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"?>
5 <info><title>Testing</title>
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>
18 The libstdc++ testsuite includes testing for standard conformance,
19 regressions, ABI, and performance.
22 <section xml:id="test.organization" xreflabel="Test Organization"><info><title>Test Organization</title></info>
25 <section xml:id="test.organization.layout" xreflabel="Directory Layout"><info><title>Directory Layout</title></info>
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.
38 All test cases for functionality required by the runtime components
39 of the C++ standard (ISO 14882) are files within the following
61 In addition, the following directories include test files:
63 <variablelist spacing="compact">
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>).
71 <term><filename class="directory">backward</filename></term>
72 <listitem>Tests for backwards compatibility and deprecated features.
76 <term><filename class="directory">demangle</filename></term>
77 <listitem>Tests for <function>__cxa_demangle</function>, the IA-64 C++ ABI
82 <term><filename class="directory">ext</filename></term>
83 <listitem>Tests for extensions.</listitem>
86 <term><filename class="directory">performance</filename></term>
87 <listitem>Tests for performance analysis, and performance regressions.
94 Some directories don't have test files, but instead contain
95 auxiliary information:
97 <variablelist spacing="compact">
99 <term><filename class="directory">config</filename></term>
100 <listitem>Files for the DejaGnu test harness.</listitem>
103 <term><filename class="directory">lib</filename></term>
104 <listitem>Files for the DejaGnu test harness.</listitem>
107 <term><filename class="directory">libstdc++*</filename></term>
108 <listitem>Files for the DejaGnu test harness.</listitem>
111 <term><filename class="directory">data</filename></term>
112 <listitem>Sample text files for testing input and output.</listitem>
115 <term><filename class="directory">util</filename></term>
116 <listitem>Files for libtestc++, utilities and testing routines.</listitem>
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
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>
148 All new tests should be written with the policy of "one test
149 case, one file" in mind.
154 <section xml:id="test.organization.naming" xreflabel="Naming Conventions"><info><title>Naming Conventions</title></info>
158 In addition, there are some special names and suffixes that are
159 used within the testsuite to designate particular kinds of
165 <term><filename class="extension">_xin.cc</filename></term>
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:
171 g++ 27_io/objects/char/3_xin.cc
172 cat 27_io/objects/char/3_xin.in | a.out</programlisting>
176 <term><filename class="extension">.in</filename></term>
178 This file contains the expected input for the corresponding <emphasis>
179 _xin.cc</emphasis> test case.
183 <term><filename class="extension">_neg.cc</filename></term>
185 This test case is expected to fail: it's a negative test. At the
186 moment, these are almost always compile time errors.
190 <term><filename class="directory">char</filename></term>
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
199 <term><filename class="directory">wchar_t</filename></term>
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
210 <term><filename class="directory">thread</filename></term>
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
219 <term><filename class="directory">performance</filename></term>
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.
234 <section xml:id="test.run" xreflabel="Running the Testsuite"><info><title>Running the Testsuite</title></info>
237 <section xml:id="test.run.basic"><info><title>Basic</title></info>
241 You can check the status of the build without installing it
242 using the DejaGnu harness, much like the rest of the gcc
244 <userinput>make check</userinput>
246 <filename class="directory"><replaceable>libbuilddir</replaceable></filename>
248 <userinput>make check-target-libstdc++-v3</userinput>
250 <filename class="directory"><replaceable>gccbuilddir</replaceable></filename>
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
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.
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.
277 <section xml:id="test.run.variations"><info><title>Variations</title></info>
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.
287 To debug the DejaGnu test harness during runs, try invoking with a
288 specific argument to the variable <varname>RUNTESTFLAGS</varname>,
291 make check-target-libstdc++-v3 RUNTESTFLAGS="-v"
295 make check-target-libstdc++-v3 RUNTESTFLAGS="-v -v"
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.
311 For example, to run only the tests for containers you could use:
314 make check-target-libstdc++-v3 RUNTESTFLAGS="conformance.exp=23_containers/*"
319 When combining this with other options in <varname>RUNTESTFLAGS</varname>
320 the <option>testsuite.exp=testfiles</option> options must come first.
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.
330 Example flags to pass down for various embedded builds are as follows:
333 --target=powerpc-eabisim <emphasis>(libgloss/sim)</emphasis>
334 make check-target-libstdc++-v3 RUNTESTFLAGS="--target_board=powerpc-sim"
336 --target=calmrisc32 <emphasis>(libgloss/sid)</emphasis>
337 make check-target-libstdc++-v3 RUNTESTFLAGS="--target_board=calmrisc32-sid"
339 --target=xscale-elf <emphasis>(newlib/sim)</emphasis>
340 make check-target-libstdc++-v3 RUNTESTFLAGS="--target_board=arm-sim"
345 Also, here is an example of how to run the libstdc++ testsuite
346 for a multilibed build directory with different ABI settings:
349 make check-target-libstdc++-v3 RUNTESTFLAGS='--target_board \"unix{-mabi=32,,-mabi=64}\"'
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:
366 runtest --tool libstdc++ --srcdir=/path/to/gcc/libstdc++-v3/testsuite
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.
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>
385 options include, but are not necessarily limited to, the
397 Five files are generated that determine what test files
398 are run. These files are:
402 <term> <filename>testsuite_files</filename> </term>
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
407 <filename class="directory"><replaceable>libsrcdir</replaceable>/testsuite</filename>
413 <term> <filename>testsuite_files_interactive</filename> </term>
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
422 <term> <filename>testsuite_files_performance</filename> </term>
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
431 <term> <filename>testsuite_thread</filename> </term>
433 This file indicates that the host system can run tests which
434 involved multiple threads.
439 <term> <filename>testsuite_wchar_t</filename> </term>
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>.
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.
472 make new-abi-baseline
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.
494 This rule compiles, but does not link or execute, the
495 <filename>testsuite_files</filename> test cases and displays the
503 make check-performance
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
526 This rule runs through the test suite under the
527 <link linkend="manual.ext.debug_mode">debug mode</link>.
539 This rule runs through the test suite under the
540 <link linkend="manual.ext.parallel_mode">parallel mode</link>.
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.
554 <section xml:id="test.run.permutations"><info><title>Permutations</title></info>
557 The tests will be compiled with a set of default compiler flags defined
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>
572 <programlisting> make check RUNTESTFLAGS=--target_board=unix/-O1/-D_GLIBCXX_ASSERTIONS</programlisting>
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).
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.
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.
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>.
623 <section xml:id="test.new_tests"><info><title>Writing a new test case</title></info>
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
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
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
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.
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 expands to a custom assertion using
661 <function>__builtin_printf</function> and
662 <function>__builtin_abort</function>
663 (to avoid using <literal>assert</literal> and being affected by
664 <literal>NDEBUG</literal>).
668 Prior to GCC 7.1, <literal>VERIFY</literal> was defined differently.
669 It usually expanded to the standard <literal>assert</literal> macro, but
670 allowed targets to define it to something different. In order to support
671 the alternative expansions of <literal>VERIFY</literal>, before any use
672 of the macro there needed to be a variable called <varname>test</varname>
673 in scope, which was usually defined like so (the attribute avoids
674 warnings about an unused variable):
676 bool test __attribute__((unused)) = true;
678 This is no longer needed, and should not be added to new tests.
682 The testsuite uses the DejaGnu framework to compile and run the tests.
683 Test cases are normal C++ files which contain special directives in
684 comments. These directives look like <literal>{ dg-* ... }</literal>
685 and tell DejaGnu what to do and what kinds of behavior are to be expected
686 for a test. The core DejaGnu directives are documented in the
687 <filename>dg.exp</filename> file installed by DejaGnu.
688 The GCC testsuites support additional directives
689 as described in the GCC internals documentation, see <link
690 xmlns:xlink="http://www.w3.org/1999/xlink"
691 xlink:href="https://gcc.gnu.org/onlinedocs/gccint/Directives.html">Syntax
692 and Descriptions of test directives</link>. GCC also defines many <link
693 xmlns:xlink="http://www.w3.org/1999/xlink"
694 xlink:href="https://gcc.gnu.org/onlinedocs/gccint/Effective-Target-Keywords.html">
695 Keywords describing target attributes</link> (a.k.a effective targets)
696 which can be used where a target <replaceable>selector</replaceable> can
701 Some directives commonly used in the libstdc++ testsuite are:
705 <term><literal>{ dg-do <replaceable>do-what-keyword</replaceable> [{ target/xfail <replaceable>selector</replaceable> }] }</literal></term>
706 <listitem>Where <replaceable>do-what-keyword</replaceable> is usually
707 one of <literal>run</literal> (which is the default),
708 <literal>compile</literal>, or <literal>link</literal>,
709 and typical selectors are targets such as <literal>*-*-gnu*</literal>
710 or an effective target such as <literal>c++11</literal>.
714 <term><literal>{ dg-require-<replaceable>support</replaceable> args }</literal></term>
715 <listitem>Skip the test if the target does not provide the required support.
716 See below for values of <replaceable>support</replaceable>.
720 <term><literal>{ dg-options <replaceable>options</replaceable> [{ target <replaceable>selector</replaceable> }] }</literal></term>
723 <term><literal>{ dg-error <replaceable>regexp</replaceable> [ <replaceable>comment</replaceable> [{ target/xfail <replaceable>selector</replaceable> } [<replaceable>line</replaceable>] ]] }</literal></term>
726 <term><literal>{ dg-excess-errors <replaceable>comment</replaceable> [{ target/xfail <replaceable>selector</replaceable> }] }</literal></term>
729 For full details of these and other directives see the main GCC DejaGnu
730 documentation in the internals manual.
734 Test cases that use features of a particular C++ standard should specify
735 the minimum required standard as an effective target:
736 <programlisting> // { dg-do run { target c++11 } }</programlisting>
738 <programlisting> // { dg-require-effective-target c++11 }</programlisting>
739 Specifying the minimum required standard for a test allows it to be run
740 using later standards, so that we can verify that C++11 components still
741 work correctly when compiled as C++14 or later. Specifying a minimum also
742 means the test will be skipped if the test is compiled using
743 an older standard, e.g. using
744 <option>RUNTESTFLAGS=--target_board=unix/-std=gnu++98</option>.
748 It is possible to indicate that a test should <emphasis>only</emphasis>
749 be run for a specific standard (and not later standards) using an
750 effective target like <literal>c++11_only</literal>. However, this means
751 the test will be skipped by default (because the default mode is
752 <literal>gnu++14</literal>), and so will only run when
753 <option>-std=gnu++11</option> or <option>-std=c++11</option> is used
754 explicitly. For tests that require a specific standard it is better to
755 use a <literal>dg-options</literal> directive:
756 <programlisting> // { dg-options "-std=gnu++11" }</programlisting>
757 This means the test will not get skipped by default, and will always use
758 the specific standard dialect that the test requires. This isn't needed
759 often, and most tests should use an effective target to specify a
760 minimum standard instead, to allow them to be tested for all
765 Similarly, tests which depend on a newer standard than the default
766 should use <literal>dg-options</literal> instead of an effective target,
767 so that they are not skipped by default.
768 For example, tests for C++17 features should use
769 <programlisting> // { dg-options "-std=gnu++17" }</programlisting>
771 <programlisting> // { dg-do run "c++1z" }</programlisting>
774 <section xml:id="tests.dg.examples"><info><title>Examples of Test Directives</title></info>
777 Example 1: Testing compilation only:
782 Example 2: Testing for expected warnings on line 36, which all targets fail:
784 // { dg-warning "string literals" "" { xfail *-*-* } 36 }
787 Example 3: Testing for expected warnings on line 36:
789 // { dg-warning "string literals" "" { target *-*-* } 36 }
792 Example 4: Testing for compilation errors on line 41:
795 // { dg-error "no match for" "" { target *-*-* } 41 }
798 Example 5: Testing with special command line settings, or without the
799 use of pre-compiled headers, in particular the
800 <filename class="headerfile">stdc++.h.gch</filename> file. Any
801 options here will override the <varname>DEFAULT_CXXFLAGS</varname> and
802 <varname>PCH_CXXFLAGS</varname> set up in the <filename>normal.exp</filename>
805 // { dg-options "-O0" { target *-*-* } }
808 Example 6: Compiling and linking a test only for C++14 and later, and only
809 if Debug Mode is active:
811 // { dg-do link { target c++14 } }
812 // { dg-require-debug-mode "" }
815 Example 7: Running a test only on x86 targets, and only for C++11 and later,
816 with specific options, and additional options for 32-bit x86:
818 // { dg-options "-fstrict-enums" }
819 // { dg-additional-options "-march=i486" { target ia32 } }
820 // { dg-do run { target { ia32 || x86_64-*-* } } }
821 // { dg-require-effective-target "c++11" }
826 More examples can be found in the
827 <filename>libstdc++-v3/testsuite/*/*.cc</filename> files.
831 <section xml:id="tests.dg.directives"><info><title>Directives Specific to Libstdc++ Tests</title></info>
834 In addition to the usual <link
835 xmlns:xlink="http://www.w3.org/1999/xlink"
836 xlink:href="https://gcc.gnu.org/onlinedocs/gccint/Require-Support.html">Variants
837 of <literal>dg-require-<replaceable>support</replaceable></literal></link>
838 several more directives are available for use in libstdc++ tests,
839 including the following:
843 <varlistentry><term><literal>dg-require-namedlocale</literal> <replaceable>name</replaceable></term>
844 <listitem><para>The named locale must be available.
847 <varlistentry><term><literal>dg-require-debug-mode ""</literal></term>
848 <listitem><para>Skip the test if the Debug Mode is not active
849 (as determined by the <literal>_GLIBCXX_DEBUG</literal> macro).
852 <varlistentry><term><literal>dg-require-parallel-mode ""</literal></term>
853 <listitem><para>Skip the test if the Parallel Mode is not active
854 (as determined by the <literal>_GLIBCXX_PARALLEL</literal> macro).
857 <varlistentry><term><literal>dg-require-profile-mode ""</literal></term>
858 <listitem><para>Skip the test if the Profile Mode is not active
859 (as determined by the <literal>_GLIBCXX_PROFILE</literal> macro).
862 <varlistentry><term><literal>dg-require-normal-mode ""</literal></term>
863 <listitem><para>Skip the test if any of Debug, Parallel or Profile
867 <varlistentry><term><literal>dg-require-atomic-builtins ""</literal></term>
868 <listitem><para>Skip the test if atomic operations on <type>bool</type>
869 and <type>int</type> are not lock-free.
872 <varlistentry><term><literal>dg-require-gthreads ""</literal></term>
873 <listitem><para>Skip the test if the C++11 thread library is not
874 supported, as determined by the <literal>_GLIBCXX_HAS_GTHREADS</literal>
878 <varlistentry><term><literal>dg-require-gthreads-timed ""</literal></term>
879 <listitem><para>Skip the test if C++11 timed mutexes are not supported,
880 as determined by the <literal>_GLIBCXX_HAS_GTHREADS</literal> and
881 <literal>_GTHREAD_USE_MUTEX_TIMEDLOCK</literal> macros.
884 <varlistentry><term><literal>dg-require-string-conversions ""</literal></term>
885 <listitem><para>Skip the test if the C++11 <function>to_string</function>
886 and <function>stoi</function>, <function>stod</function> etc. functions
887 are not fully supported (including wide character versions).
890 <varlistentry><term><literal>dg-require-filesystem-ts ""</literal></term>
891 <listitem><para>Skip the test if the Filesystem TS is not supported.
900 <section xml:id="test.harness" xreflabel="Test Harness and Utilities"><info><title>Test Harness and Utilities</title></info>
903 <section xml:id="test.harness.dejagnu"><info><title>DejaGnu Harness Details</title></info>
906 Underlying details of testing for conformance and regressions are
907 abstracted via the GNU DejaGnu package. This is similar to the
912 <para>This is information for those looking at making changes to the testsuite
913 structure, and/or needing to trace DejaGnu's actions with
914 <option>--verbose</option>.
915 This will not be useful to people who are "merely" adding new tests
916 to the existing structure.
919 <para>The first key point when working with DejaGnu is the idea of a "tool".
920 Files, directories, and functions are all implicitly used when they are
921 named after the tool in use. Here, the tool will always be "libstdc++".
924 <para>The <code>lib</code> subdir contains support routines. The
925 <code>lib/libstdc++.exp</code> file ("support library") is loaded
926 automagically, and must explicitly load the others. For example, files can
927 be copied from the core compiler's support directory into <code>lib</code>.
930 <para>Some routines in <code>lib/libstdc++.exp</code> are callbacks, some are
931 our own. Callbacks must be prefixed with the name of the tool. To easily
932 distinguish the others, by convention our own routines are named "v3-*".
935 <para>The next key point when working with DejaGnu is "test files". Any
936 directory whose name starts with the tool name will be searched for test files.
937 (We have only one.) In those directories, any <code>.exp</code> file is
938 considered a test file, and will be run in turn. Our main test file is called
939 <code>normal.exp</code>; it runs all the tests in testsuite_files using the
940 callbacks loaded from the support library.
943 <para>The <code>config</code> directory is searched for any particular "target
944 board" information unique to this library. This is currently unused and sets
945 only default variables.
950 <section xml:id="test.harness.utils"><info><title>Utilities</title></info>
955 The testsuite directory also contains some files that implement
956 functionality that is intended to make writing test cases easier,
957 or to avoid duplication, or to provide error checking in a way that
958 is consistent across platforms and test harnesses. A stand-alone
959 executable, called <emphasis>abi_check</emphasis>, and a static
960 library called <emphasis>libtestc++</emphasis> are
961 constructed. Both of these items are not installed, and only used
966 These files include the following functionality:
972 <emphasis>testsuite_abi.h</emphasis>,
973 <emphasis>testsuite_abi.cc</emphasis>,
974 <emphasis>testsuite_abi_check.cc</emphasis>
977 Creates the executable <emphasis>abi_check</emphasis>.
978 Used to check correctness of symbol versioning, visibility of
979 exported symbols, and compatibility on symbols in the shared
980 library, for hosts that support this feature. More information
981 can be found in the ABI documentation <link linkend="appendix.porting.abi">here</link>
986 <emphasis>testsuite_allocator.h</emphasis>,
987 <emphasis>testsuite_allocator.cc</emphasis>
990 Contains specialized allocators that keep track of construction
991 and destruction. Also, support for overriding global new and
992 delete operators, including verification that new and delete
993 are called during execution, and that allocation over max_size
999 <emphasis>testsuite_character.h</emphasis>
1002 Contains <code>std::char_traits</code> and
1003 <code>std::codecvt</code> specializations for a user-defined
1009 <emphasis>testsuite_hooks.h</emphasis>,
1010 <emphasis>testsuite_hooks.cc</emphasis>
1013 A large number of utilities, including:
1016 <listitem><para>VERIFY</para></listitem>
1017 <listitem><para>set_memory_limits</para></listitem>
1018 <listitem><para>verify_demangle</para></listitem>
1019 <listitem><para>run_tests_wrapped_locale</para></listitem>
1020 <listitem><para>run_tests_wrapped_env</para></listitem>
1021 <listitem><para>try_named_locale</para></listitem>
1022 <listitem><para>try_mkfifo</para></listitem>
1023 <listitem><para>func_callback</para></listitem>
1024 <listitem><para>counter</para></listitem>
1025 <listitem><para>copy_tracker</para></listitem>
1026 <listitem><para>copy_constructor</para></listitem>
1027 <listitem><para>assignment_operator</para></listitem>
1028 <listitem><para>destructor</para></listitem>
1030 <para>pod_char, pod_int and associated char_traits specializations</para>
1036 <emphasis>testsuite_io.h</emphasis>
1039 Error, exception, and constraint checking for
1040 <code>std::streambuf, std::basic_stringbuf, std::basic_filebuf</code>.
1045 <emphasis>testsuite_iterators.h</emphasis>
1048 Wrappers for various iterators.
1053 <emphasis>testsuite_performance.h</emphasis>
1056 A number of class abstractions for performance counters, and
1057 reporting functions including:
1060 <listitem><para>time_counter</para></listitem>
1061 <listitem><para>resource_counter</para></listitem>
1062 <listitem><para>report_performance</para></listitem>
1070 <section xml:id="test.special"><info><title>Special Topics</title></info>
1073 <section xml:id="test.exception.safety"><info><title>
1074 Qualifying Exception Safety Guarantees
1076 <primary>Test</primary>
1077 <secondary>Exception Safety</secondary>
1082 <section xml:id="test.exception.safety.overview"><info><title>Overview</title></info>
1086 Testing is composed of running a particular test sequence,
1087 and looking at what happens to the surrounding code when
1088 exceptions are thrown. Each test is composed of measuring
1089 initial state, executing a particular sequence of code under
1090 some instrumented conditions, measuring a final state, and
1091 then examining the differences between the two states.
1095 Test sequences are composed of constructed code sequences
1096 that exercise a particular function or member function, and
1097 either confirm no exceptions were generated, or confirm the
1098 consistency/coherency of the test subject in the event of a
1103 Random code paths can be constructed using the basic test
1104 sequences and instrumentation as above, only combined in a
1105 random or pseudo-random way.
1108 <para> To compute the code paths that throw, test instruments
1109 are used that throw on allocation events
1110 (<classname>__gnu_cxx::throw_allocator_random</classname>
1111 and <classname>__gnu_cxx::throw_allocator_limit</classname>)
1112 and copy, assignment, comparison, increment, swap, and
1114 (<classname>__gnu_cxx::throw_type_random</classname>
1115 and <classname>__gnu_cxx::throw_type_limit</classname>). Looping
1116 through a given test sequence and conditionally throwing in
1117 all instrumented places. Then, when the test sequence
1118 completes without an exception being thrown, assume all
1119 potential error paths have been exercised in a sequential
1125 <section xml:id="test.exception.safety.status"><info><title>
1137 <filename>testsuite/23_containers/list/modifiers/3.cc</filename>.
1143 Policy Based Data Structures
1146 For example, take the test
1147 functor <classname>rand_reg_test</classname> in
1148 in <filename>testsuite/ext/pb_ds/regression/tree_no_data_map_rand.cc</filename>. This uses <classname>container_rand_regression_test</classname> in
1149 <filename>testsuite/util/regression/rand/assoc/container_rand_regression_test.h</filename>.
1154 Which has several tests for container member functions,
1155 Includes control and test container objects. Configuration includes
1156 random seed, iterations, number of distinct values, and the
1157 probability that an exception will be thrown. Assumes instantiating
1158 container uses an extension
1159 allocator, <classname>__gnu_cxx::throw_allocator_random</classname>,
1160 as the allocator type.
1166 C++11 Container Requirements.
1170 Coverage is currently limited to testing container
1171 requirements for exception safety,
1172 although <classname>__gnu_cxx::throw_type</classname> meets
1173 the additional type requirements for testing numeric data
1174 structures and instantiating algorithms.
1178 Of particular interest is extending testing to algorithms and
1179 then to parallel algorithms. Also io and locales.
1183 The test instrumentation should also be extended to add
1184 instrumentation to <classname>iterator</classname>
1185 and <classname>const_iterator</classname> types that throw
1186 conditionally on iterator operations.
1193 <section xml:id="test.exception.safety.containers"><info><title>
1194 C++11 Requirements Test Sequence Descriptions
1205 Basic consistency on exception propagation tests. For
1206 each container, an object of that container is constructed,
1207 a specific member function is exercised in
1208 a <literal>try</literal> block, and then any thrown
1209 exceptions lead to error checking in the appropriate
1210 <literal>catch</literal> block. The container's use of
1211 resources is compared to the container's use prior to the
1212 test block. Resource monitoring is limited to allocations
1213 made through the container's <type>allocator_type</type>,
1214 which should be sufficient for container data
1215 structures. Included in these tests are member functions
1216 are <type>iterator</type> and <type>const_iterator</type>
1217 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>,
1218 and <function>rehash</function>. The container in question is
1219 instantiated with two instrumented template arguments,
1220 with <classname>__gnu_cxx::throw_allocator_limit</classname>
1221 as the allocator type, and
1222 with <classname>__gnu_cxx::throw_type_limit</classname> as
1223 the value type. This allows the test to loop through
1224 conditional throw points.
1228 The general form is demonstrated in
1229 <filename>testsuite/23_containers/list/requirements/exception/basic.cc
1230 </filename>. The instantiating test object is <classname>__gnu_test::basic_safety</classname> and is detailed in <filename>testsuite/util/exception/safety.h</filename>.
1237 Generation Prohibited
1241 Exception generation tests. For each container, an object of
1242 that container is constructed and all member functions
1243 required to not throw exceptions are exercised. Included in
1244 these tests are member functions
1245 are <type>iterator</type> and <type>const_iterator</type> operations, <function>erase</function>, <function>pop_front</function>, <function>pop_back</function>, <function>swap</function>,
1246 and <function>clear</function>. The container in question is
1247 instantiated with two instrumented template arguments,
1248 with <classname>__gnu_cxx::throw_allocator_random</classname>
1249 as the allocator type, and
1250 with <classname>__gnu_cxx::throw_type_random</classname> as
1251 the value type. This test does not loop, an instead is sudden
1252 death: first error fails.
1255 The general form is demonstrated in
1256 <filename>testsuite/23_containers/list/requirements/exception/generation_prohibited.cc
1257 </filename>. The instantiating test object is <classname>__gnu_test::generation_prohibited</classname> and is detailed in <filename>testsuite/util/exception/safety.h</filename>.
1264 Propagation Consistent
1268 Container rollback on exception propagation tests. For
1269 each container, an object of that container is constructed,
1270 a specific member function that requires rollback to a previous
1271 known good state is exercised in
1272 a <literal>try</literal> block, and then any thrown
1273 exceptions lead to error checking in the appropriate
1274 <literal>catch</literal> block. The container is compared to
1275 the container's last known good state using such parameters
1276 as size, contents, and iterator references. Included in these
1277 tests are member functions
1278 are <function>push_front</function>, <function>push_back</function>, <function>insert</function>,
1279 and <function>rehash</function>. The container in question is
1280 instantiated with two instrumented template arguments,
1281 with <classname>__gnu_cxx::throw_allocator_limit</classname>
1282 as the allocator type, and
1283 with <classname>__gnu_cxx::throw_type_limit</classname> as
1284 the value type. This allows the test to loop through
1285 conditional throw points.
1289 The general form demonstrated in
1290 <filename>testsuite/23_containers/list/requirements/exception/propagation_coherent.cc
1291 </filename>. The instantiating test object is <classname>__gnu_test::propagation_coherent</classname> and is detailed in <filename>testsuite/util/exception/safety.h</filename>.