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| <h4 class="subsection">9.2.1 Linespec Locations</h4> |
| |
| <p><a name="index-linespec-locations-563"></a> |
| A <dfn>linespec</dfn> is a colon-separated list of source location parameters such |
| as file name, function name, etc. Here are all the different ways of |
| specifying a linespec: |
| |
| <dl> |
| <dt><var>linenum</var><dd>Specifies the line number <var>linenum</var> of the current source file. |
| |
| <br><dt><code>-</code><var>offset</var><dt><code>+</code><var>offset</var><dd>Specifies the line <var>offset</var> lines before or after the <dfn>current |
| line</dfn>. For the <code>list</code> command, the current line is the last one |
| printed; for the breakpoint commands, this is the line at which |
| execution stopped in the currently selected <dfn>stack frame</dfn> |
| (see <a href="Frames.html#Frames">Frames</a>, for a description of stack frames.) When |
| used as the second of the two linespecs in a <code>list</code> command, |
| this specifies the line <var>offset</var> lines up or down from the first |
| linespec. |
| |
| <br><dt><var>filename</var><code>:</code><var>linenum</var><dd>Specifies the line <var>linenum</var> in the source file <var>filename</var>. |
| If <var>filename</var> is a relative file name, then it will match any |
| source file name with the same trailing components. For example, if |
| <var>filename</var> is ‘<samp><span class="samp">gcc/expr.c</span></samp>’, then it will match source file |
| name of <samp><span class="file">/build/trunk/gcc/expr.c</span></samp>, but not |
| <samp><span class="file">/build/trunk/libcpp/expr.c</span></samp> or <samp><span class="file">/build/trunk/gcc/x-expr.c</span></samp>. |
| |
| <br><dt><var>function</var><dd>Specifies the line that begins the body of the function <var>function</var>. |
| For example, in C, this is the line with the open brace. |
| |
| <p>By default, in C<tt>++</tt> and Ada, <var>function</var> is interpreted as |
| specifying all functions named <var>function</var> in all scopes. For |
| C<tt>++</tt>, this means in all namespaces and classes. For Ada, this |
| means in all packages. |
| |
| <p>For example, assuming a program with C<tt>++</tt> symbols named |
| <code>A::B::func</code> and <code>B::func</code>, both commands <kbd>break func</kbd><!-- /@w --> and <kbd>break B::func</kbd><!-- /@w --> set a breakpoint on both symbols. |
| |
| <p>Commands that accept a linespec let you override this with the |
| <code>-qualified</code> option. For example, <kbd>break -qualified func</kbd><!-- /@w --> sets a breakpoint on a free-function named <code>func</code> ignoring |
| any C<tt>++</tt> class methods and namespace functions called <code>func</code>. |
| |
| <p>See <a href="Explicit-Locations.html#Explicit-Locations">Explicit Locations</a>. |
| |
| <br><dt><var>function</var><code>:</code><var>label</var><dd>Specifies the line where <var>label</var> appears in <var>function</var>. |
| |
| <br><dt><var>filename</var><code>:</code><var>function</var><dd>Specifies the line that begins the body of the function <var>function</var> |
| in the file <var>filename</var>. You only need the file name with a |
| function name to avoid ambiguity when there are identically named |
| functions in different source files. |
| |
| <br><dt><var>label</var><dd>Specifies the line at which the label named <var>label</var> appears |
| in the function corresponding to the currently selected stack frame. |
| If there is no current selected stack frame (for instance, if the inferior |
| is not running), then <span class="sc">gdb</span> will not search for a label. |
| |
| <p><a name="index-breakpoint-at-static-probe-point-564"></a><br><dt><code>-pstap|-probe-stap </code><span class="roman">[</span><var>objfile</var><code>:</code><span class="roman">[</span><var>provider</var><code>:</code><span class="roman">]</span><span class="roman">]</span><var>name</var><dd>The <span class="sc">gnu</span>/Linux tool <code>SystemTap</code> provides a way for |
| applications to embed static probes. See <a href="Static-Probe-Points.html#Static-Probe-Points">Static Probe Points</a>, for more |
| information on finding and using static probes. This form of linespec |
| specifies the location of such a static probe. |
| |
| <p>If <var>objfile</var> is given, only probes coming from that shared library |
| or executable matching <var>objfile</var> as a regular expression are considered. |
| If <var>provider</var> is given, then only probes from that provider are considered. |
| If several probes match the spec, <span class="sc">gdb</span> will insert a breakpoint at |
| each one of those probes. |
| </dl> |
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