[libc-commits] [libc] [libc][Semaphore] Add public sem_t type and entry (PR #213489)

[Jeff Bailey via libc-commits]

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@@ -0,0 +1,33 @@
+//===-- Linux implementation of sem_init ----------------------------------===//
+//
+// 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 "src/semaphore/sem_init.h"
+
+#include "hdr/errno_macros.h"
+#include "hdr/limits_macros.h"
+#include "hdr/types/sem_t.h"
+#include "src/__support/CPP/new.h"
+#include "src/__support/common.h"
+#include "src/__support/libc_errno.h"
+#include "src/__support/macros/config.h"
+#include "src/semaphore/linux/semaphore.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, sem_init,
+                   (sem_t * sem, int pshared, unsigned int value)) {
+  if (value > SEM_VALUE_MAX) {
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kaladron wrote:

Many of these functions need LIBC_CRASH_ON_NULLPTR for any place where we need the pointer to be non-null.  Passing a nullptr to the kernel is fine so we don't need to waste time on those checks, but here it would cause a segfault.  (Consider this for all functions please)

https://github.com/llvm/llvm-project/pull/213489