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