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