LLVM  3.7.0
Windows/Program.inc
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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"
17 #include "llvm/Support/Errc.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 
31 namespace llvm {
32 using namespace sys;
33 
34 ProcessInfo::ProcessInfo() : ProcessHandle(0), Pid(0), ReturnCode(0) {}
35 
36 ErrorOr<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 
100 static 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.
143 static 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.
149 static 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.
162 static 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
174 static 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 
204 static 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 
245 static 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 
401 namespace llvm {
402 ProcessInfo 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 
465 std::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 
472 std::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 
479 std::error_code
480 llvm::sys::writeFileWithEncoding(StringRef FileName, StringRef Contents,
481  WindowsEncodingMethod Encoding) {
482  std::error_code EC;
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())
519 
520  return EC;
521 }
522 
523 bool 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 }
bool can_execute(const Twine &Path)
Can we execute this file?
Definition: FileSystem.h:378
std::error_code ChangeStdoutToBinary()
UTF-8 is the LLVM native encoding, being the same as "do not perform encoding conversion"...
Definition: Program.h:141
bool argumentsFitWithinSystemLimits(ArrayRef< const char * > Args)
Return true if the given arguments fit within system-specific argument length limits.
ErrorOr< std::string > findProgramByName(StringRef Name, ArrayRef< StringRef > Paths=ArrayRef< StringRef >())
Find the first executable file Name in Paths.
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
Definition: ErrorHandling.h:98
std::error_code make_error_code(BitcodeError E)
Definition: ReaderWriter.h:150
#define UNI_UTF16_BYTE_ORDER_MARK_NATIVE
Definition: ConvertUTF.h:115
#define rc(i)
#define P(N)
std::error_code mapWindowsError(unsigned EV)
std::error_code UTF8ToUTF16(StringRef utf8, SmallVectorImpl< wchar_t > &utf16)
std::error_code UTF16ToUTF8(const wchar_t *utf16, size_t utf16_len, SmallVectorImpl< char > &utf8)
void SplitString(StringRef Source, SmallVectorImpl< StringRef > &OutFragments, StringRef Delimiters=" \t\n\v\f\r")
SplitString - Split up the specified string according to the specified delimiters, appending the result fragments to the output list.
static bool Execute(ProcessInfo &PI, StringRef Program, const char **args, const char **env, const StringRef **Redirects, unsigned memoryLimit, std::string *ErrMsg)
SmallVectorImpl< T >::const_pointer c_str(SmallVectorImpl< T > &str)
std::error_code UTF16ToCurCP(const wchar_t *utf16, size_t utf16_len, SmallVectorImpl< char > &utf8)
Convert from UTF16 to the current code page used in the system.
std::error_code writeFileWithEncoding(StringRef FileName, StringRef Contents, WindowsEncodingMethod Encoding=WEM_UTF8)
Saves the UTF8-encoded contents string into the file FileName using a specific encoding.
bool MakeErrMsg(std::string *ErrMsg, const std::string &prefix)
WindowsEncodingMethod
File encoding options when writing contents that a non-UTF8 tool will read (on Windows systems)...
Definition: Program.h:138
The file should be opened in text mode on platforms that make this distinction.
Definition: FileSystem.h:592
std::error_code ChangeStdinToBinary()
A raw_ostream that writes to a file descriptor.
Definition: raw_ostream.h:345
static const size_t npos
Definition: StringRef.h:44
#define I(x, y, z)
Definition: MD5.cpp:54
ProcessInfo Wait(const ProcessInfo &PI, unsigned SecondsToWait, bool WaitUntilTerminates, std::string *ErrMsg=nullptr)
This function waits for the process specified by PI to finish.
std::error_code status(const Twine &path, file_status &result)
Get file status as if by POSIX stat().
std::error_code widenPath(const Twine &Path8, SmallVectorImpl< wchar_t > &Path16)