mingw/info/gdb/Frame-Annotations.html

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  11 <p>
  12 Node:<a name="Frame%20Annotations">Frame Annotations</a>,
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  18
  19 <h3 class="section">Frames</h3>
  20
  21    <p>Whenever GDB prints a frame, it annotates it.  For example, this applies
  22 to frames printed when GDB stops, output from commands such as
  23 <code>backtrace</code> or <code>up</code>, etc.
  24
  25    <p>The frame annotation begins with
  26
  27 <pre class="smallexample">     ^Z^Zframe-begin <var>level</var> <var>address</var>
  28      <var>level-string</var>
  29      </pre>
  30
  31 <p>where <var>level</var> is the number of the frame (0 is the innermost frame,
  32 and other frames have positive numbers), <var>address</var> is the address of
  33 the code executing in that frame, and <var>level-string</var> is a string
  34 designed to convey the level to the user.  <var>address</var> is in the form
  35 <code>0x</code> followed by one or more lowercase hex digits (note that this
  36 does not depend on the language).  The frame ends with
  37
  38 <pre class="smallexample">     ^Z^Zframe-end
  39      </pre>
  40
  41    <p>Between these annotations is the main body of the frame, which can
  42 consist of
  43
  44      <ul>
  45 <li>
  46      <pre class="smallexample">          ^Z^Zfunction-call
  47           <var>function-call-string</var>
  48           </pre>
  49
  50      <p>where <var>function-call-string</var> is text designed to convey to the user
  51 that this frame is associated with a function call made by GDB to a
  52 function in the program being debugged.
  53
  54      </p><li>
  55      <pre class="smallexample">          ^Z^Zsignal-handler-caller
  56           <var>signal-handler-caller-string</var>
  57           </pre>
  58
  59      <p>where <var>signal-handler-caller-string</var> is text designed to convey to
  60 the user that this frame is associated with whatever mechanism is used
  61 by this operating system to call a signal handler (it is the frame which
  62 calls the signal handler, not the frame for the signal handler itself).
  63
  64      </p><li>A normal frame.
  65
  66      <p>This can optionally (depending on whether this is thought of as
  67 interesting information for the user to see) begin with
  68
  69      <pre class="smallexample">          ^Z^Zframe-address
  70           <var>address</var>
  71           ^Z^Zframe-address-end
  72           <var>separator-string</var>
  73           </pre>
  74
  75      <p>where <var>address</var> is the address executing in the frame (the same
  76 address as in the <code>frame-begin</code> annotation, but printed in a form
  77 which is intended for user consumption--in particular, the syntax varies
  78 depending on the language), and <var>separator-string</var> is a string
  79 intended to separate this address from what follows for the user's
  80 benefit.
  81
  82      <p>Then comes
  83
  84      <pre class="smallexample">          ^Z^Zframe-function-name
  85           <var>function-name</var>
  86           ^Z^Zframe-args
  87           <var>arguments</var>
  88           </pre>
  89
  90      <p>where <var>function-name</var> is the name of the function executing in the
  91 frame, or <code>??</code> if not known, and <var>arguments</var> are the arguments
  92 to the frame, with parentheses around them (each argument is annotated
  93 individually as well, see <a href="Value-Annotations.html#Value%20Annotations">Value Annotations</a>).
  94
  95      <p>If source information is available, a reference to it is then printed:
  96
  97      <pre class="smallexample">          ^Z^Zframe-source-begin
  98           <var>source-intro-string</var>
  99           ^Z^Zframe-source-file
 100           <var>filename</var>
 101           ^Z^Zframe-source-file-end
 102           :
 103           ^Z^Zframe-source-line
 104           <var>line-number</var>
 105           ^Z^Zframe-source-end
 106           </pre>
 107
 108      <p>where <var>source-intro-string</var> separates for the user's benefit the
 109 reference from the text which precedes it, <var>filename</var> is the name of
 110 the source file, and <var>line-number</var> is the line number within that
 111 file (the first line is line 1).
 112
 113      <p>If GDB prints some information about where the frame is from (which
 114 library, which load segment, etc.; currently only done on the RS/6000),
 115 it is annotated with
 116
 117      <pre class="smallexample">          ^Z^Zframe-where
 118           <var>information</var>
 119           </pre>
 120
 121      <p>Then, if source is to actually be displayed for this frame (for example,
 122 this is not true for output from the <code>backtrace</code> command), then a
 123 <code>source</code> annotation (see <a href="Source-Annotations.html#Source%20Annotations">Source Annotations</a>) is displayed.  Unlike
 124 most annotations, this is output instead of the normal text which would be
 125 output, not in addition.
 126 </ul>
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