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| <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>Testing</title><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /><meta name="keywords" content="ISO C++, test, testsuite, performance, conformance, ABI, exception safety" /><meta name="keywords" content="ISO C++, library" /><meta name="keywords" content="ISO C++, runtime, library" /><link rel="home" href="../index.html" title="The GNU C++ Library" /><link rel="up" href="appendix_porting.html" title="Appendix B. Porting and Maintenance" /><link rel="prev" href="internals.html" title="Porting to New Hardware or Operating Systems" /><link rel="next" href="abi.html" title="ABI Policy and Guidelines" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Testing</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="internals.html">Prev</a> </td><th width="60%" align="center">Appendix B. |
| Porting and Maintenance |
| |
| </th><td width="20%" align="right"> <a accesskey="n" href="abi.html">Next</a></td></tr></table><hr /></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="manual.intro.setup.test"></a>Testing</h2></div></div></div><p> |
| The libstdc++ testsuite includes testing for standard conformance, |
| regressions, ABI, and performance. |
| </p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="test.organization"></a>Test Organization</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a id="test.organization.layout"></a>Directory Layout</h4></div></div></div><p> |
| The directory |
| <code class="filename"><em class="replaceable"><code>gccsrcdir</code></em>/libstdc++-v3/testsuite</code> |
| contains the individual test cases organized in sub-directories |
| corresponding to clauses of the C++ standard (detailed below), |
| the DejaGnu test harness support files, and sources to various |
| testsuite utilities that are packaged in a separate testing library. |
| </p><p> |
| All test cases for functionality required by the runtime components |
| of the C++ standard (ISO 14882) are files within the following |
| directories: |
| |
| </p><pre class="programlisting"> |
| 17_intro |
| 18_support |
| 19_diagnostics |
| 20_util |
| 21_strings |
| 22_locale |
| 23_containers |
| 24_iterators |
| 25_algorithms |
| 26_numerics |
| 27_io |
| 28_regex |
| 29_atomics |
| 30_threads |
| </pre><p> |
| </p><p> |
| In addition, the following directories include test files: |
| |
| </p><div class="variablelist"><dl class="variablelist compact"><dt><span class="term"><code class="filename">tr1</code></span></dt><dd>Tests for components as described by the Technical Report |
| on Standard Library Extensions (TR1). |
| </dd><dt><span class="term"><code class="filename">backward</code></span></dt><dd>Tests for backwards compatibility and deprecated features. |
| </dd><dt><span class="term"><code class="filename">demangle</code></span></dt><dd>Tests for <code class="function">__cxa_demangle</code>, the IA-64 C++ ABI |
| demangler. |
| </dd><dt><span class="term"><code class="filename">ext</code></span></dt><dd>Tests for extensions.</dd><dt><span class="term"><code class="filename">performance</code></span></dt><dd>Tests for performance analysis, and performance regressions. |
| </dd></dl></div><p> |
| </p><p> |
| Some directories don't have test files, but instead contain |
| auxiliary information: |
| |
| </p><div class="variablelist"><dl class="variablelist compact"><dt><span class="term"><code class="filename">config</code></span></dt><dd>Files for the DejaGnu test harness.</dd><dt><span class="term"><code class="filename">lib</code></span></dt><dd>Files for the DejaGnu test harness.</dd><dt><span class="term"><code class="filename">libstdc++*</code></span></dt><dd>Files for the DejaGnu test harness.</dd><dt><span class="term"><code class="filename">data</code></span></dt><dd>Sample text files for testing input and output.</dd><dt><span class="term"><code class="filename">util</code></span></dt><dd>Files for libtestc++, utilities and testing routines.</dd></dl></div><p> |
| </p><p> |
| Within a directory that includes test files, there may be |
| additional subdirectories, or files. Originally, test cases |
| were appended to one file that represented a particular section |
| of the chapter under test, and was named accordingly. For |
| instance, to test items related to <code class="code"> 21.3.6.1 - |
| <code class="function">basic_string::find</code> [lib.string::find]</code> |
| in the standard, the following was used: |
| </p><pre class="programlisting"> 21_strings/find.cc </pre><p> |
| However, that practice soon became a liability as the test cases |
| became huge and unwieldy, and testing new or extended |
| functionality (like wide characters or named locales) became |
| frustrating, leading to aggressive pruning of test cases on some |
| platforms that covered up implementation errors. Now, the test |
| suite has a policy of one file, one test case, which solves the |
| above issues and gives finer grained results and more manageable |
| error debugging. As an example, the test case quoted above |
| becomes: |
| </p><pre class="programlisting"> 21_strings/basic_string/find/char/1.cc |
| 21_strings/basic_string/find/char/2.cc |
| 21_strings/basic_string/find/char/3.cc |
| 21_strings/basic_string/find/wchar_t/1.cc |
| 21_strings/basic_string/find/wchar_t/2.cc |
| 21_strings/basic_string/find/wchar_t/3.cc</pre><p> |
| </p><p> |
| All new tests should be written with the policy of "one test |
| case, one file" in mind. |
| </p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a id="test.organization.naming"></a>Naming Conventions</h4></div></div></div><p> |
| In addition, there are some special names and suffixes that are |
| used within the testsuite to designate particular kinds of |
| tests. |
| </p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="filename">_xin.cc</code></span></dt><dd> |
| This test case expects some kind of interactive input in order |
| to finish or pass. At the moment, the interactive tests are not |
| run by default. Instead, they are run by hand, like: |
| <pre class="programlisting"> |
| g++ 27_io/objects/char/3_xin.cc |
| cat 27_io/objects/char/3_xin.in | a.out</pre></dd><dt><span class="term"><code class="filename">.in</code></span></dt><dd> |
| This file contains the expected input for the corresponding <span class="emphasis"><em> |
| _xin.cc</em></span> test case. |
| </dd><dt><span class="term"><code class="filename">_neg.cc</code></span></dt><dd> |
| This test case is expected to fail: it's a negative test. At the |
| moment, these are almost always compile time errors. |
| </dd><dt><span class="term"><code class="filename">char</code></span></dt><dd> |
| This can either be a directory name or part of a longer file |
| name, and indicates that this file, or the files within this |
| directory are testing the <code class="code">char</code> instantiation of a |
| template. |
| </dd><dt><span class="term"><code class="filename">wchar_t</code></span></dt><dd> |
| This can either be a directory name or part of a longer file |
| name, and indicates that this file, or the files within this |
| directory are testing the <code class="code">wchar_t</code> instantiation of |
| a template. Some hosts do not support <code class="code">wchar_t</code> |
| functionality, so for these targets, all of these tests will not |
| be run. |
| </dd><dt><span class="term"><code class="filename">thread</code></span></dt><dd> |
| This can either be a directory name or part of a longer file |
| name, and indicates that this file, or the files within this |
| directory are testing situations where multiple threads are |
| being used. |
| </dd><dt><span class="term"><code class="filename">performance</code></span></dt><dd> |
| This can either be an enclosing directory name or part of a |
| specific file name. This indicates a test that is used to |
| analyze runtime performance, for performance regression testing, |
| or for other optimization related analysis. At the moment, these |
| test cases are not run by default. |
| </dd></dl></div></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="test.run"></a>Running the Testsuite</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a id="test.run.basic"></a>Basic</h4></div></div></div><p> |
| You can check the status of the build without installing it |
| using the DejaGnu harness, much like the rest of the gcc |
| tools, i.e. |
| <strong class="userinput"><code>make check</code></strong> |
| in the |
| <code class="filename"><em class="replaceable"><code>libbuilddir</code></em></code> |
| directory, or |
| <strong class="userinput"><code>make check-target-libstdc++-v3</code></strong> |
| in the |
| <code class="filename"><em class="replaceable"><code>gccbuilddir</code></em></code> |
| directory. |
| </p><p> |
| These commands are functionally equivalent and will create a |
| '<code class="filename">testsuite</code>' directory underneath |
| <code class="filename"><em class="replaceable"><code>libbuilddir</code></em></code> |
| containing the results of the |
| tests. Two results files will be generated: |
| <code class="filename">libstdc++.sum</code>, which is a PASS/FAIL summary |
| for each test, and |
| <code class="filename">libstdc++.log</code> which is a log of |
| the exact command-line passed to the compiler, the compiler |
| output, and the executable output (if any) for each test. |
| </p><p> |
| Archives of test results for various versions and platforms are |
| available on the GCC website in the <a class="link" href="http://gcc.gnu.org/gcc-4.3/buildstat.html" target="_top">build |
| status</a> section of each individual release, and are also |
| archived on a daily basis on the <a class="link" href="http://gcc.gnu.org/ml/gcc-testresults/current" target="_top">gcc-testresults</a> |
| mailing list. Please check either of these places for a similar |
| combination of source version, operating system, and host CPU. |
| </p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a id="test.run.variations"></a>Variations</h4></div></div></div><p> |
| There are several options for running tests, including testing |
| the regression tests, testing a subset of the regression tests, |
| testing the performance tests, testing just compilation, testing |
| installed tools, etc. In addition, there is a special rule for |
| checking the exported symbols of the shared library. |
| </p><p> |
| To debug the DejaGnu test harness during runs, try invoking with a |
| specific argument to the variable <code class="varname">RUNTESTFLAGS</code>, |
| like so: |
| </p><pre class="programlisting"> |
| make check-target-libstdc++-v3 RUNTESTFLAGS="-v" |
| </pre><p> |
| or |
| </p><pre class="programlisting"> |
| make check-target-libstdc++-v3 RUNTESTFLAGS="-v -v" |
| </pre><p> |
| </p><p> |
| To run a subset of the library tests, you can either generate the |
| <code class="filename">testsuite_files</code> file (described below) by running |
| <strong class="userinput"><code>make testsuite_files</code></strong> in the |
| <code class="filename"><em class="replaceable"><code>libbuilddir</code></em>/testsuite</code> |
| directory, then edit the |
| file to remove the tests you don't want and then run the testsuite as |
| normal, or you can specify a testsuite and a subset of tests in the |
| <code class="varname">RUNTESTFLAGS</code> variable. |
| </p><p> |
| For example, to run only the tests for containers you could use: |
| |
| </p><pre class="programlisting"> |
| make check-target-libstdc++-v3 RUNTESTFLAGS="conformance.exp=23_containers/*" |
| </pre><p> |
| </p><p> |
| When combining this with other options in <code class="varname">RUNTESTFLAGS</code> |
| the <code class="option">testsuite.exp=testfiles</code> options must come first. |
| </p><p> |
| There are two ways to run on a simulator: set up <code class="envar">DEJAGNU</code> |
| to point to a specially crafted <code class="filename">site.exp</code>, |
| or pass down <code class="option">--target_board</code> flags. |
| </p><p> |
| Example flags to pass down for various embedded builds are as follows: |
| |
| </p><pre class="programlisting"> |
| --target=powerpc-eabisim <span class="emphasis"><em>(libgloss/sim)</em></span> |
| make check-target-libstdc++-v3 RUNTESTFLAGS="--target_board=powerpc-sim" |
| |
| --target=calmrisc32 <span class="emphasis"><em>(libgloss/sid)</em></span> |
| make check-target-libstdc++-v3 RUNTESTFLAGS="--target_board=calmrisc32-sid" |
| |
| --target=xscale-elf <span class="emphasis"><em>(newlib/sim)</em></span> |
| make check-target-libstdc++-v3 RUNTESTFLAGS="--target_board=arm-sim" |
| </pre><p> |
| </p><p> |
| Also, here is an example of how to run the libstdc++ testsuite |
| for a multilibed build directory with different ABI settings: |
| |
| </p><pre class="programlisting"> |
| make check-target-libstdc++-v3 RUNTESTFLAGS='--target_board \"unix{-mabi=32,,-mabi=64}\"' |
| </pre><p> |
| </p><p> |
| You can run the tests with a compiler and library that have |
| already been installed. Make sure that the compiler (e.g., |
| <span class="command"><strong>g++</strong></span>) is in your <code class="envar">PATH</code>. If you are |
| using shared libraries, then you must also ensure that the |
| directory containing the shared version of libstdc++ is in your |
| <code class="envar">LD_LIBRARY_PATH</code>, or |
| <a class="link" href="using_dynamic_or_shared.html#manual.intro.using.linkage.dynamic" title="Finding Dynamic or Shared Libraries">equivalent</a>. |
| If your GCC source tree is at |
| <code class="filename">/path/to/gcc</code>, |
| then you can run the tests as follows: |
| |
| </p><pre class="programlisting"> |
| runtest --tool libstdc++ --srcdir=/path/to/gcc/libstdc++-v3/testsuite |
| </pre><p> |
| </p><p> |
| The testsuite will create a number of files in the directory in |
| which you run this command,. Some of those files might use the |
| same name as files created by other testsuites (like the ones |
| for GCC and G++), so you should not try to run all the |
| testsuites in parallel from the same directory. |
| </p><p> |
| In addition, there are some testing options that are mostly of |
| interest to library maintainers and system integrators. As such, |
| these tests may not work on all CPU and host combinations, and |
| may need to be executed in the |
| <code class="filename"><em class="replaceable"><code>libbuilddir</code></em>/testsuite</code> |
| directory. These |
| options include, but are not necessarily limited to, the |
| following: |
| </p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><strong class="userinput"><code> |
| make testsuite_files |
| </code></strong></span></dt><dd><p> |
| Five files are generated that determine what test files |
| are run. These files are: |
| |
| </p><div class="variablelist"><dl class="variablelist"><dt><span class="term"> <code class="filename">testsuite_files</code> </span></dt><dd> |
| This is a list of all the test cases that will be run. Each |
| test case is on a separate line, given with an absolute path |
| from the |
| <code class="filename"><em class="replaceable"><code>libsrcdir</code></em>/testsuite</code> |
| directory. |
| </dd><dt><span class="term"> <code class="filename">testsuite_files_interactive</code> </span></dt><dd> |
| This is a list of all the interactive test cases, using the |
| same format as the file list above. These tests are not run |
| by default. |
| </dd><dt><span class="term"> <code class="filename">testsuite_files_performance</code> </span></dt><dd> |
| This is a list of all the performance test cases, using the |
| same format as the file list above. These tests are not run |
| by default. |
| </dd><dt><span class="term"> <code class="filename">testsuite_thread</code> </span></dt><dd> |
| This file indicates that the host system can run tests which |
| involved multiple threads. |
| </dd><dt><span class="term"> <code class="filename">testsuite_wchar_t</code> </span></dt><dd> |
| This file indicates that the host system can run the |
| <code class="code">wchar_t</code> tests, and corresponds to the macro |
| definition <code class="literal">_GLIBCXX_USE_WCHAR_T</code> in the |
| file <code class="filename">c++config.h</code>. |
| </dd></dl></div><p> |
| </p></dd><dt><span class="term"><strong class="userinput"><code> |
| make check-abi |
| </code></strong></span></dt><dd><p> |
| The library ABI can be tested. This involves testing the shared |
| library against a baseline list of symbol exports that defines the |
| previous version of the ABI. The tests require that no exported |
| symbols are removed, no new symbols are added to the old symbol |
| versions, and any new symbols have the latest symbol version. |
| See <a class="link" href="abi.html#abi.versioning" title="Versioning">Versioning</a> for more details |
| of the ABI version history. |
| </p></dd><dt><span class="term"><strong class="userinput"><code> |
| make new-abi-baseline |
| </code></strong></span></dt><dd><p> |
| Generate a new baseline set of symbols exported from the library |
| (written to a file under |
| <code class="filename"><em class="replaceable"><code>libsrcdir</code></em>/config/abi/post/<em class="replaceable"><code>target</code></em>/</code>). |
| A different baseline symbols file is needed for each architecture and |
| is used by the <code class="literal">check-abi</code> target described above. |
| The files are usually re-generated by target maintainers for releases. |
| </p></dd><dt><span class="term"><strong class="userinput"><code> |
| make check-compile |
| </code></strong></span></dt><dd><p> |
| This rule compiles, but does not link or execute, the |
| <code class="filename">testsuite_files</code> test cases and displays the |
| output on stdout. |
| </p></dd><dt><span class="term"><strong class="userinput"><code> |
| make check-performance |
| </code></strong></span></dt><dd><p> |
| This rule runs through the |
| <code class="filename">testsuite_files_performance</code> test cases and |
| collects information for performance analysis and can be used to |
| spot performance regressions. Various timing information is |
| collected, as well as number of hard page faults, and memory |
| used. This is not run by default, and the implementation is in |
| flux. |
| </p></dd><dt><span class="term"><strong class="userinput"><code> |
| make check-debug |
| </code></strong></span></dt><dd><p> |
| This rule runs through the test suite under the |
| <a class="link" href="debug_mode.html" title="Chapter 17. Debug Mode">debug mode</a>. |
| </p></dd><dt><span class="term"><strong class="userinput"><code> |
| make check-parallel |
| </code></strong></span></dt><dd><p> |
| This rule runs through the test suite under the |
| <a class="link" href="parallel_mode.html" title="Chapter 18. Parallel Mode">parallel mode</a>. |
| </p></dd></dl></div><p> |
| We are interested in any strange failures of the testsuite; |
| please email the main libstdc++ mailing list if you see |
| something odd or have questions. |
| </p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a id="test.run.permutations"></a>Permutations</h4></div></div></div><p> |
| The tests will be compiled with a set of default compiler flags defined |
| by the |
| <code class="filename"><em class="replaceable"><code>libbuilddir</code></em>/scripts/testsuite_flags</code> |
| file, as well as options specified in individual tests. You can run |
| the tests with different options by adding them to the output of |
| the <code class="option">--cxxflags</code> option of that script, or by setting |
| the <code class="varname">CXXFLAGS</code> variable when running |
| <span class="command"><strong>make</strong></span>, or via options for the DejaGnu test framework |
| (described below). The latter approach uses the |
| <code class="option">--target_board</code> option that was shown earlier, |
| but requires DejaGnu version 1.5.3 or newer to work reliably, so that the |
| <code class="literal">dg-options</code> in the test aren't overridden. |
| For example, to run the tests with |
| <code class="option">-O1 -D_GLIBCXX_ASSERTIONS</code> |
| you could use: |
| </p><pre class="programlisting"> make check RUNTESTFLAGS=--target_board=unix/-O1/-D_GLIBCXX_ASSERTIONS</pre><p> |
| </p><p> |
| The <code class="option">--target_board</code> option can also be used to run the |
| tests multiple times in different variations. For example, to run the |
| entire testsuite three times using <code class="option">-O3</code> but with |
| different <code class="option">-std</code> options: |
| </p><pre class="programlisting"> make check 'RUNTESTFLAGS=--target_board=unix/-O3\"{-std=gnu++98,-std=gnu++11,-std=gnu++14}\"'</pre><p> |
| N.B. that set of variations could also be written as |
| <code class="literal">unix/-O3\"{-std=gnu++98,-std=gnu++11,}\"</code> so that |
| the third variation would use the default for <code class="option">-std</code> |
| (which is <code class="option">-std=gnu++14</code> as of GCC 6). |
| </p><p> |
| To run the libstdc++ test suite under the |
| <a class="link" href="debug_mode.html" title="Chapter 17. Debug Mode">debug mode</a>, use |
| <strong class="userinput"><code>make check-debug</code></strong>. Alternatively, edit |
| <code class="filename"><em class="replaceable"><code>libbuilddir</code></em>/scripts/testsuite_flags</code> |
| to add the compile-time flag <code class="option">-D_GLIBCXX_DEBUG</code> to the |
| result printed by the <code class="option">--cxxflags</code> |
| option. Additionally, add the |
| <code class="option">-D_GLIBCXX_DEBUG_PEDANTIC</code> flag to turn on |
| pedantic checking. The libstdc++ test suite should produce |
| the same results under debug mode that it does under release mode: |
| any deviation indicates an error in either the library or the test suite. |
| Note, however, that the number of tests that PASS may change, because |
| some test cases are skipped in normal mode, and some are skipped in |
| debug mode, as determined by the |
| <code class="literal">dg-require-<em class="replaceable"><code>support</code></em></code> |
| directives described below. |
| </p><p> |
| The <a class="link" href="parallel_mode.html" title="Chapter 18. Parallel Mode">parallel |
| mode</a> can be tested using |
| <strong class="userinput"><code>make check-parallel</code></strong>, or in much the same manner |
| as the debug mode, substituting |
| <code class="option">-D_GLIBCXX_PARALLEL</code> for |
| <code class="option">-D_GLIBCXX_DEBUG</code> in the previous paragraph. |
| </p><p> |
| Or, just run the testsuite |
| <code class="option">-D_GLIBCXX_DEBUG</code> or <code class="option">-D_GLIBCXX_PARALLEL</code> |
| in <code class="varname">CXXFLAGS</code> or <code class="varname">RUNTESTFLAGS</code>. |
| </p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="test.new_tests"></a>Writing a new test case</h3></div></div></div><p> |
| The first step in making a new test case is to choose the correct |
| directory and file name, given the organization as previously |
| described. |
| </p><p> |
| All files are copyright the FSF, and GPL'd: this is very |
| important. The first copyright year should correspond to the date |
| the file was checked in to version control. If a test is copied from |
| an existing file it should retain the copyright years from the |
| original file. |
| </p><p> |
| The DejaGnu instructions say to always return <code class="literal">0</code> |
| from <code class="function">main</code> to indicate success. Strictly speaking |
| this is redundant in C++, since returning from <code class="function">main</code> |
| is defined to return <code class="literal">0</code>. Most tests still have an |
| explicit return. |
| </p><p> |
| A bunch of utility functions and classes have already been |
| abstracted out into the testsuite utility library, <code class="code"> |
| libtestc++</code>. To use this functionality, just include the |
| appropriate header file: the library or specific object files will |
| automatically be linked in as part of the testsuite run. |
| </p><p> |
| Tests that need to perform runtime checks should use the |
| <code class="literal">VERIFY</code> macro, defined in the |
| <code class="filename"><testsuite_hooks.h></code> header. |
| This expands to a custom assertion using |
| <code class="function">__builtin_printf</code> and |
| <code class="function">__builtin_abort</code> |
| (to avoid using <code class="literal">assert</code> and being affected by |
| <code class="literal">NDEBUG</code>). |
| </p><p> |
| Prior to GCC 7.1, <code class="literal">VERIFY</code> was defined differently. |
| It usually expanded to the standard <code class="literal">assert</code> macro, but |
| allowed targets to define it to something different. In order to support |
| the alternative expansions of <code class="literal">VERIFY</code>, before any use |
| of the macro there needed to be a variable called <code class="varname">test</code> |
| in scope, which was usually defined like so (the attribute avoids |
| warnings about an unused variable): |
| </p><pre class="programlisting"> |
| bool test __attribute__((unused)) = true; |
| </pre><p> |
| This is no longer needed, and should not be added to new tests. |
| </p><p> |
| The testsuite uses the DejaGnu framework to compile and run the tests. |
| Test cases are normal C++ files which contain special directives in |
| comments. These directives look like <code class="literal">{ dg-* ... }</code> |
| and tell DejaGnu what to do and what kinds of behavior are to be expected |
| for a test. The core DejaGnu directives are documented in the |
| <code class="filename">dg.exp</code> file installed by DejaGnu. |
| The GCC testsuites support additional directives |
| as described in the GCC internals documentation, see <a class="link" href="https://gcc.gnu.org/onlinedocs/gccint/Directives.html" target="_top">Syntax |
| and Descriptions of test directives</a>. GCC also defines many <a class="link" href="https://gcc.gnu.org/onlinedocs/gccint/Effective-Target-Keywords.html" target="_top"> |
| Keywords describing target attributes</a> (a.k.a effective targets) |
| which can be used where a target <em class="replaceable"><code>selector</code></em> can |
| appear. |
| </p><p> |
| Some directives commonly used in the libstdc++ testsuite are: |
| |
| </p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="literal">{ dg-do <em class="replaceable"><code>do-what-keyword</code></em> [{ target/xfail <em class="replaceable"><code>selector</code></em> }] }</code></span></dt><dd>Where <em class="replaceable"><code>do-what-keyword</code></em> is usually |
| one of <code class="literal">run</code> (which is the default), |
| <code class="literal">compile</code>, or <code class="literal">link</code>, |
| and typical selectors are targets such as <code class="literal">*-*-gnu*</code> |
| or an effective target such as <code class="literal">c++11</code>. |
| </dd><dt><span class="term"><code class="literal">{ dg-require-<em class="replaceable"><code>support</code></em> args }</code></span></dt><dd>Skip the test if the target does not provide the required support. |
| See below for values of <em class="replaceable"><code>support</code></em>. |
| </dd><dt><span class="term"><code class="literal">{ dg-options <em class="replaceable"><code>options</code></em> [{ target <em class="replaceable"><code>selector</code></em> }] }</code></span></dt><dd></dd><dt><span class="term"><code class="literal">{ dg-error <em class="replaceable"><code>regexp</code></em> [ <em class="replaceable"><code>comment</code></em> [{ target/xfail <em class="replaceable"><code>selector</code></em> } [<em class="replaceable"><code>line</code></em>] ]] }</code></span></dt><dd></dd><dt><span class="term"><code class="literal">{ dg-excess-errors <em class="replaceable"><code>comment</code></em> [{ target/xfail <em class="replaceable"><code>selector</code></em> }] }</code></span></dt><dd></dd></dl></div><p> |
| For full details of these and other directives see the main GCC DejaGnu |
| documentation in the internals manual. |
| </p><p> |
| Test cases that use features of a particular C++ standard should specify |
| the minimum required standard as an effective target: |
| </p><pre class="programlisting"> // { dg-do run { target c++11 } }</pre><p> |
| or |
| </p><pre class="programlisting"> // { dg-require-effective-target c++11 }</pre><p> |
| Specifying the minimum required standard for a test allows it to be run |
| using later standards, so that we can verify that C++11 components still |
| work correctly when compiled as C++14 or later. Specifying a minimum also |
| means the test will be skipped if the test is compiled using |
| an older standard, e.g. using |
| <code class="option">RUNTESTFLAGS=--target_board=unix/-std=gnu++98</code>. |
| </p><p> |
| It is possible to indicate that a test should <span class="emphasis"><em>only</em></span> |
| be run for a specific standard (and not later standards) using an |
| effective target like <code class="literal">c++11_only</code>. However, this means |
| the test will be skipped by default (because the default mode is |
| <code class="literal">gnu++14</code>), and so will only run when |
| <code class="option">-std=gnu++11</code> or <code class="option">-std=c++11</code> is used |
| explicitly. For tests that require a specific standard it is better to |
| use a <code class="literal">dg-options</code> directive: |
| </p><pre class="programlisting"> // { dg-options "-std=gnu++11" }</pre><p> |
| This means the test will not get skipped by default, and will always use |
| the specific standard dialect that the test requires. This isn't needed |
| often, and most tests should use an effective target to specify a |
| minimum standard instead, to allow them to be tested for all |
| possible variations. |
| </p><p> |
| Similarly, tests which depend on a newer standard than the default |
| must use <code class="literal">dg-options</code> instead of (or in addition to) |
| an effective target, so that they are not skipped by default. |
| For example, tests for C++17 features should use |
| </p><pre class="programlisting"> // { dg-options "-std=gnu++17" }</pre><p> |
| before any <code class="literal">dg-do</code> such as: |
| </p><pre class="programlisting"> // { dg-do run "c++17" }</pre><p> |
| The <code class="literal">dg-options</code> directive must come first, so that |
| the <code class="literal">-std</code> flag has already been added to the options |
| before checking the <code class="literal">c++17</code> target. |
| </p><div class="section"><div class="titlepage"><div><div><h4 class="title"><a id="tests.dg.examples"></a>Examples of Test Directives</h4></div></div></div><p> |
| Example 1: Testing compilation only: |
| </p><pre class="programlisting"> |
| // { dg-do compile } |
| </pre><p> |
| |
| Example 2: Testing for expected warnings on line 36, which all targets fail: |
| </p><pre class="programlisting"> |
| // { dg-warning "string literals" "" { xfail *-*-* } 36 } |
| </pre><p> |
| |
| Example 3: Testing for expected warnings on line 36: |
| </p><pre class="programlisting"> |
| // { dg-warning "string literals" "" { target *-*-* } 36 } |
| </pre><p> |
| |
| Example 4: Testing for compilation errors on line 41: |
| </p><pre class="programlisting"> |
| // { dg-do compile } |
| // { dg-error "no match for" "" { target *-*-* } 41 } |
| </pre><p> |
| |
| Example 5: Testing with special command line settings, or without the |
| use of pre-compiled headers, in particular the |
| <code class="filename">stdc++.h.gch</code> file. Any |
| options here will override the <code class="varname">DEFAULT_CXXFLAGS</code> and |
| <code class="varname">PCH_CXXFLAGS</code> set up in the <code class="filename">normal.exp</code> |
| file: |
| </p><pre class="programlisting"> |
| // { dg-options "-O0" { target *-*-* } } |
| </pre><p> |
| |
| Example 6: Compiling and linking a test only for C++14 and later, and only |
| if Debug Mode is active: |
| </p><pre class="programlisting"> |
| // { dg-do link { target c++14 } } |
| // { dg-require-debug-mode "" } |
| </pre><p> |
| |
| Example 7: Running a test only on x86 targets, and only for C++11 and later, |
| with specific options, and additional options for 32-bit x86: |
| </p><pre class="programlisting"> |
| // { dg-options "-fstrict-enums" } |
| // { dg-additional-options "-march=i486" { target ia32 } } |
| // { dg-do run { target { ia32 || x86_64-*-* } } } |
| // { dg-require-effective-target "c++11" } |
| </pre><p> |
| </p><p> |
| More examples can be found in the |
| <code class="filename">libstdc++-v3/testsuite/*/*.cc</code> files. |
| </p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a id="tests.dg.directives"></a>Directives Specific to Libstdc++ Tests</h4></div></div></div><p> |
| In addition to the usual <a class="link" href="https://gcc.gnu.org/onlinedocs/gccint/Require-Support.html" target="_top">Variants |
| of <code class="literal">dg-require-<em class="replaceable"><code>support</code></em></code></a> |
| several more directives are available for use in libstdc++ tests, |
| including the following: |
| </p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="literal">dg-require-namedlocale</code> <em class="replaceable"><code>name</code></em></span></dt><dd><p>The named locale must be available. |
| </p></dd><dt><span class="term"><code class="literal">dg-require-debug-mode ""</code></span></dt><dd><p>Skip the test if the Debug Mode is not active |
| (as determined by the <code class="literal">_GLIBCXX_DEBUG</code> macro). |
| </p></dd><dt><span class="term"><code class="literal">dg-require-parallel-mode ""</code></span></dt><dd><p>Skip the test if the Parallel Mode is not active |
| (as determined by the <code class="literal">_GLIBCXX_PARALLEL</code> macro). |
| </p></dd><dt><span class="term"><code class="literal">dg-require-normal-mode ""</code></span></dt><dd><p>Skip the test if Debug or Parallel Mode is active. |
| </p></dd><dt><span class="term"><code class="literal">dg-require-atomic-builtins ""</code></span></dt><dd><p>Skip the test if atomic operations on <span class="type">bool</span> |
| and <span class="type">int</span> are not lock-free. |
| </p></dd><dt><span class="term"><code class="literal">dg-require-gthreads ""</code></span></dt><dd><p>Skip the test if the C++11 thread library is not |
| supported, as determined by the <code class="literal">_GLIBCXX_HAS_GTHREADS</code> |
| macro. |
| </p></dd><dt><span class="term"><code class="literal">dg-require-gthreads-timed ""</code></span></dt><dd><p>Skip the test if C++11 timed mutexes are not supported, |
| as determined by the <code class="literal">_GLIBCXX_HAS_GTHREADS</code> and |
| <code class="literal">_GTHREAD_USE_MUTEX_TIMEDLOCK</code> macros. |
| </p></dd><dt><span class="term"><code class="literal">dg-require-string-conversions ""</code></span></dt><dd><p>Skip the test if the C++11 <code class="function">to_string</code> |
| and <code class="function">stoi</code>, <code class="function">stod</code> etc. functions |
| are not fully supported (including wide character versions). |
| </p></dd><dt><span class="term"><code class="literal">dg-require-filesystem-ts ""</code></span></dt><dd><p>Skip the test if the Filesystem TS is not supported. |
| </p></dd></dl></div></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="test.harness"></a>Test Harness and Utilities</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a id="test.harness.dejagnu"></a>DejaGnu Harness Details</h4></div></div></div><p> |
| Underlying details of testing for conformance and regressions are |
| abstracted via the GNU DejaGnu package. This is similar to the |
| rest of GCC. |
| </p><p>This is information for those looking at making changes to the testsuite |
| structure, and/or needing to trace DejaGnu's actions with |
| <code class="option">--verbose</code>. |
| This will not be useful to people who are "merely" adding new tests |
| to the existing structure. |
| </p><p>The first key point when working with DejaGnu is the idea of a "tool". |
| Files, directories, and functions are all implicitly used when they are |
| named after the tool in use. Here, the tool will always be "libstdc++". |
| </p><p>The <code class="code">lib</code> subdir contains support routines. The |
| <code class="code">lib/libstdc++.exp</code> file ("support library") is loaded |
| automagically, and must explicitly load the others. For example, files can |
| be copied from the core compiler's support directory into <code class="code">lib</code>. |
| </p><p>Some routines in <code class="code">lib/libstdc++.exp</code> are callbacks, some are |
| our own. Callbacks must be prefixed with the name of the tool. To easily |
| distinguish the others, by convention our own routines are named "v3-*". |
| </p><p>The next key point when working with DejaGnu is "test files". Any |
| directory whose name starts with the tool name will be searched for test files. |
| (We have only one.) In those directories, any <code class="code">.exp</code> file is |
| considered a test file, and will be run in turn. Our main test file is called |
| <code class="code">normal.exp</code>; it runs all the tests in testsuite_files using the |
| callbacks loaded from the support library. |
| </p><p>The <code class="code">config</code> directory is searched for any particular "target |
| board" information unique to this library. This is currently unused and sets |
| only default variables. |
| </p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a id="test.harness.utils"></a>Utilities</h4></div></div></div><p> |
| </p><p> |
| The testsuite directory also contains some files that implement |
| functionality that is intended to make writing test cases easier, |
| or to avoid duplication, or to provide error checking in a way that |
| is consistent across platforms and test harnesses. A stand-alone |
| executable, called <span class="emphasis"><em>abi_check</em></span>, and a static |
| library called <span class="emphasis"><em>libtestc++</em></span> are |
| constructed. Both of these items are not installed, and only used |
| during testing. |
| </p><p> |
| These files include the following functionality: |
| </p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> |
| <span class="emphasis"><em>testsuite_abi.h</em></span>, |
| <span class="emphasis"><em>testsuite_abi.cc</em></span>, |
| <span class="emphasis"><em>testsuite_abi_check.cc</em></span> |
| </p><p> |
| Creates the executable <span class="emphasis"><em>abi_check</em></span>. |
| Used to check correctness of symbol versioning, visibility of |
| exported symbols, and compatibility on symbols in the shared |
| library, for hosts that support this feature. More information |
| can be found in the ABI documentation <a class="link" href="abi.html" title="ABI Policy and Guidelines">here</a> |
| </p></li><li class="listitem"><p> |
| <span class="emphasis"><em>testsuite_allocator.h</em></span>, |
| <span class="emphasis"><em>testsuite_allocator.cc</em></span> |
| </p><p> |
| Contains specialized allocators that keep track of construction |
| and destruction. Also, support for overriding global new and |
| delete operators, including verification that new and delete |
| are called during execution, and that allocation over max_size |
| fails. |
| </p></li><li class="listitem"><p> |
| <span class="emphasis"><em>testsuite_character.h</em></span> |
| </p><p> |
| Contains <code class="code">std::char_traits</code> and |
| <code class="code">std::codecvt</code> specializations for a user-defined |
| POD. |
| </p></li><li class="listitem"><p> |
| <span class="emphasis"><em>testsuite_hooks.h</em></span>, |
| <span class="emphasis"><em>testsuite_hooks.cc</em></span> |
| </p><p> |
| A large number of utilities, including: |
| </p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p>VERIFY</p></li><li class="listitem"><p>set_memory_limits</p></li><li class="listitem"><p>verify_demangle</p></li><li class="listitem"><p>run_tests_wrapped_locale</p></li><li class="listitem"><p>run_tests_wrapped_env</p></li><li class="listitem"><p>try_named_locale</p></li><li class="listitem"><p>try_mkfifo</p></li><li class="listitem"><p>func_callback</p></li><li class="listitem"><p>counter</p></li><li class="listitem"><p>copy_tracker</p></li><li class="listitem"><p>copy_constructor</p></li><li class="listitem"><p>assignment_operator</p></li><li class="listitem"><p>destructor</p></li><li class="listitem"><p>pod_char, pod_int and associated char_traits specializations</p></li></ul></div></li><li class="listitem"><p> |
| <span class="emphasis"><em>testsuite_io.h</em></span> |
| </p><p> |
| Error, exception, and constraint checking for |
| <code class="code">std::streambuf, std::basic_stringbuf, std::basic_filebuf</code>. |
| </p></li><li class="listitem"><p> |
| <span class="emphasis"><em>testsuite_iterators.h</em></span> |
| </p><p> |
| Wrappers for various iterators. |
| </p></li><li class="listitem"><p> |
| <span class="emphasis"><em>testsuite_performance.h</em></span> |
| </p><p> |
| A number of class abstractions for performance counters, and |
| reporting functions including: |
| </p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p>time_counter</p></li><li class="listitem"><p>resource_counter</p></li><li class="listitem"><p>report_performance</p></li></ul></div></li></ul></div></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="test.special"></a>Special Topics</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a id="test.exception.safety"></a> |
| Qualifying Exception Safety Guarantees |
| <a id="id-1.3.6.3.5.7.2.1.1.1" class="indexterm"></a> |
| </h4></div></div></div><div class="section"><div class="titlepage"><div><div><h5 class="title"><a id="test.exception.safety.overview"></a>Overview</h5></div></div></div><p> |
| Testing is composed of running a particular test sequence, |
| and looking at what happens to the surrounding code when |
| exceptions are thrown. Each test is composed of measuring |
| initial state, executing a particular sequence of code under |
| some instrumented conditions, measuring a final state, and |
| then examining the differences between the two states. |
| </p><p> |
| Test sequences are composed of constructed code sequences |
| that exercise a particular function or member function, and |
| either confirm no exceptions were generated, or confirm the |
| consistency/coherency of the test subject in the event of a |
| thrown exception. |
| </p><p> |
| Random code paths can be constructed using the basic test |
| sequences and instrumentation as above, only combined in a |
| random or pseudo-random way. |
| </p><p> To compute the code paths that throw, test instruments |
| are used that throw on allocation events |
| (<code class="classname">__gnu_cxx::throw_allocator_random</code> |
| and <code class="classname">__gnu_cxx::throw_allocator_limit</code>) |
| and copy, assignment, comparison, increment, swap, and |
| various operators |
| (<code class="classname">__gnu_cxx::throw_type_random</code> |
| and <code class="classname">__gnu_cxx::throw_type_limit</code>). Looping |
| through a given test sequence and conditionally throwing in |
| all instrumented places. Then, when the test sequence |
| completes without an exception being thrown, assume all |
| potential error paths have been exercised in a sequential |
| manner. |
| </p></div><div class="section"><div class="titlepage"><div><div><h5 class="title"><a id="test.exception.safety.status"></a> |
| Existing tests |
| </h5></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> |
| Ad Hoc |
| </p><p> |
| For example, |
| <code class="filename">testsuite/23_containers/list/modifiers/3.cc</code>. |
| </p></li><li class="listitem"><p> |
| Policy Based Data Structures |
| </p><p> |
| For example, take the test |
| functor <code class="classname">rand_reg_test</code> in |
| in <code class="filename">testsuite/ext/pb_ds/regression/tree_no_data_map_rand.cc</code>. This uses <code class="classname">container_rand_regression_test</code> in |
| <code class="filename">testsuite/util/regression/rand/assoc/container_rand_regression_test.h</code>. |
| |
| </p><p> |
| Which has several tests for container member functions, |
| Includes control and test container objects. Configuration includes |
| random seed, iterations, number of distinct values, and the |
| probability that an exception will be thrown. Assumes instantiating |
| container uses an extension |
| allocator, <code class="classname">__gnu_cxx::throw_allocator_random</code>, |
| as the allocator type. |
| </p></li><li class="listitem"><p> |
| C++11 Container Requirements. |
| </p><p> |
| Coverage is currently limited to testing container |
| requirements for exception safety, |
| although <code class="classname">__gnu_cxx::throw_type</code> meets |
| the additional type requirements for testing numeric data |
| structures and instantiating algorithms. |
| </p><p> |
| Of particular interest is extending testing to algorithms and |
| then to parallel algorithms. Also io and locales. |
| </p><p> |
| The test instrumentation should also be extended to add |
| instrumentation to <code class="classname">iterator</code> |
| and <code class="classname">const_iterator</code> types that throw |
| conditionally on iterator operations. |
| </p></li></ul></div></div><div class="section"><div class="titlepage"><div><div><h5 class="title"><a id="test.exception.safety.containers"></a> |
| C++11 Requirements Test Sequence Descriptions |
| </h5></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> |
| Basic |
| </p><p> |
| Basic consistency on exception propagation tests. For |
| each container, an object of that container is constructed, |
| a specific member function is exercised in |
| a <code class="literal">try</code> block, and then any thrown |
| exceptions lead to error checking in the appropriate |
| <code class="literal">catch</code> block. The container's use of |
| resources is compared to the container's use prior to the |
| test block. Resource monitoring is limited to allocations |
| made through the container's <span class="type">allocator_type</span>, |
| which should be sufficient for container data |
| structures. Included in these tests are member functions |
| are <span class="type">iterator</span> and <span class="type">const_iterator</span> |
| operations, <code class="function">pop_front</code>, <code class="function">pop_back</code>, <code class="function">push_front</code>, <code class="function">push_back</code>, <code class="function">insert</code>, <code class="function">erase</code>, <code class="function">swap</code>, <code class="function">clear</code>, |
| and <code class="function">rehash</code>. The container in question is |
| instantiated with two instrumented template arguments, |
| with <code class="classname">__gnu_cxx::throw_allocator_limit</code> |
| as the allocator type, and |
| with <code class="classname">__gnu_cxx::throw_type_limit</code> as |
| the value type. This allows the test to loop through |
| conditional throw points. |
| </p><p> |
| The general form is demonstrated in |
| <code class="filename">testsuite/23_containers/list/requirements/exception/basic.cc |
| </code>. The instantiating test object is <code class="classname">__gnu_test::basic_safety</code> and is detailed in <code class="filename">testsuite/util/exception/safety.h</code>. |
| </p></li><li class="listitem"><p> |
| Generation Prohibited |
| </p><p> |
| Exception generation tests. For each container, an object of |
| that container is constructed and all member functions |
| required to not throw exceptions are exercised. Included in |
| these tests are member functions |
| are <span class="type">iterator</span> and <span class="type">const_iterator</span> operations, <code class="function">erase</code>, <code class="function">pop_front</code>, <code class="function">pop_back</code>, <code class="function">swap</code>, |
| and <code class="function">clear</code>. The container in question is |
| instantiated with two instrumented template arguments, |
| with <code class="classname">__gnu_cxx::throw_allocator_random</code> |
| as the allocator type, and |
| with <code class="classname">__gnu_cxx::throw_type_random</code> as |
| the value type. This test does not loop, an instead is sudden |
| death: first error fails. |
| </p><p> |
| The general form is demonstrated in |
| <code class="filename">testsuite/23_containers/list/requirements/exception/generation_prohibited.cc |
| </code>. The instantiating test object is <code class="classname">__gnu_test::generation_prohibited</code> and is detailed in <code class="filename">testsuite/util/exception/safety.h</code>. |
| </p></li><li class="listitem"><p> |
| Propagation Consistent |
| </p><p> |
| Container rollback on exception propagation tests. For |
| each container, an object of that container is constructed, |
| a specific member function that requires rollback to a previous |
| known good state is exercised in |
| a <code class="literal">try</code> block, and then any thrown |
| exceptions lead to error checking in the appropriate |
| <code class="literal">catch</code> block. The container is compared to |
| the container's last known good state using such parameters |
| as size, contents, and iterator references. Included in these |
| tests are member functions |
| are <code class="function">push_front</code>, <code class="function">push_back</code>, <code class="function">insert</code>, |
| and <code class="function">rehash</code>. The container in question is |
| instantiated with two instrumented template arguments, |
| with <code class="classname">__gnu_cxx::throw_allocator_limit</code> |
| as the allocator type, and |
| with <code class="classname">__gnu_cxx::throw_type_limit</code> as |
| the value type. This allows the test to loop through |
| conditional throw points. |
| </p><p> |
| The general form demonstrated in |
| <code class="filename">testsuite/23_containers/list/requirements/exception/propagation_coherent.cc |
| </code>. The instantiating test object is <code class="classname">__gnu_test::propagation_coherent</code> and is detailed in <code class="filename">testsuite/util/exception/safety.h</code>. |
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