[libc] Add POSIX functions posix_spawn_file_actions_*.

Namely, posix_spawn_file_actions_addclose,
posix_spawn_file_actions_adddup2, posix_spawn_file_actions_addopen,
posix_spawn_file_actions_destroy, posix_spawn_file_actions_init have
been added.

Reviewed By: michaelrj, lntue

Differential Revision: https://reviews.llvm.org/D135603

12 files changed, 412 insertions, 0 deletions

diff --git a/libc/src/spawn/CMakeLists.txt b/libc/src/spawn/CMakeLists.txt
new file mode 100644
index 000000000000..95a0c7436d26
--- /dev/null
+++ b/libc/src/spawn/CMakeLists.txt
@@ -0,0 +1,65 @@
+add_header_library(
+  file_actions
+  HDRS
+    file_actions.h
+  DEPENDS
+    libc.include.spawn
+)
+
+add_entrypoint_object(
+  posix_spawn_file_actions_init
+  SRCS
+    posix_spawn_file_actions_init.cpp
+  HDRS
+    posix_spawn_file_actions_init.h
+  DEPENDS
+    libc.include.spawn
+)
+
+add_entrypoint_object(
+  posix_spawn_file_actions_destroy
+  SRCS
+    posix_spawn_file_actions_destroy.cpp
+  HDRS
+    posix_spawn_file_actions_destroy.h
+  DEPENDS
+    .file_actions
+    libc.include.errno
+    libc.include.spawn
+)
+
+add_entrypoint_object(
+  posix_spawn_file_actions_adddup2
+  SRCS
+    posix_spawn_file_actions_adddup2.cpp
+  HDRS
+    posix_spawn_file_actions_adddup2.h
+  DEPENDS
+    .file_actions
+    libc.include.errno
+    libc.include.spawn
+)
+
+add_entrypoint_object(
+  posix_spawn_file_actions_addopen
+  SRCS
+    posix_spawn_file_actions_addopen.cpp
+  HDRS
+    posix_spawn_file_actions_addopen.h
+  DEPENDS
+    .file_actions
+    libc.include.errno
+    libc.include.spawn
+)
+
+add_entrypoint_object(
+  posix_spawn_file_actions_addclose
+  SRCS
+    posix_spawn_file_actions_addclose.cpp
+  HDRS
+    posix_spawn_file_actions_addclose.h
+  DEPENDS
+    .file_actions
+    libc.include.errno
+    libc.include.spawn
+)
diff --git a/libc/src/spawn/file_actions.h b/libc/src/spawn/file_actions.h
new file mode 100644
index 000000000000..11d9fb70d193
--- /dev/null
+++ b/libc/src/spawn/file_actions.h
@@ -0,0 +1,58 @@
+//===-- Spawn file actions  -------------------------------------*- 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_SPAWN_FILE_ACTIONS_H
+#define LLVM_LIBC_SRC_SPAWN_FILE_ACTIONS_H
+
+#include <spawn.h> // For mode_t
+#include <stdint.h>
+
+namespace __llvm_libc {
+
+struct BaseSpawnFileAction {
+  enum ActionType {
+    OPEN = 111,
+    CLOSE = 222,
+    DUP2 = 333,
+  };
+
+  ActionType type;
+  BaseSpawnFileAction *next;
+};
+
+struct SpawnFileOpenAction : public BaseSpawnFileAction {
+  const char *path;
+  int fd;
+  int oflag;
+  mode_t mode;
+};
+
+struct SpawnFileCloseAction : public BaseSpawnFileAction {
+  int fd;
+};
+
+struct SpawnFileDup2Action : public BaseSpawnFileAction {
+  int fd;
+  int newfd;
+};
+
+inline void enque_spawn_action(posix_spawn_file_actions_t *actions,
+                               BaseSpawnFileAction *act) {
+  if (actions->__back != nullptr) {
+    auto *back = reinterpret_cast<BaseSpawnFileAction *>(actions->__back);
+    back->next = act;
+    actions->__back = act;
+  } else {
+    // First action is being added.
+    actions->__front = actions->__back = act;
+  }
+}
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_SPAWN_FILE_ACTIONS_H
diff --git a/libc/src/spawn/posix_spawn_file_actions_addclose.cpp b/libc/src/spawn/posix_spawn_file_actions_addclose.cpp
new file mode 100644
index 000000000000..81d3878fe81d
--- /dev/null
+++ b/libc/src/spawn/posix_spawn_file_actions_addclose.cpp
@@ -0,0 +1,38 @@
+//===-- Implementation of posix_spawn_file_actions_addclose ---------------===//
+//
+// 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 "posix_spawn_file_actions_addclose.h"
+
+#include "file_actions.h"
+#include "src/__support/common.h"
+
+#include <errno.h>
+#include <spawn.h>
+#include <stdlib.h> // For malloc
+
+namespace __llvm_libc {
+
+LLVM_LIBC_FUNCTION(int, posix_spawn_file_actions_addclose,
+                   (posix_spawn_file_actions_t *__restrict actions, int fd)) {
+  if (actions == nullptr)
+    return EINVAL;
+  if (fd < 0)
+    return EBADF;
+
+  auto *act = reinterpret_cast<SpawnFileCloseAction *>(
+      malloc(sizeof(SpawnFileCloseAction)));
+  if (act == nullptr)
+    return ENOMEM;
+
+  act->type = BaseSpawnFileAction::CLOSE;
+  act->fd = fd;
+  enque_spawn_action(actions, act);
+  return 0;
+}
+
+} // namespace __llvm_libc
diff --git a/libc/src/spawn/posix_spawn_file_actions_addclose.h b/libc/src/spawn/posix_spawn_file_actions_addclose.h
new file mode 100644
index 000000000000..5eda292760da
--- /dev/null
+++ b/libc/src/spawn/posix_spawn_file_actions_addclose.h
@@ -0,0 +1,21 @@
+//===-- Impl header for posix_spawn_file_actions_addclose -------*- 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_SPAWN_POSIX_SPAWN_FILE_ACTIONS_ADDCLOSE_H
+#define LLVM_LIBC_SRC_SPAWN_POSIX_SPAWN_FILE_ACTIONS_ADDCLOSE_H
+
+#include <spawn.h>
+
+namespace __llvm_libc {
+
+int posix_spawn_file_actions_addclose(
+    posix_spawn_file_actions_t *__restrict actions, int fd);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_SPAWN_POSIX_SPAWN_FILE_ACTIONS_ADDCLOSE_H
diff --git a/libc/src/spawn/posix_spawn_file_actions_adddup2.cpp b/libc/src/spawn/posix_spawn_file_actions_adddup2.cpp
new file mode 100644
index 000000000000..a6a7f07110e9
--- /dev/null
+++ b/libc/src/spawn/posix_spawn_file_actions_adddup2.cpp
@@ -0,0 +1,40 @@
+//===-- Implementation of posix_spawn_file_actions_adddup2 ----------------===//
+//
+// 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 "posix_spawn_file_actions_adddup2.h"
+
+#include "file_actions.h"
+#include "src/__support/common.h"
+
+#include <errno.h>
+#include <spawn.h>
+#include <stdlib.h> // For malloc
+
+namespace __llvm_libc {
+
+LLVM_LIBC_FUNCTION(int, posix_spawn_file_actions_adddup2,
+                   (posix_spawn_file_actions_t * actions, int fd, int newfd)) {
+  if (actions == nullptr)
+    return EINVAL;
+  if (fd < 0 || newfd < 0)
+    return EBADF;
+
+  auto *act = reinterpret_cast<SpawnFileDup2Action *>(
+      malloc(sizeof(SpawnFileDup2Action)));
+  if (act == nullptr)
+    return ENOMEM;
+
+  act->type = BaseSpawnFileAction::DUP2;
+  act->fd = fd;
+  act->newfd = newfd;
+  act->next = nullptr;
+  enque_spawn_action(actions, act);
+  return 0;
+}
+
+} // namespace __llvm_libc
diff --git a/libc/src/spawn/posix_spawn_file_actions_adddup2.h b/libc/src/spawn/posix_spawn_file_actions_adddup2.h
new file mode 100644
index 000000000000..33444184f973
--- /dev/null
+++ b/libc/src/spawn/posix_spawn_file_actions_adddup2.h
@@ -0,0 +1,21 @@
+//===-- Impl header for posix_spawn_file_actions_adddup2 --------*- 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_SPAWN_POSIX_SPAWN_FILE_ACTIONS_ADDDUP2_H
+#define LLVM_LIBC_SRC_SPAWN_POSIX_SPAWN_FILE_ACTIONS_ADDDUP2_H
+
+#include <spawn.h>
+
+namespace __llvm_libc {
+
+int posix_spawn_file_actions_adddup2(posix_spawn_file_actions_t *actions,
+                                     int fd, int newfd);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_SPAWN_POSIX_SPAWN_FILE_ACTIONS_ADDDUP2_H
diff --git a/libc/src/spawn/posix_spawn_file_actions_addopen.cpp b/libc/src/spawn/posix_spawn_file_actions_addopen.cpp
new file mode 100644
index 000000000000..ac286631c056
--- /dev/null
+++ b/libc/src/spawn/posix_spawn_file_actions_addopen.cpp
@@ -0,0 +1,43 @@
+//===-- Implementation of posix_spawn_file_actions_addopen ----------------===//
+//
+// 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 "posix_spawn_file_actions_addopen.h"
+
+#include "file_actions.h"
+#include "src/__support/common.h"
+
+#include <errno.h>
+#include <spawn.h>
+#include <stdlib.h> // For malloc
+
+namespace __llvm_libc {
+
+LLVM_LIBC_FUNCTION(int, posix_spawn_file_actions_addopen,
+                   (posix_spawn_file_actions_t *__restrict actions, int fd,
+                    const char *__restrict path, int oflag, mode_t mode)) {
+  if (actions == nullptr)
+    return EINVAL;
+  if (fd < 0)
+    return EBADF;
+
+  auto *act = reinterpret_cast<SpawnFileOpenAction *>(
+      malloc(sizeof(SpawnFileOpenAction)));
+  if (act == nullptr)
+    return ENOMEM;
+
+  act->type = BaseSpawnFileAction::OPEN;
+  act->fd = fd;
+  act->path = path;
+  act->oflag = oflag;
+  act->mode = mode;
+  act->next = nullptr;
+  enque_spawn_action(actions, act);
+  return 0;
+}
+
+} // namespace __llvm_libc
diff --git a/libc/src/spawn/posix_spawn_file_actions_addopen.h b/libc/src/spawn/posix_spawn_file_actions_addopen.h
new file mode 100644
index 000000000000..ff757d42e514
--- /dev/null
+++ b/libc/src/spawn/posix_spawn_file_actions_addopen.h
@@ -0,0 +1,22 @@
+//===-- Impl header for posix_spawn_file_actions_addopen --------*- 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_SPAWN_POSIX_SPAWN_FILE_ACTIONS_ADDOPEN_H
+#define LLVM_LIBC_SRC_SPAWN_POSIX_SPAWN_FILE_ACTIONS_ADDOPEN_H
+
+#include <spawn.h>
+
+namespace __llvm_libc {
+
+int posix_spawn_file_actions_addopen(
+    posix_spawn_file_actions_t *__restrict actions, int fd,
+    const char *__restrict path, int oflag, mode_t mode);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_SPAWN_POSIX_SPAWN_FILE_ACTIONS_ADDOPEN_H
diff --git a/libc/src/spawn/posix_spawn_file_actions_destroy.cpp b/libc/src/spawn/posix_spawn_file_actions_destroy.cpp
new file mode 100644
index 000000000000..83346462c95b
--- /dev/null
+++ b/libc/src/spawn/posix_spawn_file_actions_destroy.cpp
@@ -0,0 +1,40 @@
+//===-- Implementation of posix_spawn_file_actions_destroy ----------------===//
+//
+// 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 "posix_spawn_file_actions_destroy.h"
+
+#include "file_actions.h"
+#include "src/__support/common.h"
+
+#include <errno.h>
+#include <spawn.h>
+#include <stdlib.h> // For free
+
+namespace __llvm_libc {
+
+LLVM_LIBC_FUNCTION(int, posix_spawn_file_actions_destroy,
+                   (posix_spawn_file_actions_t * actions)) {
+  if (actions == nullptr)
+    return EINVAL;
+  if (actions->__front == nullptr)
+    return 0;
+
+  auto *act = reinterpret_cast<BaseSpawnFileAction *>(actions->__front);
+  actions->__front = nullptr;
+  actions->__back = nullptr;
+
+  while (act != nullptr) {
+    auto *next = act->next;
+    free(act);
+    act = next;
+  }
+
+  return 0;
+}
+
+} // namespace __llvm_libc
diff --git a/libc/src/spawn/posix_spawn_file_actions_destroy.h b/libc/src/spawn/posix_spawn_file_actions_destroy.h
new file mode 100644
index 000000000000..89f3c55dd99b
--- /dev/null
+++ b/libc/src/spawn/posix_spawn_file_actions_destroy.h
@@ -0,0 +1,20 @@
+//===-- Impl header for posix_spawn_file_actions_destroy --------*- 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_SPAWN_POSIX_SPAWN_FILE_ACTIONS_DESTROY_H
+#define LLVM_LIBC_SRC_SPAWN_POSIX_SPAWN_FILE_ACTIONS_DESTROY_H
+
+#include <spawn.h>
+
+namespace __llvm_libc {
+
+int posix_spawn_file_actions_destroy(posix_spawn_file_actions_t *actions);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_SPAWN_POSIX_SPAWN_FILE_ACTIONS_DESTROY_H
diff --git a/libc/src/spawn/posix_spawn_file_actions_init.cpp b/libc/src/spawn/posix_spawn_file_actions_init.cpp
new file mode 100644
index 000000000000..99502ff44962
--- /dev/null
+++ b/libc/src/spawn/posix_spawn_file_actions_init.cpp
@@ -0,0 +1,24 @@
+//===-- Implementation of posix_spawn_file_actions_init -------------------===//
+//
+// 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 "posix_spawn_file_actions_init.h"
+
+#include "src/__support/common.h"
+
+#include <spawn.h>
+
+namespace __llvm_libc {
+
+LLVM_LIBC_FUNCTION(int, posix_spawn_file_actions_init,
+                   (posix_spawn_file_actions_t * actions)) {
+  actions->__front = nullptr;
+  actions->__back = nullptr;
+  return 0;
+}
+
+} // namespace __llvm_libc
diff --git a/libc/src/spawn/posix_spawn_file_actions_init.h b/libc/src/spawn/posix_spawn_file_actions_init.h
new file mode 100644
index 000000000000..da354e1b0eba
--- /dev/null
+++ b/libc/src/spawn/posix_spawn_file_actions_init.h
@@ -0,0 +1,20 @@
+//===-- Implementation header for posix_spawn_file_actions_init -*- 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_SPAWN_POSIX_SPAWN_FILE_ACTIONS_INIT_H
+#define LLVM_LIBC_SRC_SPAWN_POSIX_SPAWN_FILE_ACTIONS_INIT_H
+
+#include <spawn.h>
+
+namespace __llvm_libc {
+
+int posix_spawn_file_actions_init(posix_spawn_file_actions_t *actions);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_SPAWN_POSIX_SPAWN_FILE_ACTIONS_INIT_H