| <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> |
| <html> |
| <!-- Copyright (C) 1988-2015 Free Software Foundation, Inc. |
| |
| Permission is granted to copy, distribute and/or modify this document |
| under the terms of the GNU Free Documentation License, Version 1.3 or |
| any later version published by the Free Software Foundation; with the |
| Invariant Sections being "Funding Free Software", the Front-Cover |
| Texts being (a) (see below), and with the Back-Cover Texts being (b) |
| (see below). A copy of the license is included in the section entitled |
| "GNU Free Documentation License". |
| |
| (a) The FSF's Front-Cover Text is: |
| |
| A GNU Manual |
| |
| (b) The FSF's Back-Cover Text is: |
| |
| You have freedom to copy and modify this GNU Manual, like GNU |
| software. Copies published by the Free Software Foundation raise |
| funds for GNU development. --> |
| <!-- Created by GNU Texinfo 5.2, http://www.gnu.org/software/texinfo/ --> |
| <head> |
| <title>GNU Compiler Collection (GCC) Internals: Miscellaneous routines</title> |
| |
| <meta name="description" content="GNU Compiler Collection (GCC) Internals: Miscellaneous routines"> |
| <meta name="keywords" content="GNU Compiler Collection (GCC) Internals: Miscellaneous routines"> |
| <meta name="resource-type" content="document"> |
| <meta name="distribution" content="global"> |
| <meta name="Generator" content="makeinfo"> |
| <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> |
| <link href="index.html#Top" rel="start" title="Top"> |
| <link href="Option-Index.html#Option-Index" rel="index" title="Option Index"> |
| <link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> |
| <link href="Libgcc.html#Libgcc" rel="up" title="Libgcc"> |
| <link href="Languages.html#Languages" rel="next" title="Languages"> |
| <link href="Exception-handling-routines.html#Exception-handling-routines" rel="prev" title="Exception handling routines"> |
| <style type="text/css"> |
| <!-- |
| a.summary-letter {text-decoration: none} |
| blockquote.smallquotation {font-size: smaller} |
| div.display {margin-left: 3.2em} |
| div.example {margin-left: 3.2em} |
| div.indentedblock {margin-left: 3.2em} |
| div.lisp {margin-left: 3.2em} |
| div.smalldisplay {margin-left: 3.2em} |
| div.smallexample {margin-left: 3.2em} |
| div.smallindentedblock {margin-left: 3.2em; font-size: smaller} |
| div.smalllisp {margin-left: 3.2em} |
| kbd {font-style:oblique} |
| pre.display {font-family: inherit} |
| pre.format {font-family: inherit} |
| pre.menu-comment {font-family: serif} |
| pre.menu-preformatted {font-family: serif} |
| pre.smalldisplay {font-family: inherit; font-size: smaller} |
| pre.smallexample {font-size: smaller} |
| pre.smallformat {font-family: inherit; font-size: smaller} |
| pre.smalllisp {font-size: smaller} |
| span.nocodebreak {white-space:nowrap} |
| span.nolinebreak {white-space:nowrap} |
| span.roman {font-family:serif; font-weight:normal} |
| span.sansserif {font-family:sans-serif; font-weight:normal} |
| ul.no-bullet {list-style: none} |
| --> |
| </style> |
| |
| |
| </head> |
| |
| <body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000"> |
| <a name="Miscellaneous-routines"></a> |
| <div class="header"> |
| <p> |
| Previous: <a href="Exception-handling-routines.html#Exception-handling-routines" accesskey="p" rel="prev">Exception handling routines</a>, Up: <a href="Libgcc.html#Libgcc" accesskey="u" rel="up">Libgcc</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> |
| </div> |
| <hr> |
| <a name="Miscellaneous-runtime-library-routines"></a> |
| <h3 class="section">4.6 Miscellaneous runtime library routines</h3> |
| |
| <a name="Cache-control-functions"></a> |
| <h4 class="subsection">4.6.1 Cache control functions</h4> |
| <dl> |
| <dt><a name="index-_005f_005fclear_005fcache"></a>Runtime Function: <em>void</em> <strong>__clear_cache</strong> <em>(char *<var>beg</var>, char *<var>end</var>)</em></dt> |
| <dd><p>This function clears the instruction cache between <var>beg</var> and <var>end</var>. |
| </p></dd></dl> |
| |
| <a name="Split-stack-functions-and-variables"></a> |
| <h4 class="subsection">4.6.2 Split stack functions and variables</h4> |
| <dl> |
| <dt><a name="index-_005f_005fsplitstack_005ffind"></a>Runtime Function: <em>void *</em> <strong>__splitstack_find</strong> <em>(void *<var>segment_arg</var>, void *<var>sp</var>, size_t <var>len</var>, void **<var>next_segment</var>, void **<var>next_sp</var>, void **<var>initial_sp</var>)</em></dt> |
| <dd><p>When using <samp>-fsplit-stack</samp>, this call may be used to iterate |
| over the stack segments. It may be called like this: |
| </p><div class="smallexample"> |
| <pre class="smallexample"> void *next_segment = NULL; |
| void *next_sp = NULL; |
| void *initial_sp = NULL; |
| void *stack; |
| size_t stack_size; |
| while ((stack = __splitstack_find (next_segment, next_sp, |
| &stack_size, &next_segment, |
| &next_sp, &initial_sp)) |
| != NULL) |
| { |
| /* Stack segment starts at stack and is |
| stack_size bytes long. */ |
| } |
| </pre></div> |
| |
| <p>There is no way to iterate over the stack segments of a different |
| thread. However, what is permitted is for one thread to call this |
| with the <var>segment_arg</var> and <var>sp</var> arguments NULL, to pass |
| <var>next_segment</var>, <var>next_sp</var>, and <var>initial_sp</var> to a different |
| thread, and then to suspend one way or another. A different thread |
| may run the subsequent <code>__splitstack_find</code> iterations. Of |
| course, this will only work if the first thread is suspended while the |
| second thread is calling <code>__splitstack_find</code>. If not, the second |
| thread could be looking at the stack while it is changing, and |
| anything could happen. |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-_005f_005fmorestack_005fsegments"></a>Variable: <strong>__morestack_segments</strong></dt> |
| <dt><a name="index-_005f_005fmorestack_005fcurrent_005fsegment"></a>Variable: <strong>__morestack_current_segment</strong></dt> |
| <dt><a name="index-_005f_005fmorestack_005finitial_005fsp"></a>Variable: <strong>__morestack_initial_sp</strong></dt> |
| <dd><p>Internal variables used by the <samp>-fsplit-stack</samp> implementation. |
| </p></dd></dl> |
| |
| |
| |
| |
| </body> |
| </html> |
