[libc] add remaining epoll functions, pipe (llvm#84587)

The epoll_wait functions need the rest of the epoll functions (create,
ctl) to be available to actually test them, as well as pipe to create a
usable file descriptor. This patch adds epoll_create, epoll_create1,
epoll_ctl, and pipe. These have tests, and the tests for epoll_wait,
epoll_pwait, and epoll_pwait2 (currently disabled) are updated to use
these newly available functions.

libc/config/linux/x86_64/entrypoints.txt

@@ -215,6 +215,9 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.stdio.fileno
 
     # sys/epoll.h entrypoints
+    libc.src.sys.epoll.epoll_create
+    libc.src.sys.epoll.epoll_create1
+    libc.src.sys.epoll.epoll_ctl
     libc.src.sys.epoll.epoll_wait
     libc.src.sys.epoll.epoll_pwait
     # TODO: Need to check if pwait2 is available before providing.
@@ -308,6 +311,7 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.unistd.link
     libc.src.unistd.linkat
     libc.src.unistd.lseek
+    libc.src.unistd.pipe
     libc.src.unistd.pread
     libc.src.unistd.pwrite
     libc.src.unistd.read

libc/hdr/CMakeLists.txt

@@ -41,4 +41,22 @@ add_proxy_header_library(
     libc.include.fenv
 )
 
+add_proxy_header_library(
+  signal_macros
+  HDRS
+    signal_macros.h
+  FULL_BUILD_DEPENDS
+    libc.include.llvm-libc-macros.signal_macros
+    libc.include.signal
+)
+
+add_proxy_header_library(
+  sys_epoll_macros
+  HDRS
+    sys_epoll_macros.h
+  FULL_BUILD_DEPENDS
+    libc.include.sys_epoll
+    libc.include.llvm-libc-macros.sys_epoll_macros
+)
+
 add_subdirectory(types)

libc/hdr/signal_macros.h

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

libc/hdr/sys_epoll_macros.h

@@ -0,0 +1,22 @@
+//===-- Definition of macros from sys/epoll.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_SYS_EPOLL_MACROS_H
+#define LLVM_LIBC_HDR_SYS_EPOLL_MACROS_H
+
+#ifdef LIBC_FULL_BUILD
+
+#include "include/llvm-libc-macros/sys-epoll-macros.h"
+
+#else // Overlay mode
+
+#include <sys/epoll.h>
+
+#endif // LLVM_LIBC_FULL_BUILD
+
+#endif // LLVM_LIBC_HDR_SYS/EPOLL_MACROS_H

libc/include/CMakeLists.txt

@@ -379,6 +379,7 @@ add_gen_header(
     .llvm-libc-types.struct_epoll_event
     .llvm-libc-types.struct_epoll_data
     .llvm-libc-types.sigset_t
+    .llvm-libc-macros.sys_epoll_macros
 )
 
 add_gen_header(

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

@@ -143,6 +143,12 @@ add_macro_header(
     sys-auxv-macros.h
 )
 
+add_macro_header(
+  sys_epoll_macros
+  HDR
+    sys-epoll-macros.h
+)
+
 add_macro_header(
   sys_ioctl_macros
   HDR

libc/include/llvm-libc-macros/linux/CMakeLists.txt

@@ -10,6 +10,12 @@ add_header(
     sched-macros.h
 )
 
+add_header(
+  sys_epoll_macros
+  HDR
+    sys-epoll-macros.h
+)
+
 add_header(
   sys_ioctl_macros
   HDR

libc/include/llvm-libc-macros/linux/sys-epoll-macros.h

@@ -0,0 +1,40 @@
+//===-- Macros defined in sys/epoll.h header file -------------------------===//
+//
+// 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_MACROS_LINUX_SYS_EPOLL_MACROS_H
+#define LLVM_LIBC_MACROS_LINUX_SYS_EPOLL_MACROS_H
+
+#include "fcntl-macros.h"
+
+// These are also defined in <linux/eventpoll.h> but that also contains a
+// different definition of the epoll_event struct that is different from the
+// userspace version.
+
+#define EPOLL_CLOEXEC O_CLOEXEC
+
+#define EPOLL_CTL_ADD 1
+#define EPOLL_CTL_DEL 2
+#define EPOLL_CTL_MOD 3
+
+#define EPOLLIN 0x1
+#define EPOLLPRI 0x2
+#define EPOLLOUT 0x4
+#define EPOLLERR 0x8
+#define EPOLLHUP 0x10
+#define EPOLLRDNORM 0x40
+#define EPOLLRDBAND 0x80
+#define EPOLLWRNORM 0x100
+#define EPOLLWRBAND 0x200
+#define EPOLLMSG 0x400
+#define EPOLLRDHUP 0x2000
+#define EPOLLEXCLUSIVE 0x10000000
+#define EPOLLWAKEUP 0x20000000
+#define EPOLLONESHOT 0x40000000
+#define EPOLLET 0x80000000
+
+#endif // LLVM_LIBC_MACROS_LINUX_SYS_EPOLL_MACROS_H

libc/include/llvm-libc-macros/sys-epoll-macros.h

@@ -0,0 +1,16 @@
+//===-- Macros defined in sys/epoll.h header file -------------------------===//
+//
+// 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_MACROS_SYS_EPOLL_MACROS_H
+#define LLVM_LIBC_MACROS_SYS_EPOLL_MACROS_H
+
+#ifdef __linux__
+#include "linux/sys-epoll-macros.h"
+#endif
+
+#endif // LLVM_LIBC_MACROS_SYS_EPOLL_MACROS_H

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

@@ -13,8 +13,8 @@
 
 // This definition can be adjusted/specialized for different targets and
 // platforms as necessary. This definition works for Linux on most targets.
-typedef struct {
+struct sigset_t {
   unsigned long __signals[__NSIGSET_WORDS];
-} sigset_t;
+};
 
 #endif // LLVM_LIBC_TYPES_SIGSET_T_H

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

@@ -11,7 +11,11 @@
 
 #include "llvm-libc-types/struct_epoll_data.h"
 
-typedef struct epoll_event {
+typedef struct
+#ifdef __x86_64__
+    [[gnu::packed]] // Necessary for compatibility.
+#endif
+    epoll_event {
   __UINT32_TYPE__ events;
   epoll_data_t data;
 } epoll_event;

libc/include/sys/epoll.h.def

@@ -11,6 +11,8 @@
 
 #include "__llvm-libc-common.h"
 
+#include "llvm-libc-macros/sys-epoll-macros.h"
+
 %%public_api()
 
 #endif // LLVM_LIBC_SYS_EPOLL_H

libc/spec/posix.td

@@ -572,6 +572,11 @@ def POSIX : StandardSpec<"POSIX"> {
           RetValSpec<OffTType>,
           [ArgSpec<IntType>, ArgSpec<OffTType>, ArgSpec<IntType>]
         >,
+        FunctionSpec<
+          "pipe",
+          RetValSpec<IntType>,
+          [ArgSpec<IntPtr>] //TODO: make this int[2]
+        >,
         FunctionSpec<
           "pread",
           RetValSpec<SSizeTType>,

libc/src/sys/epoll/CMakeLists.txt

@@ -2,6 +2,27 @@ if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
   add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
 endif()
 
+add_entrypoint_object(
+  epoll_create
+  ALIAS
+  DEPENDS
+    .${LIBC_TARGET_OS}.epoll_create
+)
+
+add_entrypoint_object(
+  epoll_create1
+  ALIAS
+  DEPENDS
+    .${LIBC_TARGET_OS}.epoll_create1
+)
+
+add_entrypoint_object(
+  epoll_ctl
+  ALIAS
+  DEPENDS
+    .${LIBC_TARGET_OS}.epoll_ctl
+)
+
 add_entrypoint_object(
   epoll_wait
   ALIAS

libc/src/sys/epoll/epoll_create.h

@@ -0,0 +1,18 @@
+//===-- Implementation header for epoll_create function ---------*- 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_SYS_EPOLL_EPOLL_CREATE_H
+#define LLVM_LIBC_SRC_SYS_EPOLL_EPOLL_CREATE_H
+
+namespace LIBC_NAMESPACE {
+
+int epoll_create(int size);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_SYS_EPOLL_EPOLL_CREATE_H

libc/src/sys/epoll/epoll_create1.h

@@ -0,0 +1,18 @@
+//===-- Implementation header for epoll_create1 function --------*- 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_SYS_EPOLL_EPOLL_CREATE1_H
+#define LLVM_LIBC_SRC_SYS_EPOLL_EPOLL_CREATE1_H
+
+namespace LIBC_NAMESPACE {
+
+int epoll_create1(int flags);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_SYS_EPOLL_EPOLL_CREATE1_H

libc/src/sys/epoll/epoll_ctl.h

@@ -0,0 +1,21 @@
+//===-- Implementation header for epoll_ctl function ------------*- 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_SYS_EPOLL_EPOLL_CTL_H
+#define LLVM_LIBC_SRC_SYS_EPOLL_EPOLL_CTL_H
+
+#include "hdr/types/struct_epoll_event.h"
+
+namespace LIBC_NAMESPACE {
+
+// TODO: event should be nullable
+int epoll_ctl(int epfd, int op, int fd, struct epoll_event *event);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_SYS_EPOLL_EPOLL_CTL_H

libc/src/sys/epoll/epoll_pwait.h

@@ -15,8 +15,8 @@
 namespace LIBC_NAMESPACE {
 
 // TODO: sigmask should be nullable
-int epoll_pwait(int epfd, epoll_event *events, int maxevents, int timeout,
-                const sigset_t *sigmask);
+int epoll_pwait(int epfd, struct epoll_event *events, int maxevents,
+                int timeout, const sigset_t *sigmask);
 
 } // namespace LIBC_NAMESPACE
 

libc/src/sys/epoll/linux/CMakeLists.txt

@@ -1,3 +1,41 @@
+add_entrypoint_object(
+  epoll_create
+  SRCS
+    epoll_create.cpp
+  HDRS
+    ../epoll_create.h
+  DEPENDS
+    libc.include.sys_syscall
+    libc.src.__support.OSUtil.osutil
+    libc.src.errno.errno
+)
+
+add_entrypoint_object(
+  epoll_create1
+  SRCS
+    epoll_create1.cpp
+  HDRS
+    ../epoll_create1.h
+  DEPENDS
+    libc.include.sys_syscall
+    libc.src.__support.OSUtil.osutil
+    libc.src.errno.errno
+)
+
+add_entrypoint_object(
+  epoll_ctl
+  SRCS
+    epoll_ctl.cpp
+  HDRS
+    ../epoll_ctl.h
+  DEPENDS
+    libc.hdr.types.struct_epoll_event
+    libc.hdr.sys_epoll_macros
+    libc.include.sys_syscall
+    libc.src.__support.OSUtil.osutil
+    libc.src.errno.errno
+)
+
 add_entrypoint_object(
   epoll_wait
   SRCS
@@ -23,7 +61,8 @@ add_entrypoint_object(
     libc.hdr.types.sigset_t
     libc.hdr.types.struct_epoll_event
     libc.hdr.types.struct_timespec
-    libc.include.signal
+    libc.hdr.sys_epoll_macros
+    libc.hdr.signal_macros
     libc.include.sys_syscall
     libc.src.__support.OSUtil.osutil
     libc.src.errno.errno
@@ -39,9 +78,9 @@ add_entrypoint_object(
     libc.hdr.types.sigset_t
     libc.hdr.types.struct_epoll_event
     libc.hdr.types.struct_timespec
-    libc.include.signal
+    libc.hdr.sys_epoll_macros
+    libc.hdr.signal_macros
     libc.include.sys_syscall
-    libc.include.time
     libc.src.__support.OSUtil.osutil
     libc.src.errno.errno
 )