[libcxx-commits] [clang] [libcxx] [libcxx] Support for using timespec_get (PR #117362)
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Fri Nov 22 10:55:57 PST 2024
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-clang
Author: Petr Hosek (petrhosek)
<details>
<summary>Changes</summary>
clock_gettime is a POSIX API that may not be available on platforms like baremetal; timespec_get is the C11 equivalent. This change adds support for using timespec_get instead of clock_gettime to improve compatibility with non-POSIX platforms. For now, this is only enabled with LLVM libc which implemented timespec_get in #<!-- -->116102, but in the future this can be expanded to other platforms.
Related to #<!-- -->84879.
---
Full diff: https://github.com/llvm/llvm-project/pull/117362.diff
3 Files Affected:
- (modified) clang/cmake/caches/Fuchsia-stage2.cmake (+2-2)
- (modified) libcxx/src/chrono.cpp (+22)
- (modified) libcxx/src/filesystem/filesystem_clock.cpp (+10)
``````````diff
diff --git a/clang/cmake/caches/Fuchsia-stage2.cmake b/clang/cmake/caches/Fuchsia-stage2.cmake
index 5af98c7b3b3fba..9355f2dfa8ee84 100644
--- a/clang/cmake/caches/Fuchsia-stage2.cmake
+++ b/clang/cmake/caches/Fuchsia-stage2.cmake
@@ -329,7 +329,7 @@ foreach(target armv6m-none-eabi;armv7m-none-eabi;armv8m.main-none-eabi)
foreach(lang C;CXX;ASM)
# TODO: The preprocessor defines workaround various issues in libc and libc++ integration.
# These should be addressed and removed over time.
- set(RUNTIMES_${target}_CMAKE_${lang}_local_flags "--target=${target} -mthumb -Wno-atomic-alignment \"-Dvfprintf(stream, format, vlist)=vprintf(format, vlist)\" \"-Dfprintf(stream, format, ...)=printf(format)\" \"-Dtimeval=struct timeval{int tv_sec; int tv_usec;}\" \"-Dgettimeofday(tv, tz)\" -D_LIBCPP_PRINT=1")
+ set(RUNTIMES_${target}_CMAKE_${lang}_local_flags "--target=${target} -mthumb -Wno-atomic-alignment \"-Dvfprintf(stream, format, vlist)=vprintf(format, vlist)\" \"-Dfprintf(stream, format, ...)=printf(format)\" -D_LIBCPP_PRINT=1")
if(${target} STREQUAL "armv8m.main-none-eabi")
set(RUNTIMES_${target}_CMAKE_${lang}_local_flags "${RUNTIMES_${target}_CMAKE_${lang}_local_flags} -mfloat-abi=softfp -march=armv8m.main+fp+dsp -mcpu=cortex-m33" CACHE STRING "")
endif()
@@ -385,7 +385,7 @@ foreach(target riscv32-unknown-elf)
foreach(lang C;CXX;ASM)
# TODO: The preprocessor defines workaround various issues in libc and libc++ integration.
# These should be addressed and removed over time.
- set(RUNTIMES_${target}_CMAKE_${lang}_FLAGS "--target=${target} -march=rv32imafc -mabi=ilp32f -Wno-atomic-alignment \"-Dvfprintf(stream, format, vlist)=vprintf(format, vlist)\" \"-Dfprintf(stream, format, ...)=printf(format)\" \"-Dtimeval=struct timeval{int tv_sec; int tv_usec;}\" \"-Dgettimeofday(tv, tz)\" -D_LIBCPP_PRINT=1" CACHE STRING "")
+ set(RUNTIMES_${target}_CMAKE_${lang}_FLAGS "--target=${target} -march=rv32imafc -mabi=ilp32f -Wno-atomic-alignment \"-Dvfprintf(stream, format, vlist)=vprintf(format, vlist)\" \"-Dfprintf(stream, format, ...)=printf(format)\" -D_LIBCPP_PRINT=1" CACHE STRING "")
endforeach()
foreach(type SHARED;MODULE;EXE)
set(RUNTIMES_${target}_CMAKE_${type}_LINKER_FLAGS "-fuse-ld=lld" CACHE STRING "")
diff --git a/libcxx/src/chrono.cpp b/libcxx/src/chrono.cpp
index f17ea5542bd99d..8e9ad82befcf32 100644
--- a/libcxx/src/chrono.cpp
+++ b/libcxx/src/chrono.cpp
@@ -31,6 +31,10 @@
# include <sys/time.h> // for gettimeofday and timeval
#endif
+#if defined(__LLVM_LIBC__)
+# define _LIBCPP_HAS_TIMESPEC_GET
+#endif
+
// OpenBSD and GPU do not have a fully conformant suite of POSIX timers, but
// it does have clock_gettime and CLOCK_MONOTONIC which is all we need.
#if defined(__APPLE__) || defined(__gnu_hurd__) || defined(__OpenBSD__) || defined(__AMDGPU__) || \
@@ -115,6 +119,15 @@ static system_clock::time_point __libcpp_system_clock_now() {
return system_clock::time_point(duration_cast<system_clock::duration>(d - nt_to_unix_epoch));
}
+#elif defined(_LIBCPP_HAS_TIMESPEC_GET)
+
+static system_clock::time_point __libcpp_system_clock_now() {
+ struct timespec ts;
+ if (timespec_get(&ts, TIME_UTC) != TIME_UTC)
+ __throw_system_error(errno, "timespec_get(TIME_UTC) failed");
+ return system_clock::time_point(seconds(ts.tv_sec) + microseconds(ts.tv_nsec / 1000));
+}
+
#elif defined(_LIBCPP_HAS_CLOCK_GETTIME)
static system_clock::time_point __libcpp_system_clock_now() {
@@ -213,6 +226,15 @@ static steady_clock::time_point __libcpp_steady_clock_now() noexcept {
return steady_clock::time_point(nanoseconds(_zx_clock_get_monotonic()));
}
+# elif defined(_LIBCPP_HAS_TIMESPEC_GET)
+
+static steady_clock::time_point __libcpp_steady_clock_now() {
+ struct timespec ts;
+ if (timespec_get(&ts, TIME_MONOTONIC) != TIME_MONOTONIC)
+ __throw_system_error(errno, "timespec_get(TIME_MONOTONIC) failed");
+ return steady_clock::time_point(seconds(tp.tv_sec) + nanoseconds(tp.tv_nsec));
+}
+
# elif defined(_LIBCPP_HAS_CLOCK_GETTIME)
static steady_clock::time_point __libcpp_steady_clock_now() {
diff --git a/libcxx/src/filesystem/filesystem_clock.cpp b/libcxx/src/filesystem/filesystem_clock.cpp
index 473a54a00f013a..b15ef4ea61632a 100644
--- a/libcxx/src/filesystem/filesystem_clock.cpp
+++ b/libcxx/src/filesystem/filesystem_clock.cpp
@@ -29,6 +29,10 @@
# include <sys/time.h> // for gettimeofday and timeval
#endif
+#if defined(__LLVM_LIBC__)
+# define _LIBCPP_HAS_TIMESPEC_GET
+#endif
+
#if defined(__APPLE__) || defined(__gnu_hurd__) || defined(__AMDGPU__) || defined(__NVPTX__) || \
(defined(_POSIX_TIMERS) && _POSIX_TIMERS > 0)
# define _LIBCPP_HAS_CLOCK_GETTIME
@@ -46,6 +50,12 @@ _FilesystemClock::time_point _FilesystemClock::now() noexcept {
GetSystemTimeAsFileTime(&time);
detail::TimeSpec tp = detail::filetime_to_timespec(time);
return time_point(__secs(tp.tv_sec) + chrono::duration_cast<duration>(__nsecs(tp.tv_nsec)));
+#elif defined(_LIBCPP_HAS_TIMESPEC_GET)
+ typedef chrono::duration<rep, nano> __nsecs;
+ struct timespec ts;
+ if (timespec_get(&ts, TIME_UTC) != TIME_UTC)
+ __throw_system_error(errno, "timespec_get(TIME_UTC) failed");
+ return time_point(__secs(ts.tv_sec) + chrono::duration_cast<duration>(__nsecs(ts.tv_nsec)));
#elif defined(_LIBCPP_HAS_CLOCK_GETTIME)
typedef chrono::duration<rep, nano> __nsecs;
struct timespec tp;
``````````
</details>
https://github.com/llvm/llvm-project/pull/117362
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