* debian/changelog: Add entry for new release.

[dejagnu.git] / doc / user.sgml

  <chapter id=runningtests>
    <title>Running Tests</title>

    <para>There are two ways to execute a test suite. The most
    common way is when there is existing support in the
    <filename>Makefile</filename>. This support consists of a
    <emphasis>check</emphasis> target. The other way is to execute the
    <command>runtest</command> program directly. To run
    <command>runtest</command> directcly from the command line requires
    either all the correct options, or the <xref linkend=local> must be setup
    correctly.</para>

    <sect1 id=makecheck xreflabel="Make Check">
      <title>Make check</title>

      <para>To run tests from an existing collection, first use
      <command>configure</command> as usual to set up the
      build directory. Then try typing:</para>

      <screen>
      make check
      </screen>

      <para>If the <emphasis>check</emphasis> target exists, it
      usually saves you some trouble. For instance, it can set up any
      auxiliary programs or other files needed by the tests. The most
      common file the check builds is the
      <emphasis>site.exp</emphasis>. The site.exp file contains
      various variables that DejaGnu used to dertermine the
      configuration of the program being tested. This is mostly for
      supporting remote testing.</para>

      <para>The <emphasis>check</emphasis> target is supported by GNU
      <productname>Automake</productname>. To have DejaGnu support added to your
      generated <filename>Makefile.in</filename>, just add the keyword
      dejagnu to the AUTOMAKE_OPTIONS variable in your
      <filename>Makefile.am</filename> file.</para>

      <para>Once you have run <emphasis>make check</emphasis> to build
      any auxiliary files, you can invoke the test driver
      <command>runtest</command> directly to repeat the tests.
      You will also have to execute <command>runtest</command>
      directly for test collections with no
      <emphasis>check</emphasis> target in the
      <filename>Makefile</filename>.</para>

    </sect1>
    
    <sect1 id=runtest xreflabel="Runtest">
      <title>Runtest</title>

      <para><command>runtest</command> is the executable test driver
      for DejaGnu. You can specify two kinds of things on the
      <command>runtest</command> command line: command line options,
      and Tcl variables for the test scripts. The options are listed
      alphabetically below.</para>

      <para><command>runtest</command> returns an exit code of
      <emphasis>1</emphasis> if any test has an unexpected result; otherwise
      (if all tests pass or fail as expected) it returns <emphasis>0</emphasis>
      as the exit code.</para>

      <sect2 id=outputs xreflabel="Output States">
        <title>Output States</title>

        <para><filename>runtest</filename> flags the outcome of each
        test as one of these cases. <xref linkend=posix> for a
        discussion of how POSIX specifies the meanings of these
        cases.</para>

        <variablelist>
        <varlistentry>
          <term>PASS</term>
          <listitem><para>The most desirable outcome: the test succeeded, and
          was expected to succeed.</para></listitem>
        </varlistentry>

        <varlistentry>
          <term>XPASS</term>
          <listitem><para>A pleasant kind of failure: a test was expected to
          fail, but succeeded. This may indicate progress; inspect the test
          case to determine whether you should amend it to stop expecting
          failure.</para></listitem>
        </varlistentry>
 
        <varlistentry>
          <term>FAIL</term>
          <listitem><para>A test failed, although it was expected to succeed.
          This may indicate regress; inspect the test case and the failing
          software to ocate the bug.</para></listitem>
        </varlistentry>
 
        <varlistentry>
          <term>XFAIL</term>
          <listitem><para>A test failed, but it was expected to fail.  This
          result indicates no change in a known bug.  If a test fails because
          the operating system where the test runs lacks some facility required
          by the test, the outcome is <emphasis>UNSUPPORTED</emphasis>
          instead.</para></listitem>
        </varlistentry>
 
        <varlistentry>
          <term>UNRESOLVED</term>
          <listitem><para>Output from a test requires manual inspection; the
          test suite could not automatically determine the outcome.  For
          example, your tests can report this outcome is when a test does not
          complete as expected.</para></listitem>
        </varlistentry>
 
        <varlistentry>
          <term>UNTESTED</term>
          <listitem><para>A test case is not yet complete, and in particular
          cannot yet produce a <emphasis>PASS</emphasis> or
          <emphasis>FAIL</emphasis>. You can also use this outcome in dummy
          ``tests'' that note explicitly the absence of a real test case for a
          particular property.</para></listitem>
        </varlistentry>
 
        <varlistentry>
          <term>UNSUPPORTED</term>
          <listitem><para>A test depends on a conditionally available feature
          that does not exist (in the configured testing environment).  For
          example, you can use this outcome to report on a test case that does
          not work on a particular target because its operating system support
          does not include a required subroutine.</para></listitem>
        </varlistentry>
      </variablelist>

      <para>runtest may also display the following messages:</para>

      <variablelist>
        <varlistentry>
          <term>ERROR</term>
          <listitem><para>Indicates a major problem (detected by the test case
          itself) in running the test. This is usually an unrecoverable error,
          such as a missing file or loss of communication to the target. (POSIX
          test suites should not emit this message; use
          <emphasis>UNSUPPORTED</emphasis>, <emphasis>UNTESTED</emphasis>, or
          <emphasis>UNRESOLVED</emphasis> instead, as
          appropriate.)</para></listitem>
        </varlistentry>

        <varlistentry>
          <term>WARNING</term>
          <listitem><para>Indicates a possible problem in running the
          test. Usually warnings correspond to recoverable errors, or display
          an important message about the following tests.</para></listitem>
        </varlistentry>

        <varlistentry>
        <term>NOTE</term>
        <listitem><para>An informational message about the test
        case.</para></listitem>
        </varlistentry>
      </variablelist>

    </sect2>

    <sect2 id=invoking xreflabel="Invoking Runtest">
      <title>Invoking Runtest</title>

      <para>This is the full set of command line options that
      <filename>runtest</filename> recognizes. Arguments may be
      abbreviated to the shortest unique string.</para>

      <variablelist>
        <varlistentry>
          <term><option>--all</option> (-a)</term>
          <listitem><para>Display all test output. By default,
          <emphasis>runtest</emphasis> shows only the output of tests that
          produce unexpected results; that is, tests with status
          <emphasis>FAIL</emphasis> (unexpected failure),
          <emphasis>XPASS</emphasis> (unexpected success), or
          <emphasis>ERROR</emphasis> (a severe error in the test case
          itself). Specify <emphasis>--all</emphasis> to see output for tests
          with status <emphasis>PASS</emphasis> (success, as expected)
          <emphasis>XFAIL</emphasis> (failure, as expected), or
          <emphasis>WARNING</emphasis> (minor error in the test case
          itself).</para></listitem>
        </varlistentry>

        <varlistentry>
          <term><option>--build [string]</option></term>
          <listitem><para><emphasis>string</emphasis> is a full configuration
          ``triple'' name as used by <command>configure</command>. This
          is the type of machine DejaGnu and the tools to be tested are built
          on. For a normal cross this is the same as the host, but for a
          canadian cross, they are seperate.</para></listitem>
        </varlistentry>

        <varlistentry>
          <term><option>--host [string]</option></term>
          <listitem><para><symbol>string</symbol> is a full configuration
          ``triple'' name as used by <emphasis>configure</emphasis>.  Use this
          option to override the default string recorded by your
          configuration's choice of host.  This choice does not change how
          anything is actually configured unless --build is also specified; it
          affects <emphasis>only</emphasis> DejaGnu procedures that compare the
          host string with particular values.  The procedures
          <emphasis>ishost</emphasis>, <emphasis>istarget</emphasis>,
          <emphasis>isnative</emphasis>, and <emphasis>setup</emphasis>xfail}
          are affected by <emphasis>--host</emphasis>. In this usage,
          <emphasis>host</emphasis> refers to the machine that the tests are to
          be run on, which may not be the same as the
          <emphasis>build</emphasis> machine. If <emphasis>--build</emphasis>
          is also specified, then <emphasis>--host</emphasis> refers to the
          machine that the tests wil, be run on, not the machine DejaGnu is run
          on.</para></listitem>
        </varlistentry>

        <varlistentry>
          <term><option>--host_board [name]</option></term>
          <listitem><para>The host board to use.</para></listitem>
        </varlistentry>

        <varlistentry>
          <term><option>--target [string]</option></term>
          <listitem><para>Use this option to override the default setting
          (running native tests). <emphasis>string</emphasis> is a full
          configuration ``triple'' name of the form
          <emphasis>cpu-vendor-os</emphasis> as used by
          <command>configure</command>. This option changes the
          configuration <emphasis>runtest</emphasis> uses for the default tool
          names, and other setup information.</para></listitem>
        </varlistentry>

        <varlistentry>
          <term><option>--debug</option> (-de)</term>
          <listitem><para>Turns on the <emphasis>expect</emphasis> internal
          debugging output. Debugging output is displayed as part of the
          <emphasis>runtest</emphasis> output, and logged to a file called
          <filename>dbg.log</filename>. The extra debugging output does
          <emphasis>not</emphasis> appear on standard output, unless the
          verbose level is greater than 2 (for instance, to see debug output
          immediately, specify <emphasis>--debug</emphasis>-v -v}). The
          debugging output shows all attempts at matching the test output of
          the tool with the scripted patterns describing expected output.  The
          output generated with <emphasis>--strace</emphasis> also goes into
          <filename>dbg.log</filename>.</para></listitem>
        </varlistentry>

        <varlistentry>
          <term><option>--help</option> (-he)</term>
          <listitem><para>Prints out a short summary of the
          <emphasis>runtest</emphasis> options, then exits (even if you also
          specify other options).</para></listitem>
        </varlistentry>

        <varlistentry>
          <term><option>--ignore [name(s)] </option></term>
          <listitem><para>The names of specific tests to
          ignore.</para></listitem>
        </varlistentry>

        <varlistentry>
          <term><option>--objdir [path]</option></term>
          <listitem><para>Use <emphasis>path</emphasis> as the top directory
          containing any auxiliary compiled test code. This defaults to
          <filename>.</filename>.  Use this option to locate pre-compiled test
          code.  You can normally prepare any auxiliary files needed with
          <emphasis>make</emphasis>.</para></listitem>
        </varlistentry>

        <varlistentry>
          <term><option>--outdir [path]</option></term>
          <listitem><para>Write output logs in directory
          <filename>path</filename>.  The default is <emphasis>.},
          the</emphasis> directory where you start
          <emphasis>runtest</emphasis>. This option affects only the summary
          and the detailed log files
          <filename>tool.sum</filename> and
          <filename>tool.log</filename>. The DejaGnu debug
          log <filename>dbg.log</filename> always appears (when requested) in
          the local directory.</para></listitem>
        </varlistentry>

        <varlistentry>
          <term><option>--reboot [name]</option></term>
          <listitem><para>Reboot the target board when
          <emphasis>runtest</emphasis> initializes. Usually, when running tests
          on a separate target board, it is safer to reboot the target to be
          certain of its state.  However, when developing test scripts,
          rebooting takes a lot of time.</para></listitem>
        </varlistentry>

        <varlistentry>
          <term><option>--srcdir [path]</option></term>
          <listitem><para>Use <filename>path</filename> as the top directory
          for test scripts to run. <emphasis>runtest</emphasis> looks in this
          directory for any subdirectory whose name begins with the toolname
          (specified with <emphasis>--tool</emphasis>). For instance, with
          <emphasis>--tool</emphasis>gdb}, <emphasis>runtest</emphasis> uses
          tests in subdirectories <filename>gdb.*</filename> (with the usual
          shell-like filename expansion).  If you do not use
          <emphasis>--srcdir</emphasis>, <emphasis>runtest</emphasis> looks for
          test directories under the current working
          directory.</para></listitem>
        </varlistentry>

        <varlistentry>
          <term><option>--strace [number]</option></term>
          <listitem><para>Turn on internal tracing for
          <emphasis>expect</emphasis>, to n levels deep. By adjusting the
          level, you can control the extent to which your output expands
          multi-level Tcl statements.  This allows you to ignore some levels of
          <emphasis>case</emphasis> or <emphasis>if</emphasis> statements.
          Each procedure call or control structure counts as one ``level''. The
          output is recorded in the same file, <filename>dbg.log</filename>,
          used for output from <emphasis>--debug</emphasis>.</para></listitem>
        </varlistentry>

        <varlistentry>
          <term><option>--connect [program]</option></term>
          <listitem><para>Connect to a target testing environment as specified
          by <emphasis>type</emphasis>, if the target is not the computer
          running <emphasis>runtest</emphasis>.  For example, use
          <emphasis>--connect</emphasis> to change the program used to connect
          to a ``bare board'' boot monitor.  The choices for
          <emphasis>type</emphasis> in the DejaGnu 1.4 distribution are
          <emphasis>rlogin</emphasis>, <emphasis>telnet</emphasis>,
          <emphasis>rsh</emphasis>, <emphasis>tip</emphasis>,
          <emphasis>kermit</emphasis>, and <emphasis>mondfe</emphasis>.</para>

          <para>The default for this option depends on the configuration most
          convenient communication method available, but often other
          alternatives work as well; you may find it useful to try alternative
          connect methods if you suspect a communication problem with your
          testing target.</para></listitem>
        </varlistentry>

        <varlistentry>
          <term><option>--baud [number]</option></term>
          <listitem><para>Set the default baud rate to something other than
          9600. (Some serial interface programs, like <emphasis>tip</emphasis>,
          use a separate initialization file instead of this
          value.)</para></listitem>
        </varlistentry>

        <varlistentry>
          <term><option>--target_board [name(s)]</option></term>
          <listitem><para>The list of target boards to run tests
          on.</para></listitem>
        </varlistentry>
        
        <varlistentry id=tool-opt>
          <term><option>--tool[name(s)]</option></term>
          <listitem><para>Specifies which test suite to run, and what
          initialization module to use. <option>--tool</option> is used
          <emphasis>only</emphasis> for these two purposes. It is
          <emphasis>not</emphasis> used to name the executable program to
          test. Executable tool names (and paths) are recorded in
          <filename>site.exp</filename> and you can override them by specifying
          Tcl variables on the command line.</para>
          
          <para>For example, including "<option>--tool</option> gcc" on the
          <emphasis>runtest</emphasis> command line runs tests from all test
          subdirectories whose names match <filename>gcc.*</filename>, and uses
          one of the initialization modules named
          <filename>config/*-gcc.exp</filename>. To specify the name of the
          compiler (perhaps as an alternative path to what
          <emphasis>runtest</emphasis> would use by default), use
          <emphasis>GCC=binname</emphasis> on the <emphasis>runtest</emphasis>
          command line.</para></listitem>
        </varlistentry>
        
        <varlistentry>
          <term><option>--tool_exec [name]</option></term>
          <listitem><para>The path to the tool executable to
          test.</para></listitem>
        </varlistentry>

        <varlistentry>
          <term><option>--tool_opts [options]</option></term>
          <listitem><para>A list of additional options to pass to the
          tool.</para></listitem>
        </varlistentry>

        <varlistentry>
          <term><option>--verbose</option> (-v)</term>
          <listitem><para>Turns on more output. Repeating this option increases
          the amount of output displayed. Level one (<emphasis>-v</emphasis>)
          is simply test output. Level two (<emphasis>-v</emphasis>-v}) shows
          messages on options, configuration, and process control.  Verbose
          messages appear in the detailed (<filename>*.log</filename>) log
          file, but not in the summary (<filename>*.sum</filename>) log
          file.</para></listitem>
        </varlistentry>
        
        <varlistentry>
          <term><option>--version</option> (-V)</term>
          <listitem><para>Prints out the version numbers of DejaGnu,
          <emphasis>expect</emphasis> and Tcl, and exits without running any
          tests.</para></listitem>
        </varlistentry>

        <varlistentry>
          <term><option>--D[0-1]</option></term>
          <listitem><para>Start the internal Tcl debugger. The Tcl debugger
          supports breakpoints, single stepping, and other common debugging
          activities. See the document "Debugger for Tcl Applications" by Don
          Libes. (Distributed in PostScript form with
          <emphasis>expect</emphasis> as the file
          <filename>expect/tcl-debug.ps.</filename>. If you specify
          <emphasis>-D1</emphasis>, the <emphasis>expect</emphasis> shell stops
          at a breakpoint as soon as DejaGnu invokes it. If you specify
          <emphasis>-D0</emphasis>, DejaGnu starts as usual, but you can enter
          the debugger by sending an interrupt (e.g. by typing
          <keycombo><keycap>C</keycap><keycap>c</keycap></keycombo>).
          </para></listitem>
        </varlistentry>

        <varlistentry>
          <term><filename>testfile</filename>.exp[=arg(s)]</term>
          <listitem><para>Specify the names of testsuites to run. By default,
          <emphasis>runtest</emphasis> runs all tests for the tool, but you can
          restrict it to particular testsuites by giving the names of the
          <emphasis>.exp expect</emphasis> scripts that control
          them. <emphasis>testsuite</emphasis>.exp may not include path
          information; use plain filenames.</para></listitem>
        </varlistentry>

        <varlistentry>
          <term><filename>testfile</filename>.exp="testfile1 ..."</term> 
          <listitem><para>Specify a subset of tests in a suite to run. For
          compiler or assembler tests, which often use a single
          <emphasis>.exp</emphasis> script covering many different source
          files, this option allows you to further restrict the tests by
          listing particular source files to compile. Some tools even support
          wildcards here.  The wildcards supported depend upon the tool, but
          typically they are <emphasis>?</emphasis>, <emphasis>*</emphasis>,
          and <emphasis>[chars]</emphasis>.</para></listitem>
        </varlistentry>

        <varlistentry>
          <term><symbol>tclvar</symbol>=value</term>
          <listitem><para>You can define Tcl variables for use by your test
          scripts in the same style used with <emphasis>make</emphasis> for
          environment variables.  For example, <emphasis>runtest
          GDB=gdb.old</emphasis> defines a variable called
          <command>GDB</command>; when your scripts refer to
          <symbol>$GDB</symbol> in this run, they use the value
          <emphasis>gdb.old</emphasis>.</para>

          <para>The default Tcl variables used for most tools are defined in
          the main DejaGnu <emphasis>Makefile</emphasis>; their values are
          captured in the <filename>site.exp</filename> file.</para></listitem>
        </varlistentry>
      </variablelist>
    </sect2>

       <sect2 id=common xreflabel="Common Operations">
        <title>Common Options</title>
        
        <para>Typically, you don't need must to use any command-line options.
        <option>--tool</option> used is only required when there are more than
        one test suite in the same directory. The default options are in the
        local site.exp file, created by "make site.exp".</para>

        <para>For example, if the directory <filename>gdb/testsuite</filename>
        contains a collection of DejaGnu tests for GDB, you can run them like
        this:</para>

        <screen>
          eg$ cd gdb/testsuite
          eg$ runtest --tool gdb
        </screen>

        <para>Test output follows, ending with:</para>

        <screen>
                === gdb Summary ===

                # of expected passes 508
                # of expected failures 103
                /usr/latest/bin/gdb version 4.14.4 -nx
        </screen>

        <para>You can use the option <emphasis>--srcdir</emphasis> to point to 
        some other directory containing a collection of tests:</para>

        <screen>
          eg$ runtest--srcdir /devo/gdb/testsuite
        </screen>

        <para>By default, <command>runtest</command> prints only the
        names of the tests it runs, output from any tests that have unexpected
        results, and a summary showing how many tests passed and how many
        failed.  To display output from all tests (whether or not they behave
        as expected), use the <emphasis>--all</emphasis> option.  For more
        verbose output about processes being run, communication, and so on, use
        <emphasis>--verbose</emphasis>. To see even more output, use multiple
        <emphasis>--verbose</emphasis> options. for a more detailed explanation
        of each <command>runtest</command> option.</para>

        <para>Test output goes into two files in your current directory:
        summary output in <filename>tool.sum</filename>,
        and detailed output in <filename>
        tool.log</filename>. (<emphasis>tool</emphasis>
        refers to the collection of tests; for example, after a run with
        <emphasis>--tool</emphasis> gdb, look for output files
        <filename>gdb.sum</filename> and
        <filename>gdb.log</filename>.)</para>
      </sect2>
    </sect1>  

    <sect1 id=outputfiles xreflabel="Output Files">

    <title>The files DejaGnu produces.</title>

    <para>DejaGnu always writes two kinds of output files: summary
    logs and detailed logs.  The contents of both of these are
    determined by your tests.</para>

    <para>For troubleshooting, a third kind of output file is useful:
    use <option>--debug</option> to request an output file showing
    details of what <productname>Expect</productname> is doing
    internally.</para>

    <sect2 id=sum xreflabel="Summary File">
      <title>Summary File</title>

      <para>DejaGnu always produces a summary output file
      <filename>tool.sum</filename>. This summary shows the names of
      all test files run; for each test file, one line of output from
      each <command>pass</command> command (showing status
      <emphasis>PASS</emphasis> or <emphasis>XPASS</emphasis>) or
      <command>fail</command> command (status
      <emphasis>FAIL</emphasis> or <emphasis>XFAIL</emphasis>);
      trailing summary statistics that count passing and failing tests
      (expected and unexpected); and the full pathname and version
      number of the tool tested.  (All possible outcomes, and all
      errors, are always reflected in the summary output file,
      regardless of whether or not you specify
      <option>--all</option>.)</para>

      <para>If any of your tests use the procedures
      <command>unresolved</command>, <command>unsupported</command>,
      or <command>runtested</command>, the summary output also
      tabulates the corresponding outcomes.</para>

      <para>For example, after <command>runtest --tool
      binutils</command>, look for a summary log in
      <filename>binutils.sum</filename>. Normally, DejaGnu writes this
      file in your current working directory; use the
      <option>--outdir</option> option to select a different
      directory.</para>

      <example>
        <title>Here is a short sample summary log</title>

        <screen>
        Test Run By rob on Mon May 25 21:40:57 PDT 1992
                 === gdb tests ===
        Running ./gdb.t00/echo.exp ...
        PASS:   Echo test
        Running ./gdb.all/help.exp ...
        PASS:   help add-symbol-file
        PASS:   help aliases
        PASS:   help breakpoint "bre" abbreviation
        FAIL:   help run "r" abbreviation
        Running ./gdb.t10/crossload.exp ...
        PASS:   m68k-elf (elf-big) explicit format; loaded
        XFAIL:  mips-ecoff (ecoff-bigmips) "ptype v_signed_char" signed C types 
                === gdb Summary ===
        # of expected passes 5
        # of expected failures 1
        # of unexpected failures 1
        /usr/latest/bin/gdb version 4.6.5 -q
      </screen>
    </example>

    </sect2>

    <sect2 id=log xreflabel="Log File">
      <title>Log File</title>

      <para>DejaGnu also saves a detailed log file
      <filename>tool.log</filename>, showing any output generated by
      tests as well as the summary output. For example, after
      <command>runtest --tool binutils</command>, look for a detailed
      log in <filename>binutils.log</filename>. Normally, DejaGnu
      writes this file in your current working directory; use the
      <option>--outdir</option> option to select a different
      directory.</para>


      <example>
        <title>Here is a brief example showing a detailed log for
        <productname>G++</productname> tests</title>

        <screen>
        Test Run By rob on Mon May 25 21:40:43 PDT 1992

                === g++ tests ===

        --- Running ./g++.other/t01-1.exp ---
        PASS:   operate delete

        --- Running ./g++.other/t01-2.exp ---
        FAIL:   i960 bug EOF
        p0000646.C: In function `int  warn_return_1 ()':
        p0000646.C:109: warning: control reaches end of non-void function
        p0000646.C: In function `int  warn_return_arg (int)':
        p0000646.C:117: warning: control reaches end of non-void function
        p0000646.C: In function `int  warn_return_sum (int, int)':
        p0000646.C:125: warning: control reaches end of non-void function
        p0000646.C: In function `struct foo warn_return_foo ()':
        p0000646.C:132: warning: control reaches end of non-void function

        --- Running ./g++.other/t01-4.exp ---
        FAIL:   abort
        900403_04.C:8: zero width for bit-field `foo'
        --- Running ./g++.other/t01-3.exp ---
        FAIL:   segment violation
        900519_12.C:9: parse error before `;'
        900519_12.C:12: Segmentation violation
        /usr/latest/bin/gcc: Internal compiler error: program cc1plus got fatal signal

                === g++ Summary ===

        # of expected passes 1
        # of expected failures 3
        /usr/latest/bin/g++ version cygnus-2.0.1
        </screen>
        </example>

    </sect2>

    <sect2 id=debugfile xreflabel="Debug Log File">
      <title>Debug Log File</title>

      <para>With the <option>--debug</option> option, you can request
      a log file showing the output from
      <productname>Expect</productname> itself, running in debugging
      mode. This file (<filename>dbg.log</filename>, in the directory
      where you start <command>runtest</command>) shows each pattern
      <productname>Expect</productname> considers in analyzing test
      output.</para>

      <para>This file reflects each <command>send</command> command,
      showing the string sent as input to the tool under test; and
      each <productname>Expect</productname> command, showing each
      pattern it compares with the tool output.</para>

      <example>
        <title>The log messages begin with a message of the form</title>

        <screen>

        expect: does {<symbol>tool output</symbol>} (spawn_id <symbol>n</symbol>)
         match pattern {<emphasis>expected pattern</emphasis>}?

        </screen>
      </example>

      <para>For every unsuccessful match,
      <productname>Expect</productname> issues a
      <emphasis>no</emphasis> after this message; if other patterns
      are specified for the same <productname>Expect</productname>
      command, they are reflected also, but without the first part of
      the message (<emphasis>expect... match pattern</emphasis>).</para>

      <para>When <productname>Expect</productname> finds a match, the
      log for the successful match ends with <emphasis>yes</emphasis>,
      followed by a record of the <productname>Expect</productname>
      variables set to describe a successful match.</para>

      <example>
        <title>Here is an excerpt from the debugging log for a
        <productname>GDB</productname> test:</title>

        <screen>
        send: sent {break gdbme.c:34\n} to spawn id 6
        expect: does {} (spawn_id 6) match pattern {Breakpoint.*at.* file
        gdbme.c, line 34.*\(gdb\) $}? no
        {.*\(gdb\) $}? no
        expect: does {} (spawn_id 0) match pattern {return} ? no
        {\(y or n\) }? no
        {buffer_full}? no
        {virtual}? no
        {memory}? no
        {exhausted}? no
        {Undefined}? no
        {command}? no
        break gdbme.c:34
        Breakpoint 8 at 0x23d8: file gdbme.c, line 34.
        (gdb) expect: does {break gdbme.c:34\r\nBreakpoint 8 at 0x23d8: 
        file gdbme.c, line 34.\r\n(gdb) } (spawn_id 6) match pattern
        {Breakpoint.*at.* file gdbme.c, line 34.*\(gdb\) $}? yes
        expect: set expect_out(0,start) {18}
        expect: set expect_out(0,end) {71}
        expect: set expect_out(0,string) {Breakpoint 8 at 0x23d8: file
        gdbme.c, line 34.\r\n(gdb) }
        epect: set expect_out(spawn_id) {6}
        expect: set expect_out(buffer) {break gdbme.c:34\r\nBreakpoint 8
        at 0x23d8: file gdbme.c, line 34.\r\n(gdb) }
        PASS:   70      0       breakpoint line number in file
        </screen>
        </example>

        <para>This example exhibits three properties of
        <productname>Expect</productname> and
        <productname>DejaGnu</productname> that might be surprising at
        first glance:</para>

        <itemizedlist mark="bullet">
        <listitem><para>Empty output for the first attempted match.  The
        first set of attempted matches shown ran against the output
        <emphasis>{}</emphasis> --- that is, no
        output. <productname>Expect</productname> begins 
        attempting to match the patterns supplied immediately; often,
        the first pass is against incomplete output (or completely
        before all output, as in this case).</para></listitem>

        <listitem><para>Interspersed tool output.  The beginning of
        the log entry for the second attempted match may be hard to
        spot: this is because the prompt <emphasis>{(gdb) }</emphasis>
        appears on the same line, just before the
        <emphasis>expect:</emphasis> that marks the beginning of the
        log entry.</para></listitem>

        <listitem><para>Fail-safe patterns.  Many of the patterns
        tested are fail-safe patterns provided by
        <productname>GDB</productname> testing utilities, to reduce
        possible indeterminacy.  It is useful to anticipate potential
        variations caused by extreme system conditions
        (<productname>GDB</productname> might issue the message
        <emphasis>virtual memory exhausted</emphasis> in rare
        circumstances), or by changes in the tested program
        (<emphasis>Undefined command</emphasis> is the likeliest
        outcome if the name of a tested command changes).</para>

        <para>The pattern <emphasis>{return}</emphasis> is a
        particularly interesting fail-safe to notice; it checks for an
        unexpected <keycap>RET</keycap> prompt.  This may happen,
        for example, if the tested tool can filter output through a
        pager.</para>

        <para>These fail-safe patterns (like the debugging log itself)
        are primarily useful while developing test scripts.  Use the
        <command>error</command> procedure to make the actions for
        fail-safe patterns produce messages starting with
        <emphasis>ERROR</emphasis> on standard output, and in the
        detailed log file.</para></listitem>
        </itemizedlist>
    </sect2>
   </sect1>
  </chapter>
  
  <chapter id=Customizing xreflabel="Customizing DejaGnu">
    <title>Customizing DejaGnu</title>
    
    <para>The site configuration file, <filename>site.exp</filename>,
    captures configuration-dependent values and propagates them to the
    DejaGnu test environment using Tcl variables.  This ties the
    DejaGnu test scripts into the <command>configure</command> and
    <command>make</command> programs. If this file is setup correctly,
    it is possible to execute a test suite merely by typing
    <command>runtest</command>.</para>

    <para>DejaGnu supports two <filename>site.exp</filename>
    files. The multiple instances of <filename>site.exp</filename> are
    loaded in a fixed order built into DejaGnu. The first file loaded
    is the local file <filename>site.exp</filename>, and then the
    optional global <filename>site.exp</filename> file as
    pointed to by the <symbol>DEJAGNU</symbol> environment
    variable.</para>

    <para>There is an optional <emphasis>master</emphasis>
    <filename>site.exp</filename>, capturing configuration values that
    apply to DejaGnu across the board, in each configuration-specific
    subdirectory of the DejaGnu library directory.
    <command>runtest</command> loads these values first. The master
    <filename>site.exp</filename> contains the default values for all
    targets and hosts supported by DejaGnu. This master file is
    identified by setting the environment variable
    <symbol>DEJAGNU</symbol> to the name of the file. This is also
    refered to as the ``global'' config file.</para>

    <para>Any directory containing a configured test suite also has a
    local <filename>site.exp</filename>, capturing configuration values
    specific to the tool under test.  Since <command>runtest</command>
    loads these values last, the individual test configuration can
    either rely on and use, or override, any of the global values from
    the global <filename>site.exp</filename> file.</para>

    <para>You can usually generate or update the testsuite's local 
    <filename>site.exp</filename> by typing <command>make
    site.exp</command> in the test suite directory, after the test
    suite is configured.</para>

    <para>You can also have a file in your home directory called
    <filename>.dejagnurc</filename>. This gets loaded first before the
    other config files. Usually this is used for personal stuff, like
    setting the <symbol>all_flag</symbol> so all the output gets
    printed, or your own verbosity levels. This file is usually
    restricted to setting command line options.</para>

    <para>You can further override the default values in a
    user-editable section of any <filename>site.exp</filename>, or by
    setting variables on the <command>runtest</command> command
    line.</para>

    <sect1 id=local xreflabel="Local Config File">
      <title>Local Config File</title>
    
      <para>It is usually more convenient to keep these <emphasis>manual
      overrides</emphasis> in the <filename>site.exp</filename>
      local to each test directory, rather than in the global
      <filename>site.exp</filename> in the installed DejaGnu
      library. This file is mostly for supplying tool specific info
      that is required by the test suite.</para>

      <para>All local <filename>site.exp</filename> files have
      two sections, separated by comment text. The first section is
      the part that is generated by <command>make</command>. It is
      essentially a collection of Tcl variable definitions based on
      <filename>Makefile</filename> environment variables. Since they
      are generated by <command>make</command>, they contain the
      values as specified by <command>configure</command>.  (You can
      also customize these values by using the <option>--site</option>
      option to <command>configure</command>.) In particular, this
      section contains the <filename>Makefile</filename>
      variables for host and target configuration data. Do not edit
      this first section; if you do, your changes are replaced next
      time you run <command>make</command>.</para>

      <example>
        <title>The first section starts with</title>

        <programlisting>
        ## these variables are automatically generated by make ##
        # Do not edit here. If you wish to override these values
        # add them to the last section
        </programlisting>
      </example>

      <para>In the second section, you can override any default values
      (locally to DejaGnu) for all the variables.  The second section
      can also contain your preferred defaults for all the command
      line options to <command>runtest</command>. This allows you to
      easily customize <command>runtest</command> for your preferences
      in each configured test-suite tree, so that you need not type
      options repeatedly on the command line.  (The second section may
      also be empty, if you do not wish to override any defaults.)</para>

      <example>
        <title>The first section ends with this line</title>

        <programlisting>
        ## All variables above are generated by configure. Do Not Edit ##
        </programlisting>
      </example>

      <para>You can make any changes under this line. If you wish to
      redefine a variable in the top section, then just put a
      duplicate value in this second section. Usually the values
      defined in this config file are related to the configuration of
      the test run. This is the ideal place to set the variables
      <symbol>host_triplet</symbol>, <symbol>build_triplet</symbol>,
      <symbol>target_triplet</symbol>. All other variables are tool
      dependant. ie for testing a compiler, the value for
      <symbol>CC</symbol> might be set to a freshly built binary, as
      opposed to one in the user's path.</para>

      <para>Here's an example local site.exp file, as used for
      <productname>GCC/G++</productname> testing.</para>

      <example>
        <title>Local Config File</title>

      <programlisting>  
      ## these variables are automatically generated by make ##
      # Do not edit here. If you wish to override these values
      # add them to the last section
      set rootme "/build/devo-builds/i586-pc-linux-gnulibc1/gcc"
      set host_triplet i586-pc-linux-gnulibc1
      set build_triplet i586-pc-linux-gnulibc1
      set target_triplet i586-pc-linux-gnulibc1
      set target_alias i586-pc-linux-gnulibc1
      set CFLAGS ""
      set CXXFLAGS "-I/build/devo-builds/i586-pc-linux-gnulibc1/gcc/../libio -I$srcdir/../libg++/src -I$srcdir/../libio -I$srcdir/../libstdc++ -I$srcdir/../libstdc++/stl -L/build/devo-builds/i586-pc-linux-gnulibc1/gcc/../libg++ -L/build/devo-builds/i586-pc-linux-gnulibc1/gcc/../libstdc++"
      append LDFLAGS " -L/build/devo-builds/i586-pc-linux-gnulibc1/gcc/../ld"
      set tmpdir /build/devo-builds/i586-pc-linux-gnulibc1/gcc/testsuite
      set srcdir "${srcdir}/testsuite"
      ## All variables above are generated by configure. Do Not Edit ##
    
      </programlisting>  
    </example>

    <para>This file defines the required fields for a local config
    file, namely the three config triplets, and the srcdir. It also
    defines several other Tcl variables that are used exclusivly by
    the GCC test suite. For most test cases, the CXXFLAGS and LDFLAGS
    are supplied by DejaGnu itself for cross testing, but to test a
    compiler, GCC needs to manipulate these itself.</para>

    </sect1>
     <sect1 id=global xreflabel="Global Config File">
      <title>Global Config File</title>
    
      <para>The master config file is where all the target specific
      config variables get set for a whole site get set. The idea is
      that for a centralized testing lab where people have to share a
      target between multiple developers. There are settings for both
      remote targets and remote hosts.  Here's an example of a Master
      Config File (also called the Global config file) for a
      <emphasis>canadian cross</emphasis>. A canadian cross is when
      you build and test a cross compiler on a machine other than the
      one it's to be hosted on.</para>

      <para>Here we have the config settings for our California
      office. Note that all config values are site dependant. Here we
      have two sets of values that we use for testing m68k-aout cross
      compilers. As both of these target boards has a different
      debugging protocol, we test on both of them in sequence.</para>

      <example>
       <title>Global Config file</title>

      <programlisting>

      # Make sure we look in the right place for the board description files.
      if ![info exists boards_dir] {
          set boards_dir {}
      }
      lappend boards_dir "/nfs/cygint/s1/cygnus/dejagnu/boards"

      verbose "Global Config File: target_triplet is $target_triplet" 2
      global target_list

      case "$target_triplet" in {
          { "native" } {
              set target_list "unix"
          }
          { "sparc64-*elf" } {
              set target_list "sparc64-sim"
          }
          { "mips-*elf" } {
              set target_list "mips-sim wilma barney"
          }
          { "mips-lsi-elf" } {
              set target_list "mips-lsi-sim{,soft-float,el}"
          }
          { "sh-*hms" } {
              set target_list { "sh-hms-sim" "bloozy" }
          }
      }
      </programlisting>
    </example>

    <para>In this case, we have support for several cross compilers,
    that all run on this host. For testing on operating systems that
    don't support Expect, DejaGnu can be run on the local build
    machine, and it can connect to the remote host and run all the
    tests for this cross compiler on that host. All the remote OS
    requires is a working telnetd.</para>

    <para>As you can see, all one does is set the variable
    <symbol>target_list</symbol> to the list of targets and options to
    test. The simple settings, like for
    <emphasis>sparc64-elf</emphasis> only require setting the name of
    the single board config file. The <emphasis>mips-elf</emphasis>
    target is more complicated. Here it sets the list to three target
    boards. One is the default mips target, and both
    <emphasis>wilma</emphasis> <emphasis>barney</emphasis> are
    symbolic names for other mips boards. Symbolic names are covered
    in the <xref linkend=addboard> chapter. The more complicated
    example is the one for <emphasis>mips-lsi-elf</emphasis>. This one
    runs the tests with multiple iterations using all possible
    combinations of the <option>--soft-float</option> and the
    <option>--el</option> (little endian) option. Needless to say,
    this last feature is mostly compiler specific.</para>

    </sect1>

    <sect1 id=boardconfig xreflabel="Board Config File">
      <title>Board Config File</title>
   
      <para>The board config file is where board specfic config data
      is stored. A board config file contains all the higher-level
      configuration settings. There is a rough inheritance scheme, where it is
      possible to base a new board description file on an existing one. There
      are also collections of custom procedures for common environments. For
      more information on adding a new board config file, go to the <xref
      linkend=addboard> chapter. </para>

      <para>An example board config file for a GNU simulator is as
      follows. <function>set_board_info</function> is a procedure that sets the
      field name to the specified value. The procedures in square brackets
      <emphasis>[]</emphasis> are <emphasis>helper procedures</emphasis>. Thes
      are used to find parts of a tool chain required to build an executable
      image that may reside in various locations. This is mostly of use for
      when the startup code, the standard C lobraries, or the tool chain itself
      is part of your build tree.</para>

      <example>
        <title>Board Config File</title>

      <programlisting>
      # This is a list of toolchains that are supported on this board.
      set_board_info target_install {sparc64-elf}

      # Load the generic configuration for this board. This will define any
      # routines needed by the tool to communicate with the board.
      load_generic_config "sim"

      # We need this for find_gcc and *_include_flags/*_link_flags.
      load_base_board_description "basic-sim"

      # Use long64 by default.
      process_multilib_options "long64"

      setup_sim sparc64

      # We only support newlib on this target. We assume that all multilib
      # options have been specified before we get here.
      set_board_info compiler  "[find_gcc]"
      set_board_info cflags  "[libgloss_include_flags] [newlib_include_flags]"
      set_board_info ldflags  "[libgloss_link_flags] [newlib_link_flags]"
      # No linker script.
      set_board_info ldscript "";

      # Used by a few gcc.c-torture testcases to delimit how large the
      # stack can be.
      set_board_info gcc,stack_size 16384
      # The simulator doesn't return exit statuses and we need to indicate this
      # the standard GCC wrapper will work with this target.
      set_board_info needs_status_wrapper 1
      # We can't pass arguments to programs.
      set_board_info noargs 1
      </programlisting>
     </example>

     <para>There are five helper procedures used in this example. The first
     one, <function>find gcc</function> looks for a copy of the GNU compiler in
     your build tree, or it uses the one in your path. This will also return
     the proper transformed name for a cross compiler if you whole build tree
     is configured for one. The next helper procedures are
     <function>libgloss_include_flags</function> &
     <function>libgloss_link_flags</function>. These return the proper flags to
     compiler and link an executable image using <xref
     linkend=libgloss>, the GNU BSP (Board Support Package). The final
     procedures are <function>newlib_include_flag</function> &
     <function>newlib_include_flag</function>. These find the Newlib C
     library, which is a reentrant standard C library for embedded systems
     comprising of non GPL'd code.</para>

    </sect1>

    <sect1 id=releng xreflabel="Remote Host Testing">
      <title>Remote Host Testing</title>

      <note><para>Thanks to Dj Delorie for the original paper that
      this section is based on.</para></note>

      <para>DejaGnu also supports running the tests on a remote
      host. To set this up, the remote host needs an ftp server, and a
      telnet server. Currently foreign operating systems used as
      remote hosts are VxWorks, VRTX, Dos/Win3.1, MacOS, and
      win95/win98/NT.</para>

      <para>The recommended source for a win95/win98/NT based ftp
      server is to get IIS (either IIS 1 or Personal Web Server) from
      <ulink
      URL="http://www.microsoft.com">http://www.microsoft.com</ulink>.
      When you install it, make sure you install the FTP server - it's
      not selected by default. Go into the IIS manager and change the
      FTP server so that it does not allow anonymous ftp. Set the home
      directory to the root directory (i.e. c:\) of a suitable
      drive. Allow writing via ftp.</para>

      <para>It will create an account like IUSR_FOOBAR where foobar is
      the name of your machine. Go into the user editor and give that
      account a password that you don't mind hanging around in the
      clear (i.e. not the same as your admin or personal
      passwords). Also, add it to all the various permission groups.</para>

      <para>You'll also need a telnet server. For win95/win98/NT, go
      to the <ulink URL="http://ataman.com">Ataman</ulink> web site,
      pick up the Ataman Remote Logon Services for Windows, and
      install it. You can get started on the eval period anyway. Add
      IUSR_FOOBAR to the list of allowed users, set the HOME directory
      to be the same as the FTP default directory. Change the Mode
      prompt to simple.</para>

      <para>Ok, now you need to pick a directory name to do all the
      testing in. For the sake of this example, we'll call it piggy
      (i.e. c:\piggy). Create this directory.</para>

      <para>You'll need a unix machine. Create a directory for the
      scripts you'll need. For this example, we'll use
      /usr/local/swamp/testing. You'll need to have a source tree
      somewhere, say /usr/src/devo. Now, copy some files from
      releng's area in SV to your machine:</para>

      <example>
        <title>Remote host setup</title>

      <screen>
      cd /usr/local/swamp/testing
      mkdir boards
      scp darkstar.welcomehome.org:/dejagnu/cst/bin/MkTestDir .
      scp darkstar.welcomehome.org:/dejagnu/site.exp .
      scp darkstar.welcomehome.org:/dejagnu/boards/useless98r2.exp boards/foobar.exp
      export DEJAGNU=/usr/local/swamp/testing/site.exp

      </screen>
      </example>

      <para>You must edit the boards/foobar.exp file to reflect your
      machine; change the hostname (foobar.com), username
      (iusr_foobar), password, and ftp_directory (c:/piggy) to match
      what you selected.</para>

      <para>Edit the global <filename> site.exp</filename> to reflect your
      boards directory:</para>

      <example>
        <title>Add The Board Directory</title>

        <programlisting>
        lappend boards_dir "/usr/local/swamp/testing/boards"
        </programlisting>
        </example>

        <para>Now run MkTestDir, which is in the contrib
        directory. The first parameter is the toolchain prefix, the
        second is the location of your devo tree. If you are testing a
        cross compiler (ex: you have sh-hms-gcc.exe in your PATH on
        the PC), do something like this:</para>

      <example>
        <title>Setup Cross Remote Testing</title>

        <programlisting>
        ./MkTestDir sh-hms /usr/dejagnu/src/devo
        </programlisting>
        </example>

        <para>If you are testing a native PC compiler (ex: you have
        gcc.exe in your PATH on the PC), do this:</para>

      <example>
        <title>Setup Native Remote Testing</title>

        <programlisting>
        ./MkTestDir '' /usr/dejagnu/src/devo
        </programlisting>
      </example>

        <para>To test the setup, <command>ftp</command> to your PC
        using the username (iusr_foobar) and password you selected. CD
        to the test directory. Upload a file to the PC. Now telnet to
        your PC using the same username and password. CD to the test
        directory. Make sure the file is there. Type "set" and/or "gcc
        -v" (or sh-hms-gcc -v) and make sure the default PATH contains
        the installation you want to test.</para>

      <example>
        <title>Run Test Remotely</title>

        <programlisting>
        cd /usr/local/swamp/testing
        make  -k -w check RUNTESTFLAGS="--host_board foobar --target_board foobar -v -v" > check.out 2>&1
        </programlisting>
        </example>

        <para>To run a specific test, use a command like this (for
        this example, you'd run this from the gcc directory that
        MkTestDir created):</para>

      <example>
        <title>Run a Test Remotely</title>

        <programlisting>
        make check RUNTESTFLAGS="--host_board sloth --target_board sloth -v compile.exp=921202-1.c"
        </programlisting>
      </example>

        <para>Note: if you are testing a cross-compiler, put in the
        correct target board. You'll also have to download more .exp
        files and modify them for your local configuration. The -v's
        are optional.</para>

    </sect1>

    <sect1 id=configfile xreflabel="Config File Values">
      <title>Config File Values</title>
    
      <para>DejaGnu uses a named array in Tcl to hold all the info for
      each machine. In the case of a canadian cross, this means host
      information as well as target information. The named array is
      called <symbol>target_info</symbol>, and it has two indices. The
      following fields are part of the array.</para>

      <sect2 id=optiondefs xreflabel="Option Variables">
        <title>Command Line Option Variables</title>

        <para>In the user editable second section of the <xref
        linkend=personal> you can not only override the configuration
        variables captured in the first section, but also specify
        default values for all on the <command>runtest</command>
        command line options.  Save for <option>--debug</option>,
        <option>--help</option>, and <option>--version</option>, each 
        command line option has an associated Tcl variable.  Use the
        Tcl <command>set</command> command to specify a new default
        value (as for the configuration variables).  The following
        table describes the correspondence between command line
        options and variables you can set in
        <filename>site.exp</filename>.  <xref linkend=invoking>, for
        explanations of the command-line options.</para>

        <para><table frame=all rowsep=0 colsep=0>
          <title>Tcl Variables For Command Line Options</title>

          <tgroup cols=3 align="char" rowsep=1 colsep=0>
          <thead><row>
            <entry>runtest</entry><entry>Tcl</entry>
            <entry>option</entry><entry>variable</entry><entry>description</entry>
          </row></thead>
          <tbody>

          <row>
            <entry>--all</entry>
            <entry>all_flag</entry>
            <entry>display all test results if set</entry>
          </row>

          <row>
            <entry>--baud</entry>
            <entry>baud</entry>
            <entry>set the default baud rate to something other than
            9600.</entry>
          </row>

          <row>
            <entry>--connect</entry>
            <entry>connectmode</entry>
            <entry><command>rlogin</command>,
            <command>telnet</command>, <command>rsh</command>,
            <command>kermit</command>, <command>tip</command>, or
            <command>mondfe</command></entry>
          </row>

          <row>
            <entry>--outdir</entry>
            <entry>outdir</entry>
            <entry>directory for <filename>tool.sum</filename> and
            <filename>tool.log.</filename></entry>
          </row>

          <row>
            <entry>--objdir</entry>
            <entry>objdir</entry>
            <entry>directory for pre-compiled binaries</entry>
          </row>

          <row>
            <entry>--reboot</entry>
            <entry>reboot</entry>
            <entry>reboot the target if set to
            <emphasis>"1"</emphasis>; do not reboot if set to
            <emphasis>"0"</emphasis> (the default).</entry>
          </row>

          <row>
            <entry>--srcdir</entry>
            <entry>srcdir</entry>
            <entry>directory of test subdirectories</entry>
          </row>

          <row>
            <entry>--strace</entry>
            <entry>tracelevel</entry>
            <entry>a number: Tcl trace depth</entry>
          </row>

          <row>
            <entry>--tool</entry>
            <entry>tool</entry>
            <entry>name of tool to test; identifies init, test subdir</entry>
          </row>

          <row>
            <entry>--verbose</entry>
            <entry>verbose</entry>
            <entry>verbosity level.  As option, use multiple times; as
            variable, set a number, 0 or greater.</entry>
          </row>

          <row>
            <entry>--target</entry>
            <entry>target_triplet</entry>
            <entry>The canonical configuration string for the target.</entry>
          </row>

          <row>
            <entry>--host</entry>
            <entry>host_triplet</entry>
            <entry>The canonical configuration string for the host.</entry>
          </row>

          <row>
            <entry>--build</entry>
            <entry>build_triplet</entry>
            <entry>The canonical configuration string for the build
            host.</entry>
          </row>

          <row>
            <entry>--mail</entry>
            <entry>address</entry>
            <entry>Email the output log to the specified address.</entry>
          </row>

          </tbody>
          </tgroup>
          </table>
        </para>

    </sect2>

    <sect2 id=personal xreflabel="Personal Config File">
      <title>Personal Config File</title>
    
      <para>The personal config file is used to customize
      <command>runtest's</command> behaviour for each person. It's
      typically used to set the user prefered setting for verbosity,
      and any experimental Tcl procedures. My personal
      <filename>~/.dejagnurc</filename> file looks like:</para>

      <example>
        <title>Personal Config File</title>

        <programlisting>
        set all_flag 1
        set RLOGIN /usr/ucb/rlogin
        set RSH /usr/local/sbin/ssh
        </programlisting>
      </example>

      <para>Here I set <symbol>all_flag</symbol> so I see all the test
      cases that PASS along with the ones that FAIL. I also set
      <symbol>RLOGIN</symbol> to the BSD version. I have
      <productname>Kerberos</productname> installed, and when I rlogin
      to a target board, it usually isn't supported. So I use the non
      secure version rather than the default that's in my path. I also
      set <symbol>RSH</symbol> to the <productname>SSH</productname>
      secure shell, as rsh is mostly used to test unix
      machines within a local network here.</para>

      </sect2>
    </sect1>

  </chapter>
  
  <chapter id=Extending xreflabel="Extending DejaGnu">
    <title>Extending DejaGnu</title>
    
    <sect1 id=addsuite  xreflabel="Adding a new Test Suite">
      <title>Adding A New Test Suite</title>
    
      <para>The testsuite for a new tool should always be located in that tools
      source directory. DejaGnu require the directory be named
      <filename>testsuite</filename>. Under this directory, the test cases go
      in a subdirectory whose name begins with the tool name. For example, for
      a tool named <emphasis>flubber</emphasis>, each subdirectory containing
      testsuites must start with <emphasis>"flubber."</emphasis>.</para>

    </sect1>

    <sect1 id=addtool xreflabel="Adding A New Tool">
      <title>Adding A New Tool</title>
    
      <para>In general, the best way to learn how to write (code or even prose)
      is to read something similar.  This principle applies to test cases and
      to test suites.  Unfortunately, well-established test suites have a way
      of developing their own conventions: as test writers become more
      experienced with DejaGnu and with Tcl, they accumulate more utilities,
      and take advantage of more and more features of
      <productname>Expect</productname> and <productname>Tcl</productname> in
      general.</para>

      <para>Inspecting such established test suites may make the prospect of
      creating an entirely new test suite appear overwhelming.  Nevertheless,
      it is quite straightforward to get a new test suite going.</para>

      <para>There is one test suite that is guaranteed not to grow more
      elaborate over time: both it and the tool it tests were created expressly
      to illustrate what it takes to get started with DejaGnu.  The
      <filename>example/</filename> directory of the DejaGnu distribution
      contains both an interactive tool called <command>calc</command>, and a
      test suite for it.  Reading this test suite, and experimenting with it,
      is a good way to supplement the information in this section.  (Thanks to
      Robert Lupton for creating calc and its test suite---and also the first
      version of this section of the manual!)</para>

      <para>To help orient you further in this task, here is an outline of the
      steps to begin building a test suite for a program example.</para>

      <itemizedlist mark=bullet>
      
      <listitem><para>Create or select a directory to contain your new
      collection of tests. Change into that directory (shown here as
      <filename>testsuite</filename>):</para>
              
      <para>Create a <filename>configure.in</filename> file in this directory,
      to control configuration-dependent choices for your tests.  So far as
      DejaGnu is concerned, the important thing is to set a value for the
      variable <symbol>target_abbrev</symbol>; this value is the link to the
      init file you will write soon.  (For simplicity, we assume the
      environment is Unix, and use <emphasis>unix</emphasis> as the
      value.)</para>

      <para>What else is needed in <filename>configure.in</filename> depends on
      the requirements of your tool, your intended test environments, and which
      configure system you use.  This example is a minimal configure.in for use
      with <productname>GNU Autoconf</productname>. </para></listitem>

      <listitem><para>Create <filename>Makefile.in</filename> (if you are using
      Autoconf), or <filename>Makefile.am</filename>(if you are using
      Automake), the source file used by configure to build your
      <filename>Makefile</filename>. If you are using GNU Automake.just add the
      keyword <emphasis>dejagnu</emphasis> to the
      <emphasis>AUTOMAKE_OPTIONS</emphasis> variable in your
      <filename>Makefile.am</filename> file. This will add all the Makefile
      support needed to run DejaGnu, and support the <xref linkend=makecheck>
      target.</para>

      <para>You also need to include two targets important to DejaGnu:
      <emphasis>check</emphasis>, to run the tests, and
      <emphasis>site.exp</emphasis>, to set up the Tcl copies of
      configuration-dependent values. This is called the <xref linkend=local>
      The check target must run the <command>runtest</command> program to
      execute the tests.</para>

      <para>The <filename>site.exp</filename> target should usually set up
      (among other things) the $tool variable for the name of your program. If
      the local site.exp file is setup correctly, it is possible to execute the
      tests by merely typing <command>runtest</command> on the command
      line.</para>

      <example>
        <title>Sample Makefile.in Fragment</title>

        <programlisting>
        # Look for a local version of DejaGnu, otherwise use one in the path
        RUNTEST = `if test -f $(top_srcdir)/../dejagnu/runtest; then \
              echo $(top_srcdir) ../dejagnu/runtest; \
            else \
               echo runtest; \
             fi`

        # The flags to pass to runtest
        RUNTESTFLAGS =

        # Execute the tests 
        check: site.exp all
        $(RUNTEST) $(RUNTESTFLAGS) \
            --tool <symbol>${example}</symbol> --srcdir $(srcdir) 

        # Make the local config file
        site.exp: ./config.status Makefile
            @echo "Making a new config file..."
            -@rm -f ./tmp?
            @touch site.exp

            -@mv site.exp site.bak
            @echo "## these variables are automatically\
 generated by make ##" > ./tmp0
            @echo "# Do not edit here. If you wish to\
 override these values" >> ./tmp0
            @echo "# add them to the last section" >> ./tmp0
            @echo "set host_os ${host_os}" >> ./tmp0
            @echo "set host_alias ${host_alias}" >> ./tmp0
            @echo "set host_cpu ${host_cpu}" >> ./tmp0
            @echo "set host_vendor ${host_vendor}" >> ./tmp0
            @echo "set target_os ${target_os}" >> ./tmp0
            @echo "set target_alias ${target_alias}" >> ./tmp0
            @echo "set target_cpu ${target_cpu}" >> ./tmp0
            @echo "set target_vendor ${target_vendor}" >> ./tmp0
            @echo "set host_triplet ${host_canonical}" >> ./tmp0
            @echo "set target_triplet ${target_canonical}">>./tmp0
            @echo "set tool binutils" >> ./tmp0
            @echo "set srcdir ${srcdir}" >> ./tmp0
            @echo "set objdir `pwd`" >> ./tmp0
            @echo "set <symbol>${examplename}</symbol> <symbol>${example}</symbol>" >> ./tmp0
            @echo "## All variables above are generated by\
 configure. Do Not Edit ##" >> ./tmp0
            @cat ./tmp0 > site.exp
            @sed < site.bak \
               -e '1,/^## All variables above are.*##/ d' \
               >> site.exp
            -@rm -f ./tmp?

            </programlisting>
            </example>
          </listitem>
          
          <listitem><para>Create a directory (in <filename>testsuite</filename>)
          called <filename>config</filename>. Make a <emphasis>Tool Init
          File</emphasis> in this directory. Its name must start with the
          <symbol>target_abbrev</symbol> value, or be named
          <filename>default.exp</filename> so call it
          <filename>config/unix.exp</filename> for our Unix based example. This
          is the file that contains the target-dependent procedures.
          Fortunately, on Unix, most of them do not have to do very much in
          order for <command>runtest</command> to run.</para>

          <para>If the program being tested is not interactive, you can get
          away with this minimal <filename>unix.exp</filename> to begin
          with:</para>

          <example>
            <title>Simple Batch Program Tool Init File</title>
          
          <programlisting>
          
          proc foo_exit {} {}
          proc foo_version {} {}

          </programlisting>
          </example>

          <para>If the program being tested is interactive, however, you might
          as well define a <emphasis>start</emphasis> routine and invoke it by
          using an init file like this:</para>

          <example>
            <title>Simple Interactive Program Tool Init File</title>

          <programlisting>
        
          proc foo_exit {} {}
          proc foo_version {} {}

          proc foo_start {} {
            global ${examplename}
            spawn ${examplename}
            expect {
                -re "" {}
            }
          }

          # Start the program running we want to test
          foo_start

          </programlisting>
          </example>
          </listitem>

          <listitem><para>Create a directory whose name begins with your tool's
          name, to contain tests. For example, if your tool's name is
          <emphasis>gcc</emphasis>, then the directories all need to start with
          <emphasis>"gcc."</emphasis>.</para></listitem>

          <listitem><para>Create a sample test file. Its name must end with
          <filename>.exp</filename>. You can use
          <filename>first-try.exp</filename>. To begin with, just write there a
          line of Tcl code to issue a message.</para>

          <example>
            <title>Testing A New Tool Config</title>

          <programlisting>

          send_user "Testing: one, two...\n"

          </programlisting>
          </example>
          </listitem>

          <listitem><para>Back in the <filename>testsuite</filename> (top
          level) directory, run <command>configure</command>. Typically you do
          this while in the build directory. You may have to specify more of a
          path, if a suitable configure is not available in your execution
          path.</para></listitem>

          <listitem><para>e now ready to triumphantly type <command>make
          check</command> or <command>runtest</command>.  You should see
          something like this:</para>

          <example>
            <title>Example Test Case Run</title>

          <screen>
          Test Run By rhl on Fri Jan 29 16:25:44 EST 1993

                === example tests ===

          Running ./example.0/first-try.exp ...
          Testing: one, two...

                === example Summary ===

         </screen>
         </example>

         <para>There is no output in the summary, because so far the example
         does not call any of the procedures that establish a test
         outcome.</para></listitem>

         <listitem><para>Write some real tests. For an interactive tool, you
         should probably write a real exit routine in fairly short order. In
         any case, you should also write a real version routine
         soon. </para></listitem>

    </itemizedlist>

    </sect1>

    <sect1 id=addtarget xreflabel="Adding A New Target">
      <title>Adding A New Target</title>
    
      <para>DejaGnu has some additional requirements for target support, beyond
      the general-purpose provisions of configure. DejaGnu must actively
      communicate with the target, rather than simply generating or managing
      code for the target architecture.  Therefore, each tool requires an
      initialization module for each target.  For new targets, you must supply
      a few Tcl procedures to adapt DejaGnu to the target.  This permits
      DejaGnu itself to remain target independent.</para>

      <para>Usually the best way to write a new initialization module is to
      edit an existing initialization module; some trial and error will be
      required. If necessary, you can use the @samp{--debug} option to see what
      is really going on.</para>

      <para>When you code an initialization module, be generous in printing
      information controlled by the <function>verbose</function>
      procedure.</para>

      <para>For cross targets, most of the work is in getting the
      communications right. Communications code (for several situations
      involving IP networks or serial lines) is available in a DejaGnu library
      file.</para>

      <para>If you suspect a communication problem, try running the connection
      interactively from <productname>Expect</productname>.  (There are three
      ways of running <productname>Expect</productname> as an interactive
      interpreter.  You can run <productname>Expect</productname> with no
      arguments, and control it completely interactively; or you can use
      <command>expect -i</command> together with other command-line options and
      arguments; or you can run the command <command>interpreter</command> from
      any <productname>Expect</productname> procedure.  Use
      <command>return</command> to get back to the calling procedure (if any),
      or <command>return -tcl</command> to make the calling procedure itself
      return to its caller; use <command>exi</command>t or end-of-file to leave
      Expect altogether.)  Run the program whose name is recorded in
      <symbol>$connectmode</symbol>, with the arguments in
      <symbol>$targetname</symbol>, to establish a connection.  You should at
      least be able to get a prompt from any target that is physically
      connected.</para>

    </sect1>

    <sect1 id=addboard xreflabel="Adding A New Board">
      <title>Adding A New Board</title>
    
      <para>Adding a new board consists of creating a new board config
      file. Examples are in
      <filename>dejagnu/baseboards</filename>. Usually to make a new
      board file, it's easiest to copy an existing one. It is also
      possible to have your file be based on a
      <emphasis>baseboard</emphasis> file with only one or two
      changes needed. Typically, this can be as simple as just
      changing the linker script. Once the new baseboard file is done,
      add it to the <symbol>boards_DATA</symbol> list in the
      <filename>dejagnu/baseboards/Makefile.am</filename>, and regenerate the
      Makefile.in using automake. Then just rebuild and install DejaGnu. You
      can test it by:</para>

      <para>There is a crude inheritance scheme going on with board files, so
      you can include one board file into another, The two main procedures used
      to do this are <function>load_generic_config</function> and
      <function>load_base_board_description</function>. The generic config file
      contains other procedures used for a certain class of target. The
      board description file is where the board specfic settings go. Commonly
      there are similar target environments with just different
      processors.</para> 

      <example>
      <title>Testing a New Board Config File</title>

      <screen>
      make check RUNTESTFLAGS="--target_board=<emphasis>newboardfile</emphasis>".
      </screen>
      </example>

      <para>Here's an example of a board config file. There are
      several <emphasis>helper procedures</emphasis> used in this
      example. A helper procedure is one that look for a tool of files
      in commonly installed locations. These are mostly used when
      testing in the build tree, because the executables to be tested
      are in the same tree as the new dejagnu files. The helper
      procedures are the ones in square braces
      <emphasis>[]</emphasis>, which is the Tcl execution characters.</para> 

      <example>
      <title>Example Board Config File</title>

      <programlisting>

      # Load the generic configuration for this board. This will define a basic
      # set of routines needed by the tool to communicate with the board.
      load_generic_config "sim"

      # basic-sim.exp is a basic description for the standard Cygnus simulator.
      load_base_board_description "basic-sim"

      # The compiler used to build for this board. This has *nothing* to do
      # with what compiler is tested if we're testing gcc.
      set_board_info compiler "[find_gcc]"

      # We only support newlib on this target.
      # However, we include libgloss so we can find the linker scripts.
      set_board_info cflags "[newlib_include_flags] [libgloss_include_flags]"
      set_board_info ldflags "[newlib_link_flags]"

      # No linker script for this board.
      set_board_info ldscript "-Tsim.ld";

      # The simulator doesn't return exit statuses and we need to indicate this.
      set_board_info needs_status_wrapper 1

      # Can't pass arguments to this target.
      set_board_info noargs 1

      # No signals.
      set_board_info gdb,nosignals 1

      # And it can't call functions.
      set_board_info gdb,cannot_call_functions 1

      </programlisting>
      </example>

    </sect1>

    <sect1 id=boarddefs xreflabel="Board File Values">
      <title>Board Config File Values</title>

      <para>These fields are all in the <symbol>board_info</symbol> These are
      all set by using the <function>set_board_info</function> procedure. The
      parameters are the field name, followed by the value to set the field
      to.</para>

         <para><table frame=all rowsep=0 colsep=0>
          <title>Common Board Info Fields</title>

          <tgroup cols=3 align="char" rowsep=1 colsep=0>
          <thead><row>
            <entry>Field</entry>
            <entry>Sample Value</entry>
            <entry>Description</entry>
          </row></thead>
          <tbody>

          <row>
            <entry>compiler</entry>
            <entry>"[find_gcc]"</entry>
            <entry>The path to the compiler to use.</entry>
          </row>

          <row>
            <entry>cflags</entry>
            <entry>"-mca"</entry>
            <entry>Compilation flags for the compiler.</entry>
          </row>

          <row>
            <entry>ldflags</entry>
            <entry>"[libgloss_link_flags] [newlib_link_flags]"</entry>
            <entry>Linking flags for the compiler.</entry>
          </row>

          <row>
            <entry>ldscript</entry>
            <entry>"-Wl,-Tidt.ld"</entry>
            <entry>The linker script to use when cross compiling.</entry>
          </row>

          <row>
            <entry>libs</entry>
            <entry>"-lgcc"</entry>
            <entry>Any additional libraries to link in.</entry>
          </row>

          <row>
            <entry>shell_prompt</entry>
            <entry>"cygmon>"</entry>
            <entry>The command prompt of the remote shell.</entry>
          </row>

          <row>
            <entry>hex_startaddr</entry>
            <entry>"0xa0020000"</entry>
            <entry>The Starting address as a string.</entry>
          </row>

          <row>
            <entry>start_addr</entry>
            <entry>0xa0008000</entry>
            <entry>The starting address as a value.</entry>
          </row>

          <row>
            <entry>startaddr</entry>
            <entry>"a0020000"</entry>
            <entry></entry>
          </row>

          <row>
            <entry>exit_statuses_bad</entry>
            <entry>1</entry>
            <entry>Whether there is an accurate exit status.</entry>
          </row>

          <row>
            <entry>reboot_delay</entry>
            <entry>10</entry>
            <entry>The delay between power off and power on.</entry>
          </row>

          <row>
            <entry>unreliable</entry>
            <entry>1</entry>
            <entry>Whether communication with the board is unreliable.</entry>
          </row>

          <row>
            <entry>sim</entry>
            <entry>[find_sim]</entry>
            <entry>The path to the simulator to use.</entry>
          </row>

          <row>
            <entry>objcopy</entry>
            <entry>$tempfil</entry>
            <entry>The path to the <command>objcopy</command> program.</entry>
          </row>

          <row>
            <entry>support_libs</entry>
            <entry>"${prefix_dir}/i386-coff/"</entry>
            <entry>Support libraries needed for cross compiling.</entry>
          </row>

          <row>
            <entry>addl_link_flags</entry>
            <entry>"-N"</entry>
            <entry>Additional link flags, rarely used.</entry>
          </row>

          </tbody>
          </tgroup>
          </table>
        </para>

         <para>These fields are used by the GCC and GDB tests, and are mostly
         only useful to somewhat trying to debug a new board file for one of
         these tools. Many of these are used only by a few testcases, and their
         purpose is esoteric. These are listed with sample values as a guide to
         better guessing if you need to change any of these.</para>

         <para><table frame=all rowsep=0 colsep=0>
          <title>Board Info Fields For GCC & GDB</title>

          <tgroup cols=3 align="char" rowsep=1 colsep=0>
          <thead><row>
            <entry>Field</entry>
            <entry>Sample Value</entry>
            <entry>Description</entry>
          </row></thead>
          <tbody>

          <row>
            <entry>strip</entry>
            <entry>$tempfile</entry>
            <entry>Strip the executable of symbols.</entry>
          </row>

          <row>
            <entry>gdb_load_offset</entry>
            <entry>"0x40050000"</entry>
          </row>

          <row>
            <entry>gdb_protocol</entry>
            <entry>"remote"</entry>
            <entry>The GDB debugging protocol to use.</entry>
          </row>

          <row>
            <entry>gdb_sect_offset</entry>
            <entry>"0x41000000";</entry>
          </row>

          <row>
            <entry>gdb_stub_ldscript</entry>
            <entry>"-Wl,-Teva-stub.ld"</entry>
            <entry>The linker script to use with a GDB stub.</entry>
          </row>

          <row>
            <entry>gdb_init_command</entry>
            <entry>"set mipsfpu none"</entry>
          </row>

          <row>
            <entry>gdb,cannot_call_functions</entry>
            <entry>1</entry>
            <entry>Whether GDB can call functions on the target,</entry>
          </row>

          <row>
            <entry>gdb,noargs</entry>
            <entry>1</entry>
            <entry>Whether the target can take command line arguments.</entry>
          </row>

          <row>
            <entry>gdb,nosignals</entry>
            <entry>1</entry>
            <entry>Whether there are signals on the target.</entry>
          </row>

          <row>
            <entry>gdb,short_int</entry>
            <entry>1</entry>
          </row>

          <row>
            <entry>gdb,start_symbol</entry>
            <entry>"_start";</entry>
            <entry>The starting symbol in the executable.</entry>
          </row>

          <row>
            <entry>gdb,target_sim_options</entry>
            <entry>"-sparclite"</entry>
            <entry>Special options to pass to the simulator.</entry>
          </row>

          <row>
            <entry>gdb,timeout</entry>
            <entry>540</entry>
            <entry>Timeout value to use for remote communication.</entry>
          </row>

          <row>
            <entry>gdb_init_command</entry>
            <entry>"print/x \$fsr = 0x0"</entry>
          </row>

          <row>
            <entry>gdb_load_offset</entry>
            <entry>"0x12020000"</entry>
          </row>

          <row>
            <entry>gdb_opts</entry>
            <entry>"--command gdbinit"</entry>
          </row>

          <row>
            <entry>gdb_prompt</entry>
            <entry>"\\(gdb960\\)"</entry>
            <entry>The prompt GDB is using.</entry>
          </row>

          <row>
            <entry>gdb_run_command</entry>
            <entry>"jump start"</entry>
          </row>

          <row>
            <entry>gdb_stub_offset</entry>
            <entry>"0x12010000"</entry>
          </row>

          <row>
            <entry>use_gdb_stub</entry>
            <entry>1</entry>
            <entry>Whether to use a GDB stub.</entry>
          </row>

          <row>
            <entry>use_vma_offset</entry>
            <entry>1</entry>
          </row>

          <row>
            <entry>wrap_m68k_aout</entry>
            <entry>1</entry>
          </row>

          <row>
            <entry>gcc,no_label_values</entry>
            <entry>1</entry>
          </row>

          <row>
            <entry>gcc,no_trampolines</entry>
            <entry>1</entry>
          </row>

          <row>
            <entry>gcc,no_varargs</entry>
            <entry>1</entry>
          </row>

          <row>
            <entry>gcc,stack_size</entry>
            <entry>16384</entry>
            <entry>Stack size to use with some GCC testcases.</entry>
          </row>

          <row>
            <entry>ieee_multilib_flags</entry>
            <entry>"-mieee";</entry>
          </row>

          <row>
            <entry>is_simulator</entry>
            <entry>1</entry>
          </row>

          <row>
            <entry>needs_status_wrapper</entry>
            <entry>1</entry>
          </row>

          <row>
            <entry>no_double</entry>
            <entry>1</entry>
          </row>

          <row>
            <entry>no_long_long</entry>
            <entry>1</entry>
          </row>

          <row>
            <entry>noargs</entry>
            <entry>1</entry>
          </row>

          <row>
            <entry>nullstone,lib</entry>
            <entry>"mips-clock.c"</entry>
          </row>

          <row>
            <entry>nullstone,ticks_per_sec</entry>
            <entry>3782018</entry>
          </row>

          <row>
            <entry>sys_speed_value</entry>
            <entry>200</entry>
          </row>

          <row>
            <entry>target_install</entry>
            <entry>{sh-hms}</entry>
          </row>

          </tbody>
          </tgroup>
          </table>
        </para>

    </sect1>

    <sect1 id=writing xreflabel="Writing A Test Case">
      <title>Writing A Test Case</title>
    
      <para>The easiest way to prepare a new test case is to base it
      on an existing one for a similar situation.  There are two major
      categories of tests: batch or interactive.  Batch oriented tests
      are usually easier to write.</para>

      <para>The GCC tests are a good example of batch oriented tests.
      All GCC tests consist primarily of a call to a single common
      procedure, Since all the tests either have no output, or only
      have a few warning messages when successfully compiled.  Any
      non-warning output is a test failure.  All the C code needed is
      kept in the test directory.  The test driver, written in Tcl,
      need only get a listing of all the C files in the directory, and
      compile them all using a generic procedure. This procedure and a
      few others supporting for these tests are kept in the library
      module <filename>lib/c-torture.exp</filename> in the GCC test
      suite. Most tests of this kind use very few
      <productname>expect</productname> features, and are coded almost
      purely in Tcl.</para>

      <para>Writing the complete suite of C tests, then, consisted of
      these steps:</para>

      <itemizedlist mark=bullet>
      <listitem><para>Copying all the C code into the test directory.
      These tests were based on the C-torture test created by Torbjorn
      Granlund (on behalf of the Free Software Foundation) for GCC
      development.</para></listitem>

      <listitem><para>Writing (and debugging) the generic Tcl procedures for
      compilation.</para></listitem>

      <listitem><para>Writing the simple test driver: its main task is to
      search the directory (using the Tcl procedure
      <emphasis>glob</emphasis> for filename expansion with wildcards)
      and call a Tcl procedure with each filename.  It also checks for
      a few errors from the testing procedure.</para></listitem>
      </itemizedlist>

      <para>Testing interactive programs is intrinsically more
      complex.  Tests for most interactive programs require some trial
      and error before they are complete.</para>

      <para>However, some interactive programs can be tested in a
      simple fashion reminiscent of batch tests.  For example, prior
      to the creation of DejaGnu, the GDB distribution already
      included a wide-ranging testing procedure.  This procedure was
      very robust, and had already undergone much more debugging and
      error checking than many recent DejaGnu test cases.
      Accordingly, the best approach was simply to encapsulate the
      existing GDB tests, for reporting purposes. Thereafter, new GDB
      tests built up a family of Tcl procedures specialized for GDB
      testing.</para>

    </sect1>

    <sect1 id=debugging xreflabel="Debugging A Test Case">
      <title>Debugging A Test Case</title>
    
      <para>These are the kinds of debugging information available
      from DejaGnu:</para>

      <itemizedlist mark=bullet>

      <listitem><para>Output controlled by test scripts themselves,
      explicitly allowed for by the test author.  This kind of
      debugging output appears in the detailed output recorded in the
      DejaGnu log file.  To do the same for new tests, use the
      <command>verbose</command> procedure (which in turn uses the
      variable also called <emphasis>verbose</emphasis>) to control
      how much output to generate.  This will make it easier for other
      people running the test to debug it if necessary.  Whenever
      possible, if <emphasis>$verbose</emphasis> is
      <emphasis>0</emphasis>, there should be no output other than the
      output from <emphasis>pass</emphasis>,
      <emphasis>fail</emphasis>, <emphasis>error</emphasis>, and
      <emphasis>warning</emphasis>.  Then, to whatever extent is
      appropriate for the particular test, allow successively higher
      values of <emphasis>$verbose</emphasis> to generate more
      information.  Be kind to other programmers who use your tests:
      provide for a lot of debugging information.</para></listitem>

      <listitem><para>Output from the internal debugging functions of
      Tcl and <productname>Expect</productname>. There is a command
      line options for each; both forms of debugging output are
      recorded in the file <filename>dbg.log</filename> in the current
      directory.</para>

      <para>Use <option>--debug</option> for information from the
       expect level; it generates displays of the expect attempts to
       match the tool output with the patterns specified. This output
       can be very helpful while developing test scripts, since it
       shows precisely the characters received.  Iterating between the
       latest attempt at a new test script and the corresponding
       <filename>dbg.log</filename> can allow you to create the final
       patterns by ``cut and paste''.  This is sometimes the best way
       to write a test case.</para></listitem>

       <listitem><para>Use <option>--strace</option> to see more
       detail at the Tcl level; this shows how Tcl procedure
       definitions expand, as they execute. The associated number
       controls the depth of definitions expanded.</para></listitem>

       <listitem><para>Finally, if the value of
       <emphasis>verbose</emphasis> is 3 or greater,DejaGnu turns on
       the expect command <command>log_user</command>.  This command
       prints all expect actions to the expect standard output, to the
       detailed log file, and (if <option>--debug</option> is on) to
       <filename>dbg.log</filename>.</para></listitem>
       </itemizedlist>

    </sect1>

    <sect1 id=adding xreflabel="Adding A Test Case To A Test Suite">
      <title>Adding A Test Case To A Test Suite.</title>
    
      <para>There are two slightly different ways to add a test
      case. One is to add the test case to an existing directory. The
      other is to create a new directory to hold your test. The
      existing test directories represent several styles of testing,
      all of which are slightly different; examine the directories for
      the tool of interest to see which (if any) is most suitable.</para>

      <para>Adding a GCC test can be very simple: just add the C code
      to any directory beginning with <filename>gcc</filename>. and it
      runs on the next <programlisting>runtest --tool
      gcc</programlisting>.</para>

      <para>To add a test to GDB, first add any source code you will
      need to the test directory. Then you can either create a new
      expect file, or add your test to an existing one (any
      file with a <emphasis>.exp</emphasis> suffix).  Creating a new
      .exp file is probably a better idea if the test is significantly
      different from existing tests. Adding it as a separate file also
      makes upgrading easier. If the C code has to be already compiled
      before the test will run, then you'll have to add it to the
      <filename>Makefile.in</filename> file for that test directory,
      then run <command>configure</command> and
      <command>make</command>.</para>

      <para>Adding a test by creating a new directory is very
      similar:</para>

      <itemizedlist mark=bullet>

      <listitem><para>Create the new directory. All subdirectory names
      begin with the name of the tool to test; e.g. G++ tests might be
      in a directory called <filename>g++.other</filename>. There can
      be multiple test directories that start with the same tool name
      (such as <emphasis>g++</emphasis>).</para></listitem>

      <listitem><para>Add the new directory name to the
      <symbol>configdirs</symbol> definition in the
      <filename>configure.in</filename> file for the test suite
      directory. This way when <command>make</command> and
      <command>configure</command> next run, they include the new
      directory.</para></listitem>

      <listitem><para>Add the new test case to the directory, as
      above. </para></listitem>

      <listitem><para>To add support in the new directory for
      configure and make, you must also create a
      <filename>Makefile.in</filename> and a
      <filename>configure.in</filename>.</para></listitem> 
      </itemizedlist>

    </sect1>

    <sect1 id=hints xreflabel="Hints On Writing A Test Case">
      <title>Hints On Writing A Test Case</title>
    
      <para>It is safest to write patterns that match all the output
      generated by the tested program; this is called closure.
      If a pattern does not match the entire output, any output that
      remains will be examined by the next <command>expect</command>
      command. In this situation, the precise boundary that determines
      which <command>expect</command> command sees what is very
      sensitive to timing between the Expect task and the task running
      the tested tool.  As a result, the test may sometimes appear to
      work, but is likely to have unpredictable results. (This problem
      is particularly likely for interactive tools, but can also
      affect batch tools---especially for tests that take a long time
      to finish.) The best way to ensure closure is to use the
      <option>-re</option> option for the <command>expect</command>
      command to write the pattern as a full regular expressions; then
      you can match the end of output using a <emphasis>$</emphasis>.
      It is also a good idea to write patterns that match all
      available output by using <emphasis>.*\</emphasis> after the
      text of interest; this will also match any intervening blank
      lines.  Sometimes an alternative is to match end of line using
      <emphasis>\r</emphasis> or <emphasis>\n</emphasis>, but this is
      usually too dependent on terminal settings.</para>

      <para>Always escape punctuation, such as <emphasis>(</emphasis>
      or <emphasis>&quot</emphasis>, in your patterns; for example, write
      <emphasis>\(</emphasis>.  If you forget to escape punctuation,
      you will usually see an error message like <programlisting>extra
      characters after close-quote.</programlisting></para>

      <para>If you have trouble understanding why a pattern does not
      match the program output, try using the <option>--debug</option>
      option to <command>runtest</command>, and examine the debug log
      carefully.</para>

      <para>Be careful not to neglect output generated by setup rather
      than by the interesting parts of a test case.  For example,
      while testing GDB, I issue a send <emphasis>set height
      0\n</emphasis> command.  The purpose is simply to make sure GDB
      never calls a paging program.  The <emphasis>set
      height</emphasis> command in GDB does not generate any
      output; but running any command makes GDB issue a new
      <emphasis>(gdb) </emphasis> prompt.  If there were no
      <command>expect</command> command to match this prompt, the
      output <emphasis>(gdb) </emphasis> begins the text seen by the
      next <command>expect</command> command---which might make that
      pattern fail to match.</para>

      <para>To preserve basic sanity, I also recommended that no test
      ever pass if there was any kind of problem in the test case.  To
      take an extreme case, tests that pass even when the tool will
      not spawn are misleading. Ideally, a test in this sort of
      situation should not fail either. Instead, print an error
      message by calling one of the DejaGnu procedures
      <command>error</command> or <command>warning</command>.</para>

    </sect1>

    <sect1 id=tvariables xreflabel="Test Case Variables">
      <title>Special variables used by test cases.</title>
    
      <para>There are special variables used by test cases. These contain
      other information from DejaGnu. Your test cases can use these variables,
      with conventional meanings (as well as the variables saved in
      <filename>site.exp</filename>. You can use the value of these variables,
      but they should never be changed.</para>

        <variablelist>
          <varlistentry>
            <term>$prms_id</term>
            <listitem><para>The tracking system (e.g. GNATS) number identifying
            a corresponding bugreport.  (<emphasis>0</emphasis>} if you do not
            specify it in the test script.)</para></listitem>
          </varlistentry>

          <varlistentry>
            <term>$item bug_id</term>
            <listitem><para>An optional bug id; may reflect a bug
            identification from another organization.  (<emphasis>0</emphasis>
            if you do not specify it.)</para></listitem>
          </varlistentry>

          <varlistentry>
            <term>$subdir</term>
            <listitem><para>The subdirectory for the current test
            case.</para></listitem>
          </varlistentry>

          <varlistentry>
            <term>$expect_out(buffer)</term>
            <listitem><para>The output from the last command. This is an
            internal variable set by Expect. More information can be found in
            the Expect manual.</para></listitem>
          </varlistentry>

          <varlistentry>
            <term>$exec_output</term>
            <listitem><para>This is the output from a
            <function>${tool}_load</function> command. This only applies to
            tools like GCC and GAS which produce an object file that must in
            turn be executed to complete a test.</para></listitem>
          </varlistentry>

          <varlistentry>
            <term>$comp_output</term>
            <listitem><para>This is the output from a
            <function>${tool}_start</function> command.  This is conventionally
            used for batch oriented programs, like GCC and GAS, that may
            produce interesting output (warnings, errors) without further
            interaction.</para></listitem> 
          </varlistentry>
        </variablelist>

    </sect1>
   
</chapter>

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