Comments - Using as

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### 3.3 Comments

There are two ways of rendering comments to `as`. In both cases the comment is equivalent to one space.

Anything from ‘`/*`’ through the next ‘`*/`’ is a comment. This means you may not nest these comments.

         /*
           The only way to include a newline ('\n') in a comment
           is to use this sort of comment.
         */

         /* This sort of comment does not nest. */

Anything from the line comment character to the next newline is considered a comment and is ignored. The line comment character is ‘`;`’ on the ARC; ‘`@`’ on the ARM; ‘`;`’ for the H8/300 family; ‘`;`’ for the HPPA; ‘`#`’ on the i386 and x86-64; ‘`#`’ on the i960; ‘`;`’ for the PDP-11; ‘`;`’ for picoJava; ‘`#`’ for Motorola PowerPC; ‘`#`’ for IBM S/390; ‘`#`’ for the Sunplus SCORE; ‘`!`’ for the Renesas / SuperH SH; ‘`!`’ on the SPARC; ‘`#`’ on the ip2k; ‘`#`’ on the m32c; ‘`#`’ on the m32r; ‘`|`’ on the 680x0; ‘`#`’ on the 68HC11 and 68HC12; ‘`#`’ on the RX; ‘`;`’ on the TMS320C6X; ‘`#`’ on the Vax; ‘`;`’ for the Z80; ‘`!`’ for the Z8000; ‘`#`’ on the V850; ‘`#`’ for Xtensa systems; see Machine Dependencies.

On some machines there are two different line comment characters. One character only begins a comment if it is the first non-whitespace character on a line, while the other always begins a comment.

The V850 assembler also supports a double dash as starting a comment that extends to the end of the line.

‘`--`’;

To be compatible with past assemblers, lines that begin with ‘`#`’ have a special interpretation. Following the ‘`#`’ should be an absolute expression (see Expressions): the logical line number of the next line. Then a string (see Strings) is allowed: if present it is a new logical file name. The rest of the line, if any, should be whitespace.

If the first non-whitespace characters on the line are not numeric, the line is ignored. (Just like a comment.)

                                   # This is an ordinary comment.
         # 42-6 "new_file_name"    # New logical file name
                                   # This is logical line # 36.

This feature is deprecated, and may disappear from future versions of `as`.