Comment Field

The assembler recognizes two types of comments in source code:

• A line whose first non-whitespace character is the hash character ( # ) is a comment. This style of comment is useful for passing C preprocessor output through the assembler. Note that comments of the form

get turned into

This can cause problems when comments of this form which aren't intended to specify line numbers precede assembly errors, since the error will be reported as occurring on a line relative to that specified in the comment. Suppose a program contains these two lines of assembly source:

If ".var" hasn't been defined, this fragment will result in the following error message:

• A comment field, appearing on a line after one or more statements. The comment field consists of the appropriate comment character and all the characters that follow it on the line:

Character	Description
|	comment character for MC68000 processors
;	comment character for PowerPC processors
#	comment character for i386 architecture processors

An assembly language source line can consist of just the comment field; in this case, it's equivalent to using the hash character comment style:

Note the warning given above for hash character comments beginning with a number.

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