[libc] Reland llvm#148948 "Implement barriers for pthreads" (llvm#151021)

Fixed build dependencies for pthread_barrier_t (add __barrier_type to
cmake dependencies)

Author: uzairnawaz

libc/config/linux/x86_64/entrypoints.txt

@@ -1056,6 +1056,9 @@ if(LLVM_LIBC_FULL_BUILD)
     libc.src.pthread.pthread_join
     libc.src.pthread.pthread_key_create
     libc.src.pthread.pthread_key_delete
+    libc.src.pthread.pthread_barrier_init
+    libc.src.pthread.pthread_barrier_wait
+    libc.src.pthread.pthread_barrier_destroy
     libc.src.pthread.pthread_mutex_destroy
     libc.src.pthread.pthread_mutex_init
     libc.src.pthread.pthread_mutex_lock

libc/hdr/CMakeLists.txt

@@ -72,6 +72,15 @@ add_proxy_header_library(
     libc.include.fenv
 )
 
+add_proxy_header_library(
+  pthread_macros
+  HDRS
+    pthread_macros.h
+  FULL_BUILD_DEPENDS
+    libc.include.llvm-libc-macros.pthread_macros
+    libc.include.pthread
+)
+
 add_proxy_header_library(
   sched_macros
   HDRS

libc/hdr/pthread_macros.h

@@ -0,0 +1,22 @@
+//===-- Definition of macros from pthread.h -------------------------------===//
+//
+// 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_HDR_PTHREAD_MACROS_H
+#define LLVM_LIBC_HDR_PTHREAD_MACROS_H
+
+#ifdef LIBC_FULL_BUILD
+
+#include "include/llvm-libc-macros/pthread-macros.h"
+
+#else // Overlay mode
+
+#include <pthread.h>
+
+#endif // LLVM_LIBC_FULL_BUILD
+
+#endif // LLVM_LIBC_HDR_PTHREAD_MACROS_H

libc/hdr/types/CMakeLists.txt

@@ -241,6 +241,22 @@ add_proxy_header_library(
     libc.include.llvm-libc-types.pid_t
 )
 
+add_proxy_header_library(
+  pthread_barrier_t
+  HDRS
+    pthread_barrier_t.h
+  FULL_BUILD_DEPENDS
+    libc.include.llvm-libc-types.pthread_barrier_t
+)
+
+add_proxy_header_library(
+  pthread_barrierattr_t
+  HDRS
+    pthread_barrierattr_t.h
+  FULL_BUILD_DEPENDS
+    libc.include.llvm-libc-types.pthread_barrierattr_t
+)
+
 add_proxy_header_library(
   atexithandler_t
   HDRS

libc/hdr/types/pthread_barrier_t.h

@@ -0,0 +1,22 @@
+//===-- Definition of macros from pthread_barrier_t.h ---------------------===//
+//
+// 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_HDR_TYPES_PTHREAD_BARRIER_T_H
+#define LLVM_LIBC_HDR_TYPES_PTHREAD_BARRIER_T_H
+
+#ifdef LIBC_FULL_BUILD
+
+#include "include/llvm-libc-types/pthread_barrier_t.h"
+
+#else // Overlay mode
+
+#error "Cannot overlay pthread_barrier_t"
+
+#endif // LLVM_LIBC_FULL_BUILD
+
+#endif // LLVM_LIBC_HDR_TYPES_PTHREAD_BARRIER_T_H

libc/hdr/types/pthread_barrierattr_t.h

@@ -0,0 +1,22 @@
+//===-- Definition of macros from pthread_barrierattr_t.h -----------------===//
+//
+// 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_HDR_TYPES_PTHREAD_BARRIERATTR_T_H
+#define LLVM_LIBC_HDR_TYPES_PTHREAD_BARRIERATTR_T_H
+
+#ifdef LIBC_FULL_BUILD
+
+#include "include/llvm-libc-types/pthread_barrierattr_t.h"
+
+#else // Overlay mode
+
+#error "Cannot overlay pthread_barrierattr_t"
+
+#endif // LLVM_LIBC_FULL_BUILD
+
+#endif // LLVM_LIBC_HDR_TYPES_PTHREAD_BARRIERATTR_T_H

libc/include/CMakeLists.txt

@@ -392,6 +392,8 @@ add_header_macro(
     .llvm-libc-types.pthread_attr_t
     .llvm-libc-types.pthread_condattr_t
     .llvm-libc-types.pthread_key_t
+    .llvm-libc-types.pthread_barrier_t
+    .llvm-libc-types.pthread_barrierattr_t
     .llvm-libc-types.pthread_mutex_t
     .llvm-libc-types.pthread_mutexattr_t
     .llvm-libc-types.pthread_once_t

libc/include/llvm-libc-macros/pthread-macros.h

@@ -22,6 +22,8 @@
 #define PTHREAD_MUTEX_STALLED 0
 #define PTHREAD_MUTEX_ROBUST 1
 
+#define PTHREAD_BARRIER_SERIAL_THREAD -1
+
 #define PTHREAD_ONCE_INIT {0}
 
 #define PTHREAD_PROCESS_PRIVATE 0

libc/include/llvm-libc-types/CMakeLists.txt

@@ -10,6 +10,7 @@ add_header(__exec_envp_t HDR __exec_envp_t.h)
 add_header(__futex_word HDR __futex_word.h)
 add_header(pid_t HDR pid_t.h)
 add_header(__mutex_type HDR __mutex_type.h DEPENDS .__futex_word .pid_t)
+add_header(__barrier_type HDR __barrier_type.h)
 add_header(__pthread_once_func_t HDR __pthread_once_func_t.h)
 add_header(__pthread_start_t HDR __pthread_start_t.h)
 add_header(__pthread_tss_dtor_t HDR __pthread_tss_dtor_t.h)
@@ -53,6 +54,8 @@ add_header(pthread_condattr_t HDR pthread_condattr_t.h DEPENDS .clockid_t)
 add_header(pthread_key_t HDR pthread_key_t.h)
 add_header(pthread_mutex_t HDR pthread_mutex_t.h DEPENDS .__futex_word .__mutex_type)
 add_header(pthread_mutexattr_t HDR pthread_mutexattr_t.h)
+add_header(pthread_barrier_t HDR pthread_barrier_t.h DEPENDS .__barrier_type)
+add_header(pthread_barrierattr_t HDR pthread_barrierattr_t.h)
 add_header(pthread_once_t HDR pthread_once_t.h DEPENDS .__futex_word)
 add_header(pthread_rwlock_t HDR pthread_rwlock_t.h DEPENDS .__futex_word .pid_t)
 add_header(pthread_rwlockattr_t HDR pthread_rwlockattr_t.h)

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

@@ -0,0 +1,21 @@
+//===-- Definition of __barrier_type type ---------------------------------===//
+//
+// 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__BARRIER_TYPE_H
+#define LLVM_LIBC_TYPES__BARRIER_TYPE_H
+
+typedef struct __attribute__((aligned(8 /* alignof (Barrier) */))) {
+  unsigned expected;
+  unsigned waiting;
+  bool blocking;
+  char entering[24 /* sizeof (CndVar) */];
+  char exiting[24 /* sizeof (CndVar) */];
+  char mutex[24 /* sizeof (Mutex) */];
+} __barrier_type;
+
+#endif // LLVM_LIBC_TYPES__BARRIER_TYPE_H