[libc-commits] [libc] [libc] Add `ctime_s` (PR #110676)

[Nick Desaulniers via libc-commits]

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@@ -0,0 +1,45 @@
+//===-- Implementation of ctime_s function --------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "ctime_s.h"
+#include "hdr/errno_macros.h"
+#include "src/__support/CPP/limits.h"
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+#include "time_utils.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+using LIBC_NAMESPACE::time_utils::TimeConstants;
+
+LLVM_LIBC_FUNCTION(int, ctime_s,
+                   (char *buffer, rsize_t buffer_size, const time_t *t_ptr)) {
+  // TODO (https://github.com/llvm/llvm-project/issues/115907): invoke
+  // constraint handler
+  if (buffer == nullptr || t_ptr == nullptr)
+    return EINVAL;
+
+  if (buffer_size < TimeConstants::ASCTIME_MAX_BYTES ||
+      buffer_size > RSIZE_MAX) {
+    buffer[0] = '\0';
+    return ERANGE;
+  }
+
+  if (*t_ptr > cpp::numeric_limits<int32_t>::max()) {
+    return EINVAL;
+  }
+
+  if (time_utils::asctime(time_utils::localtime(t_ptr), buffer, buffer_size) ==
+      nullptr) {
+    return EINVAL;
+  }
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nickdesaulniers wrote:

Remove parens for single statement conditionals.

https://llvm.org/docs/CodingStandards.html#don-t-use-braces-on-simple-single-statement-bodies-of-if-else-loop-statements

https://github.com/llvm/llvm-project/pull/110676