1//===- Win32/Program.cpp - Win32 Program Implementation ------- -*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file provides the Win32 specific implementation of the Program class.
11//
12//===----------------------------------------------------------------------===//
13
14#include "WindowsSupport.h"
15#include "llvm/ADT/StringExtras.h"
16#include "llvm/Support/ConvertUTF.h"
17#include "llvm/Support/Errc.h"
18#include "llvm/Support/FileSystem.h"
19#include "llvm/Support/WindowsError.h"
20#include "llvm/Support/raw_ostream.h"
21#include <cstdio>
22#include <fcntl.h>
23#include <io.h>
24#include <malloc.h>
25
26//===----------------------------------------------------------------------===//
27//=== WARNING: Implementation here must contain only Win32 specific code
28//===          and must not be UNIX code
29//===----------------------------------------------------------------------===//
30
31namespace llvm {
32
33ProcessInfo::ProcessInfo() : ProcessHandle(0), Pid(0), ReturnCode(0) {}
34
35ErrorOr<std::string> sys::findProgramByName(StringRef Name,
36                                            ArrayRef<StringRef> Paths) {
37  assert(!Name.empty() && "Must have a name!");
38
39  if (Name.find_first_of("/\\") != StringRef::npos)
40    return std::string(Name);
41
42  const wchar_t *Path = nullptr;
43  std::wstring PathStorage;
44  if (!Paths.empty()) {
45    PathStorage.reserve(Paths.size() * MAX_PATH);
46    for (unsigned i = 0; i < Paths.size(); ++i) {
47      if (i)
48        PathStorage.push_back(L';');
49      StringRef P = Paths[i];
50      SmallVector<wchar_t, MAX_PATH> TmpPath;
51      if (std::error_code EC = windows::UTF8ToUTF16(P, TmpPath))
52        return EC;
53      PathStorage.append(TmpPath.begin(), TmpPath.end());
54    }
55    Path = PathStorage.c_str();
56  }
57
58  SmallVector<wchar_t, MAX_PATH> U16Name;
59  if (std::error_code EC = windows::UTF8ToUTF16(Name, U16Name))
60    return EC;
61
62  SmallVector<StringRef, 12> PathExts;
63  PathExts.push_back("");
64  PathExts.push_back(".exe"); // FIXME: This must be in %PATHEXT%.
65  if (const char *PathExtEnv = std::getenv("PATHEXT"))
66    SplitString(PathExtEnv, PathExts, ";");
67
68  SmallVector<wchar_t, MAX_PATH> U16Result;
69  DWORD Len = MAX_PATH;
70  for (StringRef Ext : PathExts) {
71    SmallVector<wchar_t, MAX_PATH> U16Ext;
72    if (std::error_code EC = windows::UTF8ToUTF16(Ext, U16Ext))
73      return EC;
74
75    do {
76      U16Result.reserve(Len);
77      // Lets attach the extension manually. That is needed for files
78      // with a point in name like aaa.bbb. SearchPathW will not add extension
79      // from its argument to such files because it thinks they already had one.
80      SmallVector<wchar_t, MAX_PATH> U16NameExt;
81      if (std::error_code EC =
82              windows::UTF8ToUTF16(Twine(Name + Ext).str(), U16NameExt))
83        return EC;
84
85      Len = ::SearchPathW(Path, c_str(U16NameExt), nullptr,
86                          U16Result.capacity(), U16Result.data(), nullptr);
87    } while (Len > U16Result.capacity());
88
89    if (Len != 0)
90      break; // Found it.
91  }
92
93  if (Len == 0)
94    return mapWindowsError(::GetLastError());
95
96  U16Result.set_size(Len);
97
98  SmallVector<char, MAX_PATH> U8Result;
99  if (std::error_code EC =
100          windows::UTF16ToUTF8(U16Result.data(), U16Result.size(), U8Result))
101    return EC;
102
103  return std::string(U8Result.begin(), U8Result.end());
104}
105
106static HANDLE RedirectIO(Optional<StringRef> Path, int fd,
107                         std::string *ErrMsg) {
108  HANDLE h;
109  if (!Path) {
110    if (!DuplicateHandle(GetCurrentProcess(), (HANDLE)_get_osfhandle(fd),
111                         GetCurrentProcess(), &h,
112                         0, TRUE, DUPLICATE_SAME_ACCESS))
113      return INVALID_HANDLE_VALUE;
114    return h;
115  }
116
117  std::string fname;
118  if (Path->empty())
119    fname = "NUL";
120  else
121    fname = *Path;
122
123  SECURITY_ATTRIBUTES sa;
124  sa.nLength = sizeof(sa);
125  sa.lpSecurityDescriptor = 0;
126  sa.bInheritHandle = TRUE;
127
128  SmallVector<wchar_t, 128> fnameUnicode;
129  if (Path->empty()) {
130    // Don't play long-path tricks on "NUL".
131    if (windows::UTF8ToUTF16(fname, fnameUnicode))
132      return INVALID_HANDLE_VALUE;
133  } else {
134    if (path::widenPath(fname, fnameUnicode))
135      return INVALID_HANDLE_VALUE;
136  }
137  h = CreateFileW(fnameUnicode.data(), fd ? GENERIC_WRITE : GENERIC_READ,
138                  FILE_SHARE_READ, &sa, fd == 0 ? OPEN_EXISTING : CREATE_ALWAYS,
139                  FILE_ATTRIBUTE_NORMAL, NULL);
140  if (h == INVALID_HANDLE_VALUE) {
141    MakeErrMsg(ErrMsg, fname + ": Can't open file for " +
142        (fd ? "input" : "output"));
143  }
144
145  return h;
146}
147
148/// ArgNeedsQuotes - Check whether argument needs to be quoted when calling
149/// CreateProcess.
150static bool ArgNeedsQuotes(const char *Str) {
151  return Str[0] == '\0' || strpbrk(Str, "\t \"&\'()*<>\\`^|") != 0;
152}
153
154/// CountPrecedingBackslashes - Returns the number of backslashes preceding Cur
155/// in the C string Start.
156static unsigned int CountPrecedingBackslashes(const char *Start,
157                                              const char *Cur) {
158  unsigned int Count = 0;
159  --Cur;
160  while (Cur >= Start && *Cur == '\\') {
161    ++Count;
162    --Cur;
163  }
164  return Count;
165}
166
167/// EscapePrecedingEscapes - Append a backslash to Dst for every backslash
168/// preceding Cur in the Start string.  Assumes Dst has enough space.
169static char *EscapePrecedingEscapes(char *Dst, const char *Start,
170                                    const char *Cur) {
171  unsigned PrecedingEscapes = CountPrecedingBackslashes(Start, Cur);
172  while (PrecedingEscapes > 0) {
173    *Dst++ = '\\';
174    --PrecedingEscapes;
175  }
176  return Dst;
177}
178
179/// ArgLenWithQuotes - Check whether argument needs to be quoted when calling
180/// CreateProcess and returns length of quoted arg with escaped quotes
181static unsigned int ArgLenWithQuotes(const char *Str) {
182  const char *Start = Str;
183  bool Quoted = ArgNeedsQuotes(Str);
184  unsigned int len = Quoted ? 2 : 0;
185
186  while (*Str != '\0') {
187    if (*Str == '\"') {
188      // We need to add a backslash, but ensure that it isn't escaped.
189      unsigned PrecedingEscapes = CountPrecedingBackslashes(Start, Str);
190      len += PrecedingEscapes + 1;
191    }
192    // Note that we *don't* need to escape runs of backslashes that don't
193    // precede a double quote!  See MSDN:
194    // http://msdn.microsoft.com/en-us/library/17w5ykft%28v=vs.85%29.aspx
195
196    ++len;
197    ++Str;
198  }
199
200  if (Quoted) {
201    // Make sure the closing quote doesn't get escaped by a trailing backslash.
202    unsigned PrecedingEscapes = CountPrecedingBackslashes(Start, Str);
203    len += PrecedingEscapes + 1;
204  }
205
206  return len;
207}
208
209}
210
211static std::unique_ptr<char[]> flattenArgs(const char **Args) {
212  // First, determine the length of the command line.
213  unsigned len = 0;
214  for (unsigned i = 0; Args[i]; i++) {
215    len += ArgLenWithQuotes(Args[i]) + 1;
216  }
217
218  // Now build the command line.
219  std::unique_ptr<char[]> command(new char[len+1]);
220  char *p = command.get();
221
222  for (unsigned i = 0; Args[i]; i++) {
223    const char *arg = Args[i];
224    const char *start = arg;
225
226    bool needsQuoting = ArgNeedsQuotes(arg);
227    if (needsQuoting)
228      *p++ = '"';
229
230    while (*arg != '\0') {
231      if (*arg == '\"') {
232        // Escape all preceding escapes (if any), and then escape the quote.
233        p = EscapePrecedingEscapes(p, start, arg);
234        *p++ = '\\';
235      }
236
237      *p++ = *arg++;
238    }
239
240    if (needsQuoting) {
241      // Make sure our quote doesn't get escaped by a trailing backslash.
242      p = EscapePrecedingEscapes(p, start, arg);
243      *p++ = '"';
244    }
245    *p++ = ' ';
246  }
247
248  *p = 0;
249  return command;
250}
251
252static bool Execute(ProcessInfo &PI, StringRef Program, const char **Args,
253                    const char **Envp, ArrayRef<Optional<StringRef>> Redirects,
254                    unsigned MemoryLimit, std::string *ErrMsg) {
255  if (!sys::fs::can_execute(Program)) {
256    if (ErrMsg)
257      *ErrMsg = "program not executable";
258    return false;
259  }
260
261  // can_execute may succeed by looking at Program + ".exe". CreateProcessW
262  // will implicitly add the .exe if we provide a command line without an
263  // executable path, but since we use an explicit executable, we have to add
264  // ".exe" ourselves.
265  SmallString<64> ProgramStorage;
266  if (!sys::fs::exists(Program))
267    Program = Twine(Program + ".exe").toStringRef(ProgramStorage);
268
269  // Windows wants a command line, not an array of args, to pass to the new
270  // process.  We have to concatenate them all, while quoting the args that
271  // have embedded spaces (or are empty).
272  std::unique_ptr<char[]> command = flattenArgs(Args);
273
274  // The pointer to the environment block for the new process.
275  std::vector<wchar_t> EnvBlock;
276
277  if (Envp) {
278    // An environment block consists of a null-terminated block of
279    // null-terminated strings. Convert the array of environment variables to
280    // an environment block by concatenating them.
281    for (unsigned i = 0; Envp[i]; ++i) {
282      SmallVector<wchar_t, MAX_PATH> EnvString;
283      if (std::error_code ec = windows::UTF8ToUTF16(Envp[i], EnvString)) {
284        SetLastError(ec.value());
285        MakeErrMsg(ErrMsg, "Unable to convert environment variable to UTF-16");
286        return false;
287      }
288
289      EnvBlock.insert(EnvBlock.end(), EnvString.begin(), EnvString.end());
290      EnvBlock.push_back(0);
291    }
292    EnvBlock.push_back(0);
293  }
294
295  // Create a child process.
296  STARTUPINFOW si;
297  memset(&si, 0, sizeof(si));
298  si.cb = sizeof(si);
299  si.hStdInput = INVALID_HANDLE_VALUE;
300  si.hStdOutput = INVALID_HANDLE_VALUE;
301  si.hStdError = INVALID_HANDLE_VALUE;
302
303  if (!Redirects.empty()) {
304    si.dwFlags = STARTF_USESTDHANDLES;
305
306    si.hStdInput = RedirectIO(Redirects[0], 0, ErrMsg);
307    if (si.hStdInput == INVALID_HANDLE_VALUE) {
308      MakeErrMsg(ErrMsg, "can't redirect stdin");
309      return false;
310    }
311    si.hStdOutput = RedirectIO(Redirects[1], 1, ErrMsg);
312    if (si.hStdOutput == INVALID_HANDLE_VALUE) {
313      CloseHandle(si.hStdInput);
314      MakeErrMsg(ErrMsg, "can't redirect stdout");
315      return false;
316    }
317    if (Redirects[1] && Redirects[2] && *Redirects[1] == *Redirects[2]) {
318      // If stdout and stderr should go to the same place, redirect stderr
319      // to the handle already open for stdout.
320      if (!DuplicateHandle(GetCurrentProcess(), si.hStdOutput,
321                           GetCurrentProcess(), &si.hStdError,
322                           0, TRUE, DUPLICATE_SAME_ACCESS)) {
323        CloseHandle(si.hStdInput);
324        CloseHandle(si.hStdOutput);
325        MakeErrMsg(ErrMsg, "can't dup stderr to stdout");
326        return false;
327      }
328    } else {
329      // Just redirect stderr
330      si.hStdError = RedirectIO(Redirects[2], 2, ErrMsg);
331      if (si.hStdError == INVALID_HANDLE_VALUE) {
332        CloseHandle(si.hStdInput);
333        CloseHandle(si.hStdOutput);
334        MakeErrMsg(ErrMsg, "can't redirect stderr");
335        return false;
336      }
337    }
338  }
339
340  PROCESS_INFORMATION pi;
341  memset(&pi, 0, sizeof(pi));
342
343  fflush(stdout);
344  fflush(stderr);
345
346  SmallVector<wchar_t, MAX_PATH> ProgramUtf16;
347  if (std::error_code ec = path::widenPath(Program, ProgramUtf16)) {
348    SetLastError(ec.value());
349    MakeErrMsg(ErrMsg,
350               std::string("Unable to convert application name to UTF-16"));
351    return false;
352  }
353
354  SmallVector<wchar_t, MAX_PATH> CommandUtf16;
355  if (std::error_code ec = windows::UTF8ToUTF16(command.get(), CommandUtf16)) {
356    SetLastError(ec.value());
357    MakeErrMsg(ErrMsg,
358               std::string("Unable to convert command-line to UTF-16"));
359    return false;
360  }
361
362  BOOL rc = CreateProcessW(ProgramUtf16.data(), CommandUtf16.data(), 0, 0,
363                           TRUE, CREATE_UNICODE_ENVIRONMENT,
364                           EnvBlock.empty() ? 0 : EnvBlock.data(), 0, &si,
365                           &pi);
366  DWORD err = GetLastError();
367
368  // Regardless of whether the process got created or not, we are done with
369  // the handles we created for it to inherit.
370  CloseHandle(si.hStdInput);
371  CloseHandle(si.hStdOutput);
372  CloseHandle(si.hStdError);
373
374  // Now return an error if the process didn't get created.
375  if (!rc) {
376    SetLastError(err);
377    MakeErrMsg(ErrMsg, std::string("Couldn't execute program '") +
378               Program.str() + "'");
379    return false;
380  }
381
382  PI.Pid = pi.dwProcessId;
383  PI.ProcessHandle = pi.hProcess;
384
385  // Make sure these get closed no matter what.
386  ScopedCommonHandle hThread(pi.hThread);
387
388  // Assign the process to a job if a memory limit is defined.
389  ScopedJobHandle hJob;
390  if (MemoryLimit != 0) {
391    hJob = CreateJobObjectW(0, 0);
392    bool success = false;
393    if (hJob) {
394      JOBOBJECT_EXTENDED_LIMIT_INFORMATION jeli;
395      memset(&jeli, 0, sizeof(jeli));
396      jeli.BasicLimitInformation.LimitFlags = JOB_OBJECT_LIMIT_PROCESS_MEMORY;
397      jeli.ProcessMemoryLimit = uintptr_t(MemoryLimit) * 1048576;
398      if (SetInformationJobObject(hJob, JobObjectExtendedLimitInformation,
399                                  &jeli, sizeof(jeli))) {
400        if (AssignProcessToJobObject(hJob, pi.hProcess))
401          success = true;
402      }
403    }
404    if (!success) {
405      SetLastError(GetLastError());
406      MakeErrMsg(ErrMsg, std::string("Unable to set memory limit"));
407      TerminateProcess(pi.hProcess, 1);
408      WaitForSingleObject(pi.hProcess, INFINITE);
409      return false;
410    }
411  }
412
413  return true;
414}
415
416namespace llvm {
417ProcessInfo sys::Wait(const ProcessInfo &PI, unsigned SecondsToWait,
418                      bool WaitUntilChildTerminates, std::string *ErrMsg) {
419  assert(PI.Pid && "invalid pid to wait on, process not started?");
420  assert(PI.ProcessHandle &&
421         "invalid process handle to wait on, process not started?");
422  DWORD milliSecondsToWait = 0;
423  if (WaitUntilChildTerminates)
424    milliSecondsToWait = INFINITE;
425  else if (SecondsToWait > 0)
426    milliSecondsToWait = SecondsToWait * 1000;
427
428  ProcessInfo WaitResult = PI;
429  DWORD WaitStatus = WaitForSingleObject(PI.ProcessHandle, milliSecondsToWait);
430  if (WaitStatus == WAIT_TIMEOUT) {
431    if (SecondsToWait) {
432      if (!TerminateProcess(PI.ProcessHandle, 1)) {
433        if (ErrMsg)
434          MakeErrMsg(ErrMsg, "Failed to terminate timed-out program");
435
436        // -2 indicates a crash or timeout as opposed to failure to execute.
437        WaitResult.ReturnCode = -2;
438        CloseHandle(PI.ProcessHandle);
439        return WaitResult;
440      }
441      WaitForSingleObject(PI.ProcessHandle, INFINITE);
442      CloseHandle(PI.ProcessHandle);
443    } else {
444      // Non-blocking wait.
445      return ProcessInfo();
446    }
447  }
448
449  // Get its exit status.
450  DWORD status;
451  BOOL rc = GetExitCodeProcess(PI.ProcessHandle, &status);
452  DWORD err = GetLastError();
453  if (err != ERROR_INVALID_HANDLE)
454    CloseHandle(PI.ProcessHandle);
455
456  if (!rc) {
457    SetLastError(err);
458    if (ErrMsg)
459      MakeErrMsg(ErrMsg, "Failed getting status for program");
460
461    // -2 indicates a crash or timeout as opposed to failure to execute.
462    WaitResult.ReturnCode = -2;
463    return WaitResult;
464  }
465
466  if (!status)
467    return WaitResult;
468
469  // Pass 10(Warning) and 11(Error) to the callee as negative value.
470  if ((status & 0xBFFF0000U) == 0x80000000U)
471    WaitResult.ReturnCode = static_cast<int>(status);
472  else if (status & 0xFF)
473    WaitResult.ReturnCode = status & 0x7FFFFFFF;
474  else
475    WaitResult.ReturnCode = 1;
476
477  return WaitResult;
478}
479
480std::error_code sys::ChangeStdinToBinary() {
481  int result = _setmode(_fileno(stdin), _O_BINARY);
482  if (result == -1)
483    return std::error_code(errno, std::generic_category());
484  return std::error_code();
485}
486
487std::error_code sys::ChangeStdoutToBinary() {
488  int result = _setmode(_fileno(stdout), _O_BINARY);
489  if (result == -1)
490    return std::error_code(errno, std::generic_category());
491  return std::error_code();
492}
493
494std::error_code
495llvm::sys::writeFileWithEncoding(StringRef FileName, StringRef Contents,
496                                 WindowsEncodingMethod Encoding) {
497  std::error_code EC;
498  llvm::raw_fd_ostream OS(FileName, EC, llvm::sys::fs::OpenFlags::F_Text);
499  if (EC)
500    return EC;
501
502  if (Encoding == WEM_UTF8) {
503    OS << Contents;
504  } else if (Encoding == WEM_CurrentCodePage) {
505    SmallVector<wchar_t, 1> ArgsUTF16;
506    SmallVector<char, 1> ArgsCurCP;
507
508    if ((EC = windows::UTF8ToUTF16(Contents, ArgsUTF16)))
509      return EC;
510
511    if ((EC = windows::UTF16ToCurCP(
512             ArgsUTF16.data(), ArgsUTF16.size(), ArgsCurCP)))
513      return EC;
514
515    OS.write(ArgsCurCP.data(), ArgsCurCP.size());
516  } else if (Encoding == WEM_UTF16) {
517    SmallVector<wchar_t, 1> ArgsUTF16;
518
519    if ((EC = windows::UTF8ToUTF16(Contents, ArgsUTF16)))
520      return EC;
521
522    // Endianness guessing
523    char BOM[2];
524    uint16_t src = UNI_UTF16_BYTE_ORDER_MARK_NATIVE;
525    memcpy(BOM, &src, 2);
526    OS.write(BOM, 2);
527    OS.write((char *)ArgsUTF16.data(), ArgsUTF16.size() << 1);
528  } else {
529    llvm_unreachable("Unknown encoding");
530  }
531
532  if (OS.has_error())
533    return make_error_code(errc::io_error);
534
535  return EC;
536}
537
538bool llvm::sys::commandLineFitsWithinSystemLimits(StringRef Program,
539                                                  ArrayRef<const char *> Args) {
540  // The documented max length of the command line passed to CreateProcess.
541  static const size_t MaxCommandStringLength = 32768;
542  // Account for the trailing space for the program path and the
543  // trailing NULL of the last argument.
544  size_t ArgLength = ArgLenWithQuotes(Program.str().c_str()) + 2;
545  for (const char* Arg : Args) {
546    // Account for the trailing space for every arg
547    ArgLength += ArgLenWithQuotes(Arg) + 1;
548    if (ArgLength > MaxCommandStringLength) {
549      return false;
550    }
551  }
552  return true;
553}
554}
555