20

Chapter 3. Command Line Options

3.3.

 D

This option has no effect whatsoever, but it is accepted to make it more likely that scripts written for

other assemblers also work with

as

.

3.4. Work Faster:

 f

 f

should only be used when assembling programs written by a (trusted) compiler.

 f

stops the

assembler from doing whitespace and comment preprocessing on the input file(s) before assembling

them. Section 4.1 Preprocessing.

Warning: if you use  f when the files actually need to be preprocessed (if they contain comments, for

example), as does not work correctly.

3.5.

.include

Search Path:

 Ipath

Use this option to add a

path

to the list of directories

as

searches for files specified in

.include

directives (Section 8.47

.include "file"

). You may use

 I

as many times as necessary to include

a variety of paths. The current working directory is always searched first; after that,

as

searches any

 I

directories in the same order as they were specified (left to right) on the command line.

3.6. Difference Tables:

 K

as

sometimes alters the code emitted for directives of the form

.word sym1 sym2

; Section 8.101

.word expressions

. You can use the

 K

option if you want a warning issued when this is done.

3.7. Include Local Labels:

 L

Labels beginning with

L

(upper case only) are called local labels. Section 6.3 Symbol Names. Nor 

mally you do not see such labels when debugging, because they are intended for the use of programs

(like compilers) that compose assembler programs, not for your notice. Normally both

as

and

ld

discard such labels, so you do not normally debug with them.

This option tells

as

to retain those

L...

symbols in the object file. Usually if you do this you also tell

the linker

ld

to preserve symbols whose names begin with

L

.

By default, a local label is any label beginning with

L

, but each target is allowed to redefine the local

label prefix. On the HPPA local labels begin with

L$

.

3.8. Configuring listing output:

 listing

The listing feature of the assembler can be enabled via the command line switch

 a

(Section 3.1

Enable Listings:

 a[cdhlns]

). This feature combines the input source file(s) with a hex dump of the

corresponding locations in the output object file, and displays them as a listing file. The format of this

listing can be controlled by pseudo ops inside the assembler source (Section 8.58

.list

Section 8.93

.title "heading"

Section 8.76

.sbttl "subheading"

Section 8.71

.psize lines, columns

Section 8.24

.eject

) and also by the following switches:

 listing lhs width=number

Sets the maximum width, in words, of the first line of the hex byte dump. This dump appears on

the left hand side of the listing output.