422cf2b506
This patch fixes the warnings which shows up when libcxx library started to be compiled in 32-bit mode on z/OS.
More specifically, the assignment from unsigned int to time_t aka long was flags as follows:
```
libcxx/include/c++/v1/__support/ibm/nanosleep.h:31:11: warning: implicit conversion changes signedness: 'unsigned int' to 'time_t' (aka 'long') [-Wsign-conversion]
__sec = sleep(static_cast<unsigned int>(__sec));
~ ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
libcxx/include/c++/v1/__support/ibm/nanosleep.h:36:36: warning: implicit conversion changes signedness: 'unsigned int' to 'long' [-Wsign-conversion]
__rem->tv_nsec = __micro_sec * 1000;
~ ~~~~~~~~~~~~^~~~~~
libcxx/include/c++/v1/__support/ibm/nanosleep.h:47:36: warning: implicit conversion changes signedness: 'unsigned int' to 'long' [-Wsign-conversion]
__rem->tv_nsec = __micro_sec * 1000;
~ ~~~~~~~~~~~~^~~~~~
3 warnings generated.
```
Here is a small test case illustrating the issue:
```
typedef long time_t ;
unsigned int sleep(unsigned int );
int main() {
time_t sec = 0;
#ifdef FIX
sec = static_cast<time_t>(sleep(static_cast<unsigned int>(sec)));
#else
sec = sleep(static_cast<unsigned int>(sec));
#endif
}
```
clang++ -c -Wsign-conversion -m32 t.C
```
t.C:8:9: warning: implicit conversion changes signedness: 'unsigned int' to 'time_t' (aka 'long') [-Wsign-conversion]
sec = sleep(static_cast<unsigned int>(sec));
~ ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Reviewed By: ldionne, #libc, Quuxplusone, Mordante
Differential Revision: https://reviews.llvm.org/D112837
56 lines
1.8 KiB
C++
56 lines
1.8 KiB
C++
// -*- C++ -*-
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//===----------------------------------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#ifndef _LIBCPP_SUPPORT_IBM_NANOSLEEP_H
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#define _LIBCPP_SUPPORT_IBM_NANOSLEEP_H
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#include <unistd.h>
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inline int nanosleep(const struct timespec* __req, struct timespec* __rem) {
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// The nanosleep() function is not available on z/OS. Therefore, we will call
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// sleep() to sleep for whole seconds and usleep() to sleep for any remaining
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// fraction of a second. Any remaining nanoseconds will round up to the next
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// microsecond.
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if (__req->tv_sec < 0 || __req->tv_nsec < 0 || __req->tv_nsec > 999999999) {
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errno = EINVAL;
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return -1;
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}
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long __micro_sec = (__req->tv_nsec + 999) / 1000;
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time_t __sec = __req->tv_sec;
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if (__micro_sec > 999999) {
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++__sec;
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__micro_sec -= 1000000;
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}
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__sec = static_cast<time_t>(sleep(static_cast<unsigned int>(__sec)));
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if (__sec) {
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if (__rem) {
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// Updating the remaining time to sleep in case of unsuccessful call to sleep().
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__rem->tv_sec = __sec;
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__rem->tv_nsec = __micro_sec * 1000;
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}
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errno = EINTR;
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return -1;
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}
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if (__micro_sec) {
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int __rt = usleep(static_cast<unsigned int>(__micro_sec));
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if (__rt != 0 && __rem) {
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// The usleep() does not provide the amount of remaining time upon its failure,
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// so the time slept will be ignored.
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__rem->tv_sec = 0;
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__rem->tv_nsec = __micro_sec * 1000;
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// The errno is already set.
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return -1;
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}
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return __rt;
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}
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return 0;
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}
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#endif // _LIBCPP_SUPPORT_IBM_NANOSLEEP_H
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