Imported Upstream version 6.10.0.49

Former-commit-id: 1d6753294b2993e1fbf92de9366bb9544db4189b

external/llvm-project/lldb/source/Host/posix/DomainSocket.cpp

@@ -0,0 +1,127 @@
+//===-- DomainSocket.cpp ----------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/Host/posix/DomainSocket.h"
+
+#include "llvm/Support/FileSystem.h"
+
+#include <stddef.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+
+using namespace lldb;
+using namespace lldb_private;
+
+#ifdef __ANDROID__
+// Android does not have SUN_LEN
+#ifndef SUN_LEN
+#define SUN_LEN(ptr)                                                           \
+  (offsetof(struct sockaddr_un, sun_path) + strlen((ptr)->sun_path))
+#endif
+#endif // #ifdef __ANDROID__
+
+namespace {
+
+const int kDomain = AF_UNIX;
+const int kType = SOCK_STREAM;
+
+bool SetSockAddr(llvm::StringRef name, const size_t name_offset,
+                 sockaddr_un *saddr_un, socklen_t &saddr_un_len) {
+  if (name.size() + name_offset > sizeof(saddr_un->sun_path))
+    return false;
+
+  memset(saddr_un, 0, sizeof(*saddr_un));
+  saddr_un->sun_family = kDomain;
+
+  memcpy(saddr_un->sun_path + name_offset, name.data(), name.size());
+
+  // For domain sockets we can use SUN_LEN in order to calculate size of
+  // sockaddr_un, but for abstract sockets we have to calculate size manually
+  // because of leading null symbol.
+  if (name_offset == 0)
+    saddr_un_len = SUN_LEN(saddr_un);
+  else
+    saddr_un_len =
+        offsetof(struct sockaddr_un, sun_path) + name_offset + name.size();
+
+#if defined(__APPLE__) || defined(__FreeBSD__) || defined(__NetBSD__)
+  saddr_un->sun_len = saddr_un_len;
+#endif
+
+  return true;
+}
+} // namespace
+
+DomainSocket::DomainSocket(bool should_close, bool child_processes_inherit)
+    : Socket(ProtocolUnixDomain, should_close, child_processes_inherit) {}
+
+DomainSocket::DomainSocket(SocketProtocol protocol,
+                           bool child_processes_inherit)
+    : Socket(protocol, true, child_processes_inherit) {}
+
+DomainSocket::DomainSocket(NativeSocket socket,
+                           const DomainSocket &listen_socket)
+    : Socket(ProtocolUnixDomain, listen_socket.m_should_close_fd,
+             listen_socket.m_child_processes_inherit) {
+  m_socket = socket;
+}
+
+Status DomainSocket::Connect(llvm::StringRef name) {
+  sockaddr_un saddr_un;
+  socklen_t saddr_un_len;
+  if (!SetSockAddr(name, GetNameOffset(), &saddr_un, saddr_un_len))
+    return Status("Failed to set socket address");
+
+  Status error;
+  m_socket = CreateSocket(kDomain, kType, 0, m_child_processes_inherit, error);
+  if (error.Fail())
+    return error;
+  if (::connect(GetNativeSocket(), (struct sockaddr *)&saddr_un, saddr_un_len) <
+      0)
+    SetLastError(error);
+
+  return error;
+}
+
+Status DomainSocket::Listen(llvm::StringRef name, int backlog) {
+  sockaddr_un saddr_un;
+  socklen_t saddr_un_len;
+  if (!SetSockAddr(name, GetNameOffset(), &saddr_un, saddr_un_len))
+    return Status("Failed to set socket address");
+
+  DeleteSocketFile(name);
+
+  Status error;
+  m_socket = CreateSocket(kDomain, kType, 0, m_child_processes_inherit, error);
+  if (error.Fail())
+    return error;
+  if (::bind(GetNativeSocket(), (struct sockaddr *)&saddr_un, saddr_un_len) ==
+      0)
+    if (::listen(GetNativeSocket(), backlog) == 0)
+      return error;
+
+  SetLastError(error);
+  return error;
+}
+
+Status DomainSocket::Accept(Socket *&socket) {
+  Status error;
+  auto conn_fd = AcceptSocket(GetNativeSocket(), nullptr, nullptr,
+                              m_child_processes_inherit, error);
+  if (error.Success())
+    socket = new DomainSocket(conn_fd, *this);
+
+  return error;
+}
+
+size_t DomainSocket::GetNameOffset() const { return 0; }
+
+void DomainSocket::DeleteSocketFile(llvm::StringRef name) {
+  llvm::sys::fs::remove(name);
+}

external/llvm-project/lldb/source/Host/posix/FileSystem.cpp

@@ -0,0 +1,80 @@
+//===-- FileSystem.cpp ------------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/Host/FileSystem.h"
+
+// C includes
+#include <dirent.h>
+#include <sys/mount.h>
+#include <sys/param.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#ifdef __linux__
+#include <linux/magic.h>
+#include <sys/mount.h>
+#include <sys/statfs.h>
+#endif
+#if defined(__NetBSD__)
+#include <sys/statvfs.h>
+#endif
+
+// lldb Includes
+#include "lldb/Host/Host.h"
+#include "lldb/Utility/Status.h"
+#include "lldb/Utility/StreamString.h"
+
+#include "llvm/Support/FileSystem.h"
+
+using namespace lldb;
+using namespace lldb_private;
+
+const char *FileSystem::DEV_NULL = "/dev/null";
+
+Status FileSystem::Symlink(const FileSpec &src, const FileSpec &dst) {
+  Status error;
+  if (::symlink(dst.GetCString(), src.GetCString()) == -1)
+    error.SetErrorToErrno();
+  return error;
+}
+
+Status FileSystem::Readlink(const FileSpec &src, FileSpec &dst) {
+  Status error;
+  char buf[PATH_MAX];
+  ssize_t count = ::readlink(src.GetCString(), buf, sizeof(buf) - 1);
+  if (count < 0)
+    error.SetErrorToErrno();
+  else {
+    buf[count] = '\0'; // Success
+    dst.SetFile(buf, false);
+  }
+  return error;
+}
+
+Status FileSystem::ResolveSymbolicLink(const FileSpec &src, FileSpec &dst) {
+  char resolved_path[PATH_MAX];
+  if (!src.GetPath(resolved_path, sizeof(resolved_path))) {
+    return Status("Couldn't get the canonical path for %s", src.GetCString());
+  }
+
+  char real_path[PATH_MAX + 1];
+  if (realpath(resolved_path, real_path) == nullptr) {
+    Status err;
+    err.SetErrorToErrno();
+    return err;
+  }
+
+  dst = FileSpec(real_path, false);
+
+  return Status();
+}
+
+FILE *FileSystem::Fopen(const char *path, const char *mode) {
+  return ::fopen(path, mode);
+}

external/llvm-project/lldb/source/Host/posix/HostInfoPosix.cpp

@@ -0,0 +1,232 @@
+//===-- HostInfoPosix.cpp ---------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#if !defined(LLDB_DISABLE_PYTHON)
+#include "Plugins/ScriptInterpreter/Python/lldb-python.h"
+#endif
+
+#include "lldb/Host/posix/HostInfoPosix.h"
+#include "lldb/Utility/Log.h"
+
+#include "clang/Basic/Version.h"
+#include "clang/Config/config.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/Twine.h"
+#include "llvm/Support/Path.h"
+#include "llvm/Support/raw_ostream.h"
+
+#include <grp.h>
+#include <limits.h>
+#include <mutex>
+#include <netdb.h>
+#include <pwd.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+using namespace lldb_private;
+
+size_t HostInfoPosix::GetPageSize() { return ::getpagesize(); }
+
+bool HostInfoPosix::GetHostname(std::string &s) {
+  char hostname[PATH_MAX];
+  hostname[sizeof(hostname) - 1] = '\0';
+  if (::gethostname(hostname, sizeof(hostname) - 1) == 0) {
+    struct hostent *h = ::gethostbyname(hostname);
+    if (h)
+      s.assign(h->h_name);
+    else
+      s.assign(hostname);
+    return true;
+  }
+  return false;
+}
+
+#ifdef __ANDROID__
+#include <android/api-level.h>
+#endif
+#if defined(__ANDROID_API__) && __ANDROID_API__ < 21
+#define USE_GETPWUID
+#endif
+
+#ifdef USE_GETPWUID
+static std::mutex s_getpwuid_lock;
+#endif
+
+const char *HostInfoPosix::LookupUserName(uint32_t uid,
+                                          std::string &user_name) {
+#ifdef USE_GETPWUID
+  // getpwuid_r is missing from android-9
+  // make getpwuid thread safe with a mutex
+  std::lock_guard<std::mutex> lock(s_getpwuid_lock);
+  struct passwd *user_info_ptr = ::getpwuid(uid);
+  if (user_info_ptr) {
+    user_name.assign(user_info_ptr->pw_name);
+    return user_name.c_str();
+  }
+#else
+  struct passwd user_info;
+  struct passwd *user_info_ptr = &user_info;
+  char user_buffer[PATH_MAX];
+  size_t user_buffer_size = sizeof(user_buffer);
+  if (::getpwuid_r(uid, &user_info, user_buffer, user_buffer_size,
+                   &user_info_ptr) == 0) {
+    if (user_info_ptr) {
+      user_name.assign(user_info_ptr->pw_name);
+      return user_name.c_str();
+    }
+  }
+#endif
+  user_name.clear();
+  return nullptr;
+}
+
+const char *HostInfoPosix::LookupGroupName(uint32_t gid,
+                                           std::string &group_name) {
+#ifndef __ANDROID__
+  char group_buffer[PATH_MAX];
+  size_t group_buffer_size = sizeof(group_buffer);
+  struct group group_info;
+  struct group *group_info_ptr = &group_info;
+  // Try the threadsafe version first
+  if (::getgrgid_r(gid, &group_info, group_buffer, group_buffer_size,
+                   &group_info_ptr) == 0) {
+    if (group_info_ptr) {
+      group_name.assign(group_info_ptr->gr_name);
+      return group_name.c_str();
+    }
+  } else {
+    // The threadsafe version isn't currently working for me on darwin, but the
+    // non-threadsafe version
+    // is, so I am calling it below.
+    group_info_ptr = ::getgrgid(gid);
+    if (group_info_ptr) {
+      group_name.assign(group_info_ptr->gr_name);
+      return group_name.c_str();
+    }
+  }
+  group_name.clear();
+#else
+  assert(false && "getgrgid_r() not supported on Android");
+#endif
+  return NULL;
+}
+
+uint32_t HostInfoPosix::GetUserID() { return getuid(); }
+
+uint32_t HostInfoPosix::GetGroupID() { return getgid(); }
+
+uint32_t HostInfoPosix::GetEffectiveUserID() { return geteuid(); }
+
+uint32_t HostInfoPosix::GetEffectiveGroupID() { return getegid(); }
+
+FileSpec HostInfoPosix::GetDefaultShell() { return FileSpec("/bin/sh", false); }
+
+bool HostInfoPosix::ComputePathRelativeToLibrary(FileSpec &file_spec,
+                                                 llvm::StringRef dir) {
+  Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);
+
+  FileSpec lldb_file_spec;
+  if (!GetLLDBPath(lldb::ePathTypeLLDBShlibDir, lldb_file_spec))
+    return false;
+
+  std::string raw_path = lldb_file_spec.GetPath();
+  // drop library directory
+  llvm::StringRef parent_path = llvm::sys::path::parent_path(raw_path);
+
+  // Most Posix systems (e.g. Linux/*BSD) will attempt to replace a */lib with
+  // */bin as the base directory for helper exe programs.  This will fail if the
+  // /lib and /bin directories are rooted in entirely different trees.
+  if (log)
+    log->Printf("HostInfoPosix::ComputePathRelativeToLibrary() attempting to "
+                "derive the %s path from this path: %s",
+                dir.data(), raw_path.c_str());
+
+  if (!parent_path.empty()) {
+    // Now write in bin in place of lib.
+    raw_path = (parent_path + dir).str();
+
+    if (log)
+      log->Printf("Host::%s() derived the bin path as: %s", __FUNCTION__,
+                  raw_path.c_str());
+  } else {
+    if (log)
+      log->Printf("Host::%s() failed to find /lib/liblldb within the shared "
+                  "lib path, bailing on bin path construction",
+                  __FUNCTION__);
+  }
+  file_spec.GetDirectory().SetString(raw_path);
+  return (bool)file_spec.GetDirectory();
+}
+
+bool HostInfoPosix::ComputeSupportExeDirectory(FileSpec &file_spec) {
+  return ComputePathRelativeToLibrary(file_spec, "/bin");
+}
+
+bool HostInfoPosix::ComputeClangDirectory(FileSpec &file_spec) {
+  return ComputePathRelativeToLibrary(
+      file_spec, (llvm::Twine("/lib") + CLANG_LIBDIR_SUFFIX + "/clang/" +
+                  CLANG_VERSION_STRING)
+                     .str());
+}
+
+bool HostInfoPosix::ComputeHeaderDirectory(FileSpec &file_spec) {
+  FileSpec temp_file("/opt/local/include/lldb", false);
+  file_spec.GetDirectory().SetCString(temp_file.GetPath().c_str());
+  return true;
+}
+
+bool HostInfoPosix::ComputePythonDirectory(FileSpec &file_spec) {
+#ifndef LLDB_DISABLE_PYTHON
+  FileSpec lldb_file_spec;
+  if (!GetLLDBPath(lldb::ePathTypeLLDBShlibDir, lldb_file_spec))
+    return false;
+
+  char raw_path[PATH_MAX];
+  lldb_file_spec.GetPath(raw_path, sizeof(raw_path));
+
+#if defined(LLDB_PYTHON_RELATIVE_LIBDIR)
+  // Build the path by backing out of the lib dir, then building
+  // with whatever the real python interpreter uses.  (e.g. lib
+  // for most, lib64 on RHEL x86_64).
+  char python_path[PATH_MAX];
+  ::snprintf(python_path, sizeof(python_path), "%s/../%s", raw_path,
+             LLDB_PYTHON_RELATIVE_LIBDIR);
+
+  char final_path[PATH_MAX];
+  realpath(python_path, final_path);
+  file_spec.GetDirectory().SetCString(final_path);
+
+  return true;
+#else
+  llvm::SmallString<256> python_version_dir;
+  llvm::raw_svector_ostream os(python_version_dir);
+  os << "/python" << PY_MAJOR_VERSION << '.' << PY_MINOR_VERSION
+     << "/site-packages";
+
+  // We may get our string truncated. Should we protect this with an assert?
+  ::strncat(raw_path, python_version_dir.c_str(),
+            sizeof(raw_path) - strlen(raw_path) - 1);
+
+  file_spec.GetDirectory().SetCString(raw_path);
+  return true;
+#endif
+#else
+  return false;
+#endif
+}
+
+bool HostInfoPosix::GetEnvironmentVar(const std::string &var_name,
+                                      std::string &var) {
+  if (const char *pvar = ::getenv(var_name.c_str())) {
+    var = std::string(pvar);
+    return true;
+  }
+  return false;
+}

external/llvm-project/lldb/source/Host/posix/HostProcessPosix.cpp

@@ -0,0 +1,95 @@
+//===-- HostProcessPosix.cpp ------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/Host/Host.h"
+#include "lldb/Host/FileSystem.h"
+#include "lldb/Host/posix/HostProcessPosix.h"
+
+#include "llvm/ADT/STLExtras.h"
+
+#include <csignal>
+#include <limits.h>
+#include <unistd.h>
+
+using namespace lldb_private;
+
+namespace {
+const int kInvalidPosixProcess = 0;
+}
+
+HostProcessPosix::HostProcessPosix()
+    : HostNativeProcessBase(kInvalidPosixProcess) {}
+
+HostProcessPosix::HostProcessPosix(lldb::process_t process)
+    : HostNativeProcessBase(process) {}
+
+HostProcessPosix::~HostProcessPosix() {}
+
+Status HostProcessPosix::Signal(int signo) const {
+  if (m_process == kInvalidPosixProcess) {
+    Status error;
+    error.SetErrorString("HostProcessPosix refers to an invalid process");
+    return error;
+  }
+
+  return HostProcessPosix::Signal(m_process, signo);
+}
+
+Status HostProcessPosix::Signal(lldb::process_t process, int signo) {
+  Status error;
+
+  if (-1 == ::kill(process, signo))
+    error.SetErrorToErrno();
+
+  return error;
+}
+
+Status HostProcessPosix::Terminate() { return Signal(SIGKILL); }
+
+Status HostProcessPosix::GetMainModule(FileSpec &file_spec) const {
+  Status error;
+
+  // Use special code here because proc/[pid]/exe is a symbolic link.
+  char link_path[PATH_MAX];
+  if (snprintf(link_path, PATH_MAX, "/proc/%" PRIu64 "/exe", m_process) != 1) {
+    error.SetErrorString("Unable to build /proc/<pid>/exe string");
+    return error;
+  }
+
+  error = FileSystem::Readlink(FileSpec{link_path, false}, file_spec);
+  if (!error.Success())
+    return error;
+
+  // If the binary has been deleted, the link name has " (deleted)" appended.
+  // Remove if there.
+  if (file_spec.GetFilename().GetStringRef().endswith(" (deleted)")) {
+    const char *filename = file_spec.GetFilename().GetCString();
+    static const size_t deleted_len = strlen(" (deleted)");
+    const size_t len = file_spec.GetFilename().GetLength();
+    file_spec.GetFilename().SetCStringWithLength(filename, len - deleted_len);
+  }
+  return error;
+}
+
+lldb::pid_t HostProcessPosix::GetProcessId() const { return m_process; }
+
+bool HostProcessPosix::IsRunning() const {
+  if (m_process == kInvalidPosixProcess)
+    return false;
+
+  // Send this process the null signal.  If it succeeds the process is running.
+  Status error = Signal(0);
+  return error.Success();
+}
+
+HostThread HostProcessPosix::StartMonitoring(
+    const Host::MonitorChildProcessCallback &callback, bool monitor_signals) {
+  return Host::StartMonitoringChildProcess(callback, m_process,
+                                           monitor_signals);
+}

external/llvm-project/lldb/source/Host/posix/HostThreadPosix.cpp

@@ -0,0 +1,65 @@
+//===-- HostThreadPosix.cpp -------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/Host/posix/HostThreadPosix.h"
+#include "lldb/Utility/Status.h"
+
+#include <errno.h>
+#include <pthread.h>
+
+using namespace lldb;
+using namespace lldb_private;
+
+HostThreadPosix::HostThreadPosix() {}
+
+HostThreadPosix::HostThreadPosix(lldb::thread_t thread)
+    : HostNativeThreadBase(thread) {}
+
+HostThreadPosix::~HostThreadPosix() {}
+
+Status HostThreadPosix::Join(lldb::thread_result_t *result) {
+  Status error;
+  if (IsJoinable()) {
+    int err = ::pthread_join(m_thread, result);
+    error.SetError(err, lldb::eErrorTypePOSIX);
+  } else {
+    if (result)
+      *result = NULL;
+    error.SetError(EINVAL, eErrorTypePOSIX);
+  }
+
+  Reset();
+  return error;
+}
+
+Status HostThreadPosix::Cancel() {
+  Status error;
+  if (IsJoinable()) {
+#ifndef __ANDROID__
+#ifndef __FreeBSD__
+    llvm_unreachable("someone is calling HostThread::Cancel()");
+#endif
+    int err = ::pthread_cancel(m_thread);
+    error.SetError(err, eErrorTypePOSIX);
+#else
+    error.SetErrorString("HostThreadPosix::Cancel() not supported on Android");
+#endif
+  }
+  return error;
+}
+
+Status HostThreadPosix::Detach() {
+  Status error;
+  if (IsJoinable()) {
+    int err = ::pthread_detach(m_thread);
+    error.SetError(err, eErrorTypePOSIX);
+  }
+  Reset();
+  return error;
+}

external/llvm-project/lldb/source/Host/posix/LockFilePosix.cpp

@@ -0,0 +1,61 @@
+//===-- LockFilePosix.cpp ---------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/Host/posix/LockFilePosix.h"
+
+#include <fcntl.h>
+#include <unistd.h>
+
+using namespace lldb;
+using namespace lldb_private;
+
+namespace {
+
+Status fileLock(int fd, int cmd, int lock_type, const uint64_t start,
+                const uint64_t len) {
+  struct flock fl;
+
+  fl.l_type = lock_type;
+  fl.l_whence = SEEK_SET;
+  fl.l_start = start;
+  fl.l_len = len;
+  fl.l_pid = ::getpid();
+
+  Status error;
+  if (::fcntl(fd, cmd, &fl) == -1)
+    error.SetErrorToErrno();
+
+  return error;
+}
+
+} // namespace
+
+LockFilePosix::LockFilePosix(int fd) : LockFileBase(fd) {}
+
+LockFilePosix::~LockFilePosix() { Unlock(); }
+
+Status LockFilePosix::DoWriteLock(const uint64_t start, const uint64_t len) {
+  return fileLock(m_fd, F_SETLKW, F_WRLCK, start, len);
+}
+
+Status LockFilePosix::DoTryWriteLock(const uint64_t start, const uint64_t len) {
+  return fileLock(m_fd, F_SETLK, F_WRLCK, start, len);
+}
+
+Status LockFilePosix::DoReadLock(const uint64_t start, const uint64_t len) {
+  return fileLock(m_fd, F_SETLKW, F_RDLCK, start, len);
+}
+
+Status LockFilePosix::DoTryReadLock(const uint64_t start, const uint64_t len) {
+  return fileLock(m_fd, F_SETLK, F_RDLCK, start, len);
+}
+
+Status LockFilePosix::DoUnlock() {
+  return fileLock(m_fd, F_SETLK, F_UNLCK, m_start, m_len);
+}

external/llvm-project/lldb/source/Host/posix/PipePosix.cpp

@@ -0,0 +1,318 @@
+//===-- PipePosix.cpp -------------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/Host/posix/PipePosix.h"
+#include "lldb/Host/HostInfo.h"
+#include "lldb/Utility/SelectHelper.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/FileSystem.h"
+
+#if defined(__GNUC__) && (__GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 8))
+#ifndef _GLIBCXX_USE_NANOSLEEP
+#define _GLIBCXX_USE_NANOSLEEP
+#endif
+#endif
+
+#include <functional>
+#include <thread>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+using namespace lldb;
+using namespace lldb_private;
+
+int PipePosix::kInvalidDescriptor = -1;
+
+enum PIPES { READ, WRITE }; // Constants 0 and 1 for READ and WRITE
+
+// pipe2 is supported by a limited set of platforms
+// TODO: Add more platforms that support pipe2.
+#if defined(__linux__) || (defined(__FreeBSD__) && __FreeBSD__ >= 10) ||       \
+    defined(__NetBSD__)
+#define PIPE2_SUPPORTED 1
+#else
+#define PIPE2_SUPPORTED 0
+#endif
+
+namespace {
+
+constexpr auto OPEN_WRITER_SLEEP_TIMEOUT_MSECS = 100;
+
+#if defined(FD_CLOEXEC) && !PIPE2_SUPPORTED
+bool SetCloexecFlag(int fd) {
+  int flags = ::fcntl(fd, F_GETFD);
+  if (flags == -1)
+    return false;
+  return (::fcntl(fd, F_SETFD, flags | FD_CLOEXEC) == 0);
+}
+#endif
+
+std::chrono::time_point<std::chrono::steady_clock> Now() {
+  return std::chrono::steady_clock::now();
+}
+}
+
+PipePosix::PipePosix()
+    : m_fds{PipePosix::kInvalidDescriptor, PipePosix::kInvalidDescriptor} {}
+
+PipePosix::PipePosix(int read_fd, int write_fd) : m_fds{read_fd, write_fd} {}
+
+PipePosix::PipePosix(PipePosix &&pipe_posix)
+    : PipeBase{std::move(pipe_posix)},
+      m_fds{pipe_posix.ReleaseReadFileDescriptor(),
+            pipe_posix.ReleaseWriteFileDescriptor()} {}
+
+PipePosix &PipePosix::operator=(PipePosix &&pipe_posix) {
+  PipeBase::operator=(std::move(pipe_posix));
+  m_fds[READ] = pipe_posix.ReleaseReadFileDescriptor();
+  m_fds[WRITE] = pipe_posix.ReleaseWriteFileDescriptor();
+  return *this;
+}
+
+PipePosix::~PipePosix() { Close(); }
+
+Status PipePosix::CreateNew(bool child_processes_inherit) {
+  if (CanRead() || CanWrite())
+    return Status(EINVAL, eErrorTypePOSIX);
+
+  Status error;
+#if PIPE2_SUPPORTED
+  if (::pipe2(m_fds, (child_processes_inherit) ? 0 : O_CLOEXEC) == 0)
+    return error;
+#else
+  if (::pipe(m_fds) == 0) {
+#ifdef FD_CLOEXEC
+    if (!child_processes_inherit) {
+      if (!SetCloexecFlag(m_fds[0]) || !SetCloexecFlag(m_fds[1])) {
+        error.SetErrorToErrno();
+        Close();
+        return error;
+      }
+    }
+#endif
+    return error;
+  }
+#endif
+
+  error.SetErrorToErrno();
+  m_fds[READ] = PipePosix::kInvalidDescriptor;
+  m_fds[WRITE] = PipePosix::kInvalidDescriptor;
+  return error;
+}
+
+Status PipePosix::CreateNew(llvm::StringRef name, bool child_process_inherit) {
+  if (CanRead() || CanWrite())
+    return Status("Pipe is already opened");
+
+  Status error;
+  if (::mkfifo(name.data(), 0660) != 0)
+    error.SetErrorToErrno();
+
+  return error;
+}
+
+Status PipePosix::CreateWithUniqueName(llvm::StringRef prefix,
+                                       bool child_process_inherit,
+                                       llvm::SmallVectorImpl<char> &name) {
+  llvm::SmallString<PATH_MAX> named_pipe_path;
+  llvm::SmallString<PATH_MAX> pipe_spec((prefix + ".%%%%%%").str());
+  FileSpec tmpdir_file_spec;
+  tmpdir_file_spec.Clear();
+  if (HostInfo::GetLLDBPath(ePathTypeLLDBTempSystemDir, tmpdir_file_spec)) {
+    tmpdir_file_spec.AppendPathComponent(pipe_spec.c_str());
+  } else {
+    tmpdir_file_spec.AppendPathComponent("/tmp");
+    tmpdir_file_spec.AppendPathComponent(pipe_spec.c_str());
+  }
+
+  // It's possible that another process creates the target path after we've
+  // verified it's available but before we create it, in which case we
+  // should try again.
+  Status error;
+  do {
+    llvm::sys::fs::createUniqueFile(tmpdir_file_spec.GetPath(),
+                                    named_pipe_path);
+    error = CreateNew(named_pipe_path, child_process_inherit);
+  } while (error.GetError() == EEXIST);
+
+  if (error.Success())
+    name = named_pipe_path;
+  return error;
+}
+
+Status PipePosix::OpenAsReader(llvm::StringRef name,
+                               bool child_process_inherit) {
+  if (CanRead() || CanWrite())
+    return Status("Pipe is already opened");
+
+  int flags = O_RDONLY | O_NONBLOCK;
+  if (!child_process_inherit)
+    flags |= O_CLOEXEC;
+
+  Status error;
+  int fd = ::open(name.data(), flags);
+  if (fd != -1)
+    m_fds[READ] = fd;
+  else
+    error.SetErrorToErrno();
+
+  return error;
+}
+
+Status
+PipePosix::OpenAsWriterWithTimeout(llvm::StringRef name,
+                                   bool child_process_inherit,
+                                   const std::chrono::microseconds &timeout) {
+  if (CanRead() || CanWrite())
+    return Status("Pipe is already opened");
+
+  int flags = O_WRONLY | O_NONBLOCK;
+  if (!child_process_inherit)
+    flags |= O_CLOEXEC;
+
+  using namespace std::chrono;
+  const auto finish_time = Now() + timeout;
+
+  while (!CanWrite()) {
+    if (timeout != microseconds::zero()) {
+      const auto dur = duration_cast<microseconds>(finish_time - Now()).count();
+      if (dur <= 0)
+        return Status("timeout exceeded - reader hasn't opened so far");
+    }
+
+    errno = 0;
+    int fd = ::open(name.data(), flags);
+    if (fd == -1) {
+      const auto errno_copy = errno;
+      // We may get ENXIO if a reader side of the pipe hasn't opened yet.
+      if (errno_copy != ENXIO)
+        return Status(errno_copy, eErrorTypePOSIX);
+
+      std::this_thread::sleep_for(
+          milliseconds(OPEN_WRITER_SLEEP_TIMEOUT_MSECS));
+    } else {
+      m_fds[WRITE] = fd;
+    }
+  }
+
+  return Status();
+}
+
+int PipePosix::GetReadFileDescriptor() const { return m_fds[READ]; }
+
+int PipePosix::GetWriteFileDescriptor() const { return m_fds[WRITE]; }
+
+int PipePosix::ReleaseReadFileDescriptor() {
+  const int fd = m_fds[READ];
+  m_fds[READ] = PipePosix::kInvalidDescriptor;
+  return fd;
+}
+
+int PipePosix::ReleaseWriteFileDescriptor() {
+  const int fd = m_fds[WRITE];
+  m_fds[WRITE] = PipePosix::kInvalidDescriptor;
+  return fd;
+}
+
+void PipePosix::Close() {
+  CloseReadFileDescriptor();
+  CloseWriteFileDescriptor();
+}
+
+Status PipePosix::Delete(llvm::StringRef name) {
+  return llvm::sys::fs::remove(name);
+}
+
+bool PipePosix::CanRead() const {
+  return m_fds[READ] != PipePosix::kInvalidDescriptor;
+}
+
+bool PipePosix::CanWrite() const {
+  return m_fds[WRITE] != PipePosix::kInvalidDescriptor;
+}
+
+void PipePosix::CloseReadFileDescriptor() {
+  if (CanRead()) {
+    close(m_fds[READ]);
+    m_fds[READ] = PipePosix::kInvalidDescriptor;
+  }
+}
+
+void PipePosix::CloseWriteFileDescriptor() {
+  if (CanWrite()) {
+    close(m_fds[WRITE]);
+    m_fds[WRITE] = PipePosix::kInvalidDescriptor;
+  }
+}
+
+Status PipePosix::ReadWithTimeout(void *buf, size_t size,
+                                  const std::chrono::microseconds &timeout,
+                                  size_t &bytes_read) {
+  bytes_read = 0;
+  if (!CanRead())
+    return Status(EINVAL, eErrorTypePOSIX);
+
+  const int fd = GetReadFileDescriptor();
+
+  SelectHelper select_helper;
+  select_helper.SetTimeout(timeout);
+  select_helper.FDSetRead(fd);
+
+  Status error;
+  while (error.Success()) {
+    error = select_helper.Select();
+    if (error.Success()) {
+      auto result = ::read(fd, reinterpret_cast<char *>(buf) + bytes_read,
+                           size - bytes_read);
+      if (result != -1) {
+        bytes_read += result;
+        if (bytes_read == size || result == 0)
+          break;
+      } else {
+        error.SetErrorToErrno();
+        break;
+      }
+    }
+  }
+  return error;
+}
+
+Status PipePosix::Write(const void *buf, size_t size, size_t &bytes_written) {
+  bytes_written = 0;
+  if (!CanWrite())
+    return Status(EINVAL, eErrorTypePOSIX);
+
+  const int fd = GetWriteFileDescriptor();
+  SelectHelper select_helper;
+  select_helper.SetTimeout(std::chrono::seconds(0));
+  select_helper.FDSetWrite(fd);
+
+  Status error;
+  while (error.Success()) {
+    error = select_helper.Select();
+    if (error.Success()) {
+      auto result =
+          ::write(fd, reinterpret_cast<const char *>(buf) + bytes_written,
+                  size - bytes_written);
+      if (result != -1) {
+        bytes_written += result;
+        if (bytes_written == size)
+          break;
+      } else {
+        error.SetErrorToErrno();
+      }
+    }
+  }
+  return error;
+}

external/llvm-project/lldb/source/Host/posix/ProcessLauncherPosixFork.cpp

@@ -0,0 +1,230 @@
+//===-- ProcessLauncherLinux.cpp --------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/Host/posix/ProcessLauncherPosixFork.h"
+#include "lldb/Host/Host.h"
+#include "lldb/Host/HostProcess.h"
+#include "lldb/Host/Pipe.h"
+#include "lldb/Target/ProcessLaunchInfo.h"
+#include "lldb/Utility/FileSpec.h"
+#include "lldb/Utility/Log.h"
+#include "llvm/Support/Errno.h"
+
+#include <limits.h>
+#include <sys/ptrace.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include <sstream>
+#include <csignal>
+
+#ifdef __ANDROID__
+#include <android/api-level.h>
+#define PT_TRACE_ME PTRACE_TRACEME
+#endif
+
+#if defined(__ANDROID_API__) && __ANDROID_API__ < 15
+#include <linux/personality.h>
+#elif defined(__linux__)
+#include <sys/personality.h>
+#endif
+
+using namespace lldb;
+using namespace lldb_private;
+
+static void FixupEnvironment(Args &env) {
+#ifdef __ANDROID__
+  // If there is no PATH variable specified inside the environment then set the
+  // path to /system/bin. It is required because the default path used by
+  // execve() is wrong on android.
+  static const char *path = "PATH=";
+  for (auto &entry : env.entries()) {
+    if (entry.ref.startswith(path))
+      return;
+  }
+  env.AppendArgument(llvm::StringRef("PATH=/system/bin"));
+#endif
+}
+
+static void LLVM_ATTRIBUTE_NORETURN ExitWithError(int error_fd,
+                                                  const char *operation) {
+  int err = errno;
+  llvm::raw_fd_ostream os(error_fd, true);
+  os << operation << " failed: " << llvm::sys::StrError(err);
+  os.flush();
+  _exit(1);
+}
+
+static void DisableASLRIfRequested(int error_fd, const ProcessLaunchInfo &info) {
+#if defined(__linux__)
+  if (info.GetFlags().Test(lldb::eLaunchFlagDisableASLR)) {
+    const unsigned long personality_get_current = 0xffffffff;
+    int value = personality(personality_get_current);
+    if (value == -1)
+      ExitWithError(error_fd, "personality get");
+
+    value = personality(ADDR_NO_RANDOMIZE | value);
+    if (value == -1)
+      ExitWithError(error_fd, "personality set");
+  }
+#endif
+}
+
+static void DupDescriptor(int error_fd, const FileSpec &file_spec, int fd,
+                          int flags) {
+  int target_fd = ::open(file_spec.GetCString(), flags, 0666);
+
+  if (target_fd == -1)
+    ExitWithError(error_fd, "DupDescriptor-open");
+
+  if (target_fd == fd)
+    return;
+
+  if (::dup2(target_fd, fd) == -1)
+    ExitWithError(error_fd, "DupDescriptor-dup2");
+
+  ::close(target_fd);
+  return;
+}
+
+static void LLVM_ATTRIBUTE_NORETURN ChildFunc(int error_fd,
+                                              const ProcessLaunchInfo &info) {
+  // Do not inherit setgid powers.
+  if (setgid(getgid()) != 0)
+    ExitWithError(error_fd, "setgid");
+
+  if (info.GetFlags().Test(eLaunchFlagLaunchInSeparateProcessGroup)) {
+    if (setpgid(0, 0) != 0)
+      ExitWithError(error_fd, "setpgid");
+  }
+
+  for (size_t i = 0; i < info.GetNumFileActions(); ++i) {
+    const FileAction &action = *info.GetFileActionAtIndex(i);
+    switch (action.GetAction()) {
+    case FileAction::eFileActionClose:
+      if (close(action.GetFD()) != 0)
+        ExitWithError(error_fd, "close");
+      break;
+    case FileAction::eFileActionDuplicate:
+      if (dup2(action.GetFD(), action.GetActionArgument()) == -1)
+        ExitWithError(error_fd, "dup2");
+      break;
+    case FileAction::eFileActionOpen:
+      DupDescriptor(error_fd, action.GetFileSpec(), action.GetFD(),
+                    action.GetActionArgument());
+      break;
+    case FileAction::eFileActionNone:
+      break;
+    }
+  }
+
+  const char **argv = info.GetArguments().GetConstArgumentVector();
+
+  // Change working directory
+  if (info.GetWorkingDirectory() &&
+      0 != ::chdir(info.GetWorkingDirectory().GetCString()))
+    ExitWithError(error_fd, "chdir");
+
+  DisableASLRIfRequested(error_fd, info);
+  Args env = info.GetEnvironmentEntries();
+  FixupEnvironment(env);
+  const char **envp = env.GetConstArgumentVector();
+
+  // Clear the signal mask to prevent the child from being affected by
+  // any masking done by the parent.
+  sigset_t set;
+  if (sigemptyset(&set) != 0 ||
+      pthread_sigmask(SIG_SETMASK, &set, nullptr) != 0)
+    ExitWithError(error_fd, "pthread_sigmask");
+
+  if (info.GetFlags().Test(eLaunchFlagDebug)) {
+    // HACK:
+    // Close everything besides stdin, stdout, and stderr that has no file
+    // action to avoid leaking. Only do this when debugging, as elsewhere we
+    // actually rely on
+    // passing open descriptors to child processes.
+    for (int fd = 3; fd < sysconf(_SC_OPEN_MAX); ++fd)
+      if (!info.GetFileActionForFD(fd) && fd != error_fd)
+        close(fd);
+
+    // Start tracing this child that is about to exec.
+    if (ptrace(PT_TRACE_ME, 0, nullptr, 0) == -1)
+      ExitWithError(error_fd, "ptrace");
+  }
+
+  // Execute.  We should never return...
+  execve(argv[0], const_cast<char *const *>(argv),
+         const_cast<char *const *>(envp));
+
+#if defined(__linux__)
+  if (errno == ETXTBSY) {
+    // On android M and earlier we can get this error because the adb deamon can
+    // hold a write
+    // handle on the executable even after it has finished uploading it. This
+    // state lasts
+    // only a short time and happens only when there are many concurrent adb
+    // commands being
+    // issued, such as when running the test suite. (The file remains open when
+    // someone does
+    // an "adb shell" command in the fork() child before it has had a chance to
+    // exec.) Since
+    // this state should clear up quickly, wait a while and then give it one
+    // more go.
+    usleep(50000);
+    execve(argv[0], const_cast<char *const *>(argv),
+           const_cast<char *const *>(envp));
+  }
+#endif
+
+  // ...unless exec fails.  In which case we definitely need to end the child
+  // here.
+  ExitWithError(error_fd, "execve");
+}
+
+HostProcess
+ProcessLauncherPosixFork::LaunchProcess(const ProcessLaunchInfo &launch_info,
+                                        Status &error) {
+  char exe_path[PATH_MAX];
+  launch_info.GetExecutableFile().GetPath(exe_path, sizeof(exe_path));
+
+  // A pipe used by the child process to report errors.
+  PipePosix pipe;
+  const bool child_processes_inherit = false;
+  error = pipe.CreateNew(child_processes_inherit);
+  if (error.Fail())
+    return HostProcess();
+
+  ::pid_t pid = ::fork();
+  if (pid == -1) {
+    // Fork failed
+    error.SetErrorStringWithFormatv("Fork failed with error message: {0}",
+                                    llvm::sys::StrError());
+    return HostProcess(LLDB_INVALID_PROCESS_ID);
+  }
+  if (pid == 0) {
+    // child process
+    pipe.CloseReadFileDescriptor();
+    ChildFunc(pipe.ReleaseWriteFileDescriptor(), launch_info);
+  }
+
+  // parent process
+
+  pipe.CloseWriteFileDescriptor();
+  char buf[1000];
+  int r = read(pipe.GetReadFileDescriptor(), buf, sizeof buf);
+
+  if (r == 0)
+    return HostProcess(pid); // No error. We're done.
+
+  error.SetErrorString(buf);
+
+  waitpid(pid, nullptr, 0);
+
+  return HostProcess();
+}