + } + static const llvm::StringSet<> InvalidatingMembers = { // Basic Insertion/Emplacement "push_front", "push_back", "emplace_front", "emplace_back", "insert", "emplace", "push", // Basic Removal/Clearing - "pop_front", "pop_back", "pop", "erase", "clear", + "pop_front", "pop_back", "pop", "clear", // Memory Management "reserve", "resize", "shrink_to_fit", // Assignment (Named) @@ -331,6 +352,7 @@ bool isContainerInvalidationMethod(const CXXMethodDecl &MD) { "append", "replace", // Modern C++ (C++17/23) "extract", "try_emplace", "insert_range", "append_range", "assign_range"}; - return InvalidatingMembers.contains(MD.getName()); + + return InvalidatingMembers.contains(MethodName); } } // namespace clang::lifetimes diff --git a/clang/test/Sema/Inputs/lifetime-analysis.h b/clang/test/Sema/Inputs/lifetime-analysis.h index f1c84ff0a3f68..a5b6d1c34d82f 100644 --- a/clang/test/Sema/Inputs/lifetime-analysis.h +++ b/clang/test/Sema/Inputs/lifetime-analysis.h @@ -90,6 +90,7 @@ struct unordered_map { T& operator[](const Key& key); iterator begin(); iterator end(); + iterator erase(iterator); }; template<typename T> diff --git a/clang/test/Sema/warn-lifetime-safety-invalidations.cpp b/clang/test/Sema/warn-lifetime-safety-invalidations.cpp index d90c952e26e5d..d23894e68fcb0 100644 --- a/clang/test/Sema/warn-lifetime-safety-invalidations.cpp +++ b/clang/test/Sema/warn-lifetime-safety-invalidations.cpp @@ -148,6 +148,21 @@ void IteratorInvalidationInAWhileLoop(std::vector<int> v) { } } +void NoIteratorInvalidationInAWhileLoopErase(std::unordered_map<int, int> mp) { + auto it = mp.begin(); + while (it != std::end(mp)) { + if (Bool()) { + auto next = it; + ++next; + mp.erase(it); // Ok. 'next' remains valid. + it = next; + } + else { + ++it; + } + } +} + void IteratorInvalidationInAForeachLoop(std::vector<int> v) { for (int& x : v) { // expected-warning {{object whose reference is captured is later invalidated}} \ // expected-note {{later used here}} _______________________________________________ llvm-branch-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
