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29
30// The Google C++ Testing and Mocking Framework (Google Test)
31//
32// This header file defines the public API for death tests. It is
33// #included by gtest.h so a user doesn't need to include this
34// directly.
35
36// IWYU pragma: private, include "gtest/gtest.h"
37// IWYU pragma: friend gtest/.*
38// IWYU pragma: friend gmock/.*
39
40#ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_DEATH_TEST_H_
41#define GOOGLETEST_INCLUDE_GTEST_GTEST_DEATH_TEST_H_
42
43#include "gtest/internal/gtest-death-test-internal.h"
44
45// This flag controls the style of death tests. Valid values are "threadsafe",
46// meaning that the death test child process will re-execute the test binary
47// from the start, running only a single death test, or "fast",
48// meaning that the child process will execute the test logic immediately
49// after forking.
50GTEST_DECLARE_string_(death_test_style);
51
52namespace testing {
53
54#if GTEST_HAS_DEATH_TEST
55
56namespace internal {
57
58// Returns a Boolean value indicating whether the caller is currently
59// executing in the context of the death test child process. Tools such as
60// Valgrind heap checkers may need this to modify their behavior in death
61// tests. IMPORTANT: This is an internal utility. Using it may break the
62// implementation of death tests. User code MUST NOT use it.
63GTEST_API_ bool InDeathTestChild();
64
65} // namespace internal
66
67// The following macros are useful for writing death tests.
68
69// Here's what happens when an ASSERT_DEATH* or EXPECT_DEATH* is
70// executed:
71//
72// 1. It generates a warning if there is more than one active
73// thread. This is because it's safe to fork() or clone() only
74// when there is a single thread.
75//
76// 2. The parent process clone()s a sub-process and runs the death
77// test in it; the sub-process exits with code 0 at the end of the
78// death test, if it hasn't exited already.
79//
80// 3. The parent process waits for the sub-process to terminate.
81//
82// 4. The parent process checks the exit code and error message of
83// the sub-process.
84//
85// Examples:
86//
87// ASSERT_DEATH(server.SendMessage(56, "Hello"), "Invalid port number");
88// for (int i = 0; i < 5; i++) {
89// EXPECT_DEATH(server.ProcessRequest(i),
90// "Invalid request .* in ProcessRequest()")
91// << "Failed to die on request " << i;
92// }
93//
94// ASSERT_EXIT(server.ExitNow(), ::testing::ExitedWithCode(0), "Exiting");
95//
96// bool KilledBySIGHUP(int exit_code) {
97// return WIFSIGNALED(exit_code) && WTERMSIG(exit_code) == SIGHUP;
98// }
99//
100// ASSERT_EXIT(client.HangUpServer(), KilledBySIGHUP, "Hanging up!");
101//
102// The final parameter to each of these macros is a matcher applied to any data
103// the sub-process wrote to stderr. For compatibility with existing tests, a
104// bare string is interpreted as a regular expression matcher.
105//
106// On the regular expressions used in death tests:
107//
108// On POSIX-compliant systems (*nix), we use the <regex.h> library,
109// which uses the POSIX extended regex syntax.
110//
111// On other platforms (e.g. Windows or Mac), we only support a simple regex
112// syntax implemented as part of Google Test. This limited
113// implementation should be enough most of the time when writing
114// death tests; though it lacks many features you can find in PCRE
115// or POSIX extended regex syntax. For example, we don't support
116// union ("x|y"), grouping ("(xy)"), brackets ("[xy]"), and
117// repetition count ("x{5,7}"), among others.
118//
119// Below is the syntax that we do support. We chose it to be a
120// subset of both PCRE and POSIX extended regex, so it's easy to
121// learn wherever you come from. In the following: 'A' denotes a
122// literal character, period (.), or a single \\ escape sequence;
123// 'x' and 'y' denote regular expressions; 'm' and 'n' are for
124// natural numbers.
125//
126// c matches any literal character c
127// \\d matches any decimal digit
128// \\D matches any character that's not a decimal digit
129// \\f matches \f
130// \\n matches \n
131// \\r matches \r
132// \\s matches any ASCII whitespace, including \n
133// \\S matches any character that's not a whitespace
134// \\t matches \t
135// \\v matches \v
136// \\w matches any letter, _, or decimal digit
137// \\W matches any character that \\w doesn't match
138// \\c matches any literal character c, which must be a punctuation
139// . matches any single character except \n
140// A? matches 0 or 1 occurrences of A
141// A* matches 0 or many occurrences of A
142// A+ matches 1 or many occurrences of A
143// ^ matches the beginning of a string (not that of each line)
144// $ matches the end of a string (not that of each line)
145// xy matches x followed by y
146//
147// If you accidentally use PCRE or POSIX extended regex features
148// not implemented by us, you will get a run-time failure. In that
149// case, please try to rewrite your regular expression within the
150// above syntax.
151//
152// This implementation is *not* meant to be as highly tuned or robust
153// as a compiled regex library, but should perform well enough for a
154// death test, which already incurs significant overhead by launching
155// a child process.
156//
157// Known caveats:
158//
159// A "threadsafe" style death test obtains the path to the test
160// program from argv[0] and re-executes it in the sub-process. For
161// simplicity, the current implementation doesn't search the PATH
162// when launching the sub-process. This means that the user must
163// invoke the test program via a path that contains at least one
164// path separator (e.g. path/to/foo_test and
165// /absolute/path/to/bar_test are fine, but foo_test is not). This
166// is rarely a problem as people usually don't put the test binary
167// directory in PATH.
168//
169
170// Asserts that a given `statement` causes the program to exit, with an
171// integer exit status that satisfies `predicate`, and emitting error output
172// that matches `matcher`.
173#define ASSERT_EXIT(statement, predicate, matcher) \
174 GTEST_DEATH_TEST_(statement, predicate, matcher, GTEST_FATAL_FAILURE_)
175
176// Like `ASSERT_EXIT`, but continues on to successive tests in the
177// test suite, if any:
178#define EXPECT_EXIT(statement, predicate, matcher) \
179 GTEST_DEATH_TEST_(statement, predicate, matcher, GTEST_NONFATAL_FAILURE_)
180
181// Asserts that a given `statement` causes the program to exit, either by
182// explicitly exiting with a nonzero exit code or being killed by a
183// signal, and emitting error output that matches `matcher`.
184#define ASSERT_DEATH(statement, matcher) \
185 ASSERT_EXIT(statement, ::testing::internal::ExitedUnsuccessfully, matcher)
186
187// Like `ASSERT_DEATH`, but continues on to successive tests in the
188// test suite, if any:
189#define EXPECT_DEATH(statement, matcher) \
190 EXPECT_EXIT(statement, ::testing::internal::ExitedUnsuccessfully, matcher)
191
192// Two predicate classes that can be used in {ASSERT,EXPECT}_EXIT*:
193
194// Tests that an exit code describes a normal exit with a given exit code.
195class GTEST_API_ ExitedWithCode {
196 public:
197 explicit ExitedWithCode(int exit_code);
198 ExitedWithCode(const ExitedWithCode&) = default;
199 void operator=(const ExitedWithCode& other) = delete;
200 bool operator()(int exit_status) const;
201
202 private:
203 const int exit_code_;
204};
205
206#if !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
207// Tests that an exit code describes an exit due to termination by a
208// given signal.
209class GTEST_API_ KilledBySignal {
210 public:
211 explicit KilledBySignal(int signum);
212 bool operator()(int exit_status) const;
213
214 private:
215 const int signum_;
216};
217#endif // !GTEST_OS_WINDOWS
218
219// EXPECT_DEBUG_DEATH asserts that the given statements die in debug mode.
220// The death testing framework causes this to have interesting semantics,
221// since the sideeffects of the call are only visible in opt mode, and not
222// in debug mode.
223//
224// In practice, this can be used to test functions that utilize the
225// LOG(DFATAL) macro using the following style:
226//
227// int DieInDebugOr12(int* sideeffect) {
228// if (sideeffect) {
229// *sideeffect = 12;
230// }
231// LOG(DFATAL) << "death";
232// return 12;
233// }
234//
235// TEST(TestSuite, TestDieOr12WorksInDgbAndOpt) {
236// int sideeffect = 0;
237// // Only asserts in dbg.
238// EXPECT_DEBUG_DEATH(DieInDebugOr12(&sideeffect), "death");
239//
240// #ifdef NDEBUG
241// // opt-mode has sideeffect visible.
242// EXPECT_EQ(12, sideeffect);
243// #else
244// // dbg-mode no visible sideeffect.
245// EXPECT_EQ(0, sideeffect);
246// #endif
247// }
248//
249// This will assert that DieInDebugReturn12InOpt() crashes in debug
250// mode, usually due to a DCHECK or LOG(DFATAL), but returns the
251// appropriate fallback value (12 in this case) in opt mode. If you
252// need to test that a function has appropriate side-effects in opt
253// mode, include assertions against the side-effects. A general
254// pattern for this is:
255//
256// EXPECT_DEBUG_DEATH({
257// // Side-effects here will have an effect after this statement in
258// // opt mode, but none in debug mode.
259// EXPECT_EQ(12, DieInDebugOr12(&sideeffect));
260// }, "death");
261//
262#ifdef NDEBUG
263
264#define EXPECT_DEBUG_DEATH(statement, regex) \
265 GTEST_EXECUTE_STATEMENT_(statement, regex)
266
267#define ASSERT_DEBUG_DEATH(statement, regex) \
268 GTEST_EXECUTE_STATEMENT_(statement, regex)
269
270#else
271
272#define EXPECT_DEBUG_DEATH(statement, regex) EXPECT_DEATH(statement, regex)
273
274#define ASSERT_DEBUG_DEATH(statement, regex) ASSERT_DEATH(statement, regex)
275
276#endif // NDEBUG for EXPECT_DEBUG_DEATH
277#endif // GTEST_HAS_DEATH_TEST
278
279// This macro is used for implementing macros such as
280// EXPECT_DEATH_IF_SUPPORTED and ASSERT_DEATH_IF_SUPPORTED on systems where
281// death tests are not supported. Those macros must compile on such systems
282// if and only if EXPECT_DEATH and ASSERT_DEATH compile with the same parameters
283// on systems that support death tests. This allows one to write such a macro on
284// a system that does not support death tests and be sure that it will compile
285// on a death-test supporting system. It is exposed publicly so that systems
286// that have death-tests with stricter requirements than GTEST_HAS_DEATH_TEST
287// can write their own equivalent of EXPECT_DEATH_IF_SUPPORTED and
288// ASSERT_DEATH_IF_SUPPORTED.
289//
290// Parameters:
291// statement - A statement that a macro such as EXPECT_DEATH would test
292// for program termination. This macro has to make sure this
293// statement is compiled but not executed, to ensure that
294// EXPECT_DEATH_IF_SUPPORTED compiles with a certain
295// parameter if and only if EXPECT_DEATH compiles with it.
296// regex - A regex that a macro such as EXPECT_DEATH would use to test
297// the output of statement. This parameter has to be
298// compiled but not evaluated by this macro, to ensure that
299// this macro only accepts expressions that a macro such as
300// EXPECT_DEATH would accept.
301// terminator - Must be an empty statement for EXPECT_DEATH_IF_SUPPORTED
302// and a return statement for ASSERT_DEATH_IF_SUPPORTED.
303// This ensures that ASSERT_DEATH_IF_SUPPORTED will not
304// compile inside functions where ASSERT_DEATH doesn't
305// compile.
306//
307// The branch that has an always false condition is used to ensure that
308// statement and regex are compiled (and thus syntactically correct) but
309// never executed. The unreachable code macro protects the terminator
310// statement from generating an 'unreachable code' warning in case
311// statement unconditionally returns or throws. The Message constructor at
312// the end allows the syntax of streaming additional messages into the
313// macro, for compilational compatibility with EXPECT_DEATH/ASSERT_DEATH.
314#define GTEST_UNSUPPORTED_DEATH_TEST(statement, regex, terminator) \
315 GTEST_AMBIGUOUS_ELSE_BLOCKER_ \
316 if (::testing::internal::AlwaysTrue()) { \
317 GTEST_LOG_(WARNING) << "Death tests are not supported on this platform.\n" \
318 << "Statement '" #statement "' cannot be verified."; \
319 } else if (::testing::internal::AlwaysFalse()) { \
320 ::testing::internal::RE::PartialMatch(".*", (regex)); \
321 GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement); \
322 terminator; \
323 } else \
324 ::testing::Message()
325
326// EXPECT_DEATH_IF_SUPPORTED(statement, regex) and
327// ASSERT_DEATH_IF_SUPPORTED(statement, regex) expand to real death tests if
328// death tests are supported; otherwise they just issue a warning. This is
329// useful when you are combining death test assertions with normal test
330// assertions in one test.
331#if GTEST_HAS_DEATH_TEST
332#define EXPECT_DEATH_IF_SUPPORTED(statement, regex) \
333 EXPECT_DEATH(statement, regex)
334#define ASSERT_DEATH_IF_SUPPORTED(statement, regex) \
335 ASSERT_DEATH(statement, regex)
336#else
337#define EXPECT_DEATH_IF_SUPPORTED(statement, regex) \
338 GTEST_UNSUPPORTED_DEATH_TEST(statement, regex, )
339#define ASSERT_DEATH_IF_SUPPORTED(statement, regex) \
340 GTEST_UNSUPPORTED_DEATH_TEST(statement, regex, return)
341#endif
342
343} // namespace testing
344
345#endif // GOOGLETEST_INCLUDE_GTEST_GTEST_DEATH_TEST_H_
346