78 lines
3.7 KiB
HTML
78 lines
3.7 KiB
HTML
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<html lang="en">
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<head>
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<title>Transformations On Global Variables - STABS</title>
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<meta name="description" content="STABS">
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<meta name="generator" content="makeinfo 4.13">
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<link title="Top" rel="start" href="index.html#Top">
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<link rel="up" href="Transformations-On-Symbol-Tables.html#Transformations-On-Symbol-Tables" title="Transformations On Symbol Tables">
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<link rel="prev" href="Transformations-On-Static-Variables.html#Transformations-On-Static-Variables" title="Transformations On Static Variables">
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<link rel="next" href="Stab-Section-Transformations.html#Stab-Section-Transformations" title="Stab Section Transformations">
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Copyright (C) 1992-2019 Free Software Foundation, Inc.
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Contributed by Cygnus Support. Written by Julia Menapace, Jim Kingdon,
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and David MacKenzie.
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Permission is granted to copy, distribute and/or modify this document
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under the terms of the GNU Free Documentation License, Version 1.3 or
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</head>
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<body>
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<div class="node">
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<a name="Transformations-On-Global-Variables"></a>
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<p>
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Next: <a rel="next" accesskey="n" href="Stab-Section-Transformations.html#Stab-Section-Transformations">Stab Section Transformations</a>,
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Previous: <a rel="previous" accesskey="p" href="Transformations-On-Static-Variables.html#Transformations-On-Static-Variables">Transformations On Static Variables</a>,
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Up: <a rel="up" accesskey="u" href="Transformations-On-Symbol-Tables.html#Transformations-On-Symbol-Tables">Transformations On Symbol Tables</a>
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<hr>
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</div>
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<h4 class="subsection">7.2.2 Transformations on Global Variables</h4>
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<p>Stabs for global variables do not contain location information. In
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this case, the debugger finds location information in the assembler or
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linker symbol table entry describing the variable. The source line:
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<pre class="example"> char g_foo = 'c';
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</pre>
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<p class="noindent">generates the stab:
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<pre class="example"> .stabs "g_foo:G2",32,0,0,0
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</pre>
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<p>The variable is represented by two symbol table entries in the object
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file (see below). The first one originated as a stab. The second one
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is an external symbol. The upper case ‘<samp><span class="samp">D</span></samp>’ signifies that the
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<code>n_type</code> field of the symbol table contains 7, <code>N_DATA</code> with
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local linkage. The stab's value is zero since the value is not used for
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<code>N_GSYM</code> stabs. The value of the linker symbol is the relocatable
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address corresponding to the variable.
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<pre class="example"> 00000000 - 00 0000 GSYM g_foo:G2
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00000080 D _g_foo
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</pre>
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<p class="noindent">These entries as transformed by the linker. The linker symbol table
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entry now holds an absolute address:
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<pre class="example"> 00000000 - 00 0000 GSYM g_foo:G2
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...
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0000e008 D _g_foo
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</pre>
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</body></html>
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