-@c Copyright (C) 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
+@c Copyright (C) 1991-2014 Free Software Foundation, Inc.
@c This is part of the GAS manual.
@c For copying conditions, see the file as.texinfo.
+@c VAX/VMS description enhanced and corrected by Klaus K"aempf, kkaempf@progis.de
@ifset GENERIC
@node Vax-Dependent
@chapter VAX Dependent Features
@end ifclear
@menu
-* Vax-Opts:: VAX Command-Line Options
+* VAX-Opts:: VAX Command-Line Options
* VAX-float:: VAX Floating Point
* VAX-directives:: Vax Machine Directives
* VAX-opcodes:: VAX Opcodes
* VAX-branch:: VAX Branch Improvement
* VAX-operands:: VAX Operands
* VAX-no:: Not Supported on VAX
+* VAX-Syntax:: VAX Syntax
@end menu
-@node Vax-Opts
+@node VAX-Opts
@section VAX Command-Line Options
@cindex command-line options ignored, VAX
@cindex VMS (VAX) options
@cindex options for VAX/VMS
@cindex VAX/VMS options
-@cindex @code{-h} option, VAX/VMS
-@cindex @code{-+} option, VAX/VMS
@cindex Vax-11 C compatibility
-@cindex symbols with lowercase, VAX/VMS
-@c FIXME! look into "I think" below, correct if needed, delete.
-The Vax version of the assembler accepts two options when
-compiled for VMS. They are @samp{-h}, and @samp{-+}. The
-@samp{-h} option prevents @code{@value{AS}} from modifying the
-symbol-table entries for symbols that contain lowercase
-characters (I think). The @samp{-+} option causes @code{@value{AS}} to
-print warning messages if the FILENAME part of the object file,
-or any symbol name is larger than 31 characters. The @samp{-+}
-option also inserts some code following the @samp{_main}
-symbol so that the object file is compatible with Vax-11
-"C".
+@cindex symbols with uppercase, VAX/VMS
+The Vax version of the assembler accepts additional options when
+compiled for VMS:
+
+@table @samp
+@cindex @samp{-h} option, VAX/VMS
+@item -h @var{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 @samp{-h @var{n}} option determines how we map names. This takes
+several values. No @samp{-h} switch at all allows case hacking as
+described above. A value of zero (@samp{-h0}) implies names should be
+upper case, and inhibits the case hack. A value of 2 (@samp{-h2})
+implies names should be all lower case, with no case hack. A value of 3
+(@samp{-h3}) implies that case should be preserved. The value 1 is
+unused. The @code{-H} option directs @code{@value{AS}} to display
+every mapped symbol during assembly.
+
+Symbols whose names include a dollar sign @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.
+
+@cindex @samp{-+} option, VAX/VMS
+@item -+
+The @samp{-+} option causes @code{@value{AS}} to truncate any symbol
+name larger than 31 characters. The @samp{-+} option also prevents some
+code following the @samp{_main} symbol normally added to make the object
+file compatible with Vax-11 "C".
+
+@cindex @samp{-1} option, VAX/VMS
+@item -1
+This option is ignored for backward compatibility with @code{@value{AS}}
+version 1.x.
+
+@cindex @samp{-H} option, VAX/VMS
+@item -H
+The @samp{-H} option causes @code{@value{AS}} to print every symbol
+which was changed by case mapping.
+@end table
@node VAX-float
@section VAX Floating Point
@cindex bitfields, not supported on VAX
Vax bit fields can not be assembled with @code{@value{AS}}. Someone
can add the required code if they really need it.
+
+@node VAX-Syntax
+@section VAX Syntax
+@menu
+* VAX-Chars:: Special Characters
+@end menu
+
+@node VAX-Chars
+@subsection Special Characters
+
+@cindex line comment character, VAX
+@cindex VAX line comment character
+The presence of a @samp{#} appearing anywhere on a line indicates the
+start of a comment that extends to the end of that line.
+
+If a @samp{#} appears as the first character of a line then the whole
+line is treated as a comment, but in this case the line can also be a
+logical line number directive (@pxref{Comments}) or a preprocessor
+control command (@pxref{Preprocessing}).
+
+@cindex line separator, VAX
+@cindex statement separator, VAX
+@cindex VAX line separator
+The @samp{;} character can be used to separate statements on the same
+line.
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