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b866c52d SS |
1 | This is a collection of tests for GDB. |
2 | ||
3 | The file gdb/README contains basic instructions on how to run the | |
4 | testsuite, while this file documents additional options and controls | |
5 | that are available. The GDB wiki may also have some pages with ideas | |
6 | and suggestions. | |
7 | ||
8 | ||
9 | Running the Testsuite | |
10 | ********************* | |
11 | ||
12 | There are two ways to run the testsuite and pass additional parameters | |
13 | to DejaGnu. The first is to do `make check' in the main build | |
14 | directory and specifying the makefile variable `RUNTESTFLAGS': | |
15 | ||
16 | make check RUNTESTFLAGS='TRANSCRIPT=y gdb.base/a2-run.exp' | |
17 | ||
18 | The second is to cd to the testsuite directory and invoke the DejaGnu | |
19 | `runtest' command directly. | |
20 | ||
21 | cd testsuite | |
22 | make site.exp | |
23 | runtest TRANSCRIPT=y | |
24 | ||
25 | (The `site.exp' file contains a handful of useful variables like host | |
26 | and target triplets, and pathnames.) | |
27 | ||
e352bf0a PA |
28 | Parallel testing |
29 | **************** | |
30 | ||
31 | If not testing with a remote host (in DejaGnu's sense), you can run | |
32 | the GDB test suite in a fully parallel mode. In this mode, each .exp | |
33 | file runs separately and maybe simultaneously. The test suite ensures | |
34 | that all the temporary files created by the test suite do not clash, | |
35 | by putting them into separate directories. This mode is primarily | |
36 | intended for use by the Makefile. | |
37 | ||
38 | For GNU make, the Makefile tries to run the tests in parallel mode if | |
39 | any -j option is given. For a non-GNU make, tests are not | |
40 | parallelized. | |
41 | ||
42 | If RUNTESTFLAGS is not empty, then by default the tests are | |
43 | serialized. This can be overridden by either using the | |
44 | `check-parallel' target in the Makefile, or by setting FORCE_PARALLEL | |
45 | to any non-empty value: | |
46 | ||
acc23c11 PA |
47 | make check-parallel RUNTESTFLAGS="--target_board=native-gdbserver" |
48 | make check RUNTESTFLAGS="--target_board=native-gdbserver" FORCE_PARALLEL=1 | |
e352bf0a PA |
49 | |
50 | If you want to use runtest directly instead of using the Makefile, see | |
51 | the description of GDB_PARALLEL below. | |
52 | ||
fb6a751f SDJ |
53 | Racy testcases |
54 | ************** | |
55 | ||
56 | Sometimes, new testcases are added to the testsuite that are not | |
57 | entirely deterministic, and can randomly pass or fail. We call them | |
58 | "racy testcases", and they can be bothersome when one is comparing | |
59 | different testsuite runs. In order to help identifying them, it is | |
60 | possible to run the tests several times in a row and ask the testsuite | |
61 | machinery to analyze the results. To do that, you need to specify the | |
62 | RACY_ITER environment variable to make: | |
63 | ||
64 | make check RACY_ITER=5 -j4 | |
65 | ||
66 | The value assigned to RACY_ITER represents the number of times you | |
67 | wish to run the tests in sequence (in the example above, the entire | |
68 | testsuite will be executed 5 times in a row, in parallel). It is also | |
69 | possible to check just a specific test: | |
70 | ||
71 | make check TESTS='gdb.base/default.exp' RACY_ITER=3 | |
72 | ||
73 | One can also decide to call the Makefile rules by hand inside the | |
74 | gdb/testsuite directory, e.g.: | |
75 | ||
76 | make check-paralell-racy -j4 | |
77 | ||
78 | In which case the value of the DEFAULT_RACY_ITER variable (inside | |
79 | gdb/testsuite/Makefile.in) will be used to determine how many | |
80 | iterations will be run. | |
81 | ||
82 | After running the tests, you shall see a file name 'racy.sum' in the | |
83 | gdb/testsuite directory. You can also inspect the generated *.log and | |
84 | *.sum files by looking into the gdb/testsuite/racy_ouputs directory. | |
85 | ||
86 | If you already have *.sum files generated from previous testsuite runs | |
87 | and you would like to analyze them without having to run the testsuite | |
88 | again, you can also use the 'analyze-racy-logs.py' script directly. | |
89 | It is located in the gdb/testsuite/ directory, and it expects a list | |
90 | of two or more *.sum files to be provided as its argument. For | |
91 | example: | |
92 | ||
93 | ./gdb/testsuite/analyze-racy-logs.py testsuite-01/gdb.sum \ | |
94 | testsuite-02/gdb.sum testsuite-03/gdb.sum | |
95 | ||
96 | The script will output its analysis report to the standard output. | |
97 | ||
71c0c615 YQ |
98 | Running the Performance Tests |
99 | ***************************** | |
100 | ||
101 | GDB Testsuite includes performance test cases, which are not run together | |
102 | with other test cases, because performance test cases are slow and need | |
103 | a quiet system. There are two ways to run the performance test cases. | |
104 | The first is to do `make check-perf' in the main build directory: | |
105 | ||
106 | make check-perf RUNTESTFLAGS="solib.exp SOLIB_COUNT=8" | |
107 | ||
108 | The second is to cd to the testsuite directory and invoke the DejaGnu | |
109 | `runtest' command directly. | |
110 | ||
111 | cd testsuite | |
112 | make site.exp | |
113 | runtest GDB_PERFTEST_MODE=both GDB_PERFTEST_TIMEOUT=4000 --directory=gdb.perf solib.exp SOLIB_COUNT=8 | |
114 | ||
115 | Only "compile", "run" and "both" are valid to GDB_PERFTEST_MODE. They | |
116 | stand for "compile tests only", "run tests only", and "compile and run | |
117 | tests" respectively. "both" is the default. GDB_PERFTEST_TIMEOUT | |
118 | specify the timeout, which is 3000 in default. The result of | |
119 | performance test is appended in `testsuite/perftest.log'. | |
120 | ||
b866c52d SS |
121 | Testsuite Parameters |
122 | ******************** | |
123 | ||
124 | The following parameters are DejaGNU variables that you can set to | |
125 | affect the testsuite run globally. | |
126 | ||
127 | TRANSCRIPT | |
128 | ||
129 | You may find it useful to have a transcript of the commands that the | |
130 | testsuite sends to GDB, for instance if GDB crashes during the run, | |
131 | and you want to reconstruct the sequence of commands. | |
132 | ||
133 | If the DejaGNU variable TRANSCRIPT is set (to any value), each | |
134 | invocation of GDB during the test run will get a transcript file | |
135 | written into the DejaGNU output directory. The file will have the | |
136 | name transcript.<n>, where <n> is an integer. The first line of the | |
137 | file shows the invocation command with all the options passed to it, | |
138 | while subsequent lines are the GDB commands. A `make check' might | |
139 | look like this: | |
140 | ||
141 | make check RUNTESTFLAGS=TRANSCRIPT=y | |
142 | ||
143 | The transcript may not be complete, as for instance tests of command | |
144 | completion may show only partial command lines. | |
145 | ||
146 | GDB | |
147 | ||
148 | By default, the testsuite exercises the GDB in the build directory, | |
149 | but you can set GDB to be a pathname to a different version. For | |
150 | instance, | |
151 | ||
152 | make check RUNTESTFLAGS=GDB=/usr/bin/gdb | |
153 | ||
154 | runs the testsuite on the GDB in /usr/bin. | |
155 | ||
156 | GDBSERVER | |
157 | ||
158 | You can set GDBSERVER to be a particular GDBserver of interest, so for | |
159 | instance | |
160 | ||
161 | make check RUNTESTFLAGS="GDB=/usr/bin/gdb GDBSERVER=/usr/bin/gdbserver" | |
162 | ||
163 | checks both the installed GDB and GDBserver. | |
164 | ||
165 | INTERNAL_GDBFLAGS | |
166 | ||
167 | Command line options passed to all GDB invocations. | |
168 | ||
169 | The default is "-nw -nx". | |
170 | ||
171 | `-nw' disables any of the windowed interfaces. | |
172 | `-nx' disables ~/.gdbinit, so that it doesn't interfere with | |
173 | the tests. | |
174 | ||
175 | This is actually considered an internal variable, and you | |
176 | won't normally want to change it. However, in some situations, | |
177 | this may be tweaked as a last resort if the testsuite doesn't | |
178 | have direct support for the specifics of your environment. | |
179 | The testsuite does not override a value provided by the user. | |
180 | ||
181 | As an example, when testing an installed GDB that has been | |
182 | configured with `--with-system-gdbinit', like by default, | |
183 | you do not want ~/.gdbinit to interfere with tests, but, you | |
184 | may want the system .gdbinit file loaded. As there's no way to | |
185 | ask the testsuite, or GDB, to load the system gdbinit but | |
186 | not ~/.gdbinit, a workaround is then to remove `-nx' from | |
187 | INTERNAL_GDBFLAGS, and point $HOME at a directory without | |
188 | a .gdbinit. For example: | |
189 | ||
190 | cd testsuite | |
191 | HOME=`pwd` runtest \ | |
192 | GDB=/usr/bin/gdb \ | |
193 | GDBSERVER=/usr/bin/gdbserver \ | |
194 | INTERNAL_GDBFLAGS=-nw | |
195 | ||
196 | GDB_PARALLEL | |
197 | ||
e352bf0a PA |
198 | To use parallel testing mode without using the the Makefile, set |
199 | GDB_PARALLEL on the runtest command line to "yes". Before starting | |
200 | the tests, you must ensure that the directories cache, outputs, and | |
201 | temp in the test suite build directory are either empty or have been | |
202 | deleted. cache in particular is used to share data across invocations | |
203 | of runtest, and files there may affect the test results. The Makefile | |
204 | automatically does these deletions. | |
205 | ||
206 | FORCE_PARALLEL | |
207 | ||
208 | Setting FORCE_PARALLEL to any non-empty value forces parallel testing | |
209 | mode even if RUNTESTFLAGS is not empty. | |
b866c52d | 210 | |
51f77c37 PA |
211 | FORCE_SEPARATE_MI_TTY |
212 | ||
213 | Setting FORCE_MI_SEPARATE_UI to 1 forces all MI testing to start GDB | |
214 | in console mode, with MI running on a separate TTY, on a secondary UI | |
215 | started with "new-ui". | |
216 | ||
b866c52d SS |
217 | GDB_INOTIFY |
218 | ||
219 | For debugging parallel mode, it is handy to be able to see when a test | |
220 | case writes to a file outside of its designated output directory. | |
221 | ||
222 | If you have the inotify-tools package installed, you can set the | |
223 | GDB_INOTIFY variable on the runtest command line. This will cause the | |
224 | test suite to watch for parallel-unsafe file creations and report | |
225 | them, both to stdout and in the test suite log file. | |
226 | ||
227 | This setting is only meaningful in conjunction with GDB_PARALLEL. | |
228 | ||
c17ef0d5 DE |
229 | TESTS |
230 | ||
231 | This variable is used to specify which set of tests to run. | |
232 | It is passed to make (not runtest) and its contents are a space separated | |
233 | list of tests to run. | |
234 | ||
235 | If using GNU make then the contents are wildcard-expanded using | |
236 | GNU make's $(wildcard) function. Test paths must be fully specified, | |
237 | relative to the "testsuite" subdirectory. This allows one to run all | |
4992aa20 JM |
238 | tests in a subdirectory by passing "gdb.subdir/*.exp", or more simply |
239 | by using the check-gdb.subdir target in the Makefile. | |
240 | ||
c17ef0d5 DE |
241 | If for some strange reason one wanted to run all tests that begin with |
242 | the letter "d" that is also possible: TESTS="*/d*.exp". | |
243 | ||
244 | Do not write */*.exp to specify all tests (assuming all tests are only | |
245 | nested one level deep, which is not necessarily true). This will pick up | |
246 | .exp files in ancillary directories like "lib" and "config". | |
247 | Instead write gdb.*/*.exp. | |
248 | ||
249 | Example: | |
250 | ||
251 | make -j10 check TESTS="gdb.server/[s-w]*.exp */x*.exp" | |
252 | ||
253 | If not using GNU make then the value is passed directly to runtest. | |
254 | If not specified, all tests are run. | |
b866c52d | 255 | |
2a31c623 PA |
256 | READ1 |
257 | ||
258 | This make (not runtest) variable is used to specify whether the | |
259 | testsuite preloads the read1.so library into expect. Any non-empty | |
260 | value means true. See "Race detection" below. | |
261 | ||
c7ab0aef SDJ |
262 | GDB_TEST_SOCKETHOST |
263 | ||
264 | This variable can provide the hostname/address that should be used | |
265 | when performing GDBserver-related tests. This is useful in some | |
266 | situations, e.g., when you want to test the IPv6 connectivity of GDB | |
267 | and GDBserver, or when using a different hostname/address is needed. | |
268 | For example, to make GDB and GDBserver use IPv6-only connections, you | |
269 | can do: | |
270 | ||
271 | make check TESTS="gdb.server/*.exp" RUNTESTFLAGS='GDB_TEST_SOCKETHOST=tcp6:[::1]' | |
272 | ||
273 | Note that only a hostname/address can be provided, without a port | |
274 | number. | |
275 | ||
f63c03b4 SDJ |
276 | TS |
277 | ||
278 | This variable turns on the timestamp printing for each line of "make | |
279 | check". Note that the timestamp will be printed on stdout output | |
280 | only. In other words, there will be no timestamp output on either | |
281 | gdb.sum and gdb.log files. If you would like to enable timestamp | |
282 | printing, you can do: | |
283 | ||
284 | make check TS=1 | |
285 | ||
286 | TS_FORMAT | |
287 | ||
288 | You can provide a custom format for timestamp printing with this | |
289 | variable. The format must be a string compatible with "strftime". | |
290 | This variable is only useful when the TS variable is also provided. | |
291 | If you would like to change the output format of the timestamp, you | |
292 | can do: | |
293 | ||
294 | make check TS=1 TS_FORMAT='[%b %H:%S]' | |
295 | ||
dd06d4d6 AH |
296 | GDBSERVER_DEBUG |
297 | ||
298 | When set gdbserver debug is sent to the file gdbserver.debug in the test | |
299 | output directory. Valid values are: | |
300 | debug - turn on gdbserver debug. | |
301 | remote - turn on gdbserver remote debug. | |
302 | all - turn on all the above debug options. | |
303 | For example, to turn on all gdbserver debugging, you can do: | |
304 | ||
305 | make check GDBSERVER_DEBUG=all | |
306 | ||
2a31c623 PA |
307 | Race detection |
308 | ************** | |
309 | ||
310 | The testsuite includes a mechanism that helps detect test races. | |
311 | ||
312 | For example, say the program running under expect outputs "abcd", and | |
313 | a test does something like this: | |
314 | ||
315 | expect { | |
316 | "a.*c" { | |
317 | } | |
318 | "b" { | |
319 | } | |
320 | "a" { | |
321 | } | |
322 | } | |
323 | ||
324 | Which case happens to match depends on what expect manages to read | |
325 | into its internal buffer in one go. If it manages to read three bytes | |
326 | or more, then the first case matches. If it manages to read two | |
327 | bytes, then the second case matches. If it manages to read only one | |
328 | byte, then the third case matches. | |
329 | ||
330 | To help detect these cases, the race detection mechanism preloads a | |
331 | library into expect that forces the `read' system call to always | |
332 | return at most 1 byte. | |
333 | ||
334 | To enable this, either pass a non-empty value in the READ1 make | |
335 | variable, or use the check-read1 make target instead of check. | |
336 | ||
337 | Examples: | |
338 | ||
339 | make -j10 check-read1 TESTS="*/paginate-*.exp" | |
340 | make -j10 check READ1="1" | |
341 | ||
b866c52d SS |
342 | Testsuite Configuration |
343 | *********************** | |
344 | ||
345 | It is possible to adjust the behavior of the testsuite by defining | |
346 | the global variables listed below, either in a `site.exp' file, | |
347 | or in a board file. | |
348 | ||
349 | gdb_test_timeout | |
350 | ||
351 | Defining this variable changes the default timeout duration used | |
352 | during communication with GDB. More specifically, the global variable | |
353 | used during testing is `timeout', but this variable gets reset to | |
354 | `gdb_test_timeout' at the beginning of each testcase, which ensures | |
355 | that any local change to `timeout' in a testcase does not affect | |
356 | subsequent testcases. | |
357 | ||
358 | This global variable comes in handy when the debugger is slower than | |
359 | normal due to the testing environment, triggering unexpected `TIMEOUT' | |
360 | test failures. Examples include when testing on a remote machine, or | |
361 | against a system where communications are slow. | |
362 | ||
363 | If not specifically defined, this variable gets automatically defined | |
364 | to the same value as `timeout' during the testsuite initialization. | |
365 | The default value of the timeout is defined in the file | |
366 | `testsuite/config/unix.exp' (at least for Unix hosts; board files may | |
367 | have their own values). | |
368 | ||
8b696e31 YQ |
369 | gdb_reverse_timeout |
370 | ||
371 | Defining this variable changes the default timeout duration when tests | |
372 | under gdb.reverse directory are running. Process record and reverse | |
373 | debugging is so slow that its tests have unexpected `TIMEOUT' test | |
374 | failures. This global variable is useful to bump up the value of | |
375 | `timeout' for gdb.reverse tests and doesn't cause any delay where | |
376 | actual failures happen in the rest of the testsuite. | |
377 | ||
b866c52d SS |
378 | |
379 | Board Settings | |
380 | ************** | |
381 | ||
382 | DejaGNU includes the concept of a "board file", which specifies | |
383 | testing details for a particular target (which are often bare circuit | |
384 | boards, thus the name). | |
385 | ||
386 | In the GDB testsuite specifically, the board file may include a | |
387 | number of "board settings" that test cases may check before deciding | |
388 | whether to exercise a particular feature. For instance, a board | |
389 | lacking any I/O devices, or perhaps simply having its I/O devices | |
390 | not wired up, should set `noinferiorio'. | |
391 | ||
392 | Here are the supported board settings: | |
393 | ||
394 | gdb,cannot_call_functions | |
395 | ||
396 | The board does not support inferior call, that is, invoking inferior | |
397 | functions in GDB. | |
398 | ||
399 | gdb,can_reverse | |
400 | ||
401 | The board supports reverse execution. | |
402 | ||
403 | gdb,no_hardware_watchpoints | |
404 | ||
405 | The board does not support hardware watchpoints. | |
406 | ||
407 | gdb,nofileio | |
408 | ||
409 | GDB is unable to intercept target file operations in remote and | |
410 | perform them on the host. | |
411 | ||
412 | gdb,noinferiorio | |
413 | ||
414 | The board is unable to provide I/O capability to the inferior. | |
415 | ||
416 | gdb,noresults | |
417 | ||
418 | A program will not return an exit code or result code (or the value | |
419 | of the result is undefined, and should not be looked at). | |
420 | ||
421 | gdb,nosignals | |
422 | ||
423 | The board does not support signals. | |
424 | ||
425 | gdb,skip_huge_test | |
426 | ||
427 | Skip time-consuming tests on the board with slow connection. | |
428 | ||
429 | gdb,skip_float_tests | |
430 | ||
431 | Skip tests related to floating point. | |
432 | ||
433 | gdb,use_precord | |
434 | ||
435 | The board supports process record. | |
436 | ||
a25eb028 MR |
437 | gdb_init_command |
438 | gdb_init_commands | |
439 | ||
440 | Commands to send to GDB every time a program is about to be run. The | |
441 | first of these settings defines a single command as a string. The | |
442 | second defines a TCL list of commands being a string each. The commands | |
443 | are sent one by one in a sequence, first from `gdb_init_command', if any, | |
444 | followed by individual commands from `gdb_init_command', if any, in this | |
445 | list's order. | |
446 | ||
b866c52d SS |
447 | gdb_server_prog |
448 | ||
449 | The location of GDBserver. If GDBserver somewhere other than its | |
450 | default location is used in test, specify the location of GDBserver in | |
451 | this variable. The location is a file name for GDBserver, and may be | |
452 | either absolute or relative to the testsuite subdirectory of the build | |
453 | directory. | |
454 | ||
455 | in_proc_agent | |
456 | ||
457 | The location of the in-process agent (used for fast tracepoints and | |
458 | other special tests). If the in-process agent of interest is anywhere | |
459 | other than its default location, set this variable. The location is a | |
460 | filename, and may be either absolute or relative to the testsuite | |
461 | subdirectory of the build directory. | |
462 | ||
463 | noargs | |
464 | ||
465 | GDB does not support argument passing for inferior. | |
466 | ||
467 | no_long_long | |
468 | ||
469 | The board does not support type long long. | |
470 | ||
471 | use_cygmon | |
472 | ||
473 | The board is running the monitor Cygmon. | |
474 | ||
475 | use_gdb_stub | |
476 | ||
477 | The tests are running with a GDB stub. | |
478 | ||
b477a5e6 PA |
479 | exit_is_reliable |
480 | ||
481 | Set to true if GDB can assume that letting the program run to end | |
482 | reliably results in program exits being reported as such, as opposed | |
483 | to, e.g., the program ending in an infinite loop or the board | |
484 | crashing/resetting. If not set, this defaults to $use_gdb_stub. In | |
485 | other words, native targets are assumed reliable by default, and | |
486 | remote stubs assumed unreliable. | |
487 | ||
b866c52d SS |
488 | gdb,predefined_tsv |
489 | ||
490 | The predefined trace state variables the board has. | |
491 | ||
f6512a69 SM |
492 | gdb,no_thread_names |
493 | ||
494 | The target doesn't support thread names. | |
b866c52d | 495 | |
968aa7ae AH |
496 | gdb,pie_flag |
497 | ||
498 | The flag required to force the compiler to produce position-independent | |
499 | executables. | |
500 | ||
501 | gdb,pie_ldflag | |
502 | ||
503 | The flag required to force the linker to produce position-independent | |
504 | executables. | |
505 | ||
6e8b1ab2 JV |
506 | gdb,nopie_flag |
507 | ||
508 | The flag required to force the compiler to produce non-position-independent | |
509 | executables. | |
510 | ||
dd06d4d6 AH |
511 | gdbserver,debug |
512 | ||
513 | When set gdbserver debug is sent to the file gdbserver.debug in the test | |
514 | output directory. Valid values are: | |
515 | "debug" - turn on gdbserver debug. | |
516 | "remote" - turn on gdbserver remote debug. | |
517 | "all" - turn on all the above debug options. | |
518 | ||
b866c52d SS |
519 | Testsuite Organization |
520 | ********************** | |
521 | ||
522 | The testsuite is entirely contained in `gdb/testsuite'. The main | |
523 | directory of the testsuite includes some makefiles and configury, but | |
524 | these are minimal, and used for little besides cleaning up, since the | |
525 | tests themselves handle the compilation of the programs that GDB will | |
526 | run. | |
527 | ||
528 | The file `testsuite/lib/gdb.exp' contains common utility procs useful | |
529 | for all GDB tests, while the directory testsuite/config contains | |
530 | configuration-specific files, typically used for special-purpose | |
531 | definitions of procs like `gdb_load' and `gdb_start'. | |
532 | ||
533 | The tests themselves are to be found in directories named | |
534 | 'testsuite/gdb.* and subdirectories of those. The names of the test | |
535 | files must always end with ".exp". DejaGNU collects the test files by | |
536 | wildcarding in the test directories, so both subdirectories and | |
537 | individual files typically get chosen and run in alphabetical order. | |
538 | ||
539 | The following lists some notable types of subdirectories and what they | |
540 | are for. Since DejaGNU finds test files no matter where they are | |
541 | located, and since each test file sets up its own compilation and | |
542 | execution environment, this organization is simply for convenience and | |
543 | intelligibility. | |
544 | ||
545 | gdb.base | |
546 | ||
547 | This is the base testsuite. The tests in it should apply to all | |
548 | configurations of GDB (but generic native-only tests may live here). | |
549 | The test programs should be in the subset of C that is both valid | |
550 | ANSI/ISO C, and C++. | |
551 | ||
552 | gdb.<lang> | |
553 | ||
554 | Language-specific tests for any language besides C. Examples are | |
9c37b5ae | 555 | gdb.cp for C++ and gdb.rust for Rust. |
b866c52d SS |
556 | |
557 | gdb.<platform> | |
558 | ||
559 | Non-portable tests. The tests are specific to a specific | |
bc23328c | 560 | configuration (host or target), such as eCos. |
b866c52d SS |
561 | |
562 | gdb.arch | |
563 | ||
564 | Architecture-specific tests that are (usually) cross-platform. | |
565 | ||
566 | gdb.<subsystem> | |
567 | ||
568 | Tests that exercise a specific GDB subsystem in more depth. For | |
569 | instance, gdb.disasm exercises various disassemblers, while | |
570 | gdb.stabs tests pathways through the stabs symbol reader. | |
571 | ||
71c0c615 YQ |
572 | gdb.perf |
573 | ||
574 | GDB performance tests. | |
575 | ||
b866c52d SS |
576 | Writing Tests |
577 | ************* | |
578 | ||
579 | In many areas, the GDB tests are already quite comprehensive; you | |
580 | should be able to copy existing tests to handle new cases. Be aware | |
581 | that older tests may use obsolete practices but have not yet been | |
582 | updated. | |
583 | ||
584 | You should try to use `gdb_test' whenever possible, since it includes | |
585 | cases to handle all the unexpected errors that might happen. However, | |
586 | it doesn't cost anything to add new test procedures; for instance, | |
587 | gdb.base/exprs.exp defines a `test_expr' that calls `gdb_test' | |
588 | multiple times. | |
589 | ||
590 | Only use `send_gdb' and `gdb_expect' when absolutely necessary. Even | |
591 | if GDB has several valid responses to a command, you can use | |
592 | `gdb_test_multiple'. Like `gdb_test', `gdb_test_multiple' recognizes | |
593 | internal errors and unexpected prompts. | |
594 | ||
595 | Do not write tests which expect a literal tab character from GDB. On | |
596 | some operating systems (e.g. OpenBSD) the TTY layer expands tabs to | |
597 | spaces, so by the time GDB's output reaches `expect' the tab is gone. | |
598 | ||
599 | The source language programs do *not* need to be in a consistent | |
600 | style. Since GDB is used to debug programs written in many different | |
601 | styles, it's worth having a mix of styles in the testsuite; for | |
602 | instance, some GDB bugs involving the display of source lines might | |
603 | never manifest themselves if the test programs used GNU coding style | |
604 | uniformly. | |
605 | ||
606 | Some testcase results need more detailed explanation: | |
607 | ||
608 | KFAIL | |
609 | ||
610 | Use KFAIL for known problem of GDB itself. You must specify the GDB | |
611 | bug report number, as in these sample tests: | |
612 | ||
613 | kfail "gdb/13392" "continue to marker 2" | |
614 | ||
615 | or | |
616 | ||
617 | setup_kfail gdb/13392 "*-*-*" | |
618 | kfail "continue to marker 2" | |
619 | ||
620 | ||
621 | XFAIL | |
622 | ||
623 | Short for "expected failure", this indicates a known problem with the | |
624 | environment. This could include limitations of the operating system, | |
625 | compiler version, and other components. | |
626 | ||
627 | This example from gdb.base/attach-pie-misread.exp is a sanity check | |
628 | for the target environment: | |
629 | ||
630 | # On x86_64 it is commonly about 4MB. | |
631 | if {$stub_size > 25000000} { | |
632 | xfail "stub size $stub_size is too large" | |
633 | return | |
634 | } | |
635 | ||
636 | You should provide bug report number for the failing component of the | |
637 | environment, if such bug report is available, as with this example | |
638 | referring to a GCC problem: | |
639 | ||
640 | if {[test_compiler_info {gcc-[0-3]-*}] | |
641 | || [test_compiler_info {gcc-4-[0-5]-*}]} { | |
642 | setup_xfail "gcc/46955" *-*-* | |
643 | } | |
644 | gdb_test "python print ttype.template_argument(2)" "&C::c" | |
645 | ||
646 | Note that it is also acceptable, and often preferable, to avoid | |
647 | running the test at all. This is the better option if the limitation | |
648 | is intrinsic to the environment, rather than a bug expected to be | |
649 | fixed in the near future. | |
739b3f1d PA |
650 | |
651 | Local vs Remote vs Native | |
652 | ************************* | |
653 | ||
654 | It's unfortunately easy to get confused in the testsuite about what's | |
655 | native and what's not, what's remote and what's not. The confusion is | |
656 | caused by the overlap in vocabulary between DejaGnu and GDB. | |
657 | ||
658 | From a DejaGnu point of view: | |
659 | ||
660 | - native: the host or target board is considered native if the its | |
661 | triplet is the same as the build system's triplet, | |
662 | ||
663 | - remote: the host or target board is considered remote if it's | |
664 | running on a different machine, and thus require ssh, for example, | |
665 | to run commands, versus simply running commands directly. | |
666 | ||
667 | Note that they are not mutually exclusive, as you can have a remote | |
668 | machine that has the same triplet as the build machine. | |
669 | ||
670 | From a GDB point of view: | |
671 | ||
672 | - native: when GDB uses system calls such as ptrace to interact | |
673 | directly with processes on the same system its running on, | |
674 | ||
675 | - remote: when GDB speaks the RSP (Remote Serial Protocol) with | |
676 | another program doing the ptrace stuff. | |
677 | ||
678 | Note that they are mutually exclusive. An inferior can only be either | |
679 | debugged with the native target, or with the remote target a specific | |
680 | time. | |
681 | ||
682 | That means that there are cases where the target is not remote for | |
683 | DejaGnu, but is remote for GDB (e.g. running GDBserver on the same | |
684 | machine). | |
685 | ||
686 | You can also have a remote target for DejaGnu, but native for GDB | |
687 | (e.g. building on x86 a GDB that runs on ARM and running the | |
688 | testsuite with a remote host). | |
689 | ||
690 | Therefore, care must be taken to check for the right kind of remote. | |
691 | Use [is_remote target] to check whether the DejaGnu target board is | |
692 | remote. When what you really want to know is whether GDB is using the | |
693 | remote protocol, because feature X is only available when GDB debugs | |
694 | natively, check gdb_protocol instead. |