as.info: VAX-Opts
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VAX Command-Line Options
The Vax version of `as' 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.
``-D' (Debug)'
``-S' (Symbol Table)'
``-T' (Token Trace)'
These are obsolete options used to debug old assemblers.
``-d' (Displacement size for JUMPs)'
This option expects a number following the `-d'. Like options
that expect filenames, the number may immediately follow the `-d'
(old standard) or constitute the whole of the command line
argument that follows `-d' (GNU standard).
``-V' (Virtualize Interpass Temporary File)'
Some other assemblers use a temporary file. This option commanded
them to keep the information in active memory rather than in a
disk file. `as' always does this, so this option is redundant.
``-J' (JUMPify Longer Branches)'
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.
``-t' (Temporary File Directory)'
Some other assemblers may use a temporary file, and this option
takes a filename being the directory to site the temporary file.
Since `as' does not use a temporary disk file, this option makes
no difference. `-t' needs exactly one filename.
The Vax version of the assembler accepts additional options when
compiled for VMS:
`-h N'
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.
The `-h N' option determines how we map names. This takes several
values. No `-h' switch at all allows case hacking as described
above. A value of zero (`-h0') implies names should be upper
case, and inhibits the case hack. A value of 2 (`-h2') implies
names should be all lower case, with no case hack. A value of 3
(`-h3') implies that case should be preserved. The value 1 is
unused. The `-H' option directs `as' to display every mapped
symbol during assembly.
Symbols whose names include a dollar sign `$' 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.
`-+'
The `-+' option causes `as' to truncate any symbol name larger
than 31 characters. The `-+' option also prevents some code
following the `_main' symbol normally added to make the object
file compatible with Vax-11 "C".
`-1'
This option is ignored for backward compatibility with `as'
version 1.x.
`-H'
The `-H' option causes `as' to print every symbol which was
changed by case mapping.
Created Wed Sep 1 16:41:08 2004 on bee with info_to_html version 0.9.6.