[libc][gpu] unify time implementation style and fix build

libc/src/__support/time/CMakeLists.txt

@@ -1,5 +1,16 @@
+add_header_library(
+  units
+  HDRS
+    units.h
+  DEPENDS
+    libc.src.__support.common
+    libc.hdr.types.time_t
+)
+
 if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
   add_subdirectory(${LIBC_TARGET_OS})
+else()
+  return()
 endif()
 
 add_object_library(
@@ -8,12 +19,3 @@ add_object_library(
   DEPENDS
     libc.src.__support.time.${LIBC_TARGET_OS}.clock_gettime
 )
-
-add_header_library(
-  units
-  HDRS
-    units.h
-  DEPENDS
-    libc.src.__support.common
-    libc.hdr.types.time_t
-)

libc/src/__support/time/gpu/CMakeLists.txt

@@ -0,0 +1,22 @@
+add_object_library(
+  time_utils
+  SRCS
+    time_utils.cpp
+  HDRS
+    time_utils.h
+  DEPENDS
+    libc.hdr.types.clock_t
+    libc.hdr.time_macros
+)
+
+add_entrypoint_object(
+  clock_gettime
+  SRCS
+    clock_gettime.cpp
+  HDRS
+    ../clock_gettime.h
+  DEPENDS
+    libc.hdr.types.clockid_t
+    libc.hdr.types.struct_timespec
+    .time_utils
+)

libc/src/__support/time/gpu/clock_gettime.cpp

@@ -0,0 +1,33 @@
+//===---------- GPU implementation of the clock_gettime 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/clock_gettime.h"
+
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+#include "src/__support/time/clock_gettime.h"
+#include "src/__support/time/gpu/time_utils.h"
+
+namespace LIBC_NAMESPACE_DECL {
+namespace internal {
+constexpr uint64_t TICKS_PER_SEC = 1000000000UL;
+
+ErrorOr<int> clock_gettime(clockid_t clockid, timespec *ts) {
+  if (clockid != CLOCK_MONOTONIC || !ts)
+    return cpp::unexpected(-1);
+
+  uint64_t ns_per_tick = TICKS_PER_SEC / GPU_CLOCKS_PER_SEC;
+  uint64_t ticks = gpu::fixed_frequency_clock();
+
+  ts->tv_nsec = (ticks * ns_per_tick) % TICKS_PER_SEC;
+  ts->tv_sec = (ticks * ns_per_tick) / TICKS_PER_SEC;
+
+  return 0;
+}
+} // namespace internal
+} // namespace LIBC_NAMESPACE_DECL

libc/src/time/gpu/CMakeLists.txt

@@ -1,14 +1,3 @@
-add_object_library(
-  time_utils
-  SRCS
-    time_utils.cpp
-  HDRS
-    time_utils.h
-  DEPENDS
-    libc.hdr.types.clock_t
-    libc.hdr.time_macros
-)
-
 add_entrypoint_object(
   clock
   SRCS
@@ -18,7 +7,8 @@ add_entrypoint_object(
   DEPENDS
     libc.include.time
     libc.src.__support.GPU.utils
-    .time_utils
+    libc.src.__support.time.clock_gettime
+    libc.src.__support.time.gpu.time_utils
 )
 
 add_entrypoint_object(
@@ -30,19 +20,7 @@ add_entrypoint_object(
   DEPENDS
     libc.include.time
     libc.src.__support.GPU.utils
-    .time_utils
-)
-
-add_entrypoint_object(
-  clock_gettime
-  SRCS
-    clock_gettime.cpp
-  HDRS
-    ../clock_gettime.h
-  DEPENDS
-    libc.hdr.types.clockid_t
-    libc.hdr.types.struct_timespec
-    .time_utils
+    libc.src.__support.time.gpu.time_utils
 )
 
 add_entrypoint_object(
@@ -54,5 +32,5 @@ add_entrypoint_object(
   DEPENDS
     libc.hdr.time_macros
     libc.hdr.types.struct_timespec
-    .time_utils
+    libc.src.__support.time.gpu.time_utils
 )

libc/src/time/gpu/clock.cpp

@@ -8,7 +8,7 @@
 
 #include "src/time/clock.h"
 #include "src/__support/macros/config.h"
-#include "src/time/gpu/time_utils.h"
+#include "src/__support/time/gpu/time_utils.h"
 
 namespace LIBC_NAMESPACE_DECL {
 

libc/src/time/gpu/clock_gettime.cpp

@@ -10,23 +10,18 @@
 
 #include "src/__support/common.h"
 #include "src/__support/macros/config.h"
-#include "time_utils.h"
+#include "src/__support/time/clock_gettime.h"
+#include "src/__support/time/gpu/time_utils.h"
 
 namespace LIBC_NAMESPACE_DECL {
 
 constexpr uint64_t TICKS_PER_SEC = 1000000000UL;
 
 LLVM_LIBC_FUNCTION(int, clock_gettime, (clockid_t clockid, timespec *ts)) {
-  if (clockid != CLOCK_MONOTONIC || !ts)
-    return -1;
-
-  uint64_t ns_per_tick = TICKS_PER_SEC / GPU_CLOCKS_PER_SEC;
-  uint64_t ticks = gpu::fixed_frequency_clock();
-
-  ts->tv_nsec = (ticks * ns_per_tick) % TICKS_PER_SEC;
-  ts->tv_sec = (ticks * ns_per_tick) / TICKS_PER_SEC;
-
-  return 0;
+  ErrorOr<int> result = internal::clock_gettime(clockid, ts);
+  if (result)
+    return result.value();
+  return result.error();
 }
 
 } // namespace LIBC_NAMESPACE_DECL

libc/src/time/gpu/nanosleep.cpp

@@ -9,7 +9,7 @@
 #include "src/time/nanosleep.h"
 
 #include "src/__support/macros/config.h"
-#include "time_utils.h"
+#include "src/__support/time/gpu/time_utils.h"
 
 namespace LIBC_NAMESPACE_DECL {