diff third_party/libuv/src/win/process.c @ 160:948de3f54cea

[ThirdParty] Added libuv
author June Park <parkjune1995@gmail.com>
date Wed, 14 Jan 2026 19:39:52 -0800
parents
children
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/third_party/libuv/src/win/process.c	Wed Jan 14 19:39:52 2026 -0800
@@ -0,0 +1,1407 @@
+/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include <assert.h>
+#include <io.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <limits.h>
+#include <wchar.h>
+
+#include "uv.h"
+#include "internal.h"
+#include "handle-inl.h"
+#include "req-inl.h"
+#include <dbghelp.h>
+#include <shlobj.h>
+#include <psapi.h>     /* GetModuleBaseNameW */
+
+
+#define SIGKILL         9
+
+
+typedef struct env_var {
+  const WCHAR* const wide;
+  const WCHAR* const wide_eq;
+  const size_t len; /* including null or '=' */
+} env_var_t;
+
+#define E_V(str) { L##str, L##str L"=", sizeof(str) }
+
+static const env_var_t required_vars[] = { /* keep me sorted */
+  E_V("HOMEDRIVE"),
+  E_V("HOMEPATH"),
+  E_V("LOGONSERVER"),
+  E_V("PATH"),
+  E_V("SYSTEMDRIVE"),
+  E_V("SYSTEMROOT"),
+  E_V("TEMP"),
+  E_V("USERDOMAIN"),
+  E_V("USERNAME"),
+  E_V("USERPROFILE"),
+  E_V("WINDIR"),
+};
+
+
+static HANDLE uv_global_job_handle_;
+static uv_once_t uv_global_job_handle_init_guard_ = UV_ONCE_INIT;
+
+
+static void uv__init_global_job_handle(void) {
+  /* Create a job object and set it up to kill all contained processes when
+   * it's closed. Since this handle is made non-inheritable and we're not
+   * giving it to anyone, we're the only process holding a reference to it.
+   * That means that if this process exits it is closed and all the processes
+   * it contains are killed. All processes created with uv_spawn that are not
+   * spawned with the UV_PROCESS_DETACHED flag are assigned to this job.
+   *
+   * We're setting the JOB_OBJECT_LIMIT_SILENT_BREAKAWAY_OK flag so only the
+   * processes that we explicitly add are affected, and *their* subprocesses
+   * are not. This ensures that our child processes are not limited in their
+   * ability to use job control on Windows versions that don't deal with
+   * nested jobs (prior to Windows 8 / Server 2012). It also lets our child
+   * processes created detached processes without explicitly breaking away
+   * from job control (which uv_spawn doesn't, either).
+   */
+  SECURITY_ATTRIBUTES attr;
+  JOBOBJECT_EXTENDED_LIMIT_INFORMATION info;
+
+  memset(&attr, 0, sizeof attr);
+  attr.bInheritHandle = FALSE;
+
+  memset(&info, 0, sizeof info);
+  info.BasicLimitInformation.LimitFlags =
+      JOB_OBJECT_LIMIT_BREAKAWAY_OK |
+      JOB_OBJECT_LIMIT_SILENT_BREAKAWAY_OK |
+      JOB_OBJECT_LIMIT_DIE_ON_UNHANDLED_EXCEPTION |
+      JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE;
+
+  uv_global_job_handle_ = CreateJobObjectW(&attr, NULL);
+  if (uv_global_job_handle_ == NULL)
+    uv_fatal_error(GetLastError(), "CreateJobObjectW");
+
+  if (!SetInformationJobObject(uv_global_job_handle_,
+                               JobObjectExtendedLimitInformation,
+                               &info,
+                               sizeof info))
+    uv_fatal_error(GetLastError(), "SetInformationJobObject");
+
+
+  if (!AssignProcessToJobObject(uv_global_job_handle_, GetCurrentProcess())) {
+    /* Make sure this handle is functional. The Windows kernel has a bug that
+     * if the first use of AssignProcessToJobObject is for a Windows Store
+     * program, subsequent attempts to use the handle with fail with
+     * INVALID_PARAMETER (87). This is possibly because all uses of the handle
+     * must be for the same Terminal Services session. We can ensure it is tied
+     * to our current session now by adding ourself to it. We could remove
+     * ourself afterwards, but there doesn't seem to be a reason to.
+     */
+    DWORD err = GetLastError();
+    if (err != ERROR_ACCESS_DENIED)
+      uv_fatal_error(err, "AssignProcessToJobObject");
+  }
+}
+
+
+static int uv__utf8_to_utf16_alloc(const char* s, WCHAR** ws_ptr) {
+  return uv__convert_utf8_to_utf16(s, ws_ptr);
+}
+
+
+static void uv__process_init(uv_loop_t* loop, uv_process_t* handle) {
+  uv__handle_init(loop, (uv_handle_t*) handle, UV_PROCESS);
+  handle->exit_cb = NULL;
+  handle->pid = 0;
+  handle->exit_signal = 0;
+  handle->wait_handle = INVALID_HANDLE_VALUE;
+  handle->process_handle = INVALID_HANDLE_VALUE;
+  handle->exit_cb_pending = 0;
+
+  UV_REQ_INIT(&handle->exit_req, UV_PROCESS_EXIT);
+  handle->exit_req.data = handle;
+}
+
+
+/*
+ * Path search functions
+ */
+
+/*
+ * Helper function for search_path
+ */
+static WCHAR* search_path_join_test(const WCHAR* dir,
+                                    size_t dir_len,
+                                    const WCHAR* name,
+                                    size_t name_len,
+                                    const WCHAR* ext,
+                                    size_t ext_len,
+                                    const WCHAR* cwd,
+                                    size_t cwd_len) {
+  WCHAR *result, *result_pos;
+  DWORD attrs;
+  if (dir_len > 2 &&
+      ((dir[0] == L'\\' || dir[0] == L'/') &&
+       (dir[1] == L'\\' || dir[1] == L'/'))) {
+    /* It's a UNC path so ignore cwd */
+    cwd_len = 0;
+  } else if (dir_len >= 1 && (dir[0] == L'/' || dir[0] == L'\\')) {
+    /* It's a full path without drive letter, use cwd's drive letter only */
+    cwd_len = 2;
+  } else if (dir_len >= 2 && dir[1] == L':' &&
+      (dir_len < 3 || (dir[2] != L'/' && dir[2] != L'\\'))) {
+    /* It's a relative path with drive letter (ext.g. D:../some/file)
+     * Replace drive letter in dir by full cwd if it points to the same drive,
+     * otherwise use the dir only.
+     */
+    if (cwd_len < 2 || _wcsnicmp(cwd, dir, 2) != 0) {
+      cwd_len = 0;
+    } else {
+      dir += 2;
+      dir_len -= 2;
+    }
+  } else if (dir_len > 2 && dir[1] == L':') {
+    /* It's an absolute path with drive letter
+     * Don't use the cwd at all
+     */
+    cwd_len = 0;
+  }
+
+  /* Allocate buffer for output */
+  result = result_pos = (WCHAR*)uv__malloc(sizeof(WCHAR) *
+      (cwd_len + 1 + dir_len + 1 + name_len + 1 + ext_len + 1));
+
+  /* Copy cwd */
+  wcsncpy(result_pos, cwd, cwd_len);
+  result_pos += cwd_len;
+
+  /* Add a path separator if cwd didn't end with one */
+  if (cwd_len && wcsrchr(L"\\/:", result_pos[-1]) == NULL) {
+    result_pos[0] = L'\\';
+    result_pos++;
+  }
+
+  /* Copy dir */
+  wcsncpy(result_pos, dir, dir_len);
+  result_pos += dir_len;
+
+  /* Add a separator if the dir didn't end with one */
+  if (dir_len && wcsrchr(L"\\/:", result_pos[-1]) == NULL) {
+    result_pos[0] = L'\\';
+    result_pos++;
+  }
+
+  /* Copy filename */
+  wcsncpy(result_pos, name, name_len);
+  result_pos += name_len;
+
+  if (ext_len) {
+    /* Add a dot if the filename didn't end with one */
+    if (name_len && result_pos[-1] != '.') {
+      result_pos[0] = L'.';
+      result_pos++;
+    }
+
+    /* Copy extension */
+    wcsncpy(result_pos, ext, ext_len);
+    result_pos += ext_len;
+  }
+
+  /* Null terminator */
+  result_pos[0] = L'\0';
+
+  attrs = GetFileAttributesW(result);
+
+  if (attrs != INVALID_FILE_ATTRIBUTES &&
+      !(attrs & FILE_ATTRIBUTE_DIRECTORY)) {
+    return result;
+  }
+
+  uv__free(result);
+  return NULL;
+}
+
+
+/*
+ * Helper function for search_path
+ */
+static WCHAR* path_search_walk_ext(const WCHAR *dir,
+                                   size_t dir_len,
+                                   const WCHAR *name,
+                                   size_t name_len,
+                                   WCHAR *cwd,
+                                   size_t cwd_len,
+                                   int name_has_ext) {
+  WCHAR* result;
+
+  /* If the name itself has a nonempty extension, try this extension first */
+  if (name_has_ext) {
+    result = search_path_join_test(dir, dir_len,
+                                   name, name_len,
+                                   L"", 0,
+                                   cwd, cwd_len);
+    if (result != NULL) {
+      return result;
+    }
+  }
+
+  /* Try .com extension */
+  result = search_path_join_test(dir, dir_len,
+                                 name, name_len,
+                                 L"com", 3,
+                                 cwd, cwd_len);
+  if (result != NULL) {
+    return result;
+  }
+
+  /* Try .exe extension */
+  result = search_path_join_test(dir, dir_len,
+                                 name, name_len,
+                                 L"exe", 3,
+                                 cwd, cwd_len);
+  if (result != NULL) {
+    return result;
+  }
+
+  return NULL;
+}
+
+
+/*
+ * search_path searches the system path for an executable filename -
+ * the windows API doesn't provide this as a standalone function nor as an
+ * option to CreateProcess.
+ *
+ * It tries to return an absolute filename.
+ *
+ * Furthermore, it tries to follow the semantics that cmd.exe, with this
+ * exception that PATHEXT environment variable isn't used. Since CreateProcess
+ * can start only .com and .exe files, only those extensions are tried. This
+ * behavior equals that of msvcrt's spawn functions.
+ *
+ * - Do not search the path if the filename already contains a path (either
+ *   relative or absolute).
+ *
+ * - If there's really only a filename, check the current directory for file,
+ *   then search all path directories.
+ *
+ * - If filename specified has *any* extension, or already contains a path
+ *   and the UV_PROCESS_WINDOWS_FILE_PATH_EXACT_NAME flag is specified,
+ *   search for the file with the exact specified filename first.
+ *
+ * - If the literal filename is not found in a directory, try *appending*
+ *   (not replacing) .com first and then .exe.
+ *
+ * - The path variable may contain relative paths; relative paths are relative
+ *   to the cwd.
+ *
+ * - Directories in path may or may not end with a trailing backslash.
+ *
+ * - CMD does not trim leading/trailing whitespace from path/pathex entries
+ *   nor from the environment variables as a whole.
+ *
+ * - When cmd.exe cannot read a directory, it will just skip it and go on
+ *   searching. However, unlike posix-y systems, it will happily try to run a
+ *   file that is not readable/executable; if the spawn fails it will not
+ *   continue searching.
+ *
+ * UNC path support: we are dealing with UNC paths in both the path and the
+ * filename. This is a deviation from what cmd.exe does (it does not let you
+ * start a program by specifying an UNC path on the command line) but this is
+ * really a pointless restriction.
+ *
+ */
+static WCHAR* search_path(const WCHAR *file,
+                            WCHAR *cwd,
+                            const WCHAR *path,
+                            unsigned int flags) {
+  int file_has_dir;
+  WCHAR* result = NULL;
+  WCHAR *file_name_start;
+  WCHAR *dot;
+  const WCHAR *dir_start, *dir_end, *dir_path;
+  size_t dir_len;
+  int name_has_ext;
+
+  size_t file_len = wcslen(file);
+  size_t cwd_len = wcslen(cwd);
+
+  /* If the caller supplies an empty filename,
+   * we're not gonna return c:\windows\.exe -- GFY!
+   */
+  if (file_len == 0
+      || (file_len == 1 && file[0] == L'.')) {
+    return NULL;
+  }
+
+  /* Find the start of the filename so we can split the directory from the
+   * name. */
+  for (file_name_start = (WCHAR*)file + file_len;
+       file_name_start > file
+           && file_name_start[-1] != L'\\'
+           && file_name_start[-1] != L'/'
+           && file_name_start[-1] != L':';
+       file_name_start--);
+
+  file_has_dir = file_name_start != file;
+
+  /* Check if the filename includes an extension */
+  dot = wcschr(file_name_start, L'.');
+  name_has_ext = (dot != NULL && dot[1] != L'\0');
+
+  if (file_has_dir) {
+    /* The file has a path inside, don't use path */
+    result = path_search_walk_ext(
+        file, file_name_start - file,
+        file_name_start, file_len - (file_name_start - file),
+        cwd, cwd_len,
+        name_has_ext || (flags & UV_PROCESS_WINDOWS_FILE_PATH_EXACT_NAME));
+
+  } else {
+    dir_end = path;
+
+    if (NeedCurrentDirectoryForExePathW(L"")) {
+      /* The file is really only a name; look in cwd first, then scan path */
+      result = path_search_walk_ext(L"", 0,
+                                    file, file_len,
+                                    cwd, cwd_len,
+                                    name_has_ext);
+    }
+
+    while (result == NULL) {
+      if (dir_end == NULL || *dir_end == L'\0') {
+        break;
+      }
+
+      /* Skip the separator that dir_end now points to */
+      if (dir_end != path || *path == L';') {
+        dir_end++;
+      }
+
+      /* Next slice starts just after where the previous one ended */
+      dir_start = dir_end;
+
+      /* If path is quoted, find quote end */
+      if (*dir_start == L'"' || *dir_start == L'\'') {
+        dir_end = wcschr(dir_start + 1, *dir_start);
+        if (dir_end == NULL) {
+          dir_end = wcschr(dir_start, L'\0');
+        }
+      }
+      /* Slice until the next ; or \0 is found */
+      dir_end = wcschr(dir_end, L';');
+      if (dir_end == NULL) {
+        dir_end = wcschr(dir_start, L'\0');
+      }
+
+      /* If the slice is zero-length, don't bother */
+      if (dir_end - dir_start == 0) {
+        continue;
+      }
+
+      dir_path = dir_start;
+      dir_len = dir_end - dir_start;
+
+      /* Adjust if the path is quoted. */
+      if (dir_path[0] == '"' || dir_path[0] == '\'') {
+        ++dir_path;
+        --dir_len;
+      }
+
+      if (dir_path[dir_len - 1] == '"' || dir_path[dir_len - 1] == '\'') {
+        --dir_len;
+      }
+
+      result = path_search_walk_ext(dir_path, dir_len,
+                                    file, file_len,
+                                    cwd, cwd_len,
+                                    name_has_ext);
+    }
+  }
+
+  return result;
+}
+
+
+/*
+ * Quotes command line arguments
+ * Returns a pointer to the end (next char to be written) of the buffer
+ */
+WCHAR* quote_cmd_arg(const WCHAR *source, WCHAR *target) {
+  size_t len = wcslen(source);
+  size_t i;
+  int quote_hit;
+  WCHAR* start;
+
+  if (len == 0) {
+    /* Need double quotation for empty argument */
+    *(target++) = L'"';
+    *(target++) = L'"';
+    return target;
+  }
+
+  if (NULL == wcspbrk(source, L" \t\"")) {
+    /* No quotation needed */
+    wcsncpy(target, source, len);
+    target += len;
+    return target;
+  }
+
+  if (NULL == wcspbrk(source, L"\"\\")) {
+    /*
+     * No embedded double quotes or backlashes, so I can just wrap
+     * quote marks around the whole thing.
+     */
+    *(target++) = L'"';
+    wcsncpy(target, source, len);
+    target += len;
+    *(target++) = L'"';
+    return target;
+  }
+
+  /*
+   * Expected input/output:
+   *   input : hello"world
+   *   output: "hello\"world"
+   *   input : hello""world
+   *   output: "hello\"\"world"
+   *   input : hello\world
+   *   output: hello\world
+   *   input : hello\\world
+   *   output: hello\\world
+   *   input : hello\"world
+   *   output: "hello\\\"world"
+   *   input : hello\\"world
+   *   output: "hello\\\\\"world"
+   *   input : hello world\
+   *   output: "hello world\\"
+   */
+
+  *(target++) = L'"';
+  start = target;
+  quote_hit = 1;
+
+  for (i = len; i > 0; --i) {
+    *(target++) = source[i - 1];
+
+    if (quote_hit && source[i - 1] == L'\\') {
+      *(target++) = L'\\';
+    } else if(source[i - 1] == L'"') {
+      quote_hit = 1;
+      *(target++) = L'\\';
+    } else {
+      quote_hit = 0;
+    }
+  }
+  target[0] = L'\0';
+  _wcsrev(start);
+  *(target++) = L'"';
+  return target;
+}
+
+
+int make_program_args(char** args, int verbatim_arguments, WCHAR** dst_ptr) {
+  char** arg;
+  WCHAR* dst = NULL;
+  WCHAR* temp_buffer = NULL;
+  size_t dst_len = 0;
+  size_t temp_buffer_len = 0;
+  WCHAR* pos;
+  int arg_count = 0;
+  int err = 0;
+
+  /* Count the required size. */
+  for (arg = args; *arg; arg++) {
+    ssize_t arg_len;
+
+    arg_len = uv_wtf8_length_as_utf16(*arg);
+    if (arg_len < 0)
+      return arg_len;
+
+    dst_len += arg_len;
+
+    if ((size_t) arg_len > temp_buffer_len)
+      temp_buffer_len = arg_len;
+
+    arg_count++;
+  }
+
+  /* Adjust for potential quotes. Also assume the worst-case scenario that
+   * every character needs escaping, so we need twice as much space. */
+  dst_len = dst_len * 2 + arg_count * 2;
+
+  /* Allocate buffer for the final command line. */
+  dst = uv__malloc(dst_len * sizeof(WCHAR));
+  if (dst == NULL) {
+    err = UV_ENOMEM;
+    goto error;
+  }
+
+  /* Allocate temporary working buffer. */
+  temp_buffer = uv__malloc(temp_buffer_len * sizeof(WCHAR));
+  if (temp_buffer == NULL) {
+    err = UV_ENOMEM;
+    goto error;
+  }
+
+  pos = dst;
+  for (arg = args; *arg; arg++) {
+    ssize_t arg_len;
+
+    /* Convert argument to wide char. */
+    arg_len = uv_wtf8_length_as_utf16(*arg);
+    assert(arg_len > 0);
+    assert(temp_buffer_len >= (size_t) arg_len);
+    uv_wtf8_to_utf16(*arg, temp_buffer, arg_len);
+
+    if (verbatim_arguments) {
+      /* Copy verbatim. */
+      wcscpy(pos, temp_buffer);
+      pos += arg_len - 1;
+    } else {
+      /* Quote/escape, if needed. */
+      pos = quote_cmd_arg(temp_buffer, pos);
+    }
+
+    *pos++ = *(arg + 1) ? L' ' : L'\0';
+    assert(pos <= dst + dst_len);
+  }
+
+  uv__free(temp_buffer);
+
+  *dst_ptr = dst;
+  return 0;
+
+error:
+  uv__free(dst);
+  uv__free(temp_buffer);
+  return err;
+}
+
+
+static int env_strncmp(const wchar_t* a, int na, const wchar_t* b) {
+  wchar_t* a_eq;
+  wchar_t* b_eq;
+  int nb;
+  int r;
+
+  if (na < 0) {
+    a_eq = wcschr(a, L'=');
+    assert(a_eq);
+    na = (int)(long)(a_eq - a);
+  } else {
+    na--;
+  }
+  b_eq = wcschr(b, L'=');
+  assert(b_eq);
+  nb = b_eq - b;
+
+  r = CompareStringOrdinal(a, na, b, nb, /*case insensitive*/TRUE);
+  return r - CSTR_EQUAL;
+}
+
+
+static int qsort_wcscmp(const void *a, const void *b) {
+  wchar_t* astr = *(wchar_t* const*)a;
+  wchar_t* bstr = *(wchar_t* const*)b;
+  return env_strncmp(astr, -1, bstr);
+}
+
+
+/*
+ * The way windows takes environment variables is different than what C does;
+ * Windows wants a contiguous block of null-terminated strings, terminated
+ * with an additional null.
+ *
+ * Windows has a few "essential" environment variables. winsock will fail
+ * to initialize if SYSTEMROOT is not defined; some APIs make reference to
+ * TEMP. SYSTEMDRIVE is probably also important. We therefore ensure that
+ * these get defined if the input environment block does not contain any
+ * values for them.
+ *
+ * Also add variables known to Cygwin to be required for correct
+ * subprocess operation in many cases:
+ * https://github.com/Alexpux/Cygwin/blob/b266b04fbbd3a595f02ea149e4306d3ab9b1fe3d/winsup/cygwin/environ.cc#L955
+ *
+ */
+int make_program_env(char* env_block[], WCHAR** dst_ptr) {
+  WCHAR* dst;
+  WCHAR* ptr;
+  char** env;
+  size_t env_len = 0;
+  size_t len;
+  size_t i;
+  size_t var_size;
+  size_t env_block_count = 1; /* 1 for null-terminator */
+  WCHAR* dst_copy;
+  WCHAR** ptr_copy;
+  WCHAR** env_copy;
+  char* p;
+  size_t required_vars_value_len[ARRAY_SIZE(required_vars)];
+
+  /* first pass: determine size in UTF-16 */
+  for (env = env_block; *env; env++) {
+    ssize_t len;
+    if (strchr(*env, '=')) {
+      len = uv_wtf8_length_as_utf16(*env);
+      if (len < 0)
+        return len;
+      env_len += len;
+      env_block_count++;
+    }
+  }
+
+  /* second pass: copy to UTF-16 environment block */
+  len = env_block_count * sizeof(WCHAR*);
+  p = uv__malloc(len + env_len * sizeof(WCHAR));
+  if (p == NULL) {
+    return UV_ENOMEM;
+  }
+  env_copy = (void*) &p[0];
+  dst_copy = (void*) &p[len];
+
+  ptr = dst_copy;
+  ptr_copy = env_copy;
+  for (env = env_block; *env; env++) {
+    ssize_t len;
+    if (strchr(*env, '=')) {
+      len = uv_wtf8_length_as_utf16(*env);
+      assert(len > 0);
+      assert((size_t) len <= env_len - (ptr - dst_copy));
+      uv_wtf8_to_utf16(*env, ptr, len);
+      *ptr_copy++ = ptr;
+      ptr += len;
+    }
+  }
+  *ptr_copy = NULL;
+  assert(env_len == 0 || env_len == (size_t) (ptr - dst_copy));
+
+  /* sort our (UTF-16) copy */
+  qsort(env_copy, env_block_count-1, sizeof(wchar_t*), qsort_wcscmp);
+
+  /* third pass: check for required variables */
+  for (ptr_copy = env_copy, i = 0; i < ARRAY_SIZE(required_vars); ) {
+    int cmp;
+    if (!*ptr_copy) {
+      cmp = -1;
+    } else {
+      cmp = env_strncmp(required_vars[i].wide_eq,
+                        required_vars[i].len,
+                        *ptr_copy);
+    }
+    if (cmp < 0) {
+      /* missing required var */
+      var_size = GetEnvironmentVariableW(required_vars[i].wide, NULL, 0);
+      required_vars_value_len[i] = var_size;
+      if (var_size != 0) {
+        env_len += required_vars[i].len;
+        env_len += var_size;
+      }
+      i++;
+    } else {
+      ptr_copy++;
+      if (cmp == 0)
+        i++;
+    }
+  }
+
+  /* final pass: copy, in sort order, and inserting required variables */
+  dst = uv__malloc((1+env_len) * sizeof(WCHAR));
+  if (!dst) {
+    uv__free(p);
+    return UV_ENOMEM;
+  }
+
+  for (ptr = dst, ptr_copy = env_copy, i = 0;
+       *ptr_copy || i < ARRAY_SIZE(required_vars);
+       ptr += len) {
+    int cmp;
+    if (i >= ARRAY_SIZE(required_vars)) {
+      cmp = 1;
+    } else if (!*ptr_copy) {
+      cmp = -1;
+    } else {
+      cmp = env_strncmp(required_vars[i].wide_eq,
+                        required_vars[i].len,
+                        *ptr_copy);
+    }
+    if (cmp < 0) {
+      /* missing required var */
+      len = required_vars_value_len[i];
+      if (len) {
+        wcscpy(ptr, required_vars[i].wide_eq);
+        ptr += required_vars[i].len;
+        var_size = GetEnvironmentVariableW(required_vars[i].wide,
+                                           ptr,
+                                           (int) (env_len - (ptr - dst)));
+        if (var_size != (DWORD) (len - 1)) { /* TODO: handle race condition? */
+          uv_fatal_error(GetLastError(), "GetEnvironmentVariableW");
+        }
+      }
+      i++;
+    } else {
+      /* copy var from env_block */
+      len = wcslen(*ptr_copy) + 1;
+      wmemcpy(ptr, *ptr_copy, len);
+      ptr_copy++;
+      if (cmp == 0)
+        i++;
+    }
+  }
+
+  /* Terminate with an extra NULL. */
+  assert(env_len == (size_t) (ptr - dst));
+  *ptr = L'\0';
+
+  uv__free(p);
+  *dst_ptr = dst;
+  return 0;
+}
+
+/*
+ * Attempt to find the value of the PATH environment variable in the child's
+ * preprocessed environment.
+ *
+ * If found, a pointer into `env` is returned. If not found, NULL is returned.
+ */
+static WCHAR* find_path(WCHAR *env) {
+  for (; env != NULL && *env != 0; env += wcslen(env) + 1) {
+    if ((env[0] == L'P' || env[0] == L'p') &&
+        (env[1] == L'A' || env[1] == L'a') &&
+        (env[2] == L'T' || env[2] == L't') &&
+        (env[3] == L'H' || env[3] == L'h') &&
+        (env[4] == L'=')) {
+      return &env[5];
+    }
+  }
+
+  return NULL;
+}
+
+/*
+ * Called on Windows thread-pool thread to indicate that
+ * a child process has exited.
+ */
+static void CALLBACK exit_wait_callback(void* data, BOOLEAN didTimeout) {
+  uv_process_t* process = (uv_process_t*) data;
+  uv_loop_t* loop = process->loop;
+
+  assert(didTimeout == FALSE);
+  assert(process);
+  assert(!process->exit_cb_pending);
+
+  process->exit_cb_pending = 1;
+
+  /* Post completed */
+  POST_COMPLETION_FOR_REQ(loop, &process->exit_req);
+}
+
+
+/* Called on main thread after a child process has exited. */
+void uv__process_proc_exit(uv_loop_t* loop, uv_process_t* handle) {
+  int64_t exit_code;
+  DWORD status;
+
+  assert(handle->exit_cb_pending);
+  handle->exit_cb_pending = 0;
+
+  /* If we're closing, don't call the exit callback. Just schedule a close
+   * callback now. */
+  if (handle->flags & UV_HANDLE_CLOSING) {
+    uv__want_endgame(loop, (uv_handle_t*) handle);
+    return;
+  }
+
+  /* Unregister from process notification. */
+  if (handle->wait_handle != INVALID_HANDLE_VALUE) {
+    UnregisterWait(handle->wait_handle);
+    handle->wait_handle = INVALID_HANDLE_VALUE;
+  }
+
+  /* Set the handle to inactive: no callbacks will be made after the exit
+   * callback. */
+  uv__handle_stop(handle);
+
+  if (GetExitCodeProcess(handle->process_handle, &status)) {
+    exit_code = status;
+  } else {
+    /* Unable to obtain the exit code. This should never happen. */
+    exit_code = uv_translate_sys_error(GetLastError());
+  }
+
+  /* Fire the exit callback. */
+  if (handle->exit_cb) {
+    handle->exit_cb(handle, exit_code, handle->exit_signal);
+  }
+}
+
+
+void uv__process_close(uv_loop_t* loop, uv_process_t* handle) {
+  uv__handle_closing(handle);
+
+  if (handle->wait_handle != INVALID_HANDLE_VALUE) {
+    /* This blocks until either the wait was cancelled, or the callback has
+     * completed. */
+    BOOL r = UnregisterWaitEx(handle->wait_handle, INVALID_HANDLE_VALUE);
+    if (!r) {
+      /* This should never happen, and if it happens, we can't recover... */
+      uv_fatal_error(GetLastError(), "UnregisterWaitEx");
+    }
+
+    handle->wait_handle = INVALID_HANDLE_VALUE;
+  }
+
+  if (!handle->exit_cb_pending) {
+    uv__want_endgame(loop, (uv_handle_t*)handle);
+  }
+}
+
+
+void uv__process_endgame(uv_loop_t* loop, uv_process_t* handle) {
+  assert(!handle->exit_cb_pending);
+  assert(handle->flags & UV_HANDLE_CLOSING);
+  assert(!(handle->flags & UV_HANDLE_CLOSED));
+
+  /* Clean-up the process handle. */
+  CloseHandle(handle->process_handle);
+
+  uv__handle_close(handle);
+}
+
+
+int uv_spawn(uv_loop_t* loop,
+             uv_process_t* process,
+             const uv_process_options_t* options) {
+  int i;
+  int err = 0;
+  WCHAR* path = NULL, *alloc_path = NULL;
+  BOOL result;
+  WCHAR* application_path = NULL, *application = NULL, *arguments = NULL,
+         *env = NULL, *cwd = NULL;
+  STARTUPINFOW startup;
+  PROCESS_INFORMATION info;
+  DWORD process_flags, cwd_len;
+  BYTE* child_stdio_buffer;
+
+  uv__process_init(loop, process);
+  process->exit_cb = options->exit_cb;
+  child_stdio_buffer = NULL;
+
+  if (options->flags & (UV_PROCESS_SETGID | UV_PROCESS_SETUID)) {
+    return UV_ENOTSUP;
+  }
+
+  if (options->file == NULL ||
+      options->args == NULL) {
+    return UV_EINVAL;
+  }
+
+  assert(options->file != NULL);
+  assert(!(options->flags & ~(UV_PROCESS_DETACHED |
+                              UV_PROCESS_SETGID |
+                              UV_PROCESS_SETUID |
+                              UV_PROCESS_WINDOWS_FILE_PATH_EXACT_NAME |
+                              UV_PROCESS_WINDOWS_HIDE |
+                              UV_PROCESS_WINDOWS_HIDE_CONSOLE |
+                              UV_PROCESS_WINDOWS_HIDE_GUI |
+                              UV_PROCESS_WINDOWS_VERBATIM_ARGUMENTS)));
+
+  err = uv__utf8_to_utf16_alloc(options->file, &application);
+  if (err)
+    goto done_uv;
+
+  err = make_program_args(
+      options->args,
+      options->flags & UV_PROCESS_WINDOWS_VERBATIM_ARGUMENTS,
+      &arguments);
+  if (err)
+    goto done_uv;
+
+  if (options->env) {
+     err = make_program_env(options->env, &env);
+     if (err)
+       goto done_uv;
+  }
+
+  if (options->cwd) {
+    /* Explicit cwd */
+    err = uv__utf8_to_utf16_alloc(options->cwd, &cwd);
+    if (err)
+      goto done_uv;
+
+    cwd_len = wcslen(cwd);
+  } else {
+    /* Inherit cwd */
+    DWORD r;
+
+    cwd_len = GetCurrentDirectoryW(0, NULL);
+    if (!cwd_len) {
+      err = GetLastError();
+      goto done;
+    }
+
+    cwd = (WCHAR*) uv__malloc(cwd_len * sizeof(WCHAR));
+    if (cwd == NULL) {
+      err = ERROR_OUTOFMEMORY;
+      goto done;
+    }
+
+    r = GetCurrentDirectoryW(cwd_len, cwd);
+    if (r == 0 || r >= cwd_len) {
+      err = GetLastError();
+      goto done;
+    }
+  }
+
+  /* If cwd is too long, shorten it */
+  if (cwd_len >= MAX_PATH) {
+    cwd_len = GetShortPathNameW(cwd, cwd, cwd_len);
+    if (cwd_len == 0) {
+      err = GetLastError();
+      goto done;
+    }
+  }
+
+  /* Get PATH environment variable. */
+  path = find_path(env);
+  if (path == NULL) {
+    DWORD path_len, r;
+
+    path_len = GetEnvironmentVariableW(L"PATH", NULL, 0);
+    if (path_len != 0) {
+      alloc_path = (WCHAR*) uv__malloc(path_len * sizeof(WCHAR));
+      if (alloc_path == NULL) {
+        err = ERROR_OUTOFMEMORY;
+        goto done;
+      }
+      path = alloc_path;
+
+      r = GetEnvironmentVariableW(L"PATH", path, path_len);
+      if (r == 0 || r >= path_len) {
+        err = GetLastError();
+        goto done;
+      }
+    }
+  }
+
+  err = uv__stdio_create(loop, options, &child_stdio_buffer);
+  if (err)
+    goto done;
+
+  application_path = search_path(application,
+                                 cwd,
+                                 path,
+                                 options->flags);
+  if (application_path == NULL) {
+    /* Not found. */
+    err = ERROR_FILE_NOT_FOUND;
+    goto done;
+  }
+
+  startup.cb = sizeof(startup);
+  startup.lpReserved = NULL;
+  startup.lpDesktop = NULL;
+  startup.lpTitle = NULL;
+  startup.dwFlags = STARTF_USESTDHANDLES | STARTF_USESHOWWINDOW;
+
+  startup.cbReserved2 = uv__stdio_size(child_stdio_buffer);
+  startup.lpReserved2 = (BYTE*) child_stdio_buffer;
+
+  startup.hStdInput = uv__stdio_handle(child_stdio_buffer, 0);
+  startup.hStdOutput = uv__stdio_handle(child_stdio_buffer, 1);
+  startup.hStdError = uv__stdio_handle(child_stdio_buffer, 2);
+
+  process_flags = CREATE_UNICODE_ENVIRONMENT;
+
+  if ((options->flags & UV_PROCESS_WINDOWS_HIDE_CONSOLE) ||
+      (options->flags & UV_PROCESS_WINDOWS_HIDE)) {
+    /* Avoid creating console window if stdio is not inherited. */
+    for (i = 0; i < options->stdio_count; i++) {
+      if (options->stdio[i].flags & UV_INHERIT_FD)
+        break;
+      if (i == options->stdio_count - 1)
+        process_flags |= CREATE_NO_WINDOW;
+    }
+  }
+  if ((options->flags & UV_PROCESS_WINDOWS_HIDE_GUI) ||
+      (options->flags & UV_PROCESS_WINDOWS_HIDE)) {
+    /* Use SW_HIDE to avoid any potential process window. */
+    startup.wShowWindow = SW_HIDE;
+  } else {
+    startup.wShowWindow = SW_SHOWDEFAULT;
+  }
+
+  if (options->flags & UV_PROCESS_DETACHED) {
+    /* Note that we're not setting the CREATE_BREAKAWAY_FROM_JOB flag. That
+     * means that libuv might not let you create a fully daemonized process
+     * when run under job control. However the type of job control that libuv
+     * itself creates doesn't trickle down to subprocesses so they can still
+     * daemonize.
+     *
+     * A reason to not do this is that CREATE_BREAKAWAY_FROM_JOB makes the
+     * CreateProcess call fail if we're under job control that doesn't allow
+     * breakaway.
+     */
+    process_flags |= DETACHED_PROCESS | CREATE_NEW_PROCESS_GROUP;
+    process_flags |= CREATE_SUSPENDED;
+  }
+
+  if (!CreateProcessW(application_path,
+                     arguments,
+                     NULL,
+                     NULL,
+                     1,
+                     process_flags,
+                     env,
+                     cwd,
+                     &startup,
+                     &info)) {
+    /* CreateProcessW failed. */
+    err = GetLastError();
+    goto done;
+  }
+
+  /* If the process isn't spawned as detached, assign to the global job object
+   * so windows will kill it when the parent process dies. */
+  if (!(options->flags & UV_PROCESS_DETACHED)) {
+    uv_once(&uv_global_job_handle_init_guard_, uv__init_global_job_handle);
+
+    if (!AssignProcessToJobObject(uv_global_job_handle_, info.hProcess)) {
+      /* AssignProcessToJobObject might fail if this process is under job
+       * control and the job doesn't have the
+       * JOB_OBJECT_LIMIT_SILENT_BREAKAWAY_OK flag set, on a Windows version
+       * that doesn't support nested jobs.
+       *
+       * When that happens we just swallow the error and continue without
+       * establishing a kill-child-on-parent-exit relationship, otherwise
+       * there would be no way for libuv applications run under job control
+       * to spawn processes at all.
+       */
+      DWORD err = GetLastError();
+      if (err != ERROR_ACCESS_DENIED)
+        uv_fatal_error(err, "AssignProcessToJobObject");
+    }
+  }
+
+  if (process_flags & CREATE_SUSPENDED) {
+    if (ResumeThread(info.hThread) == ((DWORD)-1)) {
+      err = GetLastError();
+      TerminateProcess(info.hProcess, 1);
+      goto done;
+    }
+  }
+
+  /* Spawn succeeded. Beyond this point, failure is reported asynchronously. */
+
+  process->process_handle = info.hProcess;
+  process->pid = info.dwProcessId;
+
+  /* Set IPC pid to all IPC pipes. */
+  for (i = 0; i < options->stdio_count; i++) {
+    const uv_stdio_container_t* fdopt = &options->stdio[i];
+    if (fdopt->flags & UV_CREATE_PIPE &&
+        fdopt->data.stream->type == UV_NAMED_PIPE &&
+        ((uv_pipe_t*) fdopt->data.stream)->ipc) {
+      ((uv_pipe_t*) fdopt->data.stream)->pipe.conn.ipc_remote_pid =
+          info.dwProcessId;
+    }
+  }
+
+  /* Setup notifications for when the child process exits. */
+  result = RegisterWaitForSingleObject(&process->wait_handle,
+      process->process_handle, exit_wait_callback, (void*)process, INFINITE,
+      WT_EXECUTEINWAITTHREAD | WT_EXECUTEONLYONCE);
+  if (!result) {
+    uv_fatal_error(GetLastError(), "RegisterWaitForSingleObject");
+  }
+
+  CloseHandle(info.hThread);
+
+  assert(!err);
+
+  /* Make the handle active. It will remain active until the exit callback is
+   * made or the handle is closed, whichever happens first. */
+  uv__handle_start(process);
+
+  goto done_uv;
+
+  /* Cleanup, whether we succeeded or failed. */
+ done:
+  err = uv_translate_sys_error(err);
+
+ done_uv:
+  uv__free(application);
+  uv__free(application_path);
+  uv__free(arguments);
+  uv__free(cwd);
+  uv__free(env);
+  uv__free(alloc_path);
+
+  if (child_stdio_buffer != NULL) {
+    /* Clean up child stdio handles. */
+    uv__stdio_destroy(child_stdio_buffer);
+    child_stdio_buffer = NULL;
+  }
+
+  return err;
+}
+
+
+static int uv__kill(HANDLE process_handle, int signum) {
+  if (signum < 0 || signum >= NSIG) {
+    return UV_EINVAL;
+  }
+
+  /* Create a dump file for the targeted process, if the registry key
+   * `HKLM:Software\Microsoft\Windows\Windows Error Reporting\LocalDumps`
+   * exists.  The location of the dumps can be influenced by the `DumpFolder`
+   * sub-key, which has a default value of `%LOCALAPPDATA%\CrashDumps`, see [0]
+   * for more detail.  Note that if the dump folder does not exist, we attempt
+   * to create it, to match behavior with WER itself.
+   * [0]: https://learn.microsoft.com/en-us/windows/win32/wer/collecting-user-mode-dumps */
+  if (signum == SIGQUIT) {
+    HKEY registry_key;
+    DWORD pid, ret;
+    WCHAR basename[MAX_PATH];
+
+    /* Get target process name. */
+    GetModuleBaseNameW(process_handle, NULL, &basename[0], sizeof(basename));
+
+    /* Get PID of target process. */
+    pid = GetProcessId(process_handle);
+
+    /* Get LocalDumps directory path. */
+    ret = RegOpenKeyExW(
+        HKEY_LOCAL_MACHINE,
+        L"SOFTWARE\\Microsoft\\Windows\\Windows Error Reporting\\LocalDumps",
+        0,
+        KEY_QUERY_VALUE,
+        &registry_key);
+    if (ret == ERROR_SUCCESS) {
+      HANDLE hDumpFile = NULL;
+      WCHAR dump_folder[MAX_PATH], dump_name[MAX_PATH];
+      DWORD dump_folder_len = sizeof(dump_folder), key_type = 0;
+      ret = RegGetValueW(registry_key,
+                         NULL,
+                         L"DumpFolder",
+                         RRF_RT_ANY,
+                         &key_type,
+                         (PVOID) dump_folder,
+                         &dump_folder_len);
+      if (ret != ERROR_SUCCESS) {
+        /* Workaround for missing uuid.dll on MinGW. */
+        static const GUID FOLDERID_LocalAppData_libuv = {
+          0xf1b32785, 0x6fba, 0x4fcf,
+              {0x9d, 0x55, 0x7b, 0x8e, 0x7f, 0x15, 0x70, 0x91}
+        };
+
+        /* Default value for `dump_folder` is `%LOCALAPPDATA%\CrashDumps`. */
+        WCHAR* localappdata;
+        SHGetKnownFolderPath(&FOLDERID_LocalAppData_libuv,
+                             0,
+                             NULL,
+                             &localappdata);
+        _snwprintf_s(dump_folder,
+                     sizeof(dump_folder),
+                     _TRUNCATE,
+                     L"%ls\\CrashDumps",
+                     localappdata);
+        CoTaskMemFree(localappdata);
+      }
+      RegCloseKey(registry_key);
+
+      /* Create dump folder if it doesn't already exist. */
+      CreateDirectoryW(dump_folder, NULL);
+
+      /* Construct dump filename from process name and PID. */
+      _snwprintf_s(dump_name,
+                   sizeof(dump_name),
+                   _TRUNCATE,
+                   L"%ls\\%ls.%d.dmp",
+                   dump_folder,
+                   basename,
+                   pid);
+
+      hDumpFile = CreateFileW(dump_name,
+                              GENERIC_WRITE,
+                              0,
+                              NULL,
+                              CREATE_NEW,
+                              FILE_ATTRIBUTE_NORMAL,
+                              NULL);
+      if (hDumpFile != INVALID_HANDLE_VALUE) {
+        DWORD dump_options, sym_options;
+        FILE_DISPOSITION_INFO DeleteOnClose = { TRUE };
+
+        /* If something goes wrong while writing it out, delete the file. */
+        SetFileInformationByHandle(hDumpFile,
+                                   FileDispositionInfo,
+                                   &DeleteOnClose,
+                                   sizeof(DeleteOnClose));
+
+        /* Tell wine to dump ELF modules as well. */
+        sym_options = SymGetOptions();
+        SymSetOptions(sym_options | 0x40000000);
+
+/* MiniDumpWithAvxXStateContext might be undef in server2012r2 or mingw < 12 */
+#ifndef MiniDumpWithAvxXStateContext
+#define MiniDumpWithAvxXStateContext 0x00200000
+#endif
+        /* We default to a fairly complete dump.  In the future, we may want to
+         * allow clients to customize what kind of dump to create. */
+        dump_options = MiniDumpWithFullMemory |
+                       MiniDumpIgnoreInaccessibleMemory |
+                       MiniDumpWithAvxXStateContext;
+
+        if (MiniDumpWriteDump(process_handle,
+                              pid,
+                              hDumpFile,
+                              dump_options,
+                              NULL,
+                              NULL,
+                              NULL)) {
+          /* Don't delete the file on close if we successfully wrote it out. */
+          FILE_DISPOSITION_INFO DontDeleteOnClose = { FALSE };
+          SetFileInformationByHandle(hDumpFile,
+                                     FileDispositionInfo,
+                                     &DontDeleteOnClose,
+                                     sizeof(DontDeleteOnClose));
+        }
+        SymSetOptions(sym_options);
+        CloseHandle(hDumpFile);
+      }
+    }
+  }
+
+  switch (signum) {
+    case SIGQUIT:
+    case SIGTERM:
+    case SIGKILL:
+    case SIGINT: {
+      /* Unconditionally terminate the process. On Windows, killed processes
+       * normally return 1. */
+      int err;
+      DWORD status;
+
+      if (TerminateProcess(process_handle, 1))
+        return 0;
+
+      /* If the process already exited before TerminateProcess was called,
+       * TerminateProcess will fail with ERROR_ACCESS_DENIED. */
+      err = GetLastError();
+      if (err == ERROR_ACCESS_DENIED) {
+        /* First check using GetExitCodeProcess() with status different from
+         * STILL_ACTIVE (259). This check can be set incorrectly by the process,
+         * though that is uncommon. */
+        if (GetExitCodeProcess(process_handle, &status) &&
+            status != STILL_ACTIVE) {
+          return UV_ESRCH;
+        }
+
+        /* But the process could have exited with code == STILL_ACTIVE, use then
+         * WaitForSingleObject with timeout zero. This is prone to a race
+         * condition as it could return WAIT_TIMEOUT because the handle might
+         * not have been signaled yet.That would result in returning the wrong
+         * error code here (UV_EACCES instead of UV_ESRCH), but we cannot fix
+         * the kernel synchronization issue that TerminateProcess is
+         * inconsistent with WaitForSingleObject with just the APIs available to
+         * us in user space. */
+        if (WaitForSingleObject(process_handle, 0) == WAIT_OBJECT_0) {
+          return UV_ESRCH;
+        }
+      }
+
+      return uv_translate_sys_error(err);
+    }
+
+    case 0: {
+      /* Health check: is the process still alive? */
+      DWORD status;
+
+      if (!GetExitCodeProcess(process_handle, &status))
+        return uv_translate_sys_error(GetLastError());
+
+      if (status != STILL_ACTIVE)
+        return UV_ESRCH;
+
+      switch (WaitForSingleObject(process_handle, 0)) {
+        case WAIT_OBJECT_0:
+          return UV_ESRCH;
+        case WAIT_FAILED:
+          return uv_translate_sys_error(GetLastError());
+        case WAIT_TIMEOUT:
+          return 0;
+        default:
+          return UV_UNKNOWN;
+      }
+    }
+
+    default:
+      /* Unsupported signal. */
+      return UV_ENOSYS;
+  }
+}
+
+
+int uv_process_kill(uv_process_t* process, int signum) {
+  int err;
+
+  if (process->process_handle == INVALID_HANDLE_VALUE) {
+    return UV_EINVAL;
+  }
+
+  err = uv__kill(process->process_handle, signum);
+  if (err) {
+    return err;  /* err is already translated. */
+  }
+
+  process->exit_signal = signum;
+
+  return 0;
+}
+
+
+int uv_kill(int pid, int signum) {
+  int err;
+  HANDLE process_handle;
+
+  if (pid == 0) {
+    process_handle = GetCurrentProcess();
+  } else {
+    process_handle = OpenProcess(PROCESS_TERMINATE | PROCESS_QUERY_INFORMATION | SYNCHRONIZE,
+                                 FALSE,
+                                 pid);
+  }
+
+  if (process_handle == NULL) {
+    err = GetLastError();
+    if (err == ERROR_INVALID_PARAMETER) {
+      return UV_ESRCH;
+    } else {
+      return uv_translate_sys_error(err);
+    }
+  }
+
+  err = uv__kill(process_handle, signum);
+  CloseHandle(process_handle);
+
+  return err;  /* err is already translated. */
+}