Author: Timm Bäder Date: 2024-05-22T12:45:17+02:00 New Revision: 9604e5ce8b5607cd88ba130314fc7ae8545542e1
URL: https://github.com/llvm/llvm-project/commit/9604e5ce8b5607cd88ba130314fc7ae8545542e1 DIFF: https://github.com/llvm/llvm-project/commit/9604e5ce8b5607cd88ba130314fc7ae8545542e1.diff LOG: [clang][Interp] Allow stepping back from a one-past-the-end pointer ... back into range of the array. Added: Modified: clang/lib/AST/Interp/Interp.h clang/lib/AST/Interp/Pointer.h clang/test/AST/Interp/arrays.cpp Removed: ################################################################################ diff --git a/clang/lib/AST/Interp/Interp.h b/clang/lib/AST/Interp/Interp.h index c5607169b25f1..7ef963c810c82 100644 --- a/clang/lib/AST/Interp/Interp.h +++ b/clang/lib/AST/Interp/Interp.h @@ -1555,8 +1555,12 @@ bool OffsetHelper(InterpState &S, CodePtr OpPC, const T &Offset, if (!CheckArray(S, OpPC, Ptr)) return false; - uint64_t Index = Ptr.getIndex(); uint64_t MaxIndex = static_cast<uint64_t>(Ptr.getNumElems()); + uint64_t Index; + if (Ptr.isOnePastEnd()) + Index = MaxIndex; + else + Index = Ptr.getIndex(); bool Invalid = false; // Helper to report an invalid offset, computed as APSInt. diff --git a/clang/lib/AST/Interp/Pointer.h b/clang/lib/AST/Interp/Pointer.h index 9468bdbf00cc0..93ca754d04a64 100644 --- a/clang/lib/AST/Interp/Pointer.h +++ b/clang/lib/AST/Interp/Pointer.h @@ -537,9 +537,6 @@ class Pointer { if (isZero()) return 0; - if (isElementPastEnd()) - return 1; - // narrow()ed element in a composite array. if (asBlockPointer().Base > sizeof(InlineDescriptor) && asBlockPointer().Base == Offset) diff --git a/clang/test/AST/Interp/arrays.cpp b/clang/test/AST/Interp/arrays.cpp index e936ec6dc894b..dd5064d993e66 100644 --- a/clang/test/AST/Interp/arrays.cpp +++ b/clang/test/AST/Interp/arrays.cpp @@ -54,6 +54,10 @@ constexpr int derefPtr(const int *d) { } static_assert(derefPtr(data) == 5, ""); +/// Make sure we can refer to the one-past-the-end element +/// and then return back to the end of the array. +static_assert((&data[5])[-1] == 1, ""); + constexpr int storePtr() { int b[] = {1,2,3,4}; int *c = b; _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
