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| <title>Debugging with GDB: Pretty-Printer Introduction</title> |
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| Next: <a href="Pretty_002dPrinter-Example.html#Pretty_002dPrinter-Example" accesskey="n" rel="next">Pretty-Printer Example</a>, Up: <a href="Pretty-Printing.html#Pretty-Printing" accesskey="u" rel="up">Pretty Printing</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p> |
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| <a name="Pretty_002dPrinter-Introduction-1"></a> |
| <h4 class="subsection">10.9.1 Pretty-Printer Introduction</h4> |
| |
| <p>When <small>GDB</small> prints a value, it first sees if there is a pretty-printer |
| registered for the value. If there is then <small>GDB</small> invokes the |
| pretty-printer to print the value. Otherwise the value is printed normally. |
| </p> |
| <p>Pretty-printers are normally named. This makes them easy to manage. |
| The ‘<samp>info pretty-printer</samp>’ command will list all the installed |
| pretty-printers with their names. |
| If a pretty-printer can handle multiple data types, then its |
| <em>subprinters</em> are the printers for the individual data types. |
| Each such subprinter has its own name. |
| The format of the name is <var>printer-name</var>;<var>subprinter-name</var>. |
| </p> |
| <p>Pretty-printers are installed by <em>registering</em> them with <small>GDB</small>. |
| Typically they are automatically loaded and registered when the corresponding |
| debug information is loaded, thus making them available without having to |
| do anything special. |
| </p> |
| <p>There are three places where a pretty-printer can be registered. |
| </p> |
| <ul> |
| <li> Pretty-printers registered globally are available when debugging |
| all inferiors. |
| |
| </li><li> Pretty-printers registered with a program space are available only |
| when debugging that program. |
| See <a href="Progspaces-In-Python.html#Progspaces-In-Python">Progspaces In Python</a>, for more details on program spaces in Python. |
| |
| </li><li> Pretty-printers registered with an objfile are loaded and unloaded |
| with the corresponding objfile (e.g., shared library). |
| See <a href="Objfiles-In-Python.html#Objfiles-In-Python">Objfiles In Python</a>, for more details on objfiles in Python. |
| </li></ul> |
| |
| <p>See <a href="Selecting-Pretty_002dPrinters.html#Selecting-Pretty_002dPrinters">Selecting Pretty-Printers</a>, for further information on how |
| pretty-printers are selected, |
| </p> |
| <p>See <a href="Writing-a-Pretty_002dPrinter.html#Writing-a-Pretty_002dPrinter">Writing a Pretty-Printer</a>, for implementing pretty printers |
| for new types. |
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