| <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> |
| <html> |
| <!-- Copyright (C) 1992-2015 Free Software Foundation, Inc. |
| Contributed by Cygnus Support. Written by Julia Menapace, Jim Kingdon, |
| and David MacKenzie. |
| |
| 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 no |
| Invariant Sections, with no Front-Cover Texts, and with no Back-Cover |
| Texts. A copy of the license is included in the section entitled "GNU |
| Free Documentation License". --> |
| <!-- Created by GNU Texinfo 5.2, http://www.gnu.org/software/texinfo/ --> |
| <head> |
| <title>STABS: Block Structure</title> |
| |
| <meta name="description" content="STABS: Block Structure"> |
| <meta name="keywords" content="STABS: Block Structure"> |
| <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="Symbol-Types-Index.html#Symbol-Types-Index" rel="index" title="Symbol Types Index"> |
| <link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> |
| <link href="Program-Structure.html#Program-Structure" rel="up" title="Program Structure"> |
| <link href="Alternate-Entry-Points.html#Alternate-Entry-Points" rel="next" title="Alternate Entry Points"> |
| <link href="Nested-Procedures.html#Nested-Procedures" rel="prev" title="Nested Procedures"> |
| <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="Block-Structure"></a> |
| <div class="header"> |
| <p> |
| Next: <a href="Alternate-Entry-Points.html#Alternate-Entry-Points" accesskey="n" rel="next">Alternate Entry Points</a>, Previous: <a href="Nested-Procedures.html#Nested-Procedures" accesskey="p" rel="prev">Nested Procedures</a>, Up: <a href="Program-Structure.html#Program-Structure" accesskey="u" rel="up">Program Structure</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Symbol-Types-Index.html#Symbol-Types-Index" title="Index" rel="index">Index</a>]</p> |
| </div> |
| <hr> |
| <a name="Block-Structure-1"></a> |
| <h3 class="section">2.7 Block Structure</h3> |
| |
| <a name="index-N_005fLBRAC"></a> |
| <a name="index-N_005fRBRAC"></a> |
| <p>The program’s block structure is represented by the <code>N_LBRAC</code> (left |
| brace) and the <code>N_RBRAC</code> (right brace) stab types. The variables |
| defined inside a block precede the <code>N_LBRAC</code> symbol for most |
| compilers, including GCC. Other compilers, such as the Convex, Acorn |
| RISC machine, and Sun <code>acc</code> compilers, put the variables after the |
| <code>N_LBRAC</code> symbol. The values of the <code>N_LBRAC</code> and |
| <code>N_RBRAC</code> symbols are the start and end addresses of the code of |
| the block, respectively. For most machines, they are relative to the |
| starting address of this source file. For the Gould NP1, they are |
| absolute. For stabs in sections (see <a href="Stab-Sections.html#Stab-Sections">Stab Sections</a>), they are |
| relative to the function in which they occur. |
| </p> |
| <p>The <code>N_LBRAC</code> and <code>N_RBRAC</code> stabs that describe the block |
| scope of a procedure are located after the <code>N_FUN</code> stab that |
| represents the procedure itself. |
| </p> |
| <p>Sun documents the desc field of <code>N_LBRAC</code> and |
| <code>N_RBRAC</code> symbols as containing the nesting level of the block. |
| However, dbx seems to not care, and GCC always sets desc to |
| zero. |
| </p> |
| <a name="index-_002ebb"></a> |
| <a name="index-_002ebe"></a> |
| <a name="index-C_005fBLOCK"></a> |
| <p>For XCOFF, block scope is indicated with <code>C_BLOCK</code> symbols. If the |
| name of the symbol is ‘<samp>.bb</samp>’, then it is the beginning of the block; |
| if the name of the symbol is ‘<samp>.be</samp>’; it is the end of the block. |
| </p> |
| |
| |
| |
| </body> |
| </html> |