[libc-commits] [libc] [libc] Add limits.h header. (PR #78887)

[via libc-commits]

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@@ -0,0 +1,247 @@
+//===-- Definition of macros from limits.h --------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef __LLVM_LIBC_MACROS_LIMITS_MACROS_H
+#define __LLVM_LIBC_MACROS_LIMITS_MACROS_H
+
+#if __has_include_next(<limits.h>)
+
+// Suppress `#include_next is a language extension` warnings.
+#ifdef __clang__
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wgnu-include-next"
+#elif defined(__GNUC__) // gcc
+#if !defined _GCC_LIMITS_H_
+#define _GCC_LIMITS_H_
+#endif
+#pragma GCC system_header
+#endif // __clang__, __GNUC__
+
+// Include compiler's header
+#include_next <limits.h>
+
+#ifdef __clang__
+#pragma clang diagnostic pop
+#endif // __clang__
+
+#endif // __has_include_next(<limits.h>)
+
+// Supplement missing macros.
+
----------------
lntue wrote:

Besides some old versions of gcc do not have `LLONG_MIN`, `LLONG_MAX`, `ULLONG_MAX` as in glibc's limits.h comments, there are also C23 new macros `*_WIDTH` that are only added to both clang and gcc recently.  The rest are for completeness.

https://github.com/llvm/llvm-project/pull/78887