as.1

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· 1 代码 · 共 362 行

.TH as 1 RISC
.SH Name
as \- RISC assembler
.SH Syntax
.B as
[ option ] ... 
.I file
.SH Description
.NXR "as command (RISC)"
The assembler,
.B as ,
produces RISC object code in RISC extended 
.B coff
format (the default) and binary assembly language. The 
.B as
assembler does not run the loader.  It accepts the argument
.I file
which is a symbolic assembly language source program.  When assembled,
it produces an object file.
.PP
The assembler,
.B as,
always defines the C preprocessor macros
.BR mips ,
.BR host_mips ,
.B unix
and
.B LANGUAGE_ASSEMBLY
to the C macro preprocessor.
It also defines
.B SYSTYPE_BSD
by default, but this changes if the
.BI \-systype " name"
option is specified (see the OPTIONS section).
.SH Options
The following options are available with 
.B as.
In addition, these options can be used with 
.MS cc 1 .
.TP 15
.B \-g0
Do not produce symbol table information for symbolic
debugging.  This is the default.
.TP 15
.B \-g1
Produce additional symbol table information for accurate
but limited symbolic debugging of partially optimized code.
.TP 15
.BR \-g " or " \-g2
Produce additional symbol table information
for full symbolic debugging and do not perform optimizations that
limit full symbolic debugging.
.TP 15
.B \-g3
Produce additional symbol table information for full
symbolic debugging for fully optimized code.  This option makes the
debugger inaccurate.
.TP 15
.B \-w
Suppress warning messages.
.TP 15
.B \-P
Run only the C macro preprocessor and place the result in a file.  If the
source file has a suffix, change the suffix to .i.  If the source file does
not have a suffix, an .i is added to the source file name.  The .i file
does not contain number lines (#). This sets the 
.B \-cpp
option.
.TP 15
.B \-E
Run only the C macro preprocessor on the file and send the result to the
standard output.
This sets the  
.B \-cpp
option.
.TP 15
.BI \-o " output"
Name the final output file
.IR output .
If this option is used, the a.out file is not affected.
.TP 15
.BI \-D name=def
.br
.ns
.TP 15
.BI \-D \*Sname
Define the
.I name
to the C macro preprocessor,
as if by #define. If definition is not given, the name is defined as 1.
.TP 15
.BI \-U \*Sname
Remove any initial definition of
.IR name .
.TP 15
.BI \-I \*Sdir
Search for #include files
whose names do not begin with slash (/)
in the directory of the
.I file
argument, then in directories specified in 
.B \-I
options,
and finally in the standard directory
.RB ( /usr/include ).
.TP 15
.B \-I
Do not search for #include files in the standard
directory
.RB ( /usr/include ).
.TP 15
.BI \-G " num"
Specify the maximum size, in bytes, of a data item that is to be accessed from
the global pointer.  The 
.I num
argument is interpreted as a decimal number.  If
.I num
is zero, data is not accessed from the global pointer.  The default
value for
.I num
is 8 bytes.
.TP 15
.B \-v
Print the passes as they execute with their arguments, input files, and 
output files.
Also prints resource usage in the C-shell
.I time
format.
.TP 15
.B \-V
Print the version of the driver and the versions of all passes.  This is 
performed with the
.MS what 1
command.
.TP 15
.B \-cpp
Run the C macro preprocessor on assembly source files before compiling.
This is the default for
.MS as 1 .
.TP 15
.B \-nocpp
Do not run the C macro preprocessor on assembly source files before compiling.
.PP
Either object file target byte ordering can be produced by
.B as.
The default target byte ordering matches the machine where the assembler is
running.  The options
.B \-EB
and
.B \-EL
specify the target byte ordering (big-endian and little-endian,
respectively).
The assembler also defines a C preprocessor macro for the
target byte ordering.  These C preprocessor macros are
.B MIPSEB
and
.B MIPSEL
for big-endian and little-endian byte ordering respectively.
.TP 15
.B \-EB
Produce object files targeted for big-endian byte ordering.  The C preprocessor
macro
.B MIPSEB
is defined by the assembler.
.TP 15
.B \-EL
Produce object files targeted for little-endian byte ordering.  The
C preprocessor macro
.B MIPSEL
is defined by the assembler.
.PP
The following option can only be used with the 
.B as
command:
.PP
.TP 15
.B \-m
Apply the M4 preprocessor to the source file before assembling it.
.PP
The following option is primarily used to provide UNIX compilation
environments other than the native compilation environment.
.TP 15
.BI \-systype " name"
Use the named compilation environment
.I name.
See
.MS compilation 7
for the compilation environments that are supported and their
.IR name s.
This has the effect of changing the standard directory for #include
files.
The new items are located in their usual paths but with
.RI / name
prepended to their paths.
Also a preprocessor macro of the form
.BI SYSTYPE_ NAME
(with
.I name
capitalized) is defined in place of the default
.B SYSTYPE_BSD.
.PP
The options described below primarily aid compiler
development and are not generally used:
.TP 15
.BI \-H c
Halt compiling after the pass specified by the character
.IR c ,
producing an intermediate file for the next pass.  The
.I c
can be
.B [ a ].
It selects the assembler pass in the same way as the
.B \-t
option.
If this option is used, the symbol table file produced and used by the passes
is the last component of the source file with the suffix changed to .T, or
a .T is added if the source file has no suffix. This file is not removed.
.TP 15
.B \-K
Build and use intermediate file names with the last component of the
source file's  name replacing its suffix with the conventional suffix for the
type of file (for example, .G file for binary assembly language).
If the source file has no suffix the conventional suffix is added to the source
file name.
These intermediate files are never removed
even when a pass encounters a fatal error.
.TP 15
.BI \-W c[c...],arg1[,arg2...]
Pass the argument[s]
.I argi
to the compiler pass[es]
.I c[c..].
The
.I c's
are one of
.B [ pab ].
The c's selects the compiler pass in the same way as the
.B \-t
option.
.PP
The options
.BR \-t [ hpab ],
.BI \-h path,
and
.BI \-B string
select a name to use for a particular pass.
These arguments are processed from left to right so their order is significant.
When the
.B \-B
option is encountered, the selection of names takes place using the last
.B \-h
and
.B \-t
options.  Therefore, the
.B \-B
option is always required when using
.B \-h
or
.BR \-t .
Sets of these options can be used to select any combination of names.
.PP
.TP 15
.BR \-t [ hpab ]
Select the names.  The names selected are those designated by the characters
following the
.B \-t
option according to the following table:
.br
.ta \w'include    \ \ 'u
\fBName     Character\fP
.br
include	h  (see note below)
.br
cpp	p
.br
as0	a
.br
as1	b
.sp +.5
If the character h is in the
.B \-t
argument then a directory is added to the list of directories to be used in 
searching for #include files.  This directory name has the form
.SM COMP_TARGET_ROOT\fR/usr/include\fIstring\fR .
This directory is to contain the include files for the
.I string
release of the compiler.  The standard directory is still searched.
.TP 15
.BI \-h \*Spath
Use
.I path
rather than the directory where the name is normally found.
.TP 15
.BI \-B \*Sstring
Append
.I string
to all names specified by the
.B \-t
option.  If 
.B \-t
option has not been processed before the
.B \-B,
the
.B \-t
option is assumed to be ``hpab''.  This list designates all
names.
.PP
Invoking the assembler with a name of the form
.BI as string
has the same effect as using a
.BI \-B string
option on the command line.
.PP
If the environment variable
.SM COMP_HOST_ROOT
is set, the value is used as the root
directory for all pass names rather than the default slash (/).
If the environment variable
.SM COMP_TARGET_ROOT
is set, the value is used as the root
directory for the includes rather than the default slash (/).
.PP
If the environment variable
.SM ROOTDIR
is set, the value is used as the root
directory for all names rather than the default
.B /usr/.
This also affects the standard directory for #include files, /usr/include .
.PP
If the environment variable
.SM TMPDIR
is set, the value is used as the directory to place any temporary files
rather than the default
.BR /tmp/ .
.PP
Other arguments are ignored.
.SH Files
.TP 15
file.o
object file
.TP 15
a.out
assembler output
.TP 15
/tmp/ctm?
temporary
.TP 15
/usr/lib/cpp
C macro preprocessor
.TP 15
/usr/lib/as0
symbolic to binary assembly language translator
.TP 15
/usr/lib/as1
binary assembly language assembler and reorganizer
.TP 15
/usr/include
standard directory for #include files
.SH See Also
cc(1), as(1), what(1)