llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang Author: Malavika Samak (malavikasamak) <details> <summary>Changes</summary> Do not warn when a string literal is indexed and the idex value is within the bounds of the length of the string. (rdar://139106996) --- Full diff: https://github.com/llvm/llvm-project/pull/115552.diff 2 Files Affected: - (modified) clang/lib/Analysis/UnsafeBufferUsage.cpp (+19-9) - (modified) clang/test/SemaCXX/warn-unsafe-buffer-usage-array.cpp (+7) ``````````diff diff --git a/clang/lib/Analysis/UnsafeBufferUsage.cpp b/clang/lib/Analysis/UnsafeBufferUsage.cpp index 2c68409b846bc8..650d51bebd66f7 100644 --- a/clang/lib/Analysis/UnsafeBufferUsage.cpp +++ b/clang/lib/Analysis/UnsafeBufferUsage.cpp @@ -436,21 +436,31 @@ AST_MATCHER(ArraySubscriptExpr, isSafeArraySubscript) { const auto *BaseDRE = dyn_cast<DeclRefExpr>(Node.getBase()->IgnoreParenImpCasts()); - if (!BaseDRE) - return false; - if (!BaseDRE->getDecl()) - return false; - const auto *CATy = Finder->getASTContext().getAsConstantArrayType( - BaseDRE->getDecl()->getType()); - if (!CATy) + const auto *SLiteral = dyn_cast<StringLiteral>(Node.getBase()->IgnoreParenImpCasts()); + uint64_t size; + + if (!BaseDRE && !SLiteral) return false; + if(BaseDRE) { + if (!BaseDRE->getDecl()) + return false; + const auto *CATy = Finder->getASTContext().getAsConstantArrayType( + BaseDRE->getDecl()->getType()); + if (!CATy) { + return false; + } + size = CATy->getLimitedSize(); + } else if(SLiteral) { + size = SLiteral->getLength(); + } + if (const auto *IdxLit = dyn_cast<IntegerLiteral>(Node.getIdx())) { const APInt ArrIdx = IdxLit->getValue(); // FIXME: ArrIdx.isNegative() we could immediately emit an error as that's a // bug if (ArrIdx.isNonNegative() && - ArrIdx.getLimitedValue() < CATy->getLimitedSize()) + ArrIdx.getLimitedValue() < size) return true; } @@ -1142,7 +1152,7 @@ class ArraySubscriptGadget : public WarningGadget { // clang-format off return stmt(arraySubscriptExpr( hasBase(ignoringParenImpCasts( - anyOf(hasPointerType(), hasArrayType()))), + anyOf(hasPointerType(), hasArrayType(), stringLiteral()))), unless(anyOf( isSafeArraySubscript(), hasIndex( diff --git a/clang/test/SemaCXX/warn-unsafe-buffer-usage-array.cpp b/clang/test/SemaCXX/warn-unsafe-buffer-usage-array.cpp index 8b2f103ec66708..0a443543d3f604 100644 --- a/clang/test/SemaCXX/warn-unsafe-buffer-usage-array.cpp +++ b/clang/test/SemaCXX/warn-unsafe-buffer-usage-array.cpp @@ -38,3 +38,10 @@ void constant_idx_unsafe(unsigned idx) { // expected-note@-1{{change type of 'buffer' to 'std::array' to label it for hardening}} buffer[10] = 0; // expected-note{{used in buffer access here}} } + +void constant_id_string() { + char safe_char = "abc"[1]; // no-warning + char abcd[5] = "abc"; + abcd[2]; // no-warning + safe_char = "abc"[3]; //expected-warning{{unsafe buffer access}} +} `````````` </details> https://github.com/llvm/llvm-project/pull/115552 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
