Author: Malavika Samak Date: 2025-01-21T15:00:30+05:30 New Revision: 2a8c12b29f8dc777a62868512bed1a2dae1ef8b2
URL: https://github.com/llvm/llvm-project/commit/2a8c12b29f8dc777a62868512bed1a2dae1ef8b2 DIFF: https://github.com/llvm/llvm-project/commit/2a8c12b29f8dc777a62868512bed1a2dae1ef8b2.diff LOG: "Reland "[Wunsafe-buffer-usage] Fix false positive when const sized array is indexed by const evaluatable expressions (#119340)"" (#123713) This reverts commit 7dd34baf5505d689161c3a8678322a394d7a2929. Fixed the assertion violation reported by 7dd34baf5505d689161c3a8678322a394d7a2929 Co-authored-by: MalavikaSamak <malavi...@apple.com> Added: Modified: clang/lib/Analysis/UnsafeBufferUsage.cpp clang/test/SemaCXX/warn-unsafe-buffer-usage-array.cpp Removed: ################################################################################ diff --git a/clang/lib/Analysis/UnsafeBufferUsage.cpp b/clang/lib/Analysis/UnsafeBufferUsage.cpp index a9aff39df64746..c064aa30e8aedc 100644 --- a/clang/lib/Analysis/UnsafeBufferUsage.cpp +++ b/clang/lib/Analysis/UnsafeBufferUsage.cpp @@ -453,8 +453,13 @@ AST_MATCHER(ArraySubscriptExpr, isSafeArraySubscript) { return false; } - if (const auto *IdxLit = dyn_cast<IntegerLiteral>(Node.getIdx())) { - const APInt ArrIdx = IdxLit->getValue(); + Expr::EvalResult EVResult; + const Expr *IndexExpr = Node.getIdx(); + if (!IndexExpr->isValueDependent() && + IndexExpr->EvaluateAsInt(EVResult, Finder->getASTContext())) { + llvm::APSInt ArrIdx = EVResult.Val.getInt(); + // FIXME: ArrIdx.isNegative() we could immediately emit an error as that's a + // bug if (ArrIdx.isNonNegative() && ArrIdx.getLimitedValue() < limit) return true; } diff --git a/clang/test/SemaCXX/warn-unsafe-buffer-usage-array.cpp b/clang/test/SemaCXX/warn-unsafe-buffer-usage-array.cpp index 7dd6c83dbba2a8..e80b54b7c69677 100644 --- a/clang/test/SemaCXX/warn-unsafe-buffer-usage-array.cpp +++ b/clang/test/SemaCXX/warn-unsafe-buffer-usage-array.cpp @@ -92,3 +92,35 @@ char access_strings() { c = array_string[5]; return c; } + +struct T { + int array[10]; +}; + +const int index = 1; + +constexpr int get_const(int x) { + if(x < 3) + return ++x; + else + return x + 5; +}; + +void array_indexed_const_expr(unsigned idx) { + // expected-note@+2 {{change type of 'arr' to 'std::array' to label it for hardening}} + // expected-warning@+1{{'arr' is an unsafe buffer that does not perform bounds checks}} + int arr[10]; + arr[sizeof(int)] = 5; + + int array[sizeof(T)]; + array[sizeof(int)] = 5; + array[sizeof(T) -1 ] = 3; + + int k = arr[6 & 5]; + k = arr[2 << index]; + k = arr[8 << index]; // expected-note {{used in buffer access here}} + k = arr[16 >> 1]; + k = arr[get_const(index)]; + k = arr[get_const(5)]; // expected-note {{used in buffer access here}} + k = arr[get_const(4)]; +} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
