From 5206df26b6240fc881231a4055b370adbf080333 Mon Sep 17 00:00:00 2001 From: Shreeyash Pandey Date: Wed, 12 Nov 2025 16:28:34 +0530 Subject: [PATCH 1/5] [libc] make clock_conversion.h common and document it clock_conversion.h implements convert_clock which shifts a timestamp from one clock domain to another. It naturally does not depend on any OS specific interface. Making it generic will allow common use. --- .../time/{linux => }/clock_conversion.h | 26 +++++++++++++++++-- libc/src/__support/time/linux/monotonicity.h | 2 +- 2 files changed, 25 insertions(+), 3 deletions(-) rename libc/src/__support/time/{linux => }/clock_conversion.h (54%) diff --git a/libc/src/__support/time/linux/clock_conversion.h b/libc/src/__support/time/clock_conversion.h similarity index 54% rename from libc/src/__support/time/linux/clock_conversion.h rename to libc/src/__support/time/clock_conversion.h index ac5357d308d7c..acf0b21516467 100644 --- a/libc/src/__support/time/linux/clock_conversion.h +++ b/libc/src/__support/time/clock_conversion.h @@ -1,10 +1,10 @@ -//===--- clock conversion linux implementation ------------------*- C++ -*-===// +//===--- clock conversion implementation ------------------*- 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___SUPPORT_TIME_LINUX_CLOCK_CONVERSION_H #define LLVM_LIBC_SRC___SUPPORT_TIME_LINUX_CLOCK_CONVERSION_H @@ -16,6 +16,28 @@ namespace LIBC_NAMESPACE_DECL { namespace internal { +/** + * @brief Convert a timespec value from one clock domain to another. + * + * The function takes a timestamp that is expressed in terms of the clock + * identified by param from and returns an equivalent timestamp expressed + * in terms of the clock identified by param to. + * + * Internally it obtains the current time of both clocks with + * clock_gettime, then subtracts the source clock’s value and + * adds the target clock’s value. The result is normalised so that + * the nanoseconds field is always in the range [0, 1 s). + * + * This is useful, for example, for converting a value obtained from + * CLOCK_MONOTONIC to CLOCK_REALTIME (or vice‑versa) so that the + * timestamp can be displayed to a user or stored in a format that + * is independent of the original clock domain. + * + * @param input The timestamp to convert + * @param from Clock ID of the original timestamp (e.g. CLOCK_MONOTONIC). + * @param to Clock ID of the desired timestamp (e.g. CLOCK_REALTIME). + * @return The converted timespec + */ LIBC_INLINE timespec convert_clock(timespec input, clockid_t from, clockid_t to) { using namespace time_units; diff --git a/libc/src/__support/time/linux/monotonicity.h b/libc/src/__support/time/linux/monotonicity.h index c7234db2e64c4..2ee260ee44ba9 100644 --- a/libc/src/__support/time/linux/monotonicity.h +++ b/libc/src/__support/time/linux/monotonicity.h @@ -12,8 +12,8 @@ #include "hdr/time_macros.h" #include "src/__support/libc_assert.h" #include "src/__support/macros/config.h" +#include "src/__support/time/clock_conversion.h" #include "src/__support/time/linux/abs_timeout.h" -#include "src/__support/time/linux/clock_conversion.h" namespace LIBC_NAMESPACE_DECL { namespace internal { // This function is separated from abs_timeout. From 24221bd7f9ac56f5d697a1458f780817e435c504 Mon Sep 17 00:00:00 2001 From: Shreeyash Pandey Date: Fri, 28 Nov 2025 23:34:30 +0530 Subject: [PATCH 2/5] [libc] modify clock_conversion related files --- libc/src/__support/time/CMakeLists.txt | 9 +++++++++ libc/src/__support/time/clock_conversion.h | 6 +++--- libc/src/__support/time/linux/CMakeLists.txt | 10 +--------- 3 files changed, 13 insertions(+), 12 deletions(-) diff --git a/libc/src/__support/time/CMakeLists.txt b/libc/src/__support/time/CMakeLists.txt index 3851037e4161f..dcb5d40ae7fb2 100644 --- a/libc/src/__support/time/CMakeLists.txt +++ b/libc/src/__support/time/CMakeLists.txt @@ -20,6 +20,15 @@ add_object_library( libc.src.__support.time.${LIBC_TARGET_OS}.clock_gettime ) +add_header_library( + clock_conversion + HDRS + clock_conversion.h + DEPENDS + .clock_gettime + libc.src.__support.time.units +) + if(TARGET libc.src.__support.time.${LIBC_TARGET_OS}.clock_settime) add_object_library( clock_settime diff --git a/libc/src/__support/time/clock_conversion.h b/libc/src/__support/time/clock_conversion.h index acf0b21516467..5e3f76f9ba864 100644 --- a/libc/src/__support/time/clock_conversion.h +++ b/libc/src/__support/time/clock_conversion.h @@ -6,8 +6,8 @@ // //===----------------------------------------------------------------===// -#ifndef LLVM_LIBC_SRC___SUPPORT_TIME_LINUX_CLOCK_CONVERSION_H -#define LLVM_LIBC_SRC___SUPPORT_TIME_LINUX_CLOCK_CONVERSION_H +#ifndef LLVM_LIBC_SRC___SUPPORT_TIME_CLOCK_CONVERSION_H +#define LLVM_LIBC_SRC___SUPPORT_TIME_CLOCK_CONVERSION_H #include "src/__support/macros/config.h" #include "src/__support/time/clock_gettime.h" @@ -62,4 +62,4 @@ LIBC_INLINE timespec convert_clock(timespec input, clockid_t from, } // namespace internal } // namespace LIBC_NAMESPACE_DECL -#endif // LLVM_LIBC_SRC___SUPPORT_TIME_LINUX_CLOCK_CONVERSION_H +#endif // LLVM_LIBC_SRC___SUPPORT_TIME_CLOCK_CONVERSION_H diff --git a/libc/src/__support/time/linux/CMakeLists.txt b/libc/src/__support/time/linux/CMakeLists.txt index 478529502b403..7762beb29495e 100644 --- a/libc/src/__support/time/linux/CMakeLists.txt +++ b/libc/src/__support/time/linux/CMakeLists.txt @@ -29,14 +29,6 @@ add_object_library( libc.src.__support.OSUtil.osutil ) -add_header_library( - clock_conversion - HDRS - clock_conversion.h - DEPENDS - .clock_gettime - libc.src.__support.time.units -) add_header_library( abs_timeout @@ -53,7 +45,7 @@ add_header_library( HDRS monotonicity.h DEPENDS - .clock_conversion + libc.src.__support.time.clock_conversion .abs_timeout libc.hdr.time_macros ) From 909fc9551c694978c204e647970bcb5fb7d1f8ab Mon Sep 17 00:00:00 2001 From: Shreeyash Pandey Date: Wed, 3 Dec 2025 18:28:46 +0530 Subject: [PATCH 3/5] [libc] fix comment formatting --- libc/src/__support/time/clock_conversion.h | 43 +++++++++++----------- 1 file changed, 21 insertions(+), 22 deletions(-) diff --git a/libc/src/__support/time/clock_conversion.h b/libc/src/__support/time/clock_conversion.h index 5e3f76f9ba864..f69a788dec2a9 100644 --- a/libc/src/__support/time/clock_conversion.h +++ b/libc/src/__support/time/clock_conversion.h @@ -16,28 +16,27 @@ namespace LIBC_NAMESPACE_DECL { namespace internal { -/** - * @brief Convert a timespec value from one clock domain to another. - * - * The function takes a timestamp that is expressed in terms of the clock - * identified by param from and returns an equivalent timestamp expressed - * in terms of the clock identified by param to. - * - * Internally it obtains the current time of both clocks with - * clock_gettime, then subtracts the source clock’s value and - * adds the target clock’s value. The result is normalised so that - * the nanoseconds field is always in the range [0, 1 s). - * - * This is useful, for example, for converting a value obtained from - * CLOCK_MONOTONIC to CLOCK_REALTIME (or vice‑versa) so that the - * timestamp can be displayed to a user or stored in a format that - * is independent of the original clock domain. - * - * @param input The timestamp to convert - * @param from Clock ID of the original timestamp (e.g. CLOCK_MONOTONIC). - * @param to Clock ID of the desired timestamp (e.g. CLOCK_REALTIME). - * @return The converted timespec - */ +// @brief Convert a timespec value from one clock domain to another. +// +// The function takes a timestamp that is expressed in terms of the clock +// identified by param from and returns an equivalent timestamp expressed +// in terms of the clock identified by param to. +// +// Internally it obtains the current time of both clocks with +// clock_gettime, then subtracts the source clock’s value and +// adds the target clock’s value. The result is normalised so that +// the nanoseconds field is always in the range [0, 1 s). +// +// This is useful, for example, for converting a value obtained from +// CLOCK_MONOTONIC to CLOCK_REALTIME (or vice‑versa) so that the +// timestamp can be displayed to a user or stored in a format that +// is independent of the original clock domain. +// +// @param input The timestamp to convert +// @param from Clock ID of the original timestamp (e.g. CLOCK_MONOTONIC). +// @param to Clock ID of the desired timestamp (e.g. CLOCK_REALTIME). +// @return The converted timespec +// LIBC_INLINE timespec convert_clock(timespec input, clockid_t from, clockid_t to) { using namespace time_units; From 08bf15945c880cf9291498714af2753bc68404a6 Mon Sep 17 00:00:00 2001 From: Shreeyash Pandey Date: Wed, 3 Dec 2025 18:33:29 +0530 Subject: [PATCH 4/5] [libc] address nit --- libc/src/__support/time/linux/CMakeLists.txt | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/libc/src/__support/time/linux/CMakeLists.txt b/libc/src/__support/time/linux/CMakeLists.txt index 7762beb29495e..1d1c961bf1b2b 100644 --- a/libc/src/__support/time/linux/CMakeLists.txt +++ b/libc/src/__support/time/linux/CMakeLists.txt @@ -45,7 +45,7 @@ add_header_library( HDRS monotonicity.h DEPENDS - libc.src.__support.time.clock_conversion .abs_timeout libc.hdr.time_macros + libc.src.__support.time.clock_conversion ) From 7bf3e08b61bf1de75d386eacad924b4d5c618a2f Mon Sep 17 00:00:00 2001 From: Shreeyash Pandey Date: Wed, 3 Dec 2025 19:23:01 +0530 Subject: [PATCH 5/5] [libc] header to 80 --- libc/src/__support/time/clock_conversion.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/libc/src/__support/time/clock_conversion.h b/libc/src/__support/time/clock_conversion.h index f69a788dec2a9..54ea4b6ca1430 100644 --- a/libc/src/__support/time/clock_conversion.h +++ b/libc/src/__support/time/clock_conversion.h @@ -1,10 +1,10 @@ -//===--- clock conversion implementation ------------------*- C++ -*-===// +//===--- clock conversion implementation ------------------------*- 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___SUPPORT_TIME_CLOCK_CONVERSION_H #define LLVM_LIBC_SRC___SUPPORT_TIME_CLOCK_CONVERSION_H