================ @@ -0,0 +1,81 @@ +//===----------------------------------------------------------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +/// +/// \file +/// This file contains the implementation of strcpy_s. +/// +//===----------------------------------------------------------------------===// + +#include "src/string/strcpy_s.h" +#define __STDC_WANT_LIB_EXT1__ 1 +#include "hdr/stdint_proxy.h" +#undef __STDC_WANT_LIB_EXT1__ +#include "hdr/types/constraint_handler_t.h" +#include "hdr/types/errno_t.h" +#include "hdr/types/rsize_t.h" +#include "src/__support/CPP/expected.h" +#include "src/__support/common.h" +#include "src/__support/constraint_handler.h" +#include "src/__support/macros/config.h" +#include "src/string/memory_utils/inline_memcpy.h" +#include "src/string/string_utils.h" + +namespace LIBC_NAMESPACE_DECL { + +LIBC_INLINE static cpp::expected<size_t, const char *> +validate(char *__restrict s1, rsize_t s1max, const char *__restrict s2) { + if (s1 == nullptr) + return cpp::unexpected("strcpy_s: s1 cannot be null"); + if (s2 == nullptr) + return cpp::unexpected("strcpy_s: s2 cannot be null"); + if (s1max > RSIZE_MAX) + return cpp::unexpected("strcpy_s: s1max cannot exceed RSIZE_MAX"); + if (s1max == 0) + return cpp::unexpected("strcpy_s: s1max cannot be 0"); + + // count can't be greater than s1max by definition, so no need to check for + // this case. + size_t count = internal::strnlen_s(s2, s1max); + if (s1max == count) + return cpp::unexpected("strcpy_s: s1max is too small for s2"); + + // Check overlap using the full regions defined by the standard, including the + // terminating null byte: + // destination: [s1, s1 + s1max) + // source: [s2, s2 + count + 1) + // Use s1max for the destination's length, not count + 1, because the + // standard allows for overwriting the entire destination region, even if + // s2's length is smaller than s1max. + const uintptr_t s1_addr = reinterpret_cast<uintptr_t>(s1); + const uintptr_t s2_addr = reinterpret_cast<uintptr_t>(s2); + if (s1_addr < s2_addr ? s2_addr - s1_addr < s1max + : s1_addr - s2_addr < count + 1) + return cpp::unexpected("strcpy_s: s1 and s2 cannot overlap"); + + return count; +} + +LLVM_LIBC_FUNCTION(errno_t, strcpy_s, + (char *__restrict s1, rsize_t s1max, + const char *__restrict s2)) { + const auto count_expected = validate(s1, s1max, s2); + + if (!count_expected.has_value()) { + if (s1 != nullptr && s1max > 0 && s1max <= RSIZE_MAX) { + s1[0] = '\0'; + } + libc_global_constraint_handler(count_expected.error(), 0, ---------------- kaladron wrote:
Actually, what is that pointer for? The other PR just has "ptr" in it. Should the line perhaps be "return libc_global_constraint (...)", and take a pair of errno_t and const char*? I'm thinking the pair could typedef'd to appendix_k_error or something? Since this is across 2 PRs (three if you count your other one) we can also commit this as it is, and then refactor when they're all landed. https://github.com/llvm/llvm-project/pull/197709 _______________________________________________ llvm-branch-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
