[libc] Make time_t 64 bits long on all platforms but arm32

[mikhail.ramalho]

Summary

This patch changes the size of time_t to be an int64_t. This still
follows the POSIX standard which only requires time_t to be an integer.

Making time_t a 64-bit integer also fixes two cases in 32 bits platforms
that use SYS_clock_nanosleep_time64 and SYS_clock_gettime64, as the name
of these calls implies, they require a 64-bit time_t. For instance, in rv32,
the 32-bit version of these syscalls is not available.

We also follow glibc here, where time_t is still a 32-bit integer in
arm32.

[mikhail.ramalho]

ping

[mikhail.ramalho]

• define time64_t as INT64_TYPE
• rebased

[mikhail.ramalho]

• define INT64_TYPE time_t
• Rebased

[sivachandra]

libc/src/time/linux/clockGetTimeImpl.h

17

cstdint is a C++ header which we cannot include in the runtime code. Use stdint.h.

[mikhail.ramalho]

• Fix header include

[mikhail.ramalho]

ping

libc/include/llvm-libc-types/time_t.h

 //===-- Definition of the type time_t -------------------------------------===//
 //
 // 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_TYPES_TIME_T_H__
 #define __LLVM_LIBC_TYPES_TIME_T_H__
 
+#if (defined(__arm__) || defined(_M_ARM))
 typedef __INTPTR_TYPE__ time_t;
+#else
+typedef __INT64_TYPE__ time_t;
+#endif
 
 #endif // __LLVM_LIBC_TYPES_TIME_T_H__

libc/src/time/linux/clockGetTimeImpl.h

 //===- Linux implementation of the POSIX clock_gettime function -*- C++ -*-===//
 //
 // 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_SRC_TIME_LINUX_CLOCKGETTIMEIMPL_H
 #define LLVM_LIBC_SRC_TIME_LINUX_CLOCKGETTIMEIMPL_H
 
 #include "src/__support/OSUtil/syscall.h" // For internal syscall function.
 #include "src/__support/common.h"
 #include "src/__support/error_or.h"
 #include "src/errno/libc_errno.h"
 
+#include <stdint.h>      // For int64_t.
 #include <sys/syscall.h> // For syscall numbers.
 #include <time.h>
 
 namespace __llvm_libc {
 namespace internal {
 
 LIBC_INLINE ErrorOr<int> clock_gettimeimpl(clockid_t clockid,
                                            struct timespec *ts) {
 #if SYS_clock_gettime
   int ret = __llvm_libc::syscall_impl<int>(SYS_clock_gettime,
                                            static_cast<long>(clockid),
                                            reinterpret_cast<long>(ts));
 #elif defined(SYS_clock_gettime64)
-  struct timespec64 ts64;
+  static_assert(
+      sizeof(time_t) == sizeof(int64_t),
+      "SYS_clock_gettime64 requires struct timespec with 64-bit members.");
   int ret = __llvm_libc::syscall_impl<int>(SYS_clock_gettime64,
                                            static_cast<long>(clockid),
-                                           reinterpret_cast<long>(&ts64));
-  ts->tv_sec = static_cast<time_t>(ts64.tv_sec);
-  ts->tv_nsec = static_cast<long>(ts64.tv_nsec);
+                                           reinterpret_cast<long>(ts));
 #else
 #error "SYS_clock_gettime and SYS_clock_gettime64 syscalls not available."
 #endif
   if (ret < 0)
     return Error(-ret);
   return ret;
 }
 
 } // namespace internal
 } // namespace __llvm_libc
 
 #endif // LLVM_LIBC_SRC_TIME_LINUX_CLOCKGETTIMEIMPL_H

libc/src/time/linux/nanosleep.cpp

 //===-- Linux implementation of nanosleep 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 "src/time/nanosleep.h"
 
 #include "src/__support/OSUtil/syscall.h" // For syscall functions.
 #include "src/__support/common.h"
 #include "src/errno/libc_errno.h"
 
+#include <stdint.h>      // For int64_t.
 #include <sys/syscall.h> // For syscall numbers.
 
 namespace __llvm_libc {
 
 LLVM_LIBC_FUNCTION(int, nanosleep,
                    (const struct timespec *req, struct timespec *rem)) {
 #if SYS_nanosleep
   int ret = __llvm_libc::syscall_impl<int>(SYS_nanosleep, req, rem);
 #elif defined(SYS_clock_nanosleep_time64)
-  int ret =
-      __llvm_libc::syscall_impl<int>(SYS_clock_nanosleep_time64, req, rem);
+  static_assert(
+      sizeof(time_t) == sizeof(int64_t),
+      "SYS_clock_gettime64 requires struct timespec with 64-bit members.");
+  int ret = __llvm_libc::syscall_impl<int>(SYS_clock_nanosleep_time64,
+                                           CLOCK_REALTIME, 0, req, rem);
 #else
 #error "SYS_nanosleep and SYS_clock_nanosleep_time64 syscalls not available."
 #endif
 
   if (ret < 0) {
     libc_errno = -ret;
     return -1;
   }
   return ret;
 }
 
 } // namespace __llvm_libc