libc/src/__support/OSUtil/linux/vdso_sym.h

   1 //===------------- Linux VDSO Symbols ---------------------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 #include "hdr/types/clock_t.h"
   9 #include "hdr/types/clockid_t.h"
  10 #include "hdr/types/struct_timespec.h"
  11 #include "hdr/types/struct_timeval.h"
  12 #include "hdr/types/time_t.h"
  13 #include "src/__support/common.h"
  14 #include <stddef.h> // For size_t.
  15
  16 // NOLINTBEGIN(llvmlibc-implementation-in-namespace)
  17 // TODO: some of the following can be defined via proxy headers.
  18 struct __kernel_timespec;
  19 struct timezone;
  20 struct riscv_hwprobe;
  21 struct getcpu_cache;
  22 struct cpu_set_t;
  23 // NOLINTEND(llvmlibc-implementation-in-namespace)
  24
  25 namespace LIBC_NAMESPACE_DECL {
  26 namespace vdso {
  27
  28 enum class VDSOSym {
  29   ClockGetTime,
  30   ClockGetTime64,
  31   GetTimeOfDay,
  32   GetCpu,
  33   Time,
  34   ClockGetRes,
  35   RTSigReturn,
  36   FlushICache,
  37   RiscvHwProbe,
  38   VDSOSymCount
  39 };
  40
  41 template <VDSOSym sym> LIBC_INLINE constexpr auto dispatcher() {
  42   if constexpr (sym == VDSOSym::ClockGetTime)
  43     return static_cast<int (*)(clockid_t, timespec *)>(nullptr);
  44   else if constexpr (sym == VDSOSym::ClockGetTime64)
  45     return static_cast<int (*)(clockid_t, __kernel_timespec *)>(nullptr);
  46   else if constexpr (sym == VDSOSym::GetTimeOfDay)
  47     return static_cast<int (*)(timeval *__restrict,
  48                                struct timezone *__restrict)>(nullptr);
  49   else if constexpr (sym == VDSOSym::GetCpu)
  50     return static_cast<int (*)(unsigned *, unsigned *, getcpu_cache *)>(
  51         nullptr);
  52   else if constexpr (sym == VDSOSym::Time)
  53     return static_cast<time_t (*)(time_t *)>(nullptr);
  54   else if constexpr (sym == VDSOSym::ClockGetRes)
  55     return static_cast<int (*)(clockid_t, timespec *)>(nullptr);
  56   else if constexpr (sym == VDSOSym::RTSigReturn)
  57     return static_cast<void (*)(void)>(nullptr);
  58   else if constexpr (sym == VDSOSym::FlushICache)
  59     return static_cast<void (*)(void *, void *, unsigned int)>(nullptr);
  60   else if constexpr (sym == VDSOSym::RiscvHwProbe)
  61     return static_cast<int (*)(riscv_hwprobe *, size_t, size_t, cpu_set_t *,
  62                                unsigned)>(nullptr);
  63   else
  64     return static_cast<void *>(nullptr);
  65 }
  66
  67 template <VDSOSym sym> using VDSOSymType = decltype(dispatcher<sym>());
  68
  69 } // namespace vdso
  70 } // namespace LIBC_NAMESPACE_DECL