test.xml revision 1.7
1<section xmlns="http://docbook.org/ns/docbook" version="5.0" 2 xml:id="manual.intro.setup.test" xreflabel="Testing"> 3<?dbhtml filename="test.html"?> 4 5<info><title>Testing</title> 6 <keywordset> 7 <keyword>ISO C++</keyword> 8 <keyword>test</keyword> 9 <keyword>testsuite</keyword> 10 <keyword>performance</keyword> 11 <keyword>conformance</keyword> 12 <keyword>ABI</keyword> 13 <keyword>exception safety</keyword> 14 </keywordset> 15</info> 16 17<para> 18The libstdc++ testsuite includes testing for standard conformance, 19regressions, ABI, and performance. 20</para> 21 22<section xml:id="test.organization" xreflabel="Test Organization"><info><title>Test Organization</title></info> 23 24 25<section xml:id="test.organization.layout" xreflabel="Directory Layout"><info><title>Directory Layout</title></info> 26 27 28<para> 29 The directory 30 <filename class="directory"><replaceable>gccsrcdir</replaceable>/libstdc++-v3/testsuite</filename> 31 contains the individual test cases organized in sub-directories 32 corresponding to clauses of the C++ standard (detailed below), 33 the DejaGnu test harness support files, and sources to various 34 testsuite utilities that are packaged in a separate testing library. 35</para> 36 37<para> 38 All test cases for functionality required by the runtime components 39 of the C++ standard (ISO 14882) are files within the following 40 directories: 41 42 <programlisting> 43 17_intro 44 18_support 45 19_diagnostics 46 20_util 47 21_strings 48 22_locale 49 23_containers 50 24_iterators 51 25_algorithms 52 26_numerics 53 27_io 54 28_regex 55 29_atomics 56 30_threads 57 </programlisting> 58</para> 59 60 <para> 61 In addition, the following directories include test files: 62 63<variablelist spacing="compact"> 64<varlistentry> 65 <term><filename class="directory">tr1</filename></term> 66 <listitem>Tests for components as described by the Technical Report 67 on Standard Library Extensions (<link linked="status.iso.tr1">TR1</link>). 68 </listitem> 69</varlistentry> 70<varlistentry> 71 <term><filename class="directory">backward</filename></term> 72 <listitem>Tests for backwards compatibility and deprecated features. 73 </listitem> 74</varlistentry> 75<varlistentry> 76 <term><filename class="directory">demangle</filename></term> 77 <listitem>Tests for <function>__cxa_demangle</function>, the IA-64 C++ ABI 78 demangler. 79 </listitem> 80</varlistentry> 81<varlistentry> 82 <term><filename class="directory">ext</filename></term> 83 <listitem>Tests for extensions.</listitem> 84</varlistentry> 85<varlistentry> 86 <term><filename class="directory">performance</filename></term> 87 <listitem>Tests for performance analysis, and performance regressions. 88 </listitem> 89</varlistentry> 90</variablelist> 91 </para> 92 93 <para> 94 Some directories don't have test files, but instead contain 95 auxiliary information: 96 97<variablelist spacing="compact"> 98<varlistentry> 99 <term><filename class="directory">config</filename></term> 100 <listitem>Files for the DejaGnu test harness.</listitem> 101</varlistentry> 102<varlistentry> 103 <term><filename class="directory">lib</filename></term> 104 <listitem>Files for the DejaGnu test harness.</listitem> 105</varlistentry> 106<varlistentry> 107 <term><filename class="directory">libstdc++*</filename></term> 108 <listitem>Files for the DejaGnu test harness.</listitem> 109</varlistentry> 110<varlistentry> 111 <term><filename class="directory">data</filename></term> 112 <listitem>Sample text files for testing input and output.</listitem> 113</varlistentry> 114<varlistentry> 115 <term><filename class="directory">util</filename></term> 116 <listitem>Files for libtestc++, utilities and testing routines.</listitem> 117</varlistentry> 118</variablelist> 119 </para> 120 121 <para> 122 Within a directory that includes test files, there may be 123 additional subdirectories, or files. Originally, test cases 124 were appended to one file that represented a particular section 125 of the chapter under test, and was named accordingly. For 126 instance, to test items related to <code> 21.3.6.1 - 127 <function>basic_string::find</function> [lib.string::find]</code> 128 in the standard, the following was used: 129<programlisting> 21_strings/find.cc </programlisting> 130 However, that practice soon became a liability as the test cases 131 became huge and unwieldy, and testing new or extended 132 functionality (like wide characters or named locales) became 133 frustrating, leading to aggressive pruning of test cases on some 134 platforms that covered up implementation errors. Now, the test 135 suite has a policy of one file, one test case, which solves the 136 above issues and gives finer grained results and more manageable 137 error debugging. As an example, the test case quoted above 138 becomes: 139<programlisting> 21_strings/basic_string/find/char/1.cc 140 21_strings/basic_string/find/char/2.cc 141 21_strings/basic_string/find/char/3.cc 142 21_strings/basic_string/find/wchar_t/1.cc 143 21_strings/basic_string/find/wchar_t/2.cc 144 21_strings/basic_string/find/wchar_t/3.cc</programlisting> 145 </para> 146 147 <para> 148 All new tests should be written with the policy of "one test 149 case, one file" in mind. 150 </para> 151</section> 152 153 154<section xml:id="test.organization.naming" xreflabel="Naming Conventions"><info><title>Naming Conventions</title></info> 155 156 157 <para> 158 In addition, there are some special names and suffixes that are 159 used within the testsuite to designate particular kinds of 160 tests. 161 </para> 162 163<variablelist> 164<varlistentry> 165 <term><filename class="extension">_xin.cc</filename></term> 166 <listitem> 167 This test case expects some kind of interactive input in order 168 to finish or pass. At the moment, the interactive tests are not 169 run by default. Instead, they are run by hand, like: 170 <programlisting> 171g++ 27_io/objects/char/3_xin.cc 172cat 27_io/objects/char/3_xin.in | a.out</programlisting> 173 </listitem> 174</varlistentry> 175<varlistentry> 176 <term><filename class="extension">.in</filename></term> 177 <listitem> 178 This file contains the expected input for the corresponding <emphasis> 179 _xin.cc</emphasis> test case. 180 </listitem> 181</varlistentry> 182<varlistentry> 183 <term><filename class="extension">_neg.cc</filename></term> 184 <listitem> 185 This test case is expected to fail: it's a negative test. At the 186 moment, these are almost always compile time errors. 187 </listitem> 188</varlistentry> 189<varlistentry> 190 <term><filename class="directory">char</filename></term> 191 <listitem> 192 This can either be a directory name or part of a longer file 193 name, and indicates that this file, or the files within this 194 directory are testing the <code>char</code> instantiation of a 195 template. 196 </listitem> 197</varlistentry> 198<varlistentry> 199 <term><filename class="directory">wchar_t</filename></term> 200 <listitem> 201 This can either be a directory name or part of a longer file 202 name, and indicates that this file, or the files within this 203 directory are testing the <code>wchar_t</code> instantiation of 204 a template. Some hosts do not support <code>wchar_t</code> 205 functionality, so for these targets, all of these tests will not 206 be run. 207 </listitem> 208</varlistentry> 209<varlistentry> 210 <term><filename class="directory">thread</filename></term> 211 <listitem> 212 This can either be a directory name or part of a longer file 213 name, and indicates that this file, or the files within this 214 directory are testing situations where multiple threads are 215 being used. 216 </listitem> 217</varlistentry> 218<varlistentry> 219 <term><filename class="directory">performance</filename></term> 220 <listitem> 221 This can either be an enclosing directory name or part of a 222 specific file name. This indicates a test that is used to 223 analyze runtime performance, for performance regression testing, 224 or for other optimization related analysis. At the moment, these 225 test cases are not run by default. 226 </listitem> 227</varlistentry> 228</variablelist> 229 230</section> 231</section> 232 233 234<section xml:id="test.run" xreflabel="Running the Testsuite"><info><title>Running the Testsuite</title></info> 235 236 237 <section xml:id="test.run.basic"><info><title>Basic</title></info> 238 239 240 <para> 241 You can check the status of the build without installing it 242 using the DejaGnu harness, much like the rest of the gcc 243 tools, i.e. 244 <userinput>make check</userinput> 245 in the 246 <filename class="directory"><replaceable>libbuilddir</replaceable></filename> 247 directory, or 248 <userinput>make check-target-libstdc++-v3</userinput> 249 in the 250 <filename class="directory"><replaceable>gccbuilddir</replaceable></filename> 251 directory. 252 </para> 253 254 <para> 255 These commands are functionally equivalent and will create a 256 '<filename class="directory">testsuite</filename>' directory underneath 257 <filename class="directory"><replaceable>libbuilddir</replaceable></filename> 258 containing the results of the 259 tests. Two results files will be generated: 260 <filename>libstdc++.sum</filename>, which is a PASS/FAIL summary 261 for each test, and 262 <filename>libstdc++.log</filename> which is a log of 263 the exact command-line passed to the compiler, the compiler 264 output, and the executable output (if any) for each test. 265 </para> 266 267 <para> 268 Archives of test results for various versions and platforms are 269 available on the GCC website in the <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://gcc.gnu.org/gcc-4.3/buildstat.html">build 270 status</link> section of each individual release, and are also 271 archived on a daily basis on the <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://gcc.gnu.org/ml/gcc-testresults/current">gcc-testresults</link> 272 mailing list. Please check either of these places for a similar 273 combination of source version, operating system, and host CPU. 274 </para> 275 </section> 276 277 <section xml:id="test.run.variations"><info><title>Variations</title></info> 278 279 <para> 280 There are several options for running tests, including testing 281 the regression tests, testing a subset of the regression tests, 282 testing the performance tests, testing just compilation, testing 283 installed tools, etc. In addition, there is a special rule for 284 checking the exported symbols of the shared library. 285 </para> 286 <para> 287 To debug the DejaGnu test harness during runs, try invoking with a 288 specific argument to the variable <varname>RUNTESTFLAGS</varname>, 289 like so: 290<programlisting> 291 make check-target-libstdc++-v3 RUNTESTFLAGS="-v" 292</programlisting> 293 or 294<programlisting> 295 make check-target-libstdc++-v3 RUNTESTFLAGS="-v -v" 296</programlisting> 297 </para> 298 299 <para> 300 To run a subset of the library tests, you can either generate the 301 <filename>testsuite_files</filename> file (described below) by running 302 <userinput>make testsuite_files</userinput> in the 303 <filename class="directory"><replaceable>libbuilddir</replaceable>/testsuite</filename> 304 directory, then edit the 305 file to remove the tests you don't want and then run the testsuite as 306 normal, or you can specify a testsuite and a subset of tests in the 307 <varname>RUNTESTFLAGS</varname> variable. 308 </para> 309 310 <para> 311 For example, to run only the tests for containers you could use: 312 313<programlisting> 314 make check-target-libstdc++-v3 RUNTESTFLAGS="conformance.exp=23_containers/*" 315</programlisting> 316 </para> 317 318 <para> 319 When combining this with other options in <varname>RUNTESTFLAGS</varname> 320 the <option>testsuite.exp=testfiles</option> options must come first. 321 </para> 322 323 <para> 324 There are two ways to run on a simulator: set up <envar>DEJAGNU</envar> 325 to point to a specially crafted <filename>site.exp</filename>, 326 or pass down <option>--target_board</option> flags. 327 </para> 328 329 <para> 330 Example flags to pass down for various embedded builds are as follows: 331 332<programlisting> 333 --target=powerpc-eabisim <emphasis>(libgloss/sim)</emphasis> 334 make check-target-libstdc++-v3 RUNTESTFLAGS="--target_board=powerpc-sim" 335 336 --target=calmrisc32 <emphasis>(libgloss/sid)</emphasis> 337 make check-target-libstdc++-v3 RUNTESTFLAGS="--target_board=calmrisc32-sid" 338 339 --target=xscale-elf <emphasis>(newlib/sim)</emphasis> 340 make check-target-libstdc++-v3 RUNTESTFLAGS="--target_board=arm-sim" 341</programlisting> 342 </para> 343 344 <para> 345 Also, here is an example of how to run the libstdc++ testsuite 346 for a multilibed build directory with different ABI settings: 347 348 <programlisting> 349 make check-target-libstdc++-v3 RUNTESTFLAGS='--target_board \"unix{-mabi=32,,-mabi=64}\"' 350</programlisting> 351 </para> 352 353 <para> 354 You can run the tests with a compiler and library that have 355 already been installed. Make sure that the compiler (e.g., 356 <command>g++</command>) is in your <envar>PATH</envar>. If you are 357 using shared libraries, then you must also ensure that the 358 directory containing the shared version of libstdc++ is in your 359 <envar>LD_LIBRARY_PATH</envar>, or 360 <link linkend="manual.intro.using.linkage.dynamic">equivalent</link>. 361 If your GCC source tree is at 362 <filename class="directory">/path/to/gcc</filename>, 363 then you can run the tests as follows: 364 365<programlisting> 366 runtest --tool libstdc++ --srcdir=/path/to/gcc/libstdc++-v3/testsuite 367</programlisting> 368 </para> 369 370 <para> 371 The testsuite will create a number of files in the directory in 372 which you run this command,. Some of those files might use the 373 same name as files created by other testsuites (like the ones 374 for GCC and G++), so you should not try to run all the 375 testsuites in parallel from the same directory. 376 </para> 377 378 <para> 379 In addition, there are some testing options that are mostly of 380 interest to library maintainers and system integrators. As such, 381 these tests may not work on all CPU and host combinations, and 382 may need to be executed in the 383 <filename class="directory"><replaceable>libbuilddir</replaceable>/testsuite</filename> 384 directory. These 385 options include, but are not necessarily limited to, the 386 following: 387 </para> 388 389<variablelist> 390<varlistentry> 391 <term><userinput> 392 make testsuite_files 393 </userinput></term>> 394 395 <listitem> 396 <para> 397 Five files are generated that determine what test files 398 are run. These files are: 399 400 <variablelist> 401 <varlistentry> 402 <term> <filename>testsuite_files</filename> </term> 403 <listitem> 404 This is a list of all the test cases that will be run. Each 405 test case is on a separate line, given with an absolute path 406 from the 407 <filename class="directory"><replaceable>libsrcdir</replaceable>/testsuite</filename> 408 directory. 409 </listitem> 410 </varlistentry> 411 412 <varlistentry> 413 <term> <filename>testsuite_files_interactive</filename> </term> 414 <listitem> 415 This is a list of all the interactive test cases, using the 416 same format as the file list above. These tests are not run 417 by default. 418 </listitem> 419 </varlistentry> 420 421 <varlistentry> 422 <term> <filename>testsuite_files_performance</filename> </term> 423 <listitem> 424 This is a list of all the performance test cases, using the 425 same format as the file list above. These tests are not run 426 by default. 427 </listitem> 428 </varlistentry> 429 430 <varlistentry> 431 <term> <filename>testsuite_thread</filename> </term> 432 <listitem> 433 This file indicates that the host system can run tests which 434 involved multiple threads. 435 </listitem> 436 </varlistentry> 437 438 <varlistentry> 439 <term> <filename>testsuite_wchar_t</filename> </term> 440 <listitem> 441 This file indicates that the host system can run the 442 <code>wchar_t</code> tests, and corresponds to the macro 443 definition <literal>_GLIBCXX_USE_WCHAR_T</literal> in the 444 file <filename>c++config.h</filename>. 445 </listitem> 446 </varlistentry> 447 </variablelist> 448 </para> 449 </listitem> 450</varlistentry> 451 452<varlistentry> 453 <term><userinput> 454 make check-abi 455 </userinput></term>> 456 457 <listitem> 458 <para> 459 The library ABI can be tested. This involves testing the shared 460 library against a baseline list of symbol exports that defines the 461 previous version of the ABI. The tests require that no exported 462 symbols are removed, no new symbols are added to the old symbol 463 versions, and any new symbols have the latest symbol version. 464 See <link linkend="abi.versioning">Versioning</link> for more details 465 of the ABI version history. 466 </para> 467 </listitem> 468</varlistentry> 469 470<varlistentry> 471 <term><userinput> 472 make new-abi-baseline 473 </userinput></term>> 474 475 <listitem> 476 <para> 477 Generate a new baseline set of symbols exported from the library 478 (written to a file under 479 <filename class="directory"><replaceable>libsrcdir</replaceable>/config/abi/post/<replaceable>target</replaceable>/</filename>). 480 A different baseline symbols file is needed for each architecture and 481 is used by the <literal>check-abi</literal> target described above. 482 The files are usually re-generated by target maintainers for releases. 483 </para> 484 </listitem> 485</varlistentry> 486 487<varlistentry> 488 <term><userinput> 489 make check-compile 490 </userinput></term>> 491 492 <listitem> 493 <para> 494 This rule compiles, but does not link or execute, the 495 <filename>testsuite_files</filename> test cases and displays the 496 output on stdout. 497 </para> 498 </listitem> 499</varlistentry> 500 501<varlistentry> 502 <term><userinput> 503 make check-performance 504 </userinput></term>> 505 506 <listitem> 507 <para> 508 This rule runs through the 509 <filename>testsuite_files_performance</filename> test cases and 510 collects information for performance analysis and can be used to 511 spot performance regressions. Various timing information is 512 collected, as well as number of hard page faults, and memory 513 used. This is not run by default, and the implementation is in 514 flux. 515 </para> 516 </listitem> 517</varlistentry> 518 519<varlistentry> 520 <term><userinput> 521 make check-debug 522 </userinput></term>> 523 524 <listitem> 525 <para> 526 This rule runs through the test suite under the 527 <link linkend="manual.ext.debug_mode">debug mode</link>. 528 </para> 529 </listitem> 530</varlistentry> 531 532<varlistentry> 533 <term><userinput> 534 make check-parallel 535 </userinput></term>> 536 537 <listitem> 538 <para> 539 This rule runs through the test suite under the 540 <link linkend="manual.ext.parallel_mode">parallel mode</link>. 541 </para> 542 </listitem> 543</varlistentry> 544 545</variablelist> 546 547 <para> 548 We are interested in any strange failures of the testsuite; 549 please email the main libstdc++ mailing list if you see 550 something odd or have questions. 551 </para> 552 </section> 553 554 <section xml:id="test.run.permutations"><info><title>Permutations</title></info> 555 556 <para> 557 The tests will be compiled with a set of default compiler flags defined 558 by the 559 <filename><replaceable>libbuilddir</replaceable>/scripts/testsuite_flags</filename> 560 file, as well as options specified in individual tests. You can run 561 the tests with different options by adding them to the output of 562 the <option>--cxxflags</option> option of that script, or by setting 563 the <varname>CXXFLAGS</varname> variable when running 564 <command>make</command>, or via options for the DejaGnu test framework 565 (described below). The latter approach uses the 566 <option>--target_board</option> option that was shown earlier, 567 but requires DejaGnu version 1.5.3 or newer to work reliably, so that the 568 <literal>dg-options</literal> in the test aren't overridden. 569 For example, to run the tests with 570 <option>-O1 -D_GLIBCXX_ASSERTIONS</option> 571 you could use: 572<programlisting> make check RUNTESTFLAGS=--target_board=unix/-O1/-D_GLIBCXX_ASSERTIONS</programlisting> 573 </para> 574 575 <para> 576 The <option>--target_board</option> option can also be used to run the 577 tests multiple times in different variations. For example, to run the 578 entire testsuite three times using <option>-O3</option> but with 579 different <option>-std</option> options: 580<programlisting> make check 'RUNTESTFLAGS=--target_board=unix/-O3\"{-std=gnu++98,-std=gnu++11,-std=gnu++14}\"'</programlisting> 581 N.B. that set of variations could also be written as 582 <literal>unix/-O3\"{-std=gnu++98,-std=gnu++11,}\"</literal> so that 583 the third variation would use the default for <option>-std</option> 584 (which is <option>-std=gnu++14</option> as of GCC 6). 585 </para> 586 587 <para> 588 To run the libstdc++ test suite under the 589 <link linkend="manual.ext.debug_mode">debug mode</link>, use 590 <userinput>make check-debug</userinput>. Alternatively, edit 591 <filename><replaceable>libbuilddir</replaceable>/scripts/testsuite_flags</filename> 592 to add the compile-time flag <option>-D_GLIBCXX_DEBUG</option> to the 593 result printed by the <option>--cxxflags</option> 594 option. Additionally, add the 595 <option>-D_GLIBCXX_DEBUG_PEDANTIC</option> flag to turn on 596 pedantic checking. The libstdc++ test suite should produce 597 the same results under debug mode that it does under release mode: 598 any deviation indicates an error in either the library or the test suite. 599 Note, however, that the number of tests that PASS may change, because 600 some test cases are skipped in normal mode, and some are skipped in 601 debug mode, as determined by the 602 <literal>dg-require-<replaceable>support</replaceable></literal> 603 directives described below. 604 </para> 605 606 <para> 607 The <link linkend="manual.ext.parallel_mode">parallel 608 mode</link> can be tested using 609 <userinput>make check-parallel</userinput>, or in much the same manner 610 as the debug mode, substituting 611 <option>-D_GLIBCXX_PARALLEL</option> for 612 <option>-D_GLIBCXX_DEBUG</option> in the previous paragraph. 613 </para> 614 615 <para> 616 Or, just run the testsuite 617 <option>-D_GLIBCXX_DEBUG</option> or <option>-D_GLIBCXX_PARALLEL</option> 618 in <varname>CXXFLAGS</varname> or <varname>RUNTESTFLAGS</varname>. 619 </para> 620 </section> 621</section> 622 623<section xml:id="test.new_tests"><info><title>Writing a new test case</title></info> 624 625 626 <para> 627 The first step in making a new test case is to choose the correct 628 directory and file name, given the organization as previously 629 described. 630 </para> 631 632 <para> 633 All files are copyright the FSF, and GPL'd: this is very 634 important. The first copyright year should correspond to the date 635 the file was checked in to version control. If a test is copied from 636 an existing file it should retain the copyright years from the 637 original file. 638 </para> 639 640 <para> 641 The DejaGnu instructions say to always return <literal>0</literal> 642 from <function>main</function> to indicate success. Strictly speaking 643 this is redundant in C++, since returning from <function>main</function> 644 is defined to return <literal>0</literal>. Most tests still have an 645 explicit return. 646 </para> 647 648 <para> 649 A bunch of utility functions and classes have already been 650 abstracted out into the testsuite utility library, <code> 651 libtestc++</code>. To use this functionality, just include the 652 appropriate header file: the library or specific object files will 653 automatically be linked in as part of the testsuite run. 654 </para> 655 656 <para> 657 Tests that need to perform runtime checks should use the 658 <literal>VERIFY</literal> macro, defined in the 659 <filename class="headerfile"><testsuite_hooks.h></filename> header. 660 This usually expands to the standard <literal>assert</literal> macro, but 661 allows targets to define it to something different. In order to support 662 the alternative expansions of <literal>VERIFY</literal>, before any 663 use of the macro there must be a variable called <varname>test</varname> 664 in scope, which is usually defined like so (the attribute avoids 665 warnings about an unused variable): 666 <programlisting> 667 bool test __attribute__((unused)) = true; 668 </programlisting> 669 </para> 670 671 <para> 672 The testsuite uses the DejaGnu framework to compile and run the tests. 673 Test cases are normal C++ files which contain special directives in 674 comments. These directives look like <literal>{ dg-* ... }</literal> 675 and tell DejaGnu what to do and what kinds of behavior are to be expected 676 for a test. The core DejaGnu directives are documented in the 677 <filename>dg.exp</filename> file installed by DejaGnu. 678 The GCC testsuites support additional directives 679 as described in the GCC internals documentation, see <link 680 xmlns:xlink="http://www.w3.org/1999/xlink" 681 xlink:href="https://gcc.gnu.org/onlinedocs/gccint/Directives.html">Syntax 682 and Descriptions of test directives</link>. GCC also defines many <link 683 xmlns:xlink="http://www.w3.org/1999/xlink" 684 xlink:href="https://gcc.gnu.org/onlinedocs/gccint/Effective-Target-Keywords.html"> 685 Keywords describing target attributes</link> (a.k.a effective targets) 686 which can be used where a target <replaceable>selector</replaceable> can 687 appear. 688 </para> 689 690 <para> 691 Some directives commonly used in the libstdc++ testsuite are: 692 693<variablelist> 694<varlistentry> 695 <term><literal>{ dg-do <replaceable>do-what-keyword</replaceable> [{ target/xfail <replaceable>selector</replaceable> }] }</literal></term> 696 <listitem>Where <replaceable>do-what-keyword</replaceable> is usually 697 one of <literal>run</literal> (which is the default), 698 <literal>compile</literal>, or <literal>link</literal>, 699 and typical selectors are targets such as <literal>*-*-gnu*</literal> 700 or an effective target such as <literal>c++11</literal>. 701 </listitem> 702</varlistentry> 703<varlistentry> 704 <term><literal>{ dg-require-<replaceable>support</replaceable> args }</literal></term> 705 <listitem>Skip the test if the target does not provide the required support. 706 See below for values of <replaceable>support</replaceable>. 707 </listitem> 708</varlistentry> 709<varlistentry> 710 <term><literal>{ dg-options <replaceable>options</replaceable> [{ target <replaceable>selector</replaceable> }] }</literal></term> 711</varlistentry> 712<varlistentry> 713 <term><literal>{ dg-error <replaceable>regexp</replaceable> [ <replaceable>comment</replaceable> [{ target/xfail <replaceable>selector</replaceable> } [<replaceable>line</replaceable>] ]] }</literal></term> 714</varlistentry> 715<varlistentry> 716 <term><literal>{ dg-excess-errors <replaceable>comment</replaceable> [{ target/xfail <replaceable>selector</replaceable> }] }</literal></term> 717</varlistentry> 718</variablelist> 719 For full details of these and other directives see the main GCC DejaGnu 720 documentation in the internals manual. 721 </para> 722 723 <para> 724 Test cases that use features of a particular C++ standard should specify 725 the minimum required standard as an effective target: 726<programlisting> // { dg-do run { target c++11 } }</programlisting> 727 or 728<programlisting> // { dg-require-effective-target c++11 }</programlisting> 729 Specifying the minimum required standard for a test allows it to be run 730 using later standards, so that we can verify that C++11 components still 731 work correctly when compiled as C++14 or later. Specifying a minimum also 732 means the test will be skipped if the test is compiled using 733 an older standard, e.g. using 734 <option>RUNTESTFLAGS=--target_board=unix/-std=gnu++98</option>. 735 </para> 736 737 <para> 738 It is possible to indicate that a test should <emphasis>only</emphasis> 739 be run for a specific standard (and not later standards) using an 740 effective target like <literal>c++11_only</literal>. However, this means 741 the test will be skipped by default (because the default mode is 742 <literal>gnu++14</literal>), and so will only run when 743 <option>-std=gnu++11</option> or <option>-std=c++11</option> is used 744 explicitly. For tests that require a specific standard it is better to 745 use a <literal>dg-options</literal> directive: 746<programlisting> // { dg-options "-std=gnu++11" }</programlisting> 747 This means the test will not get skipped by default, and will always use 748 the specific standard dialect that the test requires. This isn't needed 749 often, and most tests should use an effective target to specify a 750 minimum standard instead, to allow them to be tested for all 751 possible variations. 752 </para> 753 754 <para> 755 Similarly, tests which depend on a newer standard than the default 756 must use <literal>dg-options</literal> instead of (or in addition to) 757 an effective target, so that they are not skipped by default. 758 For example, tests for C++17 features should use 759<programlisting> // { dg-options "-std=gnu++17" }</programlisting> 760 before any <literal>dg-do</literal> such as: 761<programlisting> // { dg-do run "c++17" }</programlisting> 762 The <literal>dg-options</literal> directive must come first, so that 763 the <literal>-std</literal> flag has already been added to the options 764 before checking the <literal>c++17</literal> target. 765 </para> 766 767<section xml:id="tests.dg.examples"><info><title>Examples of Test Directives</title></info> 768 769 <para> 770Example 1: Testing compilation only: 771<programlisting> 772// { dg-do compile } 773</programlisting> 774 775Example 2: Testing for expected warnings on line 36, which all targets fail: 776<programlisting> 777// { dg-warning "string literals" "" { xfail *-*-* } 36 } 778</programlisting> 779 780Example 3: Testing for expected warnings on line 36: 781<programlisting> 782// { dg-warning "string literals" "" { target *-*-* } 36 } 783</programlisting> 784 785Example 4: Testing for compilation errors on line 41: 786<programlisting> 787// { dg-do compile } 788// { dg-error "no match for" "" { target *-*-* } 41 } 789</programlisting> 790 791Example 5: Testing with special command line settings, or without the 792use of pre-compiled headers, in particular the 793<filename class="headerfile">stdc++.h.gch</filename> file. Any 794options here will override the <varname>DEFAULT_CXXFLAGS</varname> and 795<varname>PCH_CXXFLAGS</varname> set up in the <filename>normal.exp</filename> 796file: 797<programlisting> 798// { dg-options "-O0" { target *-*-* } } 799</programlisting> 800 801Example 6: Compiling and linking a test only for C++14 and later, and only 802if Debug Mode is active: 803<programlisting> 804// { dg-do link { target c++14 } } 805// { dg-require-debug-mode "" } 806</programlisting> 807 808Example 7: Running a test only on x86 targets, and only for C++11 and later, 809with specific options, and additional options for 32-bit x86: 810<programlisting> 811// { dg-options "-fstrict-enums" } 812// { dg-additional-options "-march=i486" { target ia32 } } 813// { dg-do run { target { ia32 || x86_64-*-* } } } 814// { dg-require-effective-target "c++11" } 815</programlisting> 816 </para> 817 818 <para> 819 More examples can be found in the 820 <filename>libstdc++-v3/testsuite/*/*.cc</filename> files. 821 </para> 822</section> 823 824<section xml:id="tests.dg.directives"><info><title>Directives Specific to Libstdc++ Tests</title></info> 825 826 <para> 827 In addition to the usual <link 828 xmlns:xlink="http://www.w3.org/1999/xlink" 829 xlink:href="https://gcc.gnu.org/onlinedocs/gccint/Require-Support.html">Variants 830 of <literal>dg-require-<replaceable>support</replaceable></literal></link> 831 several more directives are available for use in libstdc++ tests, 832 including the following: 833 </para> 834 835 <variablelist> 836 <varlistentry><term><literal>dg-require-namedlocale</literal> <replaceable>name</replaceable></term> 837 <listitem><para>The named locale must be available. 838 </para></listitem> 839 </varlistentry> 840 <varlistentry><term><literal>dg-require-debug-mode ""</literal></term> 841 <listitem><para>Skip the test if the Debug Mode is not active 842 (as determined by the <literal>_GLIBCXX_DEBUG</literal> macro). 843 </para></listitem> 844 </varlistentry> 845 <varlistentry><term><literal>dg-require-parallel-mode ""</literal></term> 846 <listitem><para>Skip the test if the Parallel Mode is not active 847 (as determined by the <literal>_GLIBCXX_PARALLEL</literal> macro). 848 </para></listitem> 849 </varlistentry> 850 <varlistentry><term><literal>dg-require-profile-mode ""</literal></term> 851 <listitem><para>Skip the test if the Profile Mode is not active 852 (as determined by the <literal>_GLIBCXX_PROFILE</literal> macro). 853 </para></listitem> 854 </varlistentry> 855 <varlistentry><term><literal>dg-require-normal-mode ""</literal></term> 856 <listitem><para>Skip the test if any of Debug, Parallel or Profile 857 Mode is active. 858 </para></listitem> 859 </varlistentry> 860 <varlistentry><term><literal>dg-require-atomic-builtins ""</literal></term> 861 <listitem><para>Skip the test if atomic operations on <type>bool</type> 862 and <type>int</type> are not lock-free. 863 </para></listitem> 864 </varlistentry> 865 <varlistentry><term><literal>dg-require-gthreads ""</literal></term> 866 <listitem><para>Skip the test if the C++11 thread library is not 867 supported, as determined by the <literal>_GLIBCXX_HAS_GTHREADS</literal> 868 macro. 869 </para></listitem> 870 </varlistentry> 871 <varlistentry><term><literal>dg-require-gthreads-timed ""</literal></term> 872 <listitem><para>Skip the test if C++11 timed mutexes are not supported, 873 as determined by the <literal>_GLIBCXX_HAS_GTHREADS</literal> and 874 <literal>_GTHREAD_USE_MUTEX_TIMEDLOCK</literal> macros. 875 </para></listitem> 876 </varlistentry> 877 <varlistentry><term><literal>dg-require-string-conversions ""</literal></term> 878 <listitem><para>Skip the test if the C++11 <function>to_string</function> 879 and <function>stoi</function>, <function>stod</function> etc. functions 880 are not fully supported (including wide character versions). 881 </para></listitem> 882 </varlistentry> 883 <varlistentry><term><literal>dg-require-filesystem-ts ""</literal></term> 884 <listitem><para>Skip the test if the Filesystem TS is not supported. 885 </para></listitem> 886 </varlistentry> 887 </variablelist> 888</section> 889 890</section> 891 892 893<section xml:id="test.harness" xreflabel="Test Harness and Utilities"><info><title>Test Harness and Utilities</title></info> 894 895 896<section xml:id="test.harness.dejagnu"><info><title>DejaGnu Harness Details</title></info> 897 898 <para> 899 Underlying details of testing for conformance and regressions are 900 abstracted via the GNU DejaGnu package. This is similar to the 901 rest of GCC. 902 </para> 903 904 905<para>This is information for those looking at making changes to the testsuite 906structure, and/or needing to trace DejaGnu's actions with 907<option>--verbose</option>. 908This will not be useful to people who are "merely" adding new tests 909to the existing structure. 910</para> 911 912<para>The first key point when working with DejaGnu is the idea of a "tool". 913Files, directories, and functions are all implicitly used when they are 914named after the tool in use. Here, the tool will always be "libstdc++". 915</para> 916 917<para>The <code>lib</code> subdir contains support routines. The 918<code>lib/libstdc++.exp</code> file ("support library") is loaded 919automagically, and must explicitly load the others. For example, files can 920be copied from the core compiler's support directory into <code>lib</code>. 921</para> 922 923<para>Some routines in <code>lib/libstdc++.exp</code> are callbacks, some are 924our own. Callbacks must be prefixed with the name of the tool. To easily 925distinguish the others, by convention our own routines are named "v3-*". 926</para> 927 928<para>The next key point when working with DejaGnu is "test files". Any 929directory whose name starts with the tool name will be searched for test files. 930(We have only one.) In those directories, any <code>.exp</code> file is 931considered a test file, and will be run in turn. Our main test file is called 932<code>normal.exp</code>; it runs all the tests in testsuite_files using the 933callbacks loaded from the support library. 934</para> 935 936<para>The <code>config</code> directory is searched for any particular "target 937board" information unique to this library. This is currently unused and sets 938only default variables. 939</para> 940 941</section> 942 943<section xml:id="test.harness.utils"><info><title>Utilities</title></info> 944 945 <para> 946 </para> 947 <para> 948 The testsuite directory also contains some files that implement 949 functionality that is intended to make writing test cases easier, 950 or to avoid duplication, or to provide error checking in a way that 951 is consistent across platforms and test harnesses. A stand-alone 952 executable, called <emphasis>abi_check</emphasis>, and a static 953 library called <emphasis>libtestc++</emphasis> are 954 constructed. Both of these items are not installed, and only used 955 during testing. 956 </para> 957 958 <para> 959 These files include the following functionality: 960 </para> 961 962 <itemizedlist> 963 <listitem> 964 <para> 965 <emphasis>testsuite_abi.h</emphasis>, 966 <emphasis>testsuite_abi.cc</emphasis>, 967 <emphasis>testsuite_abi_check.cc</emphasis> 968 </para> 969 <para> 970 Creates the executable <emphasis>abi_check</emphasis>. 971 Used to check correctness of symbol versioning, visibility of 972 exported symbols, and compatibility on symbols in the shared 973 library, for hosts that support this feature. More information 974 can be found in the ABI documentation <link linkend="appendix.porting.abi">here</link> 975 </para> 976 </listitem> 977 <listitem> 978 <para> 979 <emphasis>testsuite_allocator.h</emphasis>, 980 <emphasis>testsuite_allocator.cc</emphasis> 981 </para> 982 <para> 983 Contains specialized allocators that keep track of construction 984 and destruction. Also, support for overriding global new and 985 delete operators, including verification that new and delete 986 are called during execution, and that allocation over max_size 987 fails. 988 </para> 989 </listitem> 990 <listitem> 991 <para> 992 <emphasis>testsuite_character.h</emphasis> 993 </para> 994 <para> 995 Contains <code>std::char_traits</code> and 996 <code>std::codecvt</code> specializations for a user-defined 997 POD. 998 </para> 999 </listitem> 1000 <listitem> 1001 <para> 1002 <emphasis>testsuite_hooks.h</emphasis>, 1003 <emphasis>testsuite_hooks.cc</emphasis> 1004 </para> 1005 <para> 1006 A large number of utilities, including: 1007 </para> 1008 <itemizedlist> 1009 <listitem><para>VERIFY</para></listitem> 1010 <listitem><para>set_memory_limits</para></listitem> 1011 <listitem><para>verify_demangle</para></listitem> 1012 <listitem><para>run_tests_wrapped_locale</para></listitem> 1013 <listitem><para>run_tests_wrapped_env</para></listitem> 1014 <listitem><para>try_named_locale</para></listitem> 1015 <listitem><para>try_mkfifo</para></listitem> 1016 <listitem><para>func_callback</para></listitem> 1017 <listitem><para>counter</para></listitem> 1018 <listitem><para>copy_tracker</para></listitem> 1019 <listitem><para>copy_constructor</para></listitem> 1020 <listitem><para>assignment_operator</para></listitem> 1021 <listitem><para>destructor</para></listitem> 1022 <listitem> 1023 <para>pod_char, pod_int and associated char_traits specializations</para> 1024 </listitem> 1025 </itemizedlist> 1026 </listitem> 1027 <listitem> 1028 <para> 1029 <emphasis>testsuite_io.h</emphasis> 1030 </para> 1031 <para> 1032 Error, exception, and constraint checking for 1033 <code>std::streambuf, std::basic_stringbuf, std::basic_filebuf</code>. 1034 </para> 1035 </listitem> 1036 <listitem> 1037 <para> 1038 <emphasis>testsuite_iterators.h</emphasis> 1039 </para> 1040 <para> 1041 Wrappers for various iterators. 1042 </para> 1043 </listitem> 1044 <listitem> 1045 <para> 1046 <emphasis>testsuite_performance.h</emphasis> 1047 </para> 1048 <para> 1049 A number of class abstractions for performance counters, and 1050 reporting functions including: 1051 </para> 1052 <itemizedlist> 1053 <listitem><para>time_counter</para></listitem> 1054 <listitem><para>resource_counter</para></listitem> 1055 <listitem><para>report_performance</para></listitem> 1056 </itemizedlist> 1057 </listitem> 1058 </itemizedlist> 1059</section> 1060 1061</section> 1062 1063<section xml:id="test.special"><info><title>Special Topics</title></info> 1064 1065 1066<section xml:id="test.exception.safety"><info><title> 1067 Qualifying Exception Safety Guarantees 1068 <indexterm> 1069 <primary>Test</primary> 1070 <secondary>Exception Safety</secondary> 1071 </indexterm> 1072</title></info> 1073 1074 1075<section xml:id="test.exception.safety.overview"><info><title>Overview</title></info> 1076 1077 1078 <para> 1079 Testing is composed of running a particular test sequence, 1080 and looking at what happens to the surrounding code when 1081 exceptions are thrown. Each test is composed of measuring 1082 initial state, executing a particular sequence of code under 1083 some instrumented conditions, measuring a final state, and 1084 then examining the differences between the two states. 1085 </para> 1086 1087 <para> 1088 Test sequences are composed of constructed code sequences 1089 that exercise a particular function or member function, and 1090 either confirm no exceptions were generated, or confirm the 1091 consistency/coherency of the test subject in the event of a 1092 thrown exception. 1093 </para> 1094 1095 <para> 1096 Random code paths can be constructed using the basic test 1097 sequences and instrumentation as above, only combined in a 1098 random or pseudo-random way. 1099 </para> 1100 1101 <para> To compute the code paths that throw, test instruments 1102 are used that throw on allocation events 1103 (<classname>__gnu_cxx::throw_allocator_random</classname> 1104 and <classname>__gnu_cxx::throw_allocator_limit</classname>) 1105 and copy, assignment, comparison, increment, swap, and 1106 various operators 1107 (<classname>__gnu_cxx::throw_type_random</classname> 1108 and <classname>__gnu_cxx::throw_type_limit</classname>). Looping 1109 through a given test sequence and conditionally throwing in 1110 all instrumented places. Then, when the test sequence 1111 completes without an exception being thrown, assume all 1112 potential error paths have been exercised in a sequential 1113 manner. 1114 </para> 1115</section> 1116 1117 1118<section xml:id="test.exception.safety.status"><info><title> 1119 Existing tests 1120</title></info> 1121 1122 1123 <itemizedlist> 1124 <listitem> 1125 <para> 1126 Ad Hoc 1127 </para> 1128 <para> 1129 For example, 1130 <filename>testsuite/23_containers/list/modifiers/3.cc</filename>. 1131 </para> 1132 </listitem> 1133 1134 <listitem> 1135 <para> 1136 Policy Based Data Structures 1137 </para> 1138 <para> 1139 For example, take the test 1140 functor <classname>rand_reg_test</classname> in 1141 in <filename>testsuite/ext/pb_ds/regression/tree_no_data_map_rand.cc</filename>. This uses <classname>container_rand_regression_test</classname> in 1142<filename>testsuite/util/regression/rand/assoc/container_rand_regression_test.h</filename>. 1143 1144 </para> 1145 1146 <para> 1147 Which has several tests for container member functions, 1148Includes control and test container objects. Configuration includes 1149random seed, iterations, number of distinct values, and the 1150probability that an exception will be thrown. Assumes instantiating 1151container uses an extension 1152allocator, <classname>__gnu_cxx::throw_allocator_random</classname>, 1153as the allocator type. 1154 </para> 1155 </listitem> 1156 1157 <listitem> 1158 <para> 1159 C++11 Container Requirements. 1160 </para> 1161 1162 <para> 1163 Coverage is currently limited to testing container 1164 requirements for exception safety, 1165 although <classname>__gnu_cxx::throw_type</classname> meets 1166 the additional type requirements for testing numeric data 1167 structures and instantiating algorithms. 1168 </para> 1169 1170 <para> 1171 Of particular interest is extending testing to algorithms and 1172 then to parallel algorithms. Also io and locales. 1173 </para> 1174 1175 <para> 1176 The test instrumentation should also be extended to add 1177 instrumentation to <classname>iterator</classname> 1178 and <classname>const_iterator</classname> types that throw 1179 conditionally on iterator operations. 1180 </para> 1181 </listitem> 1182 </itemizedlist> 1183</section> 1184 1185 1186<section xml:id="test.exception.safety.containers"><info><title> 1187C++11 Requirements Test Sequence Descriptions 1188</title></info> 1189 1190 1191 <itemizedlist> 1192 <listitem> 1193 <para> 1194 Basic 1195 </para> 1196 1197 <para> 1198 Basic consistency on exception propagation tests. For 1199 each container, an object of that container is constructed, 1200 a specific member function is exercised in 1201 a <literal>try</literal> block, and then any thrown 1202 exceptions lead to error checking in the appropriate 1203 <literal>catch</literal> block. The container's use of 1204 resources is compared to the container's use prior to the 1205 test block. Resource monitoring is limited to allocations 1206 made through the container's <type>allocator_type</type>, 1207 which should be sufficient for container data 1208 structures. Included in these tests are member functions 1209 are <type>iterator</type> and <type>const_iterator</type> 1210 operations, <function>pop_front</function>, <function>pop_back</function>, <function>push_front</function>, <function>push_back</function>, <function>insert</function>, <function>erase</function>, <function>swap</function>, <function>clear</function>, 1211 and <function>rehash</function>. The container in question is 1212 instantiated with two instrumented template arguments, 1213 with <classname>__gnu_cxx::throw_allocator_limit</classname> 1214 as the allocator type, and 1215 with <classname>__gnu_cxx::throw_type_limit</classname> as 1216 the value type. This allows the test to loop through 1217 conditional throw points. 1218 </para> 1219 1220 <para> 1221 The general form is demonstrated in 1222 <filename>testsuite/23_containers/list/requirements/exception/basic.cc 1223 </filename>. The instantiating test object is <classname>__gnu_test::basic_safety</classname> and is detailed in <filename>testsuite/util/exception/safety.h</filename>. 1224 </para> 1225 </listitem> 1226 1227 1228 <listitem> 1229 <para> 1230 Generation Prohibited 1231 </para> 1232 1233 <para> 1234 Exception generation tests. For each container, an object of 1235 that container is constructed and all member functions 1236 required to not throw exceptions are exercised. Included in 1237 these tests are member functions 1238 are <type>iterator</type> and <type>const_iterator</type> operations, <function>erase</function>, <function>pop_front</function>, <function>pop_back</function>, <function>swap</function>, 1239 and <function>clear</function>. The container in question is 1240 instantiated with two instrumented template arguments, 1241 with <classname>__gnu_cxx::throw_allocator_random</classname> 1242 as the allocator type, and 1243 with <classname>__gnu_cxx::throw_type_random</classname> as 1244 the value type. This test does not loop, an instead is sudden 1245 death: first error fails. 1246 </para> 1247 <para> 1248 The general form is demonstrated in 1249 <filename>testsuite/23_containers/list/requirements/exception/generation_prohibited.cc 1250 </filename>. The instantiating test object is <classname>__gnu_test::generation_prohibited</classname> and is detailed in <filename>testsuite/util/exception/safety.h</filename>. 1251 </para> 1252 </listitem> 1253 1254 1255 <listitem> 1256 <para> 1257 Propagation Consistent 1258 </para> 1259 1260 <para> 1261 Container rollback on exception propagation tests. For 1262 each container, an object of that container is constructed, 1263 a specific member function that requires rollback to a previous 1264 known good state is exercised in 1265 a <literal>try</literal> block, and then any thrown 1266 exceptions lead to error checking in the appropriate 1267 <literal>catch</literal> block. The container is compared to 1268 the container's last known good state using such parameters 1269 as size, contents, and iterator references. Included in these 1270 tests are member functions 1271 are <function>push_front</function>, <function>push_back</function>, <function>insert</function>, 1272 and <function>rehash</function>. The container in question is 1273 instantiated with two instrumented template arguments, 1274 with <classname>__gnu_cxx::throw_allocator_limit</classname> 1275 as the allocator type, and 1276 with <classname>__gnu_cxx::throw_type_limit</classname> as 1277 the value type. This allows the test to loop through 1278 conditional throw points. 1279 </para> 1280 1281 <para> 1282 The general form demonstrated in 1283 <filename>testsuite/23_containers/list/requirements/exception/propagation_coherent.cc 1284 </filename>. The instantiating test object is <classname>__gnu_test::propagation_coherent</classname> and is detailed in <filename>testsuite/util/exception/safety.h</filename>. 1285 </para> 1286 </listitem> 1287 </itemizedlist> 1288 1289</section> 1290 1291</section> 1292 1293</section> 1294 1295</section> 1296