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<h4 class="subsection">9.48.1 VAX Command-Line Options</h4>
<p><a name="index-command_002dline-options-ignored_002c-VAX-2326"></a><a name="index-VAX-command_002dline-options-ignored-2327"></a>The Vax version of <code>as</code> accepts any of the following options,
gives a warning message that the option was ignored and proceeds.
These options are for compatibility with scripts designed for other
people's assemblers.
<a name="index-g_t_0040code_007b_002dD_007d_002c-ignored-on-VAX-2328"></a>
<a name="index-g_t_0040code_007b_002dS_007d_002c-ignored-on-VAX-2329"></a>
<a name="index-g_t_0040code_007b_002dT_007d_002c-ignored-on-VAX-2330"></a>
<dl><dt><code>-D (Debug)</code><dt><code>-S (Symbol Table)</code><dt><code>-T (Token Trace)</code><dd>These are obsolete options used to debug old assemblers.
<p><a name="index-g_t_0040code_007b_002dd_007d_002c-VAX-option-2331"></a><br><dt><code>-d (Displacement size for JUMPs)</code><dd>This option expects a number following the ‘<samp><span class="samp">-d</span></samp>’. Like options
that expect filenames, the number may immediately follow the
‘<samp><span class="samp">-d</span></samp>’ (old standard) or constitute the whole of the command line
argument that follows ‘<samp><span class="samp">-d</span></samp>’ (<span class="sc">gnu</span> standard).
<p><a name="index-g_t_0040code_007b_002dV_007d_002c-redundant-on-VAX-2332"></a><br><dt><code>-V (Virtualize Interpass Temporary File)</code><dd>Some other assemblers use a temporary file. This option
commanded them to keep the information in active memory rather
than in a disk file. <code>as</code> always does this, so this
option is redundant.
<p><a name="index-g_t_0040code_007b_002dJ_007d_002c-ignored-on-VAX-2333"></a><br><dt><code>-J (JUMPify Longer Branches)</code><dd>Many 32-bit computers permit a variety of branch instructions
to do the same job. Some of these instructions are short (and
fast) but have a limited range; others are long (and slow) but
can branch anywhere in virtual memory. Often there are 3
flavors of branch: short, medium and long. Some other
assemblers would emit short and medium branches, unless told by
this option to emit short and long branches.
<p><a name="index-g_t_0040code_007b_002dt_007d_002c-ignored-on-VAX-2334"></a><br><dt><code>-t (Temporary File Directory)</code><dd>Some other assemblers may use a temporary file, and this option
takes a filename being the directory to site the temporary
file. Since <code>as</code> does not use a temporary disk file, this
option makes no difference. ‘<samp><span class="samp">-t</span></samp>’ needs exactly one
filename.
</dl>
<p><a name="index-VMS-_0028VAX_0029-options-2335"></a><a name="index-options-for-VAX_002fVMS-2336"></a><a name="index-VAX_002fVMS-options-2337"></a><a name="index-Vax_002d11-C-compatibility-2338"></a><a name="index-symbols-with-uppercase_002c-VAX_002fVMS-2339"></a>The Vax version of the assembler accepts additional options when
compiled for VMS:
<a name="index-g_t_0040samp_007b_002dh_007d-option_002c-VAX_002fVMS-2340"></a>
<dl><dt>‘<samp><span class="samp">-h </span><var>n</var></samp>’<dd>External symbol or section (used for global variables) names are not
case sensitive on VAX/VMS and always mapped to upper case. This is
contrary to the C language definition which explicitly distinguishes
upper and lower case. To implement a standard conforming C compiler,
names must be changed (mapped) to preserve the case information. The
default mapping is to convert all lower case characters to uppercase and
adding an underscore followed by a 6 digit hex value, representing a 24
digit binary value. The one digits in the binary value represent which
characters are uppercase in the original symbol name.
<p>The ‘<samp><span class="samp">-h </span><var>n</var></samp>’ option determines how we map names. This takes
several values. No ‘<samp><span class="samp">-h</span></samp>’ switch at all allows case hacking as
described above. A value of zero (‘<samp><span class="samp">-h0</span></samp>’) implies names should be
upper case, and inhibits the case hack. A value of 2 (‘<samp><span class="samp">-h2</span></samp>’)
implies names should be all lower case, with no case hack. A value of 3
(‘<samp><span class="samp">-h3</span></samp>’) implies that case should be preserved. The value 1 is
unused. The <code>-H</code> option directs <code>as</code> to display
every mapped symbol during assembly.
<p>Symbols whose names include a dollar sign ‘<samp><span class="samp">$</span></samp>’ are exceptions to the
general name mapping. These symbols are normally only used to reference
VMS library names. Such symbols are always mapped to upper case.
<p><a name="index-g_t_0040samp_007b_002d_002b_007d-option_002c-VAX_002fVMS-2341"></a><br><dt>‘<samp><span class="samp">-+</span></samp>’<dd>The ‘<samp><span class="samp">-+</span></samp>’ option causes <code>as</code> to truncate any symbol
name larger than 31 characters. The ‘<samp><span class="samp">-+</span></samp>’ option also prevents some
code following the ‘<samp><span class="samp">_main</span></samp>’ symbol normally added to make the object
file compatible with Vax-11 "C".
<p><a name="index-g_t_0040samp_007b_002d1_007d-option_002c-VAX_002fVMS-2342"></a><br><dt>‘<samp><span class="samp">-1</span></samp>’<dd>This option is ignored for backward compatibility with <code>as</code>
version 1.x.
<p><a name="index-g_t_0040samp_007b_002dH_007d-option_002c-VAX_002fVMS-2343"></a><br><dt>‘<samp><span class="samp">-H</span></samp>’<dd>The ‘<samp><span class="samp">-H</span></samp>’ option causes <code>as</code> to print every symbol
which was changed by case mapping.
</dl>
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