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