Program.inc revision 42f756f39e835aab0476f35c410b7e18fa8b670e 
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 "Windows.h"
15#include <cstdio>
16#include <fcntl.h>
17#include <io.h>
18#include <malloc.h>
19
20//===----------------------------------------------------------------------===//
21//=== WARNING: Implementation here must contain only Win32 specific code
22//===          and must not be UNIX code
23//===----------------------------------------------------------------------===//
24
25namespace {
26  struct Win32ProcessInfo {
27    HANDLE hProcess;
28    DWORD  dwProcessId;
29  };
30}
31
32namespace llvm {
33using namespace sys;
34
35// This function just uses the PATH environment variable to find the program.
36Path sys::FindProgramByName(const std::string& progName) {
37  // Check some degenerate cases
38  if (progName.length() == 0) // no program
39    return Path();
40  Path temp;
41  if (!temp.set(progName)) // invalid name
42    return Path();
43  // Return paths with slashes verbatim.
44  if (progName.find('\\') != std::string::npos ||
45      progName.find('/') != std::string::npos)
46    return temp;
47
48  // At this point, the file name is valid and does not contain slashes.
49  // Let Windows search for it.
50  char buffer[MAX_PATH];
51  char *dummy = NULL;
52  DWORD len = SearchPath(NULL, progName.c_str(), ".exe", MAX_PATH,
53                         buffer, &dummy);
54
55  // See if it wasn't found.
56  if (len == 0)
57    return Path();
58
59  // See if we got the entire path.
60  if (len < MAX_PATH)
61    return Path(buffer);
62
63  // Buffer was too small; grow and retry.
64  while (true) {
65    char *b = reinterpret_cast<char *>(_alloca(len+1));
66    DWORD len2 = SearchPath(NULL, progName.c_str(), ".exe", len+1, b, &dummy);
67
68    // It is unlikely the search failed, but it's always possible some file
69    // was added or removed since the last search, so be paranoid...
70    if (len2 == 0)
71      return Path();
72    else if (len2 <= len)
73      return Path(b);
74
75    len = len2;
76  }
77}
78
79static HANDLE RedirectIO(const Path *path, int fd, std::string* ErrMsg) {
80  HANDLE h;
81  if (path == 0) {
82    DuplicateHandle(GetCurrentProcess(), (HANDLE)_get_osfhandle(fd),
83                    GetCurrentProcess(), &h,
84                    0, TRUE, DUPLICATE_SAME_ACCESS);
85    return h;
86  }
87
88  const char *fname;
89  if (path->isEmpty())
90    fname = "NUL";
91  else
92    fname = path->c_str();
93
94  SECURITY_ATTRIBUTES sa;
95  sa.nLength = sizeof(sa);
96  sa.lpSecurityDescriptor = 0;
97  sa.bInheritHandle = TRUE;
98
99  h = CreateFile(fname, fd ? GENERIC_WRITE : GENERIC_READ, FILE_SHARE_READ,
100                 &sa, fd == 0 ? OPEN_EXISTING : CREATE_ALWAYS,
101                 FILE_ATTRIBUTE_NORMAL, NULL);
102  if (h == INVALID_HANDLE_VALUE) {
103    MakeErrMsg(ErrMsg, std::string(fname) + ": Can't open file for " +
104        (fd ? "input: " : "output: "));
105  }
106
107  return h;
108}
109
110/// ArgNeedsQuotes - Check whether argument needs to be quoted when calling
111/// CreateProcess.
112static bool ArgNeedsQuotes(const char *Str) {
113  return Str[0] == '\0' || strpbrk(Str, "\t \"&\'()*<>\\`^|") != 0;
114}
115
116/// CountPrecedingBackslashes - Returns the number of backslashes preceding Cur
117/// in the C string Start.
118static unsigned int CountPrecedingBackslashes(const char *Start,
119                                              const char *Cur) {
120  unsigned int Count = 0;
121  --Cur;
122  while (Cur >= Start && *Cur == '\\') {
123    ++Count;
124    --Cur;
125  }
126  return Count;
127}
128
129/// EscapePrecedingEscapes - Append a backslash to Dst for every backslash
130/// preceding Cur in the Start string.  Assumes Dst has enough space.
131static char *EscapePrecedingEscapes(char *Dst, const char *Start,
132                                    const char *Cur) {
133  unsigned PrecedingEscapes = CountPrecedingBackslashes(Start, Cur);
134  while (PrecedingEscapes > 0) {
135    *Dst++ = '\\';
136    --PrecedingEscapes;
137  }
138  return Dst;
139}
140
141/// ArgLenWithQuotes - Check whether argument needs to be quoted when calling
142/// CreateProcess and returns length of quoted arg with escaped quotes
143static unsigned int ArgLenWithQuotes(const char *Str) {
144  const char *Start = Str;
145  bool Quoted = ArgNeedsQuotes(Str);
146  unsigned int len = Quoted ? 2 : 0;
147
148  while (*Str != '\0') {
149    if (*Str == '\"') {
150      // We need to add a backslash, but ensure that it isn't escaped.
151      unsigned PrecedingEscapes = CountPrecedingBackslashes(Start, Str);
152      len += PrecedingEscapes + 1;
153    }
154    // Note that we *don't* need to escape runs of backslashes that don't
155    // precede a double quote!  See MSDN:
156    // http://msdn.microsoft.com/en-us/library/17w5ykft%28v=vs.85%29.aspx
157
158    ++len;
159    ++Str;
160  }
161
162  if (Quoted) {
163    // Make sure the closing quote doesn't get escaped by a trailing backslash.
164    unsigned PrecedingEscapes = CountPrecedingBackslashes(Start, Str);
165    len += PrecedingEscapes + 1;
166  }
167
168  return len;
169}
170
171}
172
173static bool Execute(Void *&Data,
174                    const Path& path,
175                    const char** args,
176                    const char** envp,
177                    const Path** redirects,
178                    unsigned memoryLimit,
179                    std::string* ErrMsg) {
180  if (Data) {
181    Win32ProcessInfo* wpi = reinterpret_cast<Win32ProcessInfo*>(Data);
182    CloseHandle(wpi->hProcess);
183    delete wpi;
184    Data = 0;
185  }
186
187  if (!path.canExecute()) {
188    if (ErrMsg)
189      *ErrMsg = "program not executable";
190    return false;
191  }
192
193  // Windows wants a command line, not an array of args, to pass to the new
194  // process.  We have to concatenate them all, while quoting the args that
195  // have embedded spaces (or are empty).
196
197  // First, determine the length of the command line.
198  unsigned len = 0;
199  for (unsigned i = 0; args[i]; i++) {
200    len += ArgLenWithQuotes(args[i]) + 1;
201  }
202
203  // Now build the command line.
204  char *command = reinterpret_cast<char *>(_alloca(len+1));
205  char *p = command;
206
207  for (unsigned i = 0; args[i]; i++) {
208    const char *arg = args[i];
209    const char *start = arg;
210
211    bool needsQuoting = ArgNeedsQuotes(arg);
212    if (needsQuoting)
213      *p++ = '"';
214
215    while (*arg != '\0') {
216      if (*arg == '\"') {
217        // Escape all preceding escapes (if any), and then escape the quote.
218        p = EscapePrecedingEscapes(p, start, arg);
219        *p++ = '\\';
220      }
221
222      *p++ = *arg++;
223    }
224
225    if (needsQuoting) {
226      // Make sure our quote doesn't get escaped by a trailing backslash.
227      p = EscapePrecedingEscapes(p, start, arg);
228      *p++ = '"';
229    }
230    *p++ = ' ';
231  }
232
233  *p = 0;
234
235  // The pointer to the environment block for the new process.
236  char *envblock = 0;
237
238  if (envp) {
239    // An environment block consists of a null-terminated block of
240    // null-terminated strings. Convert the array of environment variables to
241    // an environment block by concatenating them.
242
243    // First, determine the length of the environment block.
244    len = 0;
245    for (unsigned i = 0; envp[i]; i++)
246      len += strlen(envp[i]) + 1;
247
248    // Now build the environment block.
249    envblock = reinterpret_cast<char *>(_alloca(len+1));
250    p = envblock;
251
252    for (unsigned i = 0; envp[i]; i++) {
253      const char *ev = envp[i];
254      size_t len = strlen(ev) + 1;
255      memcpy(p, ev, len);
256      p += len;
257    }
258
259    *p = 0;
260  }
261
262  // Create a child process.
263  STARTUPINFO si;
264  memset(&si, 0, sizeof(si));
265  si.cb = sizeof(si);
266  si.hStdInput = INVALID_HANDLE_VALUE;
267  si.hStdOutput = INVALID_HANDLE_VALUE;
268  si.hStdError = INVALID_HANDLE_VALUE;
269
270  if (redirects) {
271    si.dwFlags = STARTF_USESTDHANDLES;
272
273    si.hStdInput = RedirectIO(redirects[0], 0, ErrMsg);
274    if (si.hStdInput == INVALID_HANDLE_VALUE) {
275      MakeErrMsg(ErrMsg, "can't redirect stdin");
276      return false;
277    }
278    si.hStdOutput = RedirectIO(redirects[1], 1, ErrMsg);
279    if (si.hStdOutput == INVALID_HANDLE_VALUE) {
280      CloseHandle(si.hStdInput);
281      MakeErrMsg(ErrMsg, "can't redirect stdout");
282      return false;
283    }
284    if (redirects[1] && redirects[2] && *(redirects[1]) == *(redirects[2])) {
285      // If stdout and stderr should go to the same place, redirect stderr
286      // to the handle already open for stdout.
287      DuplicateHandle(GetCurrentProcess(), si.hStdOutput,
288                      GetCurrentProcess(), &si.hStdError,
289                      0, TRUE, DUPLICATE_SAME_ACCESS);
290    } else {
291      // Just redirect stderr
292      si.hStdError = RedirectIO(redirects[2], 2, ErrMsg);
293      if (si.hStdError == INVALID_HANDLE_VALUE) {
294        CloseHandle(si.hStdInput);
295        CloseHandle(si.hStdOutput);
296        MakeErrMsg(ErrMsg, "can't redirect stderr");
297        return false;
298      }
299    }
300  }
301
302  PROCESS_INFORMATION pi;
303  memset(&pi, 0, sizeof(pi));
304
305  fflush(stdout);
306  fflush(stderr);
307  BOOL rc = CreateProcess(path.c_str(), command, NULL, NULL, TRUE, 0,
308                          envblock, NULL, &si, &pi);
309  DWORD err = GetLastError();
310
311  // Regardless of whether the process got created or not, we are done with
312  // the handles we created for it to inherit.
313  CloseHandle(si.hStdInput);
314  CloseHandle(si.hStdOutput);
315  CloseHandle(si.hStdError);
316
317  // Now return an error if the process didn't get created.
318  if (!rc) {
319    SetLastError(err);
320    MakeErrMsg(ErrMsg, std::string("Couldn't execute program '") +
321               path.str() + "'");
322    return false;
323  }
324  Win32ProcessInfo* wpi = new Win32ProcessInfo;
325  wpi->hProcess = pi.hProcess;
326  wpi->dwProcessId = pi.dwProcessId;
327  Data = wpi;
328
329  // Make sure these get closed no matter what.
330  ScopedCommonHandle hThread(pi.hThread);
331
332  // Assign the process to a job if a memory limit is defined.
333  ScopedJobHandle hJob;
334  if (memoryLimit != 0) {
335    hJob = CreateJobObject(0, 0);
336    bool success = false;
337    if (hJob) {
338      JOBOBJECT_EXTENDED_LIMIT_INFORMATION jeli;
339      memset(&jeli, 0, sizeof(jeli));
340      jeli.BasicLimitInformation.LimitFlags = JOB_OBJECT_LIMIT_PROCESS_MEMORY;
341      jeli.ProcessMemoryLimit = uintptr_t(memoryLimit) * 1048576;
342      if (SetInformationJobObject(hJob, JobObjectExtendedLimitInformation,
343                                  &jeli, sizeof(jeli))) {
344        if (AssignProcessToJobObject(hJob, pi.hProcess))
345          success = true;
346      }
347    }
348    if (!success) {
349      SetLastError(GetLastError());
350      MakeErrMsg(ErrMsg, std::string("Unable to set memory limit"));
351      TerminateProcess(pi.hProcess, 1);
352      WaitForSingleObject(pi.hProcess, INFINITE);
353      return false;
354    }
355  }
356
357  return true;
358}
359
360static int WaitAux(void *&Data, const Path &path,
361                   unsigned secondsToWait,
362                   std::string* ErrMsg) {
363  if (Data == 0) {
364    MakeErrMsg(ErrMsg, "Process not started!");
365    return -1;
366  }
367
368  Win32ProcessInfo* wpi = reinterpret_cast<Win32ProcessInfo*>(Data);
369  HANDLE hProcess = wpi->hProcess;
370
371  // Wait for the process to terminate.
372  DWORD millisecondsToWait = INFINITE;
373  if (secondsToWait > 0)
374    millisecondsToWait = secondsToWait * 1000;
375
376  if (WaitForSingleObject(hProcess, millisecondsToWait) == WAIT_TIMEOUT) {
377    if (!TerminateProcess(hProcess, 1)) {
378      MakeErrMsg(ErrMsg, "Failed to terminate timed-out program.");
379      // -2 indicates a crash or timeout as opposed to failure to execute.
380      return -2;
381    }
382    WaitForSingleObject(hProcess, INFINITE);
383  }
384
385  // Get its exit status.
386  DWORD status;
387  BOOL rc = GetExitCodeProcess(hProcess, &status);
388  DWORD err = GetLastError();
389
390  if (!rc) {
391    SetLastError(err);
392    MakeErrMsg(ErrMsg, "Failed getting status for program.");
393    // -2 indicates a crash or timeout as opposed to failure to execute.
394    return -2;
395  }
396
397  if (!status)
398    return 0;
399
400  // Pass 10(Warning) and 11(Error) to the callee as negative value.
401  if ((status & 0xBFFF0000U) == 0x80000000U)
402    return (int)status;
403
404  if (status & 0xFF)
405    return status & 0x7FFFFFFF;
406
407  return 1;
408}
409
410static int Wait(void *&Data, const Path &path,
411                unsigned secondsToWait,
412                std::string* ErrMsg) {
413  int Ret = WaitAux(Data, path, secondsToWait, ErrMsg);
414
415  Win32ProcessInfo* wpi = reinterpret_cast<Win32ProcessInfo*>(Data);
416  CloseHandle(wpi->hProcess);
417  delete wpi;
418  Data = 0;
419
420  return Ret;
421}
422
423namespace llvm {
424error_code ChangeStdinToBinary(){
425  int result = _setmode( _fileno(stdin), _O_BINARY );
426  if (result == -1)
427    return error_code(errno, generic_category());
428  return make_error_code(errc::success);
429}
430
431error_code ChangeStdoutToBinary(){
432  int result = _setmode( _fileno(stdout), _O_BINARY );
433  if (result == -1)
434    return error_code(errno, generic_category());
435  return make_error_code(errc::success);
436}
437
438error_code ChangeStderrToBinary(){
439  int result = _setmode( _fileno(stderr), _O_BINARY );
440  if (result == -1)
441    return error_code(errno, generic_category());
442  return make_error_code(errc::success);
443}
444
445bool llvm::sys::argumentsFitWithinSystemLimits(ArrayRef<const char*> Args) {
446  // The documented max length of the command line passed to CreateProcess.
447  static const size_t MaxCommandStringLength = 32768;
448  size_t ArgLength = 0;
449  for (ArrayRef<const char*>::iterator I = Args.begin(), E = Args.end();
450       I != E; ++I) {
451    // Account for the trailing space for every arg but the last one and the
452    // trailing NULL of the last argument.
453    ArgLength += ArgLenWithQuotes(*I) + 1;
454    if (ArgLength > MaxCommandStringLength) {
455      return false;
456    }
457  }
458  return true;
459}
460
461}
462