aboutsummaryrefslogtreecommitdiff
path: root/support/tst-support_capture_subprocess.c
blob: 5672fba0f7f4d94c2eebe05d659dc1f25b6b55c0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
/* Test capturing output from a subprocess.
   Copyright (C) 2017 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <support/capture_subprocess.h>
#include <support/check.h>
#include <support/support.h>
#include <sys/wait.h>
#include <unistd.h>

/* Write one byte at *P to FD and advance *P.  Do nothing if *P is
   '\0'.  */
static void
transfer (const unsigned char **p, int fd)
{
  if (**p != '\0')
    {
      TEST_VERIFY (write (fd, *p, 1) == 1);
      ++*p;
    }
}

/* Determine the order in which stdout and stderr are written.  */
enum write_mode { out_first, err_first, interleave,
                  write_mode_last =  interleave };

/* Describe what to write in the subprocess.  */
struct test
{
  char *out;
  char *err;
  enum write_mode write_mode;
  int signal;
  int status;
};

/* For use with support_capture_subprocess.  */
static void
callback (void *closure)
{
  const struct test *test = closure;
  bool mode_ok = false;
  switch (test->write_mode)
    {
    case out_first:
      TEST_VERIFY (fputs (test->out, stdout) >= 0);
      TEST_VERIFY (fflush (stdout) == 0);
      TEST_VERIFY (fputs (test->err, stderr) >= 0);
      TEST_VERIFY (fflush (stderr) == 0);
      mode_ok = true;
      break;
    case err_first:
      TEST_VERIFY (fputs (test->err, stderr) >= 0);
      TEST_VERIFY (fflush (stderr) == 0);
      TEST_VERIFY (fputs (test->out, stdout) >= 0);
      TEST_VERIFY (fflush (stdout) == 0);
      mode_ok = true;
      break;
    case interleave:
      {
        const unsigned char *pout = (const unsigned char *) test->out;
        const unsigned char *perr = (const unsigned char *) test->err;
        do
          {
            transfer (&pout, STDOUT_FILENO);
            transfer (&perr, STDERR_FILENO);
          }
        while (*pout != '\0' || *perr != '\0');
      }
      mode_ok = true;
      break;
    }
  TEST_VERIFY (mode_ok);

  if (test->signal != 0)
    raise (test->signal);
  exit (test->status);
}

/* Create a heap-allocated random string of letters.  */
static char *
random_string (size_t length)
{
  char *result = xmalloc (length + 1);
  for (size_t i = 0; i < length; ++i)
    result[i] = 'a' + (rand () % 26);
  result[length] = '\0';
  return result;
}

/* Check that the specific stream from the captured subprocess matches
   expectations.  */
static void
check_stream (const char *what, const struct xmemstream *stream,
              const char *expected)
{
  if (strcmp (stream->buffer, expected) != 0)
    {
      support_record_failure ();
      printf ("error: captured %s data incorrect\n"
              "  expected: %s\n"
              "  actual:   %s\n",
              what, expected, stream->buffer);
    }
  if (stream->length != strlen (expected))
    {
      support_record_failure ();
      printf ("error: captured %s data length incorrect\n"
              "  expected: %zu\n"
              "  actual:   %zu\n",
              what, strlen (expected), stream->length);
    }
}

static int
do_test (void)
{
  const int lengths[] = {0, 1, 17, 512, 20000, -1};

  /* Test multiple combinations of support_capture_subprocess.

     length_idx_stdout: Index into the lengths array above,
       controls how many bytes are written by the subprocess to
       standard output.
     length_idx_stderr: Same for standard error.
     write_mode: How standard output and standard error writes are
       ordered.
     signal: Exit with no signal if zero, with SIGTERM if one.
     status: Process exit status: 0 if zero, 3 if one.  */
  for (int length_idx_stdout = 0; lengths[length_idx_stdout] >= 0;
       ++length_idx_stdout)
    for (int length_idx_stderr = 0; lengths[length_idx_stderr] >= 0;
         ++length_idx_stderr)
      for (int write_mode = 0; write_mode < write_mode_last; ++write_mode)
        for (int signal = 0; signal < 2; ++signal)
          for (int status = 0; status < 2; ++status)
            {
              struct test test =
                {
                  .out = random_string (lengths[length_idx_stdout]),
                  .err = random_string (lengths[length_idx_stderr]),
                  .write_mode = write_mode,
                  .signal = signal * SIGTERM, /* 0 or SIGTERM.  */
                  .status = status * 3,       /* 0 or 3.  */
                };
              TEST_VERIFY (strlen (test.out) == lengths[length_idx_stdout]);
              TEST_VERIFY (strlen (test.err) == lengths[length_idx_stderr]);

              struct support_capture_subprocess result
                = support_capture_subprocess (callback, &test);
              check_stream ("stdout", &result.out, test.out);
              check_stream ("stderr", &result.err, test.err);
              if (test.signal != 0)
                {
                  TEST_VERIFY (WIFSIGNALED (result.status));
                  TEST_VERIFY (WTERMSIG (result.status) == test.signal);
                }
              else
                {
                  TEST_VERIFY (WIFEXITED (result.status));
                  TEST_VERIFY (WEXITSTATUS (result.status) == test.status);
                }
              support_capture_subprocess_free (&result);
              free (test.out);
              free (test.err);
            }
  return 0;
}

#include <support/test-driver.c>