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| Previous: <a href="Sharing.html#Sharing" accesskey="p" rel="prev">Sharing</a>, Up: <a href="RTL.html#RTL" accesskey="u" rel="up">RTL</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p> |
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| <a name="Reading-RTL-1"></a> |
| <h3 class="section">13.22 Reading RTL</h3> |
| |
| <p>To read an RTL object from a file, call <code>read_rtx</code>. It takes one |
| argument, a stdio stream, and returns a single RTL object. This routine |
| is defined in <samp>read-rtl.c</samp>. It is not available in the compiler |
| itself, only the various programs that generate the compiler back end |
| from the machine description. |
| </p> |
| <p>People frequently have the idea of using RTL stored as text in a file as |
| an interface between a language front end and the bulk of GCC. This |
| idea is not feasible. |
| </p> |
| <p>GCC was designed to use RTL internally only. Correct RTL for a given |
| program is very dependent on the particular target machine. And the RTL |
| does not contain all the information about the program. |
| </p> |
| <p>The proper way to interface GCC to a new language front end is with |
| the “tree” data structure, described in the files <samp>tree.h</samp> and |
| <samp>tree.def</samp>. The documentation for this structure (see <a href="GENERIC.html#GENERIC">GENERIC</a>) |
| is incomplete. |
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