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<h3>Table of Contents</h3>
<ul class="link-list" role="directory">
<li><a href="#class-Tracer-label-Example">Example</a>
<li><a href="#class-Tracer-label-Copyright">Copyright</a>
</ul>
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<div id="class-metadata">
<div id="parent-class-section" class="nav-section">
<h3>Parent</h3>
<p class="link"><a href="Object.html">Object</a>
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<!-- Method Quickref -->
<div id="method-list-section" class="nav-section">
<h3>Methods</h3>
<ul class="link-list" role="directory">
<li ><a href="#method-c-add_filter">::add_filter</a>
<li ><a href="#method-c-off">::off</a>
<li ><a href="#method-c-on">::on</a>
<li ><a href="#method-c-set_get_line_procs">::set_get_line_procs</a>
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<h1 id="class-Tracer" class="class">
class Tracer
</h1>
<section class="description">
<p>Outputs a source level execution trace of a Ruby program.</p>
<p>It does this by registering an event handler with <a href="Kernel.html#method-i-set_trace_func"><code>Kernel#set_trace_func</code></a> for processing incoming events. It also provides methods for filtering unwanted trace output (see <a href="Tracer.html#method-c-add_filter"><code>Tracer.add_filter</code></a>, <a href="Tracer.html#method-c-on"><code>Tracer.on</code></a>, and <a href="Tracer.html#method-c-off"><code>Tracer.off</code></a>).</p>
<h2 id="class-Tracer-label-Example">Example<span><a href="#class-Tracer-label-Example">¶</a> <a href="#top">↑</a></span></h2>
<p>Consider the following Ruby script</p>
<pre class="ruby"><span class="ruby-keyword">class</span> <span class="ruby-constant">A</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">square</span>(<span class="ruby-identifier">a</span>)
<span class="ruby-keyword">return</span> <span class="ruby-identifier">a</span><span class="ruby-operator">*</span><span class="ruby-identifier">a</span>
<span class="ruby-keyword">end</span>
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">a</span> = <span class="ruby-constant">A</span>.<span class="ruby-identifier">new</span>
<span class="ruby-identifier">a</span>.<span class="ruby-identifier">square</span>(<span class="ruby-value">5</span>)
</pre>
<p>Running the above script using <code>ruby -r tracer example.rb</code> will output the following trace to STDOUT (Note you can also explicitly <code>require 'tracer'</code>)</p>
<pre>#0:<internal:lib/rubygems/custom_require>:38:Kernel:<: -
#0:example.rb:3::-: class A
#0:example.rb:3::C: class A
#0:example.rb:4::-: def square(a)
#0:example.rb:7::E: end
#0:example.rb:9::-: a = A.new
#0:example.rb:10::-: a.square(5)
#0:example.rb:4:A:>: def square(a)
#0:example.rb:5:A:-: return a*a
#0:example.rb:6:A:<: end
| | | | |
| | | | ---------------------+ event
| | | ------------------------+ class
| | --------------------------+ line
| ------------------------------------+ filename
---------------------------------------+ thread</pre>
<p><a href="Symbol.html"><code>Symbol</code></a> table used for displaying incoming events:</p>
<dl class="rdoc-list note-list"><dt>+}+
<dd>
<p>call a C-language routine</p>
</dd><dt>+{+
<dd>
<p>return from a C-language routine</p>
</dd><dt>+>+
<dd>
<p>call a Ruby method</p>
</dd><dt><code>C</code>
<dd>
<p>start a class or module definition</p>
</dd><dt><code>E</code>
<dd>
<p>finish a class or module definition</p>
</dd><dt><code>-</code>
<dd>
<p>execute code on a new line</p>
</dd><dt>+^+
<dd>
<p>raise an exception</p>
</dd><dt>+<+
<dd>
<p>return from a Ruby method</p>
</dd></dl>
<h2 id="class-Tracer-label-Copyright">Copyright<span><a href="#class-Tracer-label-Copyright">¶</a> <a href="#top">↑</a></span></h2>
<p>by Keiju ISHITSUKA(keiju@ishitsuka.com)</p>
</section>
<section id="5Buntitled-5D" class="documentation-section">
<section class="constants-list">
<header>
<h3>Constants</h3>
</header>
<dl>
<dt id="EVENT_SYMBOL">EVENT_SYMBOL
<dd><p><a href="Symbol.html"><code>Symbol</code></a> table used for displaying trace information</p>
<dt id="Single">Single
<dd><p>Reference to singleton instance of <a href="Tracer.html"><code>Tracer</code></a></p>
<dt id="display_c_call">display_c_call
<dd>
<dt id="display_process_id">display_process_id
<dd>
<dt id="display_thread_id">display_thread_id
<dd>
<dt id="stdout">stdout
<dd>
<dt id="verbose">verbose
<dd>
</dl>
</section>
<section class="attribute-method-details" class="method-section">
<header>
<h3>Attributes</h3>
</header>
<div id="attribute-c-display_c_call" class="method-detail">
<div class="method-heading attribute-method-heading">
<span class="method-name">display_c_call</span><span
class="attribute-access-type">[RW]</span>
</div>
<div class="method-description">
<p>display C-routine calls in trace output (defaults to false)</p>
</div>
</div>
<div id="attribute-c-display_c_call-3F" class="method-detail">
<div class="method-heading attribute-method-heading">
<span class="method-name">display_c_call?</span><span
class="attribute-access-type">[RW]</span>
</div>
<div class="method-description">
<p>display C-routine calls in trace output (defaults to false)</p>
</div>
</div>
<div id="attribute-c-display_process_id" class="method-detail">
<div class="method-heading attribute-method-heading">
<span class="method-name">display_process_id</span><span
class="attribute-access-type">[RW]</span>
</div>
<div class="method-description">
<p>display process id in trace output (defaults to false)</p>
</div>
</div>
<div id="attribute-c-display_process_id-3F" class="method-detail">
<div class="method-heading attribute-method-heading">
<span class="method-name">display_process_id?</span><span
class="attribute-access-type">[RW]</span>
</div>
<div class="method-description">
<p>display process id in trace output (defaults to false)</p>
</div>
</div>
<div id="attribute-c-display_thread_id" class="method-detail">
<div class="method-heading attribute-method-heading">
<span class="method-name">display_thread_id</span><span
class="attribute-access-type">[RW]</span>
</div>
<div class="method-description">
<p>display thread id in trace output (defaults to true)</p>
</div>
</div>
<div id="attribute-c-display_thread_id-3F" class="method-detail">
<div class="method-heading attribute-method-heading">
<span class="method-name">display_thread_id?</span><span
class="attribute-access-type">[RW]</span>
</div>
<div class="method-description">
<p>display thread id in trace output (defaults to true)</p>
</div>
</div>
<div id="attribute-c-stdout" class="method-detail">
<div class="method-heading attribute-method-heading">
<span class="method-name">stdout</span><span
class="attribute-access-type">[RW]</span>
</div>
<div class="method-description">
<p>output stream used to output trace (defaults to STDOUT)</p>
</div>
</div>
<div id="attribute-c-stdout_mutex" class="method-detail">
<div class="method-heading attribute-method-heading">
<span class="method-name">stdout_mutex</span><span
class="attribute-access-type">[R]</span>
</div>
<div class="method-description">
<p>mutex lock used by tracer for displaying trace output</p>
</div>
</div>
<div id="attribute-c-verbose" class="method-detail">
<div class="method-heading attribute-method-heading">
<span class="method-name">verbose</span><span
class="attribute-access-type">[RW]</span>
</div>
<div class="method-description">
<p>display additional debug information (defaults to false)</p>
</div>
</div>
<div id="attribute-c-verbose-3F" class="method-detail">
<div class="method-heading attribute-method-heading">
<span class="method-name">verbose?</span><span
class="attribute-access-type">[RW]</span>
</div>
<div class="method-description">
<p>display additional debug information (defaults to false)</p>
</div>
</div>
</section>
<section id="public-class-5Buntitled-5D-method-details" class="method-section">
<header>
<h3>Public Class Methods</h3>
</header>
<div id="method-c-add_filter" class="method-detail ">
<div class="method-heading">
<span class="method-name">add_filter</span><span
class="method-args">(p = nil, &b)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>Used to filter unwanted trace output</p>
<p>Example which only outputs lines of code executed within the <a href="Kernel.html"><code>Kernel</code></a> class:</p>
<pre class="ruby"><span class="ruby-constant">Tracer</span>.<span class="ruby-identifier">add_filter</span> <span class="ruby-keyword">do</span> <span class="ruby-operator">|</span><span class="ruby-identifier">event</span>, <span class="ruby-identifier">file</span>, <span class="ruby-identifier">line</span>, <span class="ruby-identifier">id</span>, <span class="ruby-identifier">binding</span>, <span class="ruby-identifier">klass</span>, <span class="ruby-operator">*</span><span class="ruby-identifier">rest</span><span class="ruby-operator">|</span>
<span class="ruby-string">"Kernel"</span> <span class="ruby-operator">==</span> <span class="ruby-identifier">klass</span>.<span class="ruby-identifier">to_s</span>
<span class="ruby-keyword">end</span>
</pre>
<div class="method-source-code" id="add_filter-source">
<pre><span class="ruby-comment"># File lib/tracer.rb, line 267</span>
<span class="ruby-keyword">def</span> <span class="ruby-constant">Tracer</span>.<span class="ruby-identifier ruby-title">add_filter</span>(<span class="ruby-identifier">p</span> = <span class="ruby-keyword">nil</span>, <span class="ruby-operator">&</span><span class="ruby-identifier">b</span>)
<span class="ruby-identifier">p</span> <span class="ruby-operator">||=</span> <span class="ruby-identifier">b</span>
<span class="ruby-constant">Single</span>.<span class="ruby-identifier">add_filter</span>(<span class="ruby-identifier">p</span>)
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-c-off" class="method-detail ">
<div class="method-heading">
<span class="method-name">off</span><span
class="method-args">()</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>Disable tracing</p>
<div class="method-source-code" id="off-source">
<pre><span class="ruby-comment"># File lib/tracer.rb, line 239</span>
<span class="ruby-keyword">def</span> <span class="ruby-constant">Tracer</span>.<span class="ruby-identifier ruby-title">off</span>
<span class="ruby-constant">Single</span>.<span class="ruby-identifier">off</span>
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-c-on" class="method-detail ">
<div class="method-heading">
<span class="method-name">on</span><span
class="method-args">() { || ... }</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>Start tracing</p>
<h3 id="method-c-on-label-Example">Example<span><a href="#method-c-on-label-Example">¶</a> <a href="#top">↑</a></span></h3>
<pre class="ruby"><span class="ruby-constant">Tracer</span>.<span class="ruby-identifier">on</span>
<span class="ruby-comment"># code to trace here</span>
<span class="ruby-constant">Tracer</span>.<span class="ruby-identifier">off</span>
</pre>
<p>You can also pass a block:</p>
<pre class="ruby"><span class="ruby-constant">Tracer</span>.<span class="ruby-identifier">on</span> {
<span class="ruby-comment"># trace everything in this block</span>
}
</pre>
<div class="method-source-code" id="on-source">
<pre><span class="ruby-comment"># File lib/tracer.rb, line 228</span>
<span class="ruby-keyword">def</span> <span class="ruby-constant">Tracer</span>.<span class="ruby-identifier ruby-title">on</span>
<span class="ruby-keyword">if</span> <span class="ruby-identifier">block_given?</span>
<span class="ruby-constant">Single</span>.<span class="ruby-identifier">on</span>{<span class="ruby-keyword">yield</span>}
<span class="ruby-keyword">else</span>
<span class="ruby-constant">Single</span>.<span class="ruby-identifier">on</span>
<span class="ruby-keyword">end</span>
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-c-set_get_line_procs" class="method-detail ">
<div class="method-heading">
<span class="method-name">set_get_line_procs</span><span
class="method-args">(file_name, p = nil, &b)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>Register an event handler <code>p</code> which is called every time a line in <code>file_name</code> is executed.</p>
<p>Example:</p>
<pre class="ruby"><span class="ruby-constant">Tracer</span>.<span class="ruby-identifier">set_get_line_procs</span>(<span class="ruby-string">"example.rb"</span>, <span class="ruby-identifier">lambda</span> { <span class="ruby-operator">|</span><span class="ruby-identifier">line</span><span class="ruby-operator">|</span>
<span class="ruby-identifier">puts</span> <span class="ruby-node">"line number executed is #{line}"</span>
})
</pre>
<div class="method-source-code" id="set_get_line_procs-source">
<pre><span class="ruby-comment"># File lib/tracer.rb, line 253</span>
<span class="ruby-keyword">def</span> <span class="ruby-constant">Tracer</span>.<span class="ruby-identifier ruby-title">set_get_line_procs</span>(<span class="ruby-identifier">file_name</span>, <span class="ruby-identifier">p</span> = <span class="ruby-keyword">nil</span>, <span class="ruby-operator">&</span><span class="ruby-identifier">b</span>)
<span class="ruby-identifier">p</span> <span class="ruby-operator">||=</span> <span class="ruby-identifier">b</span>
<span class="ruby-constant">Single</span>.<span class="ruby-identifier">set_get_line_procs</span>(<span class="ruby-identifier">file_name</span>, <span class="ruby-identifier">p</span>)
<span class="ruby-keyword">end</span></pre>
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